Whey protein film with oxygen scavenging function by incorporation of ascorbic acid.

PubMed

Janjarasskul, Theeranun; Tananuwong, Kanitha; Krochta, John M

2011-01-01

Residual O(2) in a package headspace can be removed by an O(2)-absorbing sachet, which can be harmful if swallowed by the consumer, or by a chemically-active plastic packaging film, which is difficult to recycle. An edible, O(2)-absorbing film would avoid these disadvantages. The objective of our research was to assess the O(2)-scavenging potential of an edible whey protein isolate (WPI) film incorporating ascorbic acid (AA). AA at 0.05, 0.1, or 0.2 M was added to 5% (w/w) heat-denatured WPI film-forming solutions with WPI : glycerol (Gly) ratio of 1: 1.00, 1: 0.80, or 1: 0.67. The pH of solutions was then adjusted to 3.5 (below pK(a1) of AA), to stabilize AA against oxidation, before film casting. The mechanical properties, O(2) permeabilities, and thermal transitions of films were measured. Activation of the O(2)-scavenging function of the AA-incorporated films was accomplished by adjustment of the films to pH ≥ 7. O(2)-scavenging ability of AA-incorporated WPI films was determined by measuring residual O(2) in the headspace of a high-barrier container. Incorporation of AA into WPI film decreased film tensile strength and further reduced O(2) permeability at each WPI : Gly ratio. AA-containing films adjusted to pH ≥ 7 demonstrated O(2) absorption proportional to AA content, consistent with theoretical O(2)-scavenging capacity. Thermal transition measurements indicated that AA was involved in WPI structural modification and decreased the degradation temperature of WPI-based film. The demonstrated O(2)-scavenging function, improved O(2) barrier and acceptable mechanical properties of AA-incorporated films indicate potential commercial usefulness. Ascorbic acid-incorporated whey protein film with oxygen scavenging function can be used to extend shelf lives of a wide variety of oxygen-sensitive products by eliminating headspace oxygen as well as oxygen permeating through the packaging wall over time. Edible oxygen-scavenger film has the advantages of avoiding both accidental consumption and nonrecyclability of conventional oxygen scavenger systems. © 2011 Institute of Food Technologists®

76 FR 11965 - Peroxyacetic Acid; Amendment to an Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

... of PAA PAA degrades rapidly to AA and HP, and HP further degrades to water and oxygen; therefore, the final degradation products of PAA are AA, water, and oxygen. As stated in Unit II., section 408(a)(3... concluded that, since HP itself degrades rapidly into oxygen and water, residues of a solution that contains...

Nonsensing residues in S3-S4 linker's C terminus affect the voltage sensor set point in K+ channels.

PubMed

Carvalho-de-Souza, Joao L; Bezanilla, Francisco

2018-02-05

Voltage sensitivity in ion channels is a function of highly conserved arginine residues in their voltage-sensing domains (VSDs), but this conservation does not explain the diversity in voltage dependence among different K + channels. Here we study the non-voltage-sensing residues 353 to 361 in Shaker K + channels and find that residues 358 and 361 strongly modulate the voltage dependence of the channel. We mutate these two residues into all possible remaining amino acids (AAs) and obtain Q-V and G-V curves. We introduced the nonconducting W434F mutation to record sensing currents in all mutants except L361R, which requires K + depletion because it is affected by W434F. By fitting Q-Vs with a sequential three-state model for two voltage dependence-related parameters ( V 0 , the voltage-dependent transition from the resting to intermediate state and V 1 , from the latter to the active state) and G-Vs with a two-state model for the voltage dependence of the pore domain parameter ( V 1/2 ), Spearman's coefficients denoting variable relationships with hydrophobicity, available area, length, width, and volume of the AAs in 358 and 361 positions could be calculated. We find that mutations in residue 358 shift Q-Vs and G-Vs along the voltage axis by affecting V 0 , V 1 , and V 1/2 according to the hydrophobicity of the AA. Mutations in residue 361 also shift both curves, but V 0 is affected by the hydrophobicity of the AA in position 361, whereas V 1 and V 1/2 are affected by size-related AA indices. Small-to-tiny AAs have opposite effects on V 1 and V 1/2 in position 358 compared with 361. We hypothesize possible coordination points in the protein that residues 358 and 361 would temporarily and differently interact with in an intermediate state of VSD activation. Our data contribute to the accumulating knowledge of voltage-dependent ion channel activation by adding functional information about the effects of so-called non-voltage-sensing residues on VSD dynamics. © 2018 Carvalho-de-Souza and Bezanilla.

Active site nanospace of aminoacyl tRNA synthetase: difference between the class I and class II synthetases.

PubMed

Dutta, Saheb; Choudhury, Kaberi; Banik, Sindrila Dutta; Nandi, Nilashis

2014-03-01

The present work is aimed at understanding the origin of the difference in the molecular organization of the active site nanospaces of the class I and class II aminoacyl tRNA synthetases (aaRSs) which are tunnel-like structures. The active site encloses the cognate amino acid (AA) and the adenosine triphosphate (ATP) to carry out aminoacylation reaction. Comparison of the structures of the active site of the class I and class II (aaRSs) shows that the nanodimensional tunnels are curved in opposite directions in the two classes. We investigated the origin of this difference using quantum mechanical computation of electrostatic potential (ESP) of substrates, surrounding residues and ions, using Atoms in Molecule (AIM) Theory and charge population analysis. We show that the difference is principally due to the variation in the spatial charge distribution of ATP in the two classes which correspond to extended and bent conformations of ATP. The present computation shows that the most feasible pathway for nucleophilic attack to alphaP is oppositely directed for class I and class II aaRSs. The available crystal structures show that the cognate AA is indeed located along the channel favorable for nucleophilic attack as predicted by the ESP analysis. It is also shown that the direction of the channel changes its orientation when the orientation of ATP is changed from extended to a bent like structure. We further used the AIM theory to confirm the direction of the approach of AA in each case and the results corroborate the results from the ESP analysis. The opposite curvatures of the active site nanospaces in class I and class II aaRSs are related with the influence of the charge distributions of the extended and bent conformations of ATP, respectively. The results of the computation of electrostatic potential by successive addition of active site residues show that their roles on the reaction are similar in both classes despite the difference in the organization of the active sites of class I and class II aaRSs. The difference in mechanism in two classes as pointed out in recent study (S. Dutta Banik and N. Nandi, J. Biomol. Struct. Dyn. 30, 701 (2012)) is related with the fact that the relative arrangement of the ATP with respect to the AA is opposite in class I and class II aaRSs as explained in the present work. The charge population difference between the reacting centers (which are the alphaP atom of ATP (q(p)) and the attacking oxygen atom of carboxylic acid group (q(o)), respectively) denoted by delta(q), is a measure of the propensity of nucleophilic attack. The population analysis of the substrate AA shows that a non-negligible difference exists between the attacking oxygens of AA in class I (syn) and in class II (anti) which is one reason for the lower value of delta(q) in class II relative to class I. The population analysis of the AA, ATP, Mg+2 ions and active site residues shows that the difference in delta(q) values of the two classes is substantially reduced. When ions and residues are considered. Thus, the bent state of ATP, Mg+2 ions and active site residues complements it cognate AA to carry out the nucleophilic reaction in class I as efficiently as occurs in class I (with the extended state of ATP, single Mg+2 ion and active site residues). This could be one reason for the two different conformations of ATP in the two classes. The mutual arrangements of AA and ATP in each aaRS are guided by the spatial charge distribution of ATP (extended and bent). The present work shows that the construction of nanospace complements the arrangement of the substrate (AA and ATP).

Enzymatic synthesis of 3-O-α-maltosyl-l-ascorbate using an engineered cyclodextrin glucanotransferase.

PubMed

Ahn, Hee-Jeong; Li, Chao; Cho, Hye-Bin; Park, Sunghoon; Chang, Pahn-Shick; Kim, Young-Wan

2015-02-15

A mutant derived from a cyclodextrin glucantransferase with an alanine residue as its acid/base catalyst residue (CGT-E284A) catalyzed regioselective glycosylation at 3-OH of l-ascorbic acid using α-maltosyl fluoride (αG2F) and l-ascorbic acid as the donor and acceptor, respectively, yielding 3-O-α-maltosyl-l-ascorbate (AA3αG2). The optimum conditions were determined by high-performance liquid chromatography analysis with 20mM αG2F and 40mM l-ascorbic acid as the substrates at pH 7.5 and 25°C with 1mg/ml of the enzyme for 24h. Calcium ions bound in CGT-E284A played an important role in the transglycosylation. CGT-E284A exhibited typical saturation kinetic behaviour for αG2F at a fixed acceptor concentration (40mM), and substrate inhibition by l-ascorbic acid was observed at high l-ascorbic acid concentrations (>60mM). AA3αG2 was isolated from a preparative scale reaction with a yield of 29%, and it showed extremely high stability under oxidative conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Contribution of microorganisms to non-extractable residue formation from biodegradable organic contaminants in soil

NASA Astrophysics Data System (ADS)

Nowak, K. M.; Girardi, C.; Miltner, A.; Schäffer, A.; Kästner, M.

2012-04-01

Biodegradation of organic contaminants in soil is actually understood as their transformation into various primary metabolites, microbial biomass, mineralisation products and non-extractable residues (NER). NER are generally considered to be composed of parent compounds or primary metabolites with hazardous potential. Up to date, however, their chemical composition remains still unclear. Studies on NER formation are limited to quantitative analyses in soils or to simple humic acids-contaminant systems. However, in the case of biodegradable organic compounds, NER may also contain microbial biomass components, e.g. fatty acids (FA) and amino acids (AA). After cell death, these biomolecules are incorporated into soil organic matter (SOM) and stabilised, ultimately forming biogenic residues which are not any more extractable. We investigated the incorporation of the 13C-label into FA and AA and their fate during biodegradation experiments in soil with isotope-labelled 2,4-dichlorophenoxyacetic acid (13C6-2,4-D) and ibuprofen (13C6-ibu) as model organic contaminants. Our study proved for the first time that nearly all NER formed from 13C6-2,4-D and 13C6-ibu in soil derived from harmless microbial biomass components stabilised in SOM. 13C-FA and 13C-AA contents in the living microbial biomass fraction decreased over time and these components were continuously incorporated into the non-living SOM pool in biotic experiments with 13C6-2,4-D and 13C6-ibu. The 13C-AA in the non-living SOM were surprisingly stable from day 32 (13C6-2,4-D) and 58 (13C6-ibu) until the end of incubation. We also studied the transformation of 13C6-2,4-D and 13C6-ibu into NER in the abiotic soil experiments. In these experiments, the total NER contents were much lower than in the corresponding biotic experiments. The absence of labelled biomolecules in the NER fraction in abiotic soils demonstrated that they consist of the potentially hazardous parent compounds and / or their metabolites. Biogenic residue formation is relevant during biodegradation of organic contaminants, whereas abiotic NER are formed from the non-biodegraded residual contaminants. Abiotic NER and biogenic residue formation are competitive processes and do not occur in a similar extent. In the biotic treatment, the rapid mineralisation of an organic compound reduces the extent of abiotic NER formation via physico-chemical interactions between a parent compound and / or its primary metabolites with SOM. Therefore, in order to properly assess the potential risks of a target contaminant in soil to humans and the environment, it is necessary to distinguish between abiotic NER and biogenic residue formation in the mass balances of contaminants.

Interaction study of rice stripe virus proteins reveals a region of the nucleocapsid protein (NP) required for NP self-interaction and nuclear localization.

PubMed

Lian, Sen; Cho, Won Kyong; Jo, Yeonhwa; Kim, Sang-Min; Kim, Kook-Hyung

2014-04-01

Rice stripe virus (RSV), which belongs to the genus Tenuivirus, is an emergent virus problem. The RSV genome is composed of four single-strand RNAs (RNA1-RNA4) and encodes seven proteins. We investigated interactions between six of the RSV proteins by yeast-two hybrid (Y2H) assay in vitro and by bimolecular fluorescence complementation (BiFC) in planta. Y2H identified self-interaction of the nucleocapsid protein (NP) and NS3, while BiFC revealed self-interaction of NP, NS3, and NCP. To identify regions(s) and/or crucial amino acid (aa) residues required for NP self-interaction, we generated various truncated and aa substitution mutants. Y2H assay showed that the N-terminal region of NP (aa 1-56) is necessary for NP self-interaction. Further analysis with substitution mutants demonstrated that additional aa residues located at 42-47 affected their interaction with full-length NP. These results indicate that the N-terminal region (aa 1-36 and 42-47) is required for NP self-interaction. BiFC and co-localization studies showed that the region required for NP self-interaction is also required for NP localization at the nucleus. Overall, our results indicate that the N-terminal region (aa 1-47) of the NP is important for NP self-interaction and that six aa residues (42-47) are essential for both NP self-interaction and nuclear localization. Copyright © 2014 Elsevier B.V. All rights reserved.

Construction and characterization of 3A-epitope-tagged foot-and-mouth disease virus.

PubMed

Ma, Xueqing; Li, Pinghua; Sun, Pu; Bai, Xingwen; Bao, Huifang; Lu, Zengjun; Fu, Yuanfang; Cao, Yimei; Li, Dong; Chen, Yingli; Qiao, Zilin; Liu, Zaixin

2015-04-01

Nonstructural protein 3A of foot-and-mouth disease virus (FMDV) is a partially conserved protein of 153 amino acids (aa) in most FMDVs examined to date. Specific deletion in the FMDV 3A protein has been associated with the inability of FMDV to grow in primary bovine cells and cause disease in cattle. However, the aa residues playing key roles in these processes are poorly understood. In this study, we constructed epitope-tagged FMDVs containing an 8 aa FLAG epitope, a 9 aa haemagglutinin (HA) epitope, and a 10 aa c-Myc epitope to substitute residues 94-101, 93-101, and 93-102 of 3A protein, respectively, using a recently developed O/SEA/Mya-98 FMDV infectious cDNA clone. Immunofluorescence assay (IFA), Western blot and sequence analysis showed that the epitope-tagged viruses stably maintained and expressed the foreign epitopes even after 10 serial passages in BHK-21 cells. The epitope-tagged viruses displayed growth properties and plaque phenotypes similar to those of the parental virus in BHK-21 cells. However, the epitope-tagged viruses exhibited lower growth rates and smaller plaque size phenotypes than those of the parental virus in primary fetal bovine kidney (FBK) cells, but similar growth properties and plaque phenotypes to those of the recombinant viruses harboring 93-102 deletion in 3A. These results demonstrate that the decreased ability of FMDV to replicate in primary bovine cells was not associated with the length of 3A, and the genetic determinant thought to play key role in decreased ability to replicate in primary bovine cells could be reduced from 93-102 residues to 8 aa residues at positions 94-101 in 3A protein. Copyright © 2015 Elsevier B.V. All rights reserved.

EBNA-2 of herpesvirus papio diverges significantly from the type A and type B EBNA-2 proteins of Epstein-Barr virus but retains an efficient transactivation domain with a conserved hydrophobic motif.

PubMed Central

Ling, P D; Ryon, J J; Hayward, S D

1993-01-01

EBNA-2 contributes to the establishment of Epstein-Barr virus (EBV) latency in B cells and to the resultant alterations in B-cell growth pattern by up-regulating expression from specific viral and cellular promoters. We have taken a comparative approach toward characterizing functional domains within EBNA-2. To this end, we have cloned and sequenced the EBNA-2 gene from the closely related baboon virus herpesvirus papio (HVP). All human EBV isolates have either a type A or type B EBNA-2 gene. However, the HVP EBNA-2 gene falls into neither the type A category nor the type B category, suggesting that the separation into these two subtypes may have been a recent evolutionary event. Comparison of the predicted amino acid sequences indicates 37% amino acid identity with EBV type A EBNA-2 and 35% amino acid identity with type B EBNA-2. To define the domains of EBNA-2 required for transcriptional activation, the DNA binding domain of the GAL4 protein was fused to overlapping segments of EBV EBNA-2. This approach identified a 40-amino-acid (40-aa) EBNA-2 activation domain located between aa 437 and 477. Transactivation ability was completely lost when the amino-terminal boundary of this domain was moved to aa 441, indicating that the motif at aa 437 to 440, Pro-Ile-Leu-Phe, contains residues critical for function. The aa 437 boundary identified in these experiments coincides precisely with a block of conserved sequences in HVP EBNA-2, and the comparable carboxy-terminal region of HVP EBNA-2 also functioned as a strong transcriptional activation domain when fused to the Gal4(1-147) protein. The EBV and HVP EBNA-2 activation domains share a mixed proline-rich, negatively charged character with a striking conservation of positionally equivalent hydrophobic residues. The importance of the individual amino acids making up the Pro-Ile-Leu-Phe motif was examined by mutagenesis. Any alteration of these residues was found to reduce transactivation efficiency, with changes at the Pro-437 and Phe-440 positions producing the most deleterious effects. Activation of the EBV latency C promoter by EBNA-2 was shown to be dependent on the presence of the carboxy-terminal activation domain. However, this requirement was generic, rather than specific, since the EBNA-2 activation domain could be replaced with those from the herpes simplex virus (HSV) VP16 protein or the EBV Rta protein. Potential karyophilic signals within EBNA-2 were examined by introducing oligonucleotides encoding positively charged amino acid groupings that might serve in this capacity into a cytoplasmic test protein, HSV delta IE175, and by examining the intracellular localization of the resulting proteins. This assay identified a strong nuclear localization signal between EBV amino acids (aa) 478 to 485, which was conserved in HVP, and a weaker noncanonical signal between EBV aa 341 to 355, which was not conserved in HVP. Images PMID:8388484

EBNA-2 of herpesvirus papio diverges significantly from the type A and type B EBNA-2 proteins of Epstein-Barr virus but retains an efficient transactivation domain with a conserved hydrophobic motif.

PubMed

Ling, P D; Ryon, J J; Hayward, S D

1993-06-01

EBNA-2 contributes to the establishment of Epstein-Barr virus (EBV) latency in B cells and to the resultant alterations in B-cell growth pattern by up-regulating expression from specific viral and cellular promoters. We have taken a comparative approach toward characterizing functional domains within EBNA-2. To this end, we have cloned and sequenced the EBNA-2 gene from the closely related baboon virus herpesvirus papio (HVP). All human EBV isolates have either a type A or type B EBNA-2 gene. However, the HVP EBNA-2 gene falls into neither the type A category nor the type B category, suggesting that the separation into these two subtypes may have been a recent evolutionary event. Comparison of the predicted amino acid sequences indicates 37% amino acid identity with EBV type A EBNA-2 and 35% amino acid identity with type B EBNA-2. To define the domains of EBNA-2 required for transcriptional activation, the DNA binding domain of the GAL4 protein was fused to overlapping segments of EBV EBNA-2. This approach identified a 40-amino-acid (40-aa) EBNA-2 activation domain located between aa 437 and 477. Transactivation ability was completely lost when the amino-terminal boundary of this domain was moved to aa 441, indicating that the motif at aa 437 to 440, Pro-Ile-Leu-Phe, contains residues critical for function. The aa 437 boundary identified in these experiments coincides precisely with a block of conserved sequences in HVP EBNA-2, and the comparable carboxy-terminal region of HVP EBNA-2 also functioned as a strong transcriptional activation domain when fused to the Gal4(1-147) protein. The EBV and HVP EBNA-2 activation domains share a mixed proline-rich, negatively charged character with a striking conservation of positionally equivalent hydrophobic residues. The importance of the individual amino acids making up the Pro-Ile-Leu-Phe motif was examined by mutagenesis. Any alteration of these residues was found to reduce transactivation efficiency, with changes at the Pro-437 and Phe-440 positions producing the most deleterious effects. Activation of the EBV latency C promoter by EBNA-2 was shown to be dependent on the presence of the carboxy-terminal activation domain. However, this requirement was generic, rather than specific, since the EBNA-2 activation domain could be replaced with those from the herpes simplex virus (HSV) VP16 protein or the EBV Rta protein. Potential karyophilic signals within EBNA-2 were examined by introducing oligonucleotides encoding positively charged amino acid groupings that might serve in this capacity into a cytoplasmic test protein, HSV delta IE175, and by examining the intracellular localization of the resulting proteins. This assay identified a strong nuclear localization signal between EBV amino acids (aa) 478 to 485, which was conserved in HVP, and a weaker noncanonical signal between EBV aa 341 to 355, which was not conserved in HVP.

Site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase from Paenibacillus macerans to enhance substrate specificity towards maltodextrin for enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G).

PubMed

Han, Ruizhi; Liu, Long; Shin, Hyun-dong; Chen, Rachel R; Du, Guocheng; Chen, Jian

2013-07-01

In this work, the site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans was conducted to improve the specificity of CGTase towards maltodextrin, which can be used as a cheap and easily soluble glycosyl donor for the enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G) by CGTase. When using maltodextrin as glycosyl donor, four mutants K47F (lysine→ phenylalanine), K47L (lysine→ leucine), K47V (lysine→ valine) and K47W (lysine→ tryptophan) showed higher AA-2G yield as compared with that produced by the wild-type CGTase. The transformation conditions (temperature, pH and the mass ratio of L-ascorbic acid to maltodextrin) were optimized and the highest titer of AA-2G produced by the mutant K47L could reach 1.97 g/l, which was 64.2% higher than that (1.20 g/l) produced by the wild-type CGTase. The reaction kinetics analysis confirmed the enhanced maltodextrin specificity, and it was also found that compared with the wild-type CGTase, the four mutants had relatively lower cyclization activities and higher disproportionation activities, which was favorable for AA-2G synthesis. The mechanism responsible for the enhanced substrate specificity was further explored by structure modeling and it was indicated that the enhancement of maltodextrin specificity may be due to the short residue chain and the removal of hydrogen bonding interactions between the side chain of residue 47 and the sugar at -3 subsite. Here the obtained mutant CGTases, especially the K47L, has a great potential in the production of AA-2G with maltodextrin as a cheap and easily soluble substrate.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lien, Shu-Pei; Shih, Yi-Ping; Chen, Hsin-Wei

Three peptides, D1 (amino acid residues 175-201), D2 (a.a. 434-467), and TM (a.a. 1128-1159), corresponding to the spike protein (S) of severe acute respiratory syndrome corona virus (SARS CoV) were synthesized and their immunological functions were investigated in three different animals models (mice, guinea pigs, and rabbits). The peptides mixture formulated either with Freund's adjuvant or synthetic adjuvant Montanide ISA-51/oligodeoxy nucleotide CpG (ISA/CpG) could elicit antisera in immunized animals which were capable of inhibiting SARS/HIV pseudovirus entry into HepG2 cells. The neutralizing epitopes were identified using peptides to block the neutralizing effect of guinea pig antisera. The major neutralizing epitopemore » was located on the D2 peptide, and the amino acid residue was fine mapped to 434-453. In BALB/c mice T-cell proliferation assay revealed that only D2 peptide contained T-cell epitope, the sequence of which corresponded to amino acid residue 434-448. The ISA/CpG formulation generated anti-D2 IgG titer comparable to those obtained from Freund's adjuvant formulation, but generated fewer antibodies against D1 or TM peptides. The highly immunogenic D2 peptide contains both neutralizing and Th cell epitopes. These results suggest that synthetic peptide D2 would be useful as a component of SARS vaccine candidates.« less

Glycomacropeptide in children with phenylketonuria: does its phenylalanine content affect blood phenylalanine control?

PubMed

Daly, A; Evans, S; Chahal, S; Santra, S; MacDonald, A

2017-08-01

In phenylketonuria (PKU), there are no data available for children with respect to evaluating casein glycomacropeptide (CGMP) as an alternative to phenylalanine-free protein substitutes [Phe-free L-amino acid (AA)]. CGMP contains a residual amount of phenylalanine, which may alter blood phenylalanine control. In a prospective 6-month pilot study, we investigated the effect on blood phenylalanine control of CGMP-amino acid (CGMP-AA) protein substitute in 22 PKU subjects (13 boys, nine girls), median age (range) 11 years (6-16 years). Twelve received CGMP-AA and nine received Phe-free L-AA, (1 CGMP-AA withdrawal). Subjects partially or wholly replaced Phe-free L-AA with CGMP-AA. If blood phenylalanine exceeded the target range, the CGMP-AA dose was reduced and replaced with Phe-free L-amino acids. The control group remained on Phe-free L-AAs. Phenylalanine, tyrosine and Phe : Tyr ratio concentrations were compared with the results for the previous year. In the CGMP-AA group, there was a significant increase in blood phenylalanine concentrations (pre-study, 275 μmol L -1 ; CGMP-AA, 317 μmol L -1 ; P = 0.02), a decrease in tyrosine concentrations (pre-study, 50 μmol L -1 ; CGMP-AA, 40 μmol L -1 ; P = 0.03) and an increase in Phe : Tyr ratios (pre-study, Phe : Tyr 4.9:1; CGMP-AA, Phe : Tyr 8:1; P = 0.02). In the control group there was a non-significant fall in phenylalanine concentrations (pre-study 325μmol/L: study 280μmol/L [p = 0.9], and no significant changes for tyrosine or phe/tyr ratios [p = 0.9]. Children taking the CGMP-AA found it more acceptable to L-AA. Blood phenylalanine control declined with CGMP-AA but, by titrating the dose of CGMP-AA, blood phenylalanine control remained within target range. The additional intake of phenylalanine may have contributed to the change in blood phenylalanine concentration. CGMP-AA use requires careful monitoring in children. © 2017 The British Dietetic Association Ltd.

Membrane-bound human orphan cytochrome P450 2U1: Sequence singularities, construction of a full 3D model, and substrate docking.

PubMed

Ducassou, Lionel; Dhers, Laura; Jonasson, Gabriella; Pietrancosta, Nicolas; Boucher, Jean-Luc; Mansuy, Daniel; André, François

2017-09-01

Human cytochrome P450 2U1 (CYP2U1) is an orphan CYP that exhibits several distinctive characteristics among the 57 human CYPs with a highly conserved sequence in almost all living organisms. We compared its protein sequence with those of the 57 human CYPs and constructed a 3D structure of a full-length CYP2U1 model bound to a POPC membrane. We also performed docking experiments of arachidonic acid (AA) and N-arachidonoylserotonin (AS) in this model. The protein sequence of CYP2U1 displayed two unique characteristics when compared to those of the human CYPs, the presence of a longer N-terminal region upstream of the putative trans-membrane helix (TMH) containing 8 proline residues, and of an insert of about 20 amino acids containing 5 arginine residues between helices A' and A. Its N-terminal part upstream of TMH involved an additional short terminal helix, in a manner similar to what was reported in the crystal structure of Saccharomyces cerevisiae CYP51. Our model also showed a specific interaction between the charged residues of insert AA' and phosphate groups of lipid polar heads, suggesting a possible role of this insert in substrate recruitment. Docking of AA and AS in this model showed these substrates in channel 2ac, with the terminal alkyl chain of AA or the indole ring of AS close to the heme, in agreement with the reported CYP2U1-catalyzed AA and AS hydroxylation regioselectivities. This model should be useful to find new endogenous or exogenous CYP2U1 substrates and to interpret the regioselectivity of their hydroxylation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Cell-free unnatural amino acid incorporation with alternative energy systems and linear expression templates.

PubMed

Shrestha, Prashanta; Smith, Mark Thomas; Bundy, Bradley Charles

2014-01-25

Site-specific incorporation of unnatural amino acids (uAAs) during protein synthesis expands the proteomic code through the addition of unique residue chemistry. This field provides a unique tool to improve pharmacokinetics, cancer treatments, vaccine development, proteomics and protein engineering. The limited ability to predict the characteristics of proteins with uAA-incorporation creates a need for a low-cost system with the potential for rapid screening. Escherichia coli-based cell-free protein synthesis is a compelling platform for uAA incorporation due to the open and accessible nature of the reaction environment. However, typical cell-free systems can be expensive due to the high cost of energizing reagents. By employing alternative energy sources, we reduce the cost of uAA-incorporation in CFPS by 55%. While alternative energy systems reduce cost, the time investment to develop gene libraries can remain cumbersome. Cell-free systems allow the direct use of PCR products known as linear expression templates, thus alleviating tedious plasmid library preparations steps. We report the specific costs of CFPS with uAA incorporation, demonstrate that LETs are suitable expression templates with uAA-incorporation, and consider the substantial reduction in labor intensity using LET-based expression for CFPS uAA incorporation. Copyright © 2013 Elsevier B.V. All rights reserved.

Ammonia pretreatment of corn stover enables facile lignin extraction

DOE PAGES

Mittal, Ashutosh; Katahira, Rui; Donohoe, Bryon S.; ...

2017-02-09

Thermochemical pretreatment of lignocellulose is often employed to render polysaccharides more digestible by carbohydrate-active enzymes to maximize sugar yields. The fate of lignin during pretreatment, however, is highly dependent on the chemistry employed and must be considered in cases where lignin valorization is targeted alongside sugar conversion—an important feature of future biorefinery development. Here, a two-step process is demonstrated in which anhydrous ammonia (AA) pretreatment is followed by mild NaOH extraction on corn stover to solubilize and fractionate lignin. As known, AA pretreatment simultaneously alters the structure of cellulose with enhanced digestibility while redistributing lignin. The AA-pretreated residue is thenmore » extracted with dilute NaOH at mild conditions to maximize lignin separation, resulting in a digestible carbohydrate-rich solid fraction and a solubilized lignin stream. Lignin removal of more than 65% with over 84% carbohydrate retention is achieved after mild NaOH extraction of AA-pretreated corn stover with 0.1 M NaOH at 25 °C. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AA-pretreated residue shows that ammonolysis of ester bonds occurs to partially liberate hydroxycinnamic acids, and the AA-pretreated/NaOH-extracted residue exhibits a global reduction of all lignin moieties caused by reduced lignin content. A significant reduction (~70%) in the weight-average molecular weight ( M w) of extracted lignin is also achieved. Imaging of AA-pretreated/NaOH extracted residues show extensive delamination and disappearance of coalesced lignin globules from within the secondary cell walls. Glycome profiling analyses demonstrates ultrastructural level cell wall modifications induced by AA pretreatment and NaOH extraction, resulting in enhanced extractability of hemicellulosic glycans, indicating enhanced polysaccharide accessibility. The glucose and xylose yields from enzymatic hydrolysis of AA-pretreated/NaOH-extracted corn stover were higher by ~80% and ~60%, respectively, compared to untreated corn stover at 1% solids loadings. For digestions at 20% solids, a benefit of NaOH extraction is realized in achieving ~150 g/L of total monomeric sugars (glucose, xylose, and arabinose) in the enzymatic hydrolysates from AA-pretreated/NaOH-extracted corn stover. Altogether, this process enables facile lignin extraction in tandem with a leading thermochemical pretreatment approach, demonstrating excellent retention of highly digestible polysaccharides in the solid phase and a highly depolymerized, soluble lignin-rich stream.« less

Ammonia pretreatment of corn stover enables facile lignin extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mittal, Ashutosh; Katahira, Rui; Donohoe, Bryon S.

Thermochemical pretreatment of lignocellulose is often employed to render polysaccharides more digestible by carbohydrate-active enzymes to maximize sugar yields. The fate of lignin during pretreatment, however, is highly dependent on the chemistry employed and must be considered in cases where lignin valorization is targeted alongside sugar conversion—an important feature of future biorefinery development. Here, a two-step process is demonstrated in which anhydrous ammonia (AA) pretreatment is followed by mild NaOH extraction on corn stover to solubilize and fractionate lignin. As known, AA pretreatment simultaneously alters the structure of cellulose with enhanced digestibility while redistributing lignin. The AA-pretreated residue is thenmore » extracted with dilute NaOH at mild conditions to maximize lignin separation, resulting in a digestible carbohydrate-rich solid fraction and a solubilized lignin stream. Lignin removal of more than 65% with over 84% carbohydrate retention is achieved after mild NaOH extraction of AA-pretreated corn stover with 0.1 M NaOH at 25 °C. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AA-pretreated residue shows that ammonolysis of ester bonds occurs to partially liberate hydroxycinnamic acids, and the AA-pretreated/NaOH-extracted residue exhibits a global reduction of all lignin moieties caused by reduced lignin content. A significant reduction (~70%) in the weight-average molecular weight ( M w) of extracted lignin is also achieved. Imaging of AA-pretreated/NaOH extracted residues show extensive delamination and disappearance of coalesced lignin globules from within the secondary cell walls. Glycome profiling analyses demonstrates ultrastructural level cell wall modifications induced by AA pretreatment and NaOH extraction, resulting in enhanced extractability of hemicellulosic glycans, indicating enhanced polysaccharide accessibility. The glucose and xylose yields from enzymatic hydrolysis of AA-pretreated/NaOH-extracted corn stover were higher by ~80% and ~60%, respectively, compared to untreated corn stover at 1% solids loadings. For digestions at 20% solids, a benefit of NaOH extraction is realized in achieving ~150 g/L of total monomeric sugars (glucose, xylose, and arabinose) in the enzymatic hydrolysates from AA-pretreated/NaOH-extracted corn stover. Altogether, this process enables facile lignin extraction in tandem with a leading thermochemical pretreatment approach, demonstrating excellent retention of highly digestible polysaccharides in the solid phase and a highly depolymerized, soluble lignin-rich stream.« less

Different effects of two mutations on the infectivity of Ebola virus glycoprotein in nine mammalian species.

PubMed

Kurosaki, Yohei; Ueda, Mahoko Takahashi; Nakano, Yusuke; Yasuda, Jiro; Koyanagi, Yoshio; Sato, Kei; Nakagawa, So

2018-01-04

Ebola virus (EBOV), which belongs to the genus Ebolavirus, causes a severe and often fatal infection in primates, including humans, whereas Reston virus (RESTV) only causes lethal disease in non-human primates. Two amino acids (aa) at positions 82 and 544 of the EBOV glycoprotein (GP) are involved in determining viral infectivity. However, it remains unclear how these two aa residues affect the infectivity of Ebolavirus species in various hosts. Here we performed viral pseudotyping experiments with EBOV and RESTV GP derivatives in 10 cell lines from 9 mammalian species. We demonstrated that isoleucine at position 544/545 increases viral infectivity in all host species, whereas valine at position 82/83 modulates viral infectivity, depending on the viral and host species. Structural modelling suggested that the former residue affects viral fusion, whereas the latter residue influences the interaction with the viral entry receptor, Niemann-Pick C1.

Different effects of two mutations on the infectivity of Ebola virus glycoprotein in nine mammalian species

PubMed Central

Nakano, Yusuke; Yasuda, Jiro; Koyanagi, Yoshio; Sato, Kei; Nakagawa, So

2018-01-01

Ebola virus (EBOV), which belongs to the genus Ebolavirus, causes a severe and often fatal infection in primates, including humans, whereas Reston virus (RESTV) only causes lethal disease in non-human primates. Two amino acids (aa) at positions 82 and 544 of the EBOV glycoprotein (GP) are involved in determining viral infectivity. However, it remains unclear how these two aa residues affect the infectivity of Ebolavirus species in various hosts. Here we performed viral pseudotyping experiments with EBOV and RESTV GP derivatives in 10 cell lines from 9 mammalian species. We demonstrated that isoleucine at position 544/545 increases viral infectivity in all host species, whereas valine at position 82/83 modulates viral infectivity, depending on the viral and host species. Structural modelling suggested that the former residue affects viral fusion, whereas the latter residue influences the interaction with the viral entry receptor, Niemann–Pick C1. PMID:29300152

Comparison of ZP3 protein sequences among vertebrate species: to obtain a consensus sequence for immunocontraception.

PubMed

Zhu, X; Naz, R K

1999-03-01

The deduced ZP3 amino acid (aa) sequences of 13 vertebrate species namely mouse, hamster, rabbit, pig, porcine, cow, dog, cat, human, bonnet, marmoset, carp, and frog were compared using the PILEUP and PRETTY alignment programs (GCG, Wisconsin, USA). The published aa sequences obtained from 13 vertebrate species indicated the overall evolutionarily conservation in the N-terminus, central region, and C-terminus of the ZP3 polypeptide. More variations of ZP3 polypeptide sequences were seen in the alignments of carp and frog from the 11 mammalian species making the leader sequence more prominent. The canonical furin proteolytic processing signal at the C-terminus was found in all the ZP3 polypeptide sequences except of carp and frog. In the central region, the ZP3 deduced aa sequences of all the 13 vertebrate species aligned well, and six relatively conserved sequences were found. There are 11 conserved cysteine residues in the central region across all species including carp and frog, indicating that these residues have longer evolutionary history. The ZP3 aa sequence similarities were examined using the GAP program (GCG). The highest aa similarities are observed between the members of the same order within the class mammalia, and also (95.4%) between pig (ungulata) and rabbit (lagomorpha). The deduced ZP3 aa sequences per se may not be enough to build a phylogenetic tree.

Group X secreted phospholipase A2 proenzyme is matured by a furin-like proprotein convertase and releases arachidonic acid inside of human HEK293 cells.

PubMed

Jemel, Ikram; Ii, Hiromi; Oslund, Rob C; Payré, Christine; Dabert-Gay, Anne-Sophie; Douguet, Dominique; Chargui, Khaoula; Scarzello, Sabine; Gelb, Michael H; Lambeau, Gérard

2011-10-21

Among mammalian secreted phospholipases A(2) (sPLA(2)s), group X sPLA(2) has the most potent hydrolyzing activity toward phosphatidylcholine and is involved in arachidonic acid (AA) release. Group X sPLA(2) is produced as a proenzyme and contains a short propeptide of 11 amino acids ending with a dibasic motif, suggesting cleavage by proprotein convertases. Although the removal of this propeptide is clearly required for enzymatic activity, the cellular location and the protease(s) involved in proenzyme conversion are unknown. Here we have analyzed the maturation of group X sPLA(2) in HEK293 cells, which have been extensively used to analyze sPLA(2)-induced AA release. Using recombinant mouse (PromGX) and human (ProhGX) proenzymes; HEK293 cells transfected with cDNAs coding for full-length ProhGX, PromGX, and propeptide mutants; and various permeable and non-permeable sPLA(2) inhibitors and protease inhibitors, we demonstrate that group X sPLA(2) is mainly converted intracellularly and releases AA before externalization from the cell. Most strikingly, the exogenous proenzyme does not elicit AA release, whereas the transfected proenzyme does elicit AA release in a way insensitive to non-permeable sPLA(2) inhibitors. In transfected cells, a permeable proprotein convertase inhibitor, but not a non-permeable one, prevents group X sPLA(2) maturation and partially blocks AA release. Mutations at the dibasic motif of the propeptide indicate that the last basic residue is required and sufficient for efficient maturation and AA release. All together, these results argue for the intracellular maturation of group X proenzyme in HEK293 cells by a furin-like proprotein convertase, leading to intracellular release of AA during secretion.

Electronic coupling through natural amino acids.

PubMed

Berstis, Laura; Beckham, Gregg T; Crowley, Michael F

2015-12-14

Myriad scientific domains concern themselves with biological electron transfer (ET) events that span across vast scales of rate and efficiency through a remarkably fine-tuned integration of amino acid (AA) sequences, electronic structure, dynamics, and environment interactions. Within this intricate scheme, many questions persist as to how proteins modulate electron-tunneling properties. To help elucidate these principles, we develop a model set of peptides representing the common α-helix and β-strand motifs including all natural AAs within implicit protein-environment solvation. Using an effective Hamiltonian strategy with density functional theory, we characterize the electronic coupling through these peptides, furthermore considering side-chain dynamics. For both motifs, predictions consistently show that backbone-mediated electronic coupling is distinctly sensitive to AA type (aliphatic, polar, aromatic, negatively charged and positively charged), and to side-chain orientation. The unique properties of these residues may be employed to design activated, deactivated, or switch-like superexchange pathways. Electronic structure calculations and Green's function analyses indicate that localized shifts in the electron density along the peptide play a role in modulating these pathways, and further substantiate the experimentally observed behavior of proline residues as superbridges. The distinct sensitivities of tunneling pathways to sequence and conformation revealed in this electronic coupling database help improve our fundamental understanding of the broad diversity of ET reactivity and provide guiding principles for peptide design.

Analysis of amyloid fibrils in the cheetah (Acinonyx jubatus).

PubMed

Bergström, Joakim; Ueda, Mitsuharu; Une, Yumi; Sun, Xuguo; Misumi, Shogo; Shoji, Shozo; Ando, Yukio

2006-06-01

Recently, a high prevalence of amyloid A (AA) amyloidosis has been documented among captive cheetahs worldwide. Biochemical analysis of amyloid fibrils extracted from the liver of a Japanese captive cheetah unequivocally showed that protein AA was the main fibril constituent. Further characterization of the AA fibril components by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis revealed three main protein AA bands with approximate molecular weights of 8, 10 and 12 kDa. Mass spectrometry analysis of the 12-kDa component observed in SDS-PAGE and Western blotting confirmed the molecular weight of a 12,381-Da peak. Our finding of a 12-kDa protein AA component provides evidence that the cheetah SAA sequence is longer than the previously reported 90 amino acid residues (approximately 10 kDa), and hence SAA is part of the amyloid fibril.

Conformation of flexibly linked triterpene dimers by using RDC-enhanced NMR spectroscopy

NASA Astrophysics Data System (ADS)

Lakshmi, Jerripothula K.; Pattnaik, Banita; Kavitha, Rachineni; Mallavadhani, Uppuluri V.; Jagadeesh, Bharatam

2018-06-01

Dimers of flexibly linked pentacyclic triterpene ursolic acid (UA) and its related frameworks such as asiatic acid (AA) and oleanolic acid (OA) have recently attracted significant attention due to their enhanced anti-cancer and anti-HCV activity compared to their respective monomers. Determination of conformation/inter-monomer orientation of these molecules is very important to understand their structure-activity relationship and to develop new scaffolds, which, however, is difficult through conventional NOE based solution-state NMR spectroscopy, due to lack of long-range NOEs. In the present work, we report a precise determination of conformation of two 1,2,3-triazole-linked triterpene dimer molecules, UA-AA and UA-OA, by employing one-bond Csbnd H residual dipolar couplings (RDCs) as additional long-range orientational restraints, measured in anisotropic PDMS/CDCl3 solvent medium.

Tetrahymena thermophila acidic ribosomal protein L37 contains an archaebacterial type of C-terminus.

PubMed

Hansen, T S; Andreasen, P H; Dreisig, H; Højrup, P; Nielsen, H; Engberg, J; Kristiansen, K

1991-09-15

We have cloned and characterized a Tetrahymena thermophila macronuclear gene (L37) encoding the acidic ribosomal protein (A-protein) L37. The gene contains a single intron located in the 3'-part of the coding region. Two major and three minor transcription start points (tsp) were mapped 39 to 63 nucleotides upstream from the translational start codon. The uppermost tsp mapped to the first T in a putative T. thermophila RNA polymerase II initiator element, TATAA. The coding region of L37 predicts a protein of 109 amino acid (aa) residues. A substantial part of the deduced aa sequence was verified by protein sequencing. The T. thermophila L37 clearly belongs to the P1-type family of eukaryotic A-proteins, but the C-terminal region has the hallmarks of archaebacterial A-proteins.

Translation system engineering in Escherichia coli enhances non-canonical amino acid incorporation into proteins.

PubMed

Gan, Rui; Perez, Jessica G; Carlson, Erik D; Ntai, Ioanna; Isaacs, Farren J; Kelleher, Neil L; Jewett, Michael C

2017-05-01

The ability to site-specifically incorporate non-canonical amino acids (ncAAs) into proteins has made possible the study of protein structure and function in fundamentally new ways, as well as the bio synthesis of unnatural polymers. However, the task of site-specifically incorporating multiple ncAAs into proteins with high purity and yield continues to present a challenge. At the heart of this challenge lies the lower efficiency of engineered orthogonal translation system components compared to their natural counterparts (e.g., translation elements that specifically use a ncAA and do not interact with the cell's natural translation apparatus). Here, we show that evolving and tuning expression levels of multiple components of an engineered translation system together as a whole enhances ncAA incorporation efficiency. Specifically, we increase protein yield when incorporating multiple p-azido-phenylalanine(pAzF) residues into proteins by (i) evolving the Methanocaldococcus jannaschii p-azido-phenylalanyl-tRNA synthetase anti-codon binding domain, (ii) evolving the elongation factor Tu amino acid-binding pocket, and (iii) tuning the expression of evolved translation machinery components in a single vector. Use of the evolved translation machinery in a genomically recoded organism lacking release factor one enabled enhanced multi-site ncAA incorporation into proteins. We anticipate that our approach to orthogonal translation system development will accelerate and expand our ability to site-specifically incorporate multiple ncAAs into proteins and biopolymers, advancing new horizons for synthetic and chemical biotechnology. Biotechnol. Bioeng. 2017;114: 1074-1086. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Amino acid profiles of rumen undegradable protein: a comparison between forages including cereal straws and alfalfa and their respective total mixed rations.

PubMed

Wang, B; Jiang, L S; Liu, J X

2018-06-01

Optimizing the amino acid (AA) profile of rumen undegradable protein (RUP) can positively affect the amount of milk protein. This study was conducted to improve knowledge regarding the AA profile of rumen undegradable protein from corn stover, rice straw and alfalfa hay as well as the total mixed ratio diets (TMR) based on one of them as forage source [forage-to-concentrate ratio of 45:55 (30% of corn stover (CS), 30% of rice straw (RS), 23% of alfalfa hay (AH) and dry matter basis)]. The other ingredients in the three TMR diets were similar. The RUP of all the forages and diets was estimated by incubation for 16 hr in the rumen of three ruminally cannulated lactating cows. All residues were corrected for microbial colonization, which was necessary in determining the AA composition of RUP from feed samples using in situ method. Compared with their original AA composition, the AA pattern of forages and forage-based diets changed drastically after rumen exposure. In addition, the extent of ruminal degradation of analysed AA was not constant among the forages. The greatest individual AA degradability of alfalfa hay and corn stover was Pro, but was His of rice straw. A remarkable difference was observed between microbial attachment corrected and uncorrected AA profiles of RUP, except for alfalfa hay and His in the three forages and TMR diets. The ruminal AA degradability of cereal straws was altered compared with alfalfa hay but not for the TMR diets. In summary, the AA composition of forages and TMR-based diets changed significantly after ruminal exposure, indicating that the original AA profiles of the feed cannot represent its AA composition of RUP. The AA profile of RUP and ruminal AA degradability for corn stover and rice straw contributed to missing information in the field. © 2017 Blackwell Verlag GmbH.

The role of nonconserved residues of Archaeoglobus fulgidus ferritin on its unique structure and biophysical properties.

PubMed

Sana, Barindra; Johnson, Eric; Le Magueres, Pierre; Criswell, Angela; Cascio, Duilio; Lim, Sierin

2013-11-08

Archaeoglobus fulgidus ferritin (AfFtn) is the only tetracosameric ferritin known to form a tetrahedral cage, a structure that remains unique in structural biology. As a result of the tetrahedral (2-3) symmetry, four openings (∼45 Å in diameter) are formed in the cage. This open tetrahedral assembly contradicts the paradigm of a typical ferritin cage: a closed assembly having octahedral (4-3-2) symmetry. To investigate the molecular mechanism affecting this atypical assembly, amino acid residues Lys-150 and Arg-151 were replaced by alanine. The data presented here shed light on the role that these residues play in shaping the unique structural features and biophysical properties of the AfFtn. The x-ray crystal structure of the K150A/R151A mutant, solved at 2.1 Å resolution, indicates that replacement of these key residues flips a "symmetry switch." The engineered molecule no longer assembles with tetrahedral symmetry but forms a typical closed octahedral ferritin cage. Small angle x-ray scattering reveals that the overall shape and size of AfFtn and AfFtn-AA in solution are consistent with those observed in their respective crystal structures. Iron binding and release kinetics of the AfFtn and AfFtn-AA were investigated to assess the contribution of cage openings to the kinetics of iron oxidation, mineralization, or reductive iron release. Identical iron binding kinetics for AfFtn and AfFtn-AA suggest that Fe(2+) ions do not utilize the triangular pores for access to the catalytic site. In contrast, relatively slow reductive iron release was observed for the closed AfFtn-AA, demonstrating involvement of the large pores in the pathway for iron release.

Isolation, Purification, Characterization and Effect upon HepG2 Cells of Anemaran from Rhizome Anemarrhena.

PubMed

Jiang, Qian-Qian; Zhao, Yun-Ping; Gao, Wen-Yuan; Li, Xia; Huang, Lu-Qi; Xiao, Pei-Gen

2013-01-01

The rhizome of Anemarrhena asphodeloides is used as food and traditional Chinese medicine for its hypoglycemic effect. The aim of this study was to investigate the isolation, purification and hypoglycemic activity of Anemaran as the active component. The influence factors (isolation duration, ratio of residuals to water and extracting times) during the isolation process were evaluated. The optimal conditions for NA and AA were extraction temperature 90ºC and 100ºC, duration 1h and 1.5 h, extraction time 3 and 3, and the solid-liquor ratio 1:20 and 1:15, respectively. Neutral and acid Anemaran (NA and AA) were isolated from the rhizome of Anemarrhena asphodeloides. Five fractions of NA-1, NA-2, NA-3, AA-1 and AA-2 were obtained after crude neutral and acid Anemaran purified through DEAE- 52 cellulose anion-exchange column. The characterizations of Anemaran and its different fractions were both analyzed by Fourier transform infrared spectroscopy (FT-IR) and scanning electron micrographs (SEM). Structural properties of different fractions were examined by FT-IR. Strong characteristic absorption peaks were observed at around 1744 cm(-1)and 1650 cm(-1) caused by the C=O group of uronic acids, and the band between 1440 cm(-1) and 1395 cm(-1) associated with the stretching vibration of C-O of galacturonic acid. Neither the crude neutral, nor the acid anemaran significantly inhibited the growth of HepG2 cells in-vitro, which indicated the low cytotoxicity of the anemaran. Furthermore, both neutral and acid anemaran showed hypoglycemic effect. The hypoglycemic effect of neutral anemaran was much higher than that of acid anemaran.

Improved prediction of residue flexibility by embedding optimized amino acid grouping into RSA-based linear models.

PubMed

Zhang, Hua; Kurgan, Lukasz

2014-12-01

Knowledge of protein flexibility is vital for deciphering the corresponding functional mechanisms. This knowledge would help, for instance, in improving computational drug design and refinement in homology-based modeling. We propose a new predictor of the residue flexibility, which is expressed by B-factors, from protein chains that use local (in the chain) predicted (or native) relative solvent accessibility (RSA) and custom-derived amino acid (AA) alphabets. Our predictor is implemented as a two-stage linear regression model that uses RSA-based space in a local sequence window in the first stage and a reduced AA pair-based space in the second stage as the inputs. This method is easy to comprehend explicit linear form in both stages. Particle swarm optimization was used to find an optimal reduced AA alphabet to simplify the input space and improve the prediction performance. The average correlation coefficients between the native and predicted B-factors measured on a large benchmark dataset are improved from 0.65 to 0.67 when using the native RSA values and from 0.55 to 0.57 when using the predicted RSA values. Blind tests that were performed on two independent datasets show consistent improvements in the average correlation coefficients by a modest value of 0.02 for both native and predicted RSA-based predictions.

Electronic coupling through natural amino acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berstis, Laura; Beckham, Gregg T., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov; Crowley, Michael F., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov

2015-12-14

Myriad scientific domains concern themselves with biological electron transfer (ET) events that span across vast scales of rate and efficiency through a remarkably fine-tuned integration of amino acid (AA) sequences, electronic structure, dynamics, and environment interactions. Within this intricate scheme, many questions persist as to how proteins modulate electron-tunneling properties. To help elucidate these principles, we develop a model set of peptides representing the common α-helix and β-strand motifs including all natural AAs within implicit protein-environment solvation. Using an effective Hamiltonian strategy with density functional theory, we characterize the electronic coupling through these peptides, furthermore considering side-chain dynamics. For bothmore » motifs, predictions consistently show that backbone-mediated electronic coupling is distinctly sensitive to AA type (aliphatic, polar, aromatic, negatively charged and positively charged), and to side-chain orientation. The unique properties of these residues may be employed to design activated, deactivated, or switch-like superexchange pathways. Electronic structure calculations and Green’s function analyses indicate that localized shifts in the electron density along the peptide play a role in modulating these pathways, and further substantiate the experimentally observed behavior of proline residues as superbridges. The distinct sensitivities of tunneling pathways to sequence and conformation revealed in this electronic coupling database help improve our fundamental understanding of the broad diversity of ET reactivity and provide guiding principles for peptide design.« less

A Quantitative Tool to Distinguish Isobaric Leucine and Isoleucine Residues for Mass Spectrometry-Based De Novo Monoclonal Antibody Sequencing

NASA Astrophysics Data System (ADS)

Poston, Chloe N.; Higgs, Richard E.; You, Jinsam; Gelfanova, Valentina; Hale, John E.; Knierman, Michael D.; Siegel, Robert; Gutierrez, Jesus A.

2014-07-01

De novo sequencing by mass spectrometry (MS) allows for the determination of the complete amino acid (AA) sequence of a given protein based on the mass difference of detected ions from MS/MS fragmentation spectra. The technique relies on obtaining specific masses that can be attributed to characteristic theoretical masses of AAs. A major limitation of de novo sequencing by MS is the inability to distinguish between the isobaric residues leucine (Leu) and isoleucine (Ile). Incorrect identification of Ile as Leu or vice versa often results in loss of activity in recombinant antibodies. This functional ambiguity is commonly resolved with costly and time-consuming AA mutation and peptide sequencing experiments. Here, we describe a set of orthogonal biochemical protocols, which experimentally determine the identity of Ile or Leu residues in monoclonal antibodies (mAb) based on the selectivity that leucine aminopeptidase shows for n-terminal Leu residues and the cleavage preference for Leu by chymotrypsin. The resulting observations are combined with germline frequencies and incorporated into a logistic regression model, called Predictor for Xle Sites (PXleS) to provide a statistical likelihood for the identity of Leu at an ambiguous site. We demonstrate that PXleS can generate a probability for an Xle site in mAbs with 96% accuracy. The implementation of PXleS precludes the expression of several possible sequences and, therefore, reduces the overall time and resources required to go from spectra generation to a biologically active sequence for a mAb when an Ile or Leu residue is in question.

A quantitative tool to distinguish isobaric leucine and isoleucine residues for mass spectrometry-based de novo monoclonal antibody sequencing.

PubMed

Poston, Chloe N; Higgs, Richard E; You, Jinsam; Gelfanova, Valentina; Hale, John E; Knierman, Michael D; Siegel, Robert; Gutierrez, Jesus A

2014-07-01

De novo sequencing by mass spectrometry (MS) allows for the determination of the complete amino acid (AA) sequence of a given protein based on the mass difference of detected ions from MS/MS fragmentation spectra. The technique relies on obtaining specific masses that can be attributed to characteristic theoretical masses of AAs. A major limitation of de novo sequencing by MS is the inability to distinguish between the isobaric residues leucine (Leu) and isoleucine (Ile). Incorrect identification of Ile as Leu or vice versa often results in loss of activity in recombinant antibodies. This functional ambiguity is commonly resolved with costly and time-consuming AA mutation and peptide sequencing experiments. Here, we describe a set of orthogonal biochemical protocols, which experimentally determine the identity of Ile or Leu residues in monoclonal antibodies (mAb) based on the selectivity that leucine aminopeptidase shows for n-terminal Leu residues and the cleavage preference for Leu by chymotrypsin. The resulting observations are combined with germline frequencies and incorporated into a logistic regression model, called Predictor for Xle Sites (PXleS) to provide a statistical likelihood for the identity of Leu at an ambiguous site. We demonstrate that PXleS can generate a probability for an Xle site in mAbs with 96% accuracy. The implementation of PXleS precludes the expression of several possible sequences and, therefore, reduces the overall time and resources required to go from spectra generation to a biologically active sequence for a mAb when an Ile or Leu residue is in question.

Group X Secreted Phospholipase A2 Proenzyme Is Matured by a Furin-like Proprotein Convertase and Releases Arachidonic Acid inside of Human HEK293 Cells*

PubMed Central

Jemel, Ikram; Ii, Hiromi; Oslund, Rob C.; Payré, Christine; Dabert-Gay, Anne-Sophie; Douguet, Dominique; Chargui, Khaoula; Scarzello, Sabine; Gelb, Michael H.; Lambeau, Gérard

2011-01-01

Among mammalian secreted phospholipases A2 (sPLA2s), group X sPLA2 has the most potent hydrolyzing activity toward phosphatidylcholine and is involved in arachidonic acid (AA) release. Group X sPLA2 is produced as a proenzyme and contains a short propeptide of 11 amino acids ending with a dibasic motif, suggesting cleavage by proprotein convertases. Although the removal of this propeptide is clearly required for enzymatic activity, the cellular location and the protease(s) involved in proenzyme conversion are unknown. Here we have analyzed the maturation of group X sPLA2 in HEK293 cells, which have been extensively used to analyze sPLA2-induced AA release. Using recombinant mouse (PromGX) and human (ProhGX) proenzymes; HEK293 cells transfected with cDNAs coding for full-length ProhGX, PromGX, and propeptide mutants; and various permeable and non-permeable sPLA2 inhibitors and protease inhibitors, we demonstrate that group X sPLA2 is mainly converted intracellularly and releases AA before externalization from the cell. Most strikingly, the exogenous proenzyme does not elicit AA release, whereas the transfected proenzyme does elicit AA release in a way insensitive to non-permeable sPLA2 inhibitors. In transfected cells, a permeable proprotein convertase inhibitor, but not a non-permeable one, prevents group X sPLA2 maturation and partially blocks AA release. Mutations at the dibasic motif of the propeptide indicate that the last basic residue is required and sufficient for efficient maturation and AA release. All together, these results argue for the intracellular maturation of group X proenzyme in HEK293 cells by a furin-like proprotein convertase, leading to intracellular release of AA during secretion. PMID:21878635

Analysis of N-acetylaminosugars by CE: a comparative derivatization study.

PubMed

Rustighi, Isabella; Campa, Cristiana; Rossi, Marco; Semeraro, Sabrina; Vetere, Amedeo; Gamini, Amelia

2009-08-01

N-linked or O-linked glycans derived from glycoprotein processing carry, an N-acetylglucosamine or an N-acetylgalactosamine respectively, at their reducing termini. The presence of the N-acetylamino group on C-2 of reducing sugar residues has been reported to hamper the derivatization reaction with a chromophore at the anomeric centre. In this paper N-acetyllactosamine, N-acetylglucosamine, N-acetylgalactosamine and several other neutral monosaccharides are coupled to three different dyes (4-aminobenzonitrile, 2-aminopyridine, 2-aminobenzoic acid (2-AA)) by reductive amination and analysed by CE with UV detection. The 2-AA derivatives showed the lowest concentration detection limits, varying approximately in the 2-3 muM range for the saccharides tested including the N-acetamido ones. The possibility to separate and detect with the same sensitivity ten 2-AA-labelled monosaccharides mainly found in mammalian or plant glycoproteins in a single CE run is highlighted. The analysis has been carried out in less than 25 min using the borate-complexation method in CZE mode. The influence of the strength of the acid used as catalyst in the chemical modification of the sugars with 2-AA is also shortly addressed.

Rationally evolving tRNAPyl for efficient incorporation of noncanonical amino acids.

PubMed

Fan, Chenguang; Xiong, Hai; Reynolds, Noah M; Söll, Dieter

2015-12-15

Genetic encoding of noncanonical amino acids (ncAAs) into proteins is a powerful approach to study protein functions. Pyrrolysyl-tRNA synthetase (PylRS), a polyspecific aminoacyl-tRNA synthetase in wide use, has facilitated incorporation of a large number of different ncAAs into proteins to date. To make this process more efficient, we rationally evolved tRNA(Pyl) to create tRNA(Pyl-opt) with six nucleotide changes. This improved tRNA was tested as substrate for wild-type PylRS as well as three characterized PylRS variants (N(ϵ)-acetyllysyl-tRNA synthetase [AcKRS], 3-iodo-phenylalanyl-tRNA synthetase [IFRS], a broad specific PylRS variant [PylRS-AA]) to incorporate ncAAs at UAG codons in super-folder green fluorescence protein (sfGFP). tRNA(Pyl-opt) facilitated a 5-fold increase in AcK incorporation into two positions of sfGFP simultaneously. In addition, AcK incorporation into two target proteins (Escherichia coli malate dehydrogenase and human histone H3) caused homogenous acetylation at multiple lysine residues in high yield. Using tRNA(Pyl-opt) with PylRS and various PylRS variants facilitated efficient incorporation of six other ncAAs into sfGFP. Kinetic analyses revealed that the mutations in tRNA(Pyl-opt) had no significant effect on the catalytic efficiency and substrate binding of PylRS enzymes. Thus tRNA(Pyl-opt) should be an excellent replacement of wild-type tRNA(Pyl) for future ncAA incorporation by PylRS enzymes. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Cloning of stanniocalcin (STC) cDNAs of divergent teleost species: Monomeric STC supports monophyly of the ancient teleosts, the osteoglossomorphs.

PubMed

Amemiya, Yutaka; Irwin, David M; Youson, John H

2006-10-01

Molecular cloning of teleost stanniocalcin (STC) cDNAs was undertaken in two species of order Osteoglossiformes of subdivision Osteoglossomorpha and one species of each of orders Cypriniformes and Perciformes within the subdivision Euteleostei. The elephantnose (Gnathonemus petersii) and the butterflyfish (Pantadon buchholzi) are basal teleosts in different osteoglossiforme suborders yet their 218 amino acid (aa) mature hormones, from prehormones of 249 and 251aa, respectively, have only 10 cysteine residues. A substitution for cysteine at the intermonomeric disulfide linkage site, implies that their STCs exist as monomeric peptides, as is the case with STC from another osteoglossormorph, arawana [Amemiya, Y., Marra, L.E., Reyhani, N., Youson, J.H., 2002. Stanniocalcin from an ancient teleost: a monomeric form of the hormone and a possible extracorpuscular distribution. Mol. Cell. Endocrinol. 188, 141-150]. The STC cDNA of the generalized teleost and cyprinid, the white sucker (Catostomus commersoni), encodes a prehormone of 249aa with a signal peptide of 31aa and a mature protein of 218aa that possesses 11 cysteine residues. The latter feature is consistent with a previous analysis that white sucker mature STC is a glycosylated, homodimeric peptide [Amemiya, Y., Marra, L.E., Reyhani, N., Youson, J.H., 2002. Stanniocalcin from an ancient teleost: a monomeric form of the hormone and a possible extracorpuscular distribution. Mol. Cell. Endocrinol. 188, 141-150]. An open reading frame of the STC cDNA of the derived teleost and perciforme, the smallmouth bass (Micropterus dolomieui), encodes a prehormone of 255aa with a signal peptide of 33aa and a mature protein of 222aa. The position of the 11 cysteines in smallmouth bass STC suggests that it exists as a homodimeric peptide. A phylogenetic analysis, using the new STC-1 amino acid sequences and those in the gene data base provided strong support for monophyly of the Osteoglossomorpha and indicated, with positioning of white sucker and smallmouth bass, that this molecule has some utility as a taxonomic marker. This analysis also suggested that two STC-1 gene sequences exist in multiple fish genomes, and that they may be a product of the fish-specific genome duplication. The mutation in the osteoglossomorph STC likely occurred after the appearance of the first teleosts and before movement of the tectonic plates.

Rationally evolving tRNAPyl for efficient incorporation of noncanonical amino acids

PubMed Central

Fan, Chenguang; Xiong, Hai; Reynolds, Noah M.; Söll, Dieter

2015-01-01

Genetic encoding of noncanonical amino acids (ncAAs) into proteins is a powerful approach to study protein functions. Pyrrolysyl-tRNA synthetase (PylRS), a polyspecific aminoacyl-tRNA synthetase in wide use, has facilitated incorporation of a large number of different ncAAs into proteins to date. To make this process more efficient, we rationally evolved tRNAPyl to create tRNAPyl-opt with six nucleotide changes. This improved tRNA was tested as substrate for wild-type PylRS as well as three characterized PylRS variants (Nϵ-acetyllysyl-tRNA synthetase [AcKRS], 3-iodo-phenylalanyl-tRNA synthetase [IFRS], a broad specific PylRS variant [PylRS-AA]) to incorporate ncAAs at UAG codons in super-folder green fluorescence protein (sfGFP). tRNAPyl-opt facilitated a 5-fold increase in AcK incorporation into two positions of sfGFP simultaneously. In addition, AcK incorporation into two target proteins (Escherichia coli malate dehydrogenase and human histone H3) caused homogenous acetylation at multiple lysine residues in high yield. Using tRNAPyl-opt with PylRS and various PylRS variants facilitated efficient incorporation of six other ncAAs into sfGFP. Kinetic analyses revealed that the mutations in tRNAPyl-opt had no significant effect on the catalytic efficiency and substrate binding of PylRS enzymes. Thus tRNAPyl-opt should be an excellent replacement of wild-type tRNAPyl for future ncAA incorporation by PylRS enzymes. PMID:26250114

In vitro digestibility of individual amino acids in rumen-undegraded protein: the modified three-step procedure and the immobilized digestive enzyme assay.

PubMed

Boucher, S E; Calsamiglia, S; Parsons, C M; Stern, M D; Moreno, M Ruiz; Vázquez-Añón, M; Schwab, C G

2009-08-01

Three soybean meal, 3 SoyPlus (West Central Cooperative, Ralston, IA), 5 distillers dried grains with solubles, and 5 fish meal samples were used to evaluate the modified 3-step in vitro procedure (TSP) and the in vitro immobilized digestive enzyme assay (IDEA; Novus International Inc., St. Louis, MO) for estimating digestibility of AA in rumen-undegraded protein (RUP-AA). In a previous experiment, each sample was ruminally incubated in situ for 16 h, and in vivo digestibility of AA in the intact samples and in the rumen-undegraded residues (RUR) was obtained for all samples using the precision-fed cecectomized rooster assay. For the modified TSP, 5 g of RUR was weighed into polyester bags, which were then heat-sealed and placed into Daisy(II) incubator bottles. Samples were incubated in a pepsin/HCl solution followed by incubation in a pancreatin solution. After this incubation, residues remaining in the bags were analyzed for AA, and digestibility of RUP-AA was calculated based on disappearance from the bags. In vitro RUP-AA digestibility estimates obtained with this procedure were highly correlated to in vivo estimates. Corresponding intact feeds were also analyzed via the pepsin/pancreatin steps of the modified TSP. In vitro estimates of AA digestibility of the feeds were highly correlated to in vivo RUP-AA digestibility, which suggests that the feeds may not need to be ruminally incubated before determining RUP-AA digestibility in vitro. The RUR were also analyzed via the IDEA kits. The IDEA values of the RUR were good predictors of RUP-AA digestibility in soybean meal, SoyPlus, and distillers dried grains with solubles, but the IDEA values were not as good predictors of RUP-AA digestibility in fish meal. However, the IDEA values of intact feed samples were also determined and were highly correlated to in vivo RUP-AA digestibility for all feed types, suggesting that the IDEA value of intact feeds may be a better predictor of RUP-AA digestibility than the IDEA value of the RUR. In conclusion, the modified TSP and IDEA kits are good approaches for estimating RUP-AA digestibility in soybean meal products, distillers dried grains with solubles, and fish meal samples.

Characterization and Promoter Analysis of a Cotton Ring-Type Ubiquitin Ligase (E3) Gene

USDA-ARS?s Scientific Manuscript database

A cotton fiber cDNA, GhRING1, and its corresponding gene have been cloned and characterized. The GhRING1 gene encodes a RING-type ubiquitin ligase (E3) containing 337 amino acids (aa). The GhRING1 protein contains a RING finger motif with conserved cysteine and histine residues at the C-terminus a...

Detection and initial characterization of protein entities consisting of the HIV glycoprotein cytoplasmic C-terminal domain alone.

PubMed

Pfeiffer, Tanya; Ruppert, Thomas; Schaal, Heiner; Bosch, Valerie

2013-06-20

Employing antibodies against the cytoplasmic tail of the HIV-1 glycoprotein (Env-CT), in addition to gp160/gp41, we have identified several novel small Env proteins (<25kD) in HIV-1 transfected and infected cells. Mass spectrometric and mutational analyses show that two mechanisms contribute to their generation. Thus the protein, designated Tr-Env-CT (for truncated Env-CT), consists of the C-terminal 139 amino acids (aa) of Env (aa 718-856) with the N-terminal Q718 modified to pyroglutamic acid. It is likely derived from full-length Env protein by proteolytic processing. A further heterogeneous set of slightly larger proteins, termed Env-CT* species, are rather derived from spliced mRNAs containing only those Env C-terminal residues (aa 719-856) which overlap with the second tat and rev coding exons. They are N-terminally extended in the same reading frame. It is conceivable that essential Env-CT functions may be fulfilled by these novel species rather than by the full-length glycoprotein itself. Copyright © 2013 Elsevier Inc. All rights reserved.

Bombyx mori ABC transporter C2 structures responsible for the receptor function of Bacillus thuringiensis Cry1Aa toxin.

PubMed

Tanaka, Shiho; Endo, Haruka; Adegawa, Satomi; Iizuka, Ami; Imamura, Kazuhiro; Kikuta, Shingo; Sato, Ryoichi

2017-12-01

Because Bombyx mori ABC transporter C2 (BmABCC2) has 1000-fold higher potential than B. mori cadherin-like protein as a receptor for Bacillus thuringiensis Cry1Aa toxin (Tanaka et al., 2013), the gate-opening ability of the latent pore under six extracellular loops (ECLs) of BmABCC2 was expected to be the reason for its higher potential (Heckel, 2012). In this study, cell swelling assays in Sf9 cells showed that BmABCC2 mutants lacking substrate-excreting activity retained receptor activity, indicating that the gate-opening activity of BmABCC2 is not responsible for Cry1Aa toxicity. The analysis of 29 BmABCC2 mutants demonstrated that 770 DYWL 773 of ECL 4 comprise a putative binding site to Cry1Aa. This suggests that specific toxicity of Cry1Aa toxin to a restricted range of lepidopteran insects is dependent on conservation and variation in the amino acid residues around 770 DYWL 773 of ECL 4 in the ABCC2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methods for Kinetic and Thermodynamic Analysis of Aminoacyl-tRNA Synthetases

PubMed Central

Francklyn, Christopher S.; First, Eric A.; Perona, John J.; Hou, Ya-Ming

2008-01-01

The accuracy of protein synthesis relies on the ability of aminoacyl-tRNA synthetases (aaRSs) to discriminate among true and near cognate substrates. To date, analysis of aaRSs function, including identification of residues of aaRS participating in amino acid and tRNA discrimination, has largely relied on the steady state kinetic pyrophosphate exchange and aminoacylation assays. Pre-steady state kinetic studies investigating a more limited set of aaRS systems have also been undertaken to assess the energetic contributions of individual enzyme-substrate interactions, particularly in the adenylation half reaction. More recently, a renewed interest in the use of rapid kinetics approaches for aaRSs has led to their application to several new aaRS systems, resulting in the identification of mechanistic differences that distinguish the two structurally distinct aaRS classes. Here, we review the techniques for thermodynamic and kinetic analysis of aaRS function. Following a brief survey of methods for the preparation of materials and for steady state kinetic analysis, this review will describe pre-steady state kinetic methods employing rapid quench and stopped-flow fluorescence for analysis of the activation and aminoacyl transfer reactions. Application of these methods to any aaRS system allows the investigator to derive detailed kinetic mechanisms for the activation and aminoacyl transfer reactions, permitting issues of substrate specificity, stereochemical mechanism, and inhibitor interaction to be addressed in a rigorous and quantitative fashion. PMID:18241792

Amino acid residues in the GerAB protein important in the function and assembly of the alanine spore germination receptor of Bacillus subtilis 168.

PubMed

Cooper, Gareth R; Moir, Anne

2011-05-01

The paradigm gerA operon is required for endospore germination in response to c-alanine as the sole germinant, and the three protein products, GerAA, GerAB, and GerAC are predicted to form a receptor complex in the spore inner membrane. GerAB shows homology to the amino acid-polyamine-organocation (APC) family of single-component transporters and is predicted to be an integral membrane protein with 10 membrane-spanning helices. Site-directed mutations were introduced into the gerAB gene at its natural location on the chromosome. Alterations to some charged or potential helix-breaking residues within membrane spans affected receptor function dramatically. In some cases, this is likely to reflect the complete loss of the GerA receptor complex, as judged by the absence of the germinant receptor protein GerAC, which suggests that the altered GerAB protein itself may be unstable or that the altered structure destabilizes the complex. Mutants that have a null phenotype for Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, Av. Real, 1, 24006 León, Spain-alanine germination but retain GerAC protein at near-normal levels are more likely to define amino acid residues of functional, rather than structural, importance. Single-amino-acid substitutions in each of the GerAB and GerAA proteins can prevent incorporation of GerAC protein into the spore; this provides strong evidence that the proteins within a specific receptor interact and that these interactions are required for receptor assembly. The lipoprotein nature of the GerAC receptor subunit is also important; an amino acid change in the prelipoprotein signal sequence in the gerAC1 mutant results in the absence of GerAC protein from the spore.

Characterization of the radical-scavenging reaction of 2-O-substituted ascorbic acid derivatives, AA-2G, AA-2P, and AA-2S: a kinetic and stoichiometric study.

PubMed

Takebayashi, Jun; Tai, Akihiro; Gohda, Eiichi; Yamamoto, Itaru

2006-04-01

The aim of this study was to characterize the antioxidant activity of three ascorbic acid (AA) derivatives O-substituted at the C-2 position of AA: ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S). The radical-scavenging activities of these AA derivatives and some common low molecular-weight antioxidants such as uric acid or glutathione against 1,1-diphenyl-picrylhydrazyl (DPPH) radical, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+), or galvinoxyl radical were kinetically and stoichiometrically evaluated under pH-controlled conditions. Those AA derivatives slowly and continuously reacted with DPPH radical and ABTS+, but not with galvinoxyl radical. They effectively reacted with DPPH radical under acidic conditions and with ABTS+ under neutral conditions. In contrast, AA immediately quenched all species of radicals tested at all pH values investigated. The reactivity of Trolox, a water-soluble vitamin E analogue, was comparable to that of AA in terms of kinetics and stoichiometrics. Uric acid and glutathione exhibited long-lasting radical-scavenging activity against these radicals under certain pH conditions. The radical-scavenging profiles of AA derivatives were closer to those of uric acid and glutathione rather than to that of AA. The number of radicals scavenged by one molecule of AA derivatives, uric acid, or glutathione was equal to or greater than that by AA or Trolox under the appropriate conditions. These data suggest the potential usage of AA derivatives as radical scavengers.

Combining reduced glutathione and ascorbic acid has supplementary beneficial effects on boar sperm cryotolerance.

PubMed

Giaretta, Elisa; Estrada, Efrén; Bucci, Diego; Spinaci, Marcella; Rodríguez-Gil, Joan E; Yeste, Marc

2015-02-01

The main aim of this work was to evaluate how supplementing freezing and thawing media with reduced glutathione (GSH) and l-ascorbic acid (AA) affected the quality parameters of frozen-thawed boar spermatozoa. With this purpose, semen samples of 12 ejaculates coming from 12 boars were used. Each ejaculate was split into seven aliquots to which 5 mM of GSH and 100 μM of AA were added separately or together at two different steps of freeze-thawing. Various sperm parameters (levels of free cysteine residues in sperm nucleoproteins, sperm viability, acrosome membrane integrity, intracellular peroxide and superoxide levels [ROS], and total and progressive motility) were evaluated before freezing and at 30 and 240 minutes after thawing. Both GSH and AA significantly improved boar sperm cryotolerance when they were separately added to freezing and thawing media. However, the highest improvement was recorded when both freezing and thawing media were supplemented with 5 mM of GSH plus 100 μM of AA. This improvement was observed in sperm viability and acrosome integrity, sperm motility, and nucleoprotein structure. Although ROS levels were not much increased by freeze-thawing procedures, the addition of GSH and AA to both freezing and thawing extenders significantly decreased intracellular peroxide levels and had no impact on superoxide levels. According to our results, we can conclude that supplementation of freezing and thawing media with both GSH and AA has a combined, beneficial effect on frozen-thawed boar sperm, which is greater than that obtained with the separate addition of either GSH or AA. Copyright © 2015 Elsevier Inc. All rights reserved.

Inhibition of free radical-induced erythrocyte hemolysis by 2-O-substituted ascorbic acid derivatives.

PubMed

Takebayashi, Jun; Kaji, Hiroaki; Ichiyama, Kenji; Makino, Kazutaka; Gohda, Eiichi; Yamamoto, Itaru; Tai, Akihiro

2007-10-15

Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was AA-2S> or =Trolox=uric acid> or =AA-2P> or =AA-2G=AA>glutathione. Although the reactivity of the AA derivatives against AAPH-derived peroxyl radical (ROO(*)) was much lower than that of AA, the derivatives exerted equal or more potent protective effects on AAPH-induced hemolysis and membrane protein oxidation. In addition, the AA derivatives were found to react per se with ROO(*), not via AA as an intermediate. These findings suggest that secondary reactions between the AA derivative radical and ROO(*) play a part in hemolysis inhibition. Delayed addition of the AA derivatives after AAPH-induced oxidation of erythrocytes had already proceeded showed weaker inhibition of hemolysis compared to that of AA. These results suggest that the AA derivatives per se act as biologically effective antioxidants under moderate oxidative stress and that AA-2G and AA-2P may be able to act under severe oxidative stress after enzymatic conversion to AA in vivo.

Fate of 14C-acrylamide in roasted and ground coffee during storage.

PubMed

Baum, Matthias; Böhm, Nadine; Görlitz, Jessica; Lantz, Ingo; Merz, Karl Heinz; Ternité, Rüdiger; Eisenbrand, Gerhard

2008-05-01

Acrylamide (AA) is formed during heating of carbohydrate rich foods in the course of the Maillard reaction. AA has been classified as probably carcinogenic to humans. Storage experiments with roasted coffee have shown that AA levels decrease depending on storage time and temperature. In the present study the fate of AA lost during storage of roasted and ground (R&G) coffee was studied, using 14C-labeled AA as radiotracer. Radiolabel was measured in coffee brew, filter residue, and volatiles. In the brew, total (14)C-label decreased during storage of R&G coffee, while activity in the filter residue built up concomitantly. [2,3-14C]-AA (14C-AA) was the only 14C-related water extractable low molecular compound in the brew detected by radio-HPLC. No formation of volatile 14C-AA-related compounds was detected during storage and coffee brewing. Close to 90% of the radiolabel in the filter residue (spent R&G coffee, spent grounds) remained firmly bound to the matrix, largely resisting extraction by aqueous ammonia, ethyl acetate, chloroform, hexane, and sequential polyenzymatic digest. Furanthiols, which are abundant as aroma components in roasted coffee, have not been found to be involved in the formation of covalent AA adducts and thus do not contribute substantially to the decrease of AA during storage.

On the Relationship Between Solar Wind Speed, Geomagnetic Activity, and the Solar Cycle Using Annual Values

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2008-01-01

The aa index can be decomposed into two separate components: the leading sporadic component due to solar activity as measured by sunspot number and the residual or recurrent component due to interplanetary disturbances, such as coronal holes. For the interval 1964-2006, a highly statistically important correlation (r = 0.749) is found between annual averages of the aa index and the solar wind speed (especially between the residual component of aa and the solar wind speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of solar wind speed are inferred to have also trended upward.

Interacting helical surfaces of the transmembrane segments of subunits a and c' of the yeast V-ATPase defined by disulfide-mediated cross-linking.

PubMed

Kawasaki-Nishi, Shoko; Nishi, Tsuyoshi; Forgac, Michael

2003-10-24

Proton translocation by the vacuolar (H+)-ATPase (or V-ATPase) has been shown by mutagenesis to be dependent upon charged residues present within transmembrane segments of subunit a as well as the three proteolipid subunits (c, c', and c"). Interaction between R735 in TM7 of subunit a and the glutamic acid residue in the middle of TM4 of subunits c and c' or TM2 of subunit c" has been proposed to be essential for proton release to the luminal compartment. In order to determine whether the helical face of TM7 of subunit a containing R735 is capable of interacting with the helical face of TM4 of subunit c' containing the essential glutamic acid residue (Glu-145), cysteine-mediated cross-linking between these subunits in yeast has been performed. Cys-less forms of subunits a and c' as well as forms containing unique cysteine residues were constructed, introduced together into a strain disrupted in both endogenous subunits, and tested for growth at neutral pH, for assembly competence and for cross-linking in the presence of cupric-phenanthroline by SDS-PAGE and Western blot analysis. Four different cysteine mutants of subunit a were each tested pairwise with ten different unique cysteine mutants of subunit c'. Strong cross-linking was observed for the pairs aS728C/c'I142C, aA731C/c'E145C, aA738C/c'F143C, aA738C/c'L147C, and aL739C/c'L147C. Partial cross-linking was observed for an additional 13 of 40 pairs analyzed. When arrayed on a helical wheel diagram, the results suggest that the helical face of TM7 of subunit a containing Arg-735 interacts with the helical face of TM4 of subunit c' centered on Val-146 and bounded by Glu-145 and Leu-147. The results are consistent with a possible rotational flexibility of one or both of these transmembrane segments as well as some flexibility of movement perpendicular to the membrane.

Sequence, overproduction and purification of Vibrio proteolyticus ribosomal protein L18 for in vitro and in vivo studies

NASA Technical Reports Server (NTRS)

Setterquist, R. A.; Smith, G. K.; Oakley, T. H.; Lee, Y. H.; Fox, G. E.

1996-01-01

A strategy suggested by comparative genomic studies was used to amplify the entire Vibrio proteolyticus (Vp) gene for ribosomal protein L18. Vp L18 and its flanking regions were sequenced and compared with the deduced amino acid (aa) sequences of other known L18 proteins. A 26-aa residue segment at the carboxy terminus contains many strongly conserved residues and may be critical for the L18 interaction with 5S rRNA. This approach should allow rapid characterization of L18 from large numbers of bacteria. Both Vp L18 and Escherichia coli (Ec) L18 were overproduced and purified using a T7 expression vector which fuses an N-terminal peptide segment (His-tag) containing 6 histidine residues to the recombinant protein. The purified fusion proteins, Vp His::L18 and Ec His::L18, were both found to bind to either the Vp 5S or Ec 5S rRNAs in vitro. Vp His::L18 protein was also shown to incorporate into Ec ribosomes in vivo. This His-tag strategy likely will have general applicability for the study of ribosomal proteins in vitro and in vivo.

Observation of the side chain O-methylation of glutamic acid or aspartic acid containing model peptides by electrospray ionization-mass spectrometry.

PubMed

Atik, A Emin; Guray, Melda Z; Yalcin, Talat

2017-03-15

O-methylation of the side chains of glutamic acid (E) and aspartic acid (D) residues is generally observed modification when an acidified methanol/water (MeOH/dH 2 O) mixture is used as a solvent system during sample preparation for proteomic research. This chemical modification may result misidentification with endogenous protein methylation; therefore, a special care should be taken during sample handling prior to mass spectrometric analysis. In the current study, we systematically examined the extent of E/D methylation and C-terminus carboxyl group of synthetic model peptides in terms of different incubation temperatures, storage times, and added acid types as well as its percentages. To monitor these effects, C-terminus amidated and free acid forms of synthetic model peptides comprised of E or D residue(s) have been analyzed by electrospray ionization-mass spectrometry (ESI-MS). Additionally, LC-MS/MS experiments were performed to confirm the formation of methylated peptide product. The results showed that the rate of methylation was increased as the temperature increases along with prolong incubation times. Moreover, the extent of methylation was remarkably high when formic acid (FA) used as a protonation agent instead of acetic acid (AA). In addition, it was found that the degree of methylation was significantly decreased by lowering acid percentages in ESI solution. More than one acidic residue containing model peptides have been also used to explore the extent of multiple methylation reaction. Lastly, the ethanol (EtOH) and isopropanol (iPrOH) have been substituted separately with MeOH in sample preparation step to investigate the extent of esterification reaction under the same experimental conditions. However, in the positive perspective of view, this method can be used as a simple, rapid and cheap method for methylation of acidic residues under normal laboratory conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of π-stacking interactions between aromatic amino acids and quercetagetin

NASA Astrophysics Data System (ADS)

Akher, Farideh Badichi; Ebrahimi, Ali; Mostafavi, Najmeh

2017-01-01

In the present study, the π-stacking interactions between quercetagetin (QUE), which is one of the most representative flavonol compounds with biological and chemical activities, and some aromatic amino acid (AA) residues has been investigated by the quantum mechanical calculations. The trend in the absolute value of stacking interaction energy |ΔE| with respect to AAs is HIS > PHE > TYR > TPR. The results show that the sum of donor-acceptor interaction energy between AAs and QUE (∑E2) and the sum of electron densities ρ calculated at BCPs and CCPs between the rings (∑ρBCPs and ∑ρCCP) can be useful descriptors for prediction of the ΔE values of the complexes. The Osbnd H bond dissociation enthalpy (BDE) slightly decreases by the π-stacking interaction, which confirms the positive effect of that interaction on the antioxidant activity of QUE. A reverse trend is observed for BDE when is compared with the |ΔE| values. A reliable relationship is also observed between the Muliken spin density (MSD) distributions of the radical species and the most convenient Osbnd H bond dissociations. In addition, reactivity is in good correlation with the antioxidant activity of the complexes.

Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

NASA Astrophysics Data System (ADS)

Sun, Aixia; Liu, Xiang; Tang, Ganghua

2017-12-01

Tumor cells have an increased nutritional demand for amino acids(AAs) to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET). Carbon-11 and fluorine-18 labeled AAs include the [1-11C] amino acids, labeling alpha-C- amino acids, the branched-chain of amino acids and N-substituted carbon-11 labeled amino acids. These tracers target protein synthesis or amino acid(AA) transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non–small cell lung cancer (NSCLC) and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

Two non-redundant fragments in the N-terminal peptide of human cytosolic methionyl-tRNA synthetase were indispensable for the multi-synthetase complex incorporation and enzyme activity.

PubMed

He, Ran; Zu, Li-Dong; Yao, Peng; Chen, Xin; Wang, En-Duo

2009-02-01

In human cytoplasm, nine aminoacyl-tRNA synthetases (aaRSs) and three protein factors form a multi-synthetase complex (MSC). Human cytosolic methionyl-tRNA synthetase (hcMetRS) is a component of the MSC. Sequence alignment revealed that hcMetRS has an N-terminal extension of 267 amino acid residues. This extension can be divided into three sub-domains: GST-like, GN, and GC sub-domains. The effect of each sub-domain in the N-terminal extension of hcMetRS on enzymatic activity and incorporation into the MSC was studied. The results of cellular assay showed that the GST-like sub-domain was responsible for the incorporation of hcMetRS into the MSC. The entire N-terminal extension of hcMetRS is indispensable for the enzymatic activity. Deletion mutagenesis revealed that a seven-amino acid motif within the sub-domain GC was important for the activity of amino acid activation. A conserved proline residue within the seven-amino acid motif was crucial, while the other six residues were moderately important for the amino acid activation activity. Thus, the last 15 residues of previously defined N-terminal extension of hcMetRS was a part of the catalytic domain; whereas the first 252 residues of hcMetRS constitute the N-terminal extended domain of hcMetRS. The formerly defined N-terminal extension of hcMetRS possesses two functions of two different domains.

Effects of aromatic amino acids, phenylacetate and phenylpropionate on fermentation of xylan by the rumen anaerobic fungi, Neocallimastix frontalis and Piromyces communis.

PubMed

Guliye, A Y; Wallace, R J

2007-10-01

Anaerobic fungi are important members of the fibrolytic community of the rumen. The aim of this study was to study their requirement for aromatic amino acids (AA) and related phenyl acids (phenylpropionic and phenylacetic acids) for optimal xylan fermentation. Neocallimastix frontalis RE1 and Piromyces communis P were grown in a defined medium containing oat spelts xylan as the sole energy source, plus one of the following N sources: ammonia; ammonia plus a complete mixture of 20 AA commonly found in protein; ammonia plus complete AA mixture minus aromatic AA; ammonia plus phenyl acids; ammonia plus complete AA mixture without aromatic AA plus phenyl acids. Both species grew in all the media, indicating no absolute requirement for AA. The complete AA mixture increased (P<0.05) acetate concentration by 18% and 15%, sugar utilization by 33% and 22% and microbial yield by about 22% and 15% in N. frontalis and P. communis, respectively, in comparison with the treatments that had ammonia as the only N source. Neither the supply of aromatic AA or phenol acids, nor their deletion from the complete AA mixture, affected the fermentation rate, products or yield of either species. AA were not essential for N. frontalis and P. communis, but their growth on xylan was stimulated. The effects could not be explained in terms of aromatic AA alone. Ruminant diets should contain sufficient protein to sustain optimal fibre digestion by ruminal fungi. Aromatic AA or phenyl acids alone cannot replace the complete AA mixture.

Antibodies against the mono-methylated arginine-glycine repeat (MMA-RG) of the Epstein-Barr virus nuclear antigen 2 (EBNA2) identify potential cellular proteins targeted in viral transformation.

PubMed

Ayoubian, Hiresh; Fröhlich, Thomas; Pogodski, Dagmar; Flatley, Andrew; Kremmer, Elisabeth; Schepers, Aloys; Feederle, Regina; Arnold, Georg J; Grässer, Friedrich A

2017-08-01

The Epstein-Barr virus is a human herpes virus with oncogenic potential. The virus-encoded nuclear antigen 2 (EBNA2) is a key mediator of viral tumorigenesis. EBNA2 features an arginine-glycine (RG) repeat at amino acids (aa)339-354 that is essential for the transformation of lymphocytes and contains symmetrically (SDMA) and asymmetrically (ADMA) di-methylated arginine residues. The SDMA-modified EBNA2 binds the survival motor neuron protein (SMN), thus mimicking SMD3, a cellular SDMA-containing protein that interacts with SMN. Accordingly, a monoclonal antibody (mAb) specific for the SDMA-modified RG repeat of EBNA2 also binds to SMD3. With the novel mAb 19D4 we now show that EBNA2 contains mono-methylated arginine (MMA) residues within the RG repeat. Using 19D4, we immune-precipitated and analysed by mass spectrometry cellular proteins in EBV-transformed B-cells that feature MMA motifs that are similar to the one in EBNA2. Among the cellular proteins identified, we confirmed by immunoprecipitation and/or Western blot analyses Aly/REF, Coilin, DDX5, FXR1, HNRNPK, LSM4, MRE11, NRIP, nucleolin, PRPF8, RBM26, SMD1 (SNRDP1) and THRAP3 proteins that are either known to contain MMA residues or feature RG repeat sequences that probably serve as methylation substrates. The identified proteins are involved in splicing, tumorigenesis, transcriptional activation, DNA stability and RNA processing or export. Furthermore, we found that several proteins involved in energy metabolism are associated with MMA-modified proteins. Interestingly, the viral EBNA1 protein that features methylated RG repeat motifs also reacted with the antibodies. Our results indicate that the region between aa 34-52 of EBNA1 contains ADMA or SDMA residues, while the region between aa 328-377 mainly contains MMA residues.

Influences of AMY1 gene copy number and protein expression on salivary alpha-amylase activity before and after citric acid stimulation in splenic asthenia children.

PubMed

Yang, Zemin; Lin, Jing; Chen, Longhui; Zhang, Min; Yang, Xiaorong; Chen, Weiwen

2015-06-01

To compare the correlations between salivary alpha-amylase (sAA) activity and amylase, alpha 1 (salivary) gene (AMYl) copy number or its gene expression between splenic asthenia and healthy children, and investigate the reasons of attenuated sAA activity ratio before and after citric acid stimulation in splenic asthenia children. Saliva samples from 20 splenic asthenia children and 29 healthy children were collected before and after citric acid stimulation. AMYl copy number, sAA activity, and total sAA and glycosylated sAA contents were determined, and their correlations were analyzed. Although splenic asthenia and healthy children had no differences in AMY1 copy number, splenic asthenia children had positive correlations between AMY1 copy number and sAA activity before or after citric acid stimulation. Splenic asthenia children had a higher sAA glycosylated proportion ratio and glycosylated sAA content ratio, while their total sAA content ratio and sAA activity ratio were lower compared with healthy children. The glycosylated sAA content ratio was higher than the total sAA content ratio in both groups. Splenic asthenia and healthy children had positive correlations between total sAA or glycosylated sAA content and sAA activity. However, the role played by glycosylated sAA content in sAA activity in healthy children increased after citric acid stimulation, while it decreased in splenic asthenia children. Genetic factors like AMY1 copy number variations, and more importantly, sAA glycosylation abnormalities leading to attenuated sAA activity after citric acid stimulation, which were the main reasons of the attenuated sAA activity ratio in splenic asthenia children compared with healthy children.

Analysis of hepatitis B virus preS1 variability and prevalence of the rs2296651 polymorphism in a Spanish population

PubMed Central

Casillas, Rosario; Tabernero, David; Gregori, Josep; Belmonte, Irene; Cortese, Maria Francesca; González, Carolina; Riveiro-Barciela, Mar; López, Rosa Maria; Quer, Josep; Esteban, Rafael; Buti, Maria; Rodríguez-Frías, Francisco

2018-01-01

AIM To determine the variability/conservation of the domain of hepatitis B virus (HBV) preS1 region that interacts with sodium-taurocholate cotransporting polypeptide (hereafter, NTCP-interacting domain) and the prevalence of the rs2296651 polymorphism (S267F, NTCP variant) in a Spanish population. METHODS Serum samples from 246 individuals were included and divided into 3 groups: patients with chronic HBV infection (CHB) (n = 41, 73% Caucasians), patients with resolved HBV infection (n = 100, 100% Caucasians) and an HBV-uninfected control group (n = 105, 100% Caucasians). Variability/conservation of the amino acid (aa) sequences of the NTCP-interacting domain, (aa 2-48 in viral genotype D) and a highly conserved preS1 domain associated with virion morphogenesis (aa 92-103 in viral genotype D) were analyzed by next-generation sequencing and compared in 18 CHB patients with viremia > 4 log IU/mL. The rs2296651 polymorphism was determined in all individuals in all 3 groups using an in-house real-time PCR melting curve analysis. RESULTS The HBV preS1 NTCP-interacting domain showed a high degree of conservation among the examined viral genomes especially between aa 9 and 21 (in the genotype D consensus sequence). As compared with the virion morphogenesis domain, the NTCP-interacting domain had a smaller proportion of HBV genotype-unrelated changes comprising > 1% of the quasispecies (25.5% vs 31.8%), but a larger proportion of genotype-associated viral polymorphisms (34% vs 27.3%), according to consensus sequences from GenBank patterns of HBV genotypes A to H. Variation/conservation in both domains depended on viral genotype, with genotype C being the most highly conserved and genotype E the most variable (limited finding, only 2 genotype E included). Of note, proline residues were highly conserved in both domains, and serine residues showed changes only to threonine or tyrosine in the virion morphogenesis domain. The rs2296651 polymorphism was not detected in any participant. CONCLUSION In our CHB population, the NTCP-interacting domain was highly conserved, particularly the proline residues and essential amino acids related with the NTCP interaction, and the prevalence of rs2296651 was low/null. PMID:29456407

Role of C-Terminal Cysteine Residues of Aspergillus fumigatus Allergen Asp f 4 in Immunoglobulin E Binding

PubMed Central

Ramachandran, Harikrishnan; Banerjee, Banani; Greenberger, Paul A.; Kelly, Kevin J.; Fink, Jordan N.; Kurup, Viswanath P.

2004-01-01

Among the several allergens cloned and expressed from Aspergillus fumigatus, Asp f 4 is a major one associated with allergic bronchopulmonary aspergillosis (ABPA). The structure-function relationship of allergens is important in understanding the immunopathogenesis, diagnosis, and treatment of allergic diseases. These include the epitopes, conformational or linear, deletion of the N or C terminus or both N and C termini, and glycosylation or nonglycosylation, all of which affect immune responses. Similarly, the role of cysteine residues present in allergens may yield useful information regarding the conformational structure of allergens and the immunoglobulin E (IgE) epitope interaction. Such information may help in developing new strategies towards immunotherapy. In order to define the role of cysteine in the interaction of the antibody with Asp f 4, we have constructed mutants by selectively deleting cysteine residues from the C-terminal region of the Asp f 4. Immunological evaluation of these engineered recombinant constructs was conducted by using sera from patients with ABPA, Aspergillus skin test-positive asthmatics, and healthy controls. The results demonstrate strong IgE binding with Asp f 4 and two truncated mutants, Asp f 41-234 (amino acids [aa] 1 to 234) and Asp f 41-241 (aa 1 to 241), while another mutant, Asp f 41-196 (aa 1 to 196), showed reactivity with fewer patients. The result suggests that deletion of cysteines and the alteration of IgE epitopes at the C-terminal end resulted in conformational changes, which may have a potential role in the immunomodulation of the disease. PMID:15013973

Genomic and functional characterization of coleopteran insect-specific α-amylase inhibitor gene from Amaranthus species.

PubMed

Bhide, Amey J; Channale, Sonal M; Yadav, Yashpal; Bhattacharjee, Kabita; Pawar, Pankaj K; Maheshwari, V L; Gupta, Vidya S; Ramasamy, Sureshkumar; Giri, Ashok P

2017-06-01

The smallest 32 amino acid α-amylase inhibitor from Amaranthus hypochondriacus (AAI) is reported. The complete gene of pre-protein (AhAI) encoding a 26 amino acid (aa) signal peptide followed by the 43 aa region and the previously identified 32 aa peptide was cloned successfully. Three cysteine residues and one disulfide bond conserved within known α-amylase inhibitors were present in AhAI. Identical genomic and open reading frame was found to be present in close relatives of A. hypochondriacus namely Amaranthus paniculatus, Achyranthes aspera and Celosia argentea. Interestingly, the 3'UTR of AhAI varied in these species. The highest expression of AhAI was observed in A. hypochondriacus inflorescence; however, it was not detected in the seed. We hypothesized that the inhibitor expressed in leaves and inflorescence might be transported to the seeds. Sub-cellular localization studies clearly indicated the involvement of AhAI signal peptide in extracellular secretion. Full length rAhAI showed differential inhibition against α-amylases from human, insects, fungi and bacteria. Particularly, α-amylases from Helicoverpa armigera (Lepidoptera) were not inhibited by AhAI while Tribolium castaneum and Callosobruchus chinensis (Coleoptera) α-amylases were completely inhibited. Molecular docking of AhAI revealed tighter interactions with active site residues of T. castaneum α-amylase compared to C. chinensis α-amylase, which could be the rationale behind the disparity in their IC 50 . Normal growth, development and adult emergence of C. chinensis were hampered after feeding on rAhAI. Altogether, the ability of AhAI to affect the growth of C. chinensis demonstrated its potential as an efficient bio-control agent, especially against stored grain pests.

Mildly abnormal general movement quality in infants is associated with higher Mead acid and lower arachidonic acid and shows a U-shaped relation with the DHA/AA ratio.

PubMed

van Goor, S A; Schaafsma, A; Erwich, J J H M; Dijck-Brouwer, D A J; Muskiet, F A J

2010-01-01

We showed that docosahexaenoic acid (DHA) supplementation during pregnancy and lactation was associated with more mildly abnormal (MA) general movements (GMs) in the infants. Since this finding was unexpected and inter-individual DHA intakes are highly variable, we explored the relationship between GM quality and erythrocyte DHA, arachidonic acid (AA), DHA/AA and Mead acid in 57 infants of this trial. MA GMs were inversely related to AA, associated with Mead acid, and associated with DHA/AA in a U-shaped manner. These relationships may indicate dependence of newborn AA status on synthesis from linoleic acid. This becomes restricted during the intrauterine period by abundant de novo synthesis of oleic and Mead acids from glucose, consistent with reduced insulin sensitivity during the third trimester. The descending part of the U-shaped relation between MA GMs and DHA/AA probably indicates DHA shortage next to AA shortage. The ascending part may reflect a different developmental trajectory that is not necessarily unfavorable. Copyright 2009 Elsevier Ltd. All rights reserved.

Assessment of postruminal amino acid digestibility of roasted and extruded whole soybeans with the precision-fed rooster assay.

PubMed

Aldrich, C G; Merchen, N R; Parsons, C M; Hussein, H S; Ingram, S; Clodfelter, J R

1997-11-01

The objectives of these studies were to predict the effects of roasting and extrusion temperatures of whole soybeans (SB) on intestinal protein digestibility in cattle. Intestinal digestibility was assessed with a two-stage in vitro or in situ ruminal incubation/precision-fed cecectomized rooster bioassay. In Exp. 1, whole SB (raw SB or SB roasted to 141, 149, or 157 degrees C exit temperature from a commercial roaster and steeped for 30 min) were incubated in strained ruminal fluid and McDougall's buffer (50:50) at 39 degrees C for 16 h. In Exp. 2, SB (ground raw SB or SB extruded at 116, 138, or 160 degrees C) were placed in polyester bags (20 x 30 cm) and suspended in the ventral rumen of steers for 16 h. Lyophilized residue of the in vitro or in situ incubations and samples of raw SB and most extensively heated SB (roasted SB at 157 degrees C or extruded SB at 160 degrees C) for each respective experiment were crop-intubated to cecectomized roosters. Total excreta were collected for 48 h after intubation and lyophilized, and amino acid (AA) concentrations were determined. In Exp. 1, total AA digestibility was 61.6 and 84.5% for unincubated whole raw SB and 157 degrees C roasted SB, respectively, and 66.2, 88.9, 91.3, and 91.6% for in vitro residues of whole raw SB and SB roasted at 141, 149, and 157 degrees C, respectively. Trypsin inhibitor (TI) activity was 20.09, 1.69, 1.54, and 1.84 mg/g fat-free DM for unincubated whole raw SB and 141, 149, and 157 degrees C roasted SB, respectively, and 30.84, 1.01, .90, and .26 mg/g fat-free DM for in vitro residues of whole raw SB, 141, 149, and 157 degrees C roasted SB, respectively. In Exp. 2, total AA digestibility was 68.5 and 87.7% for unincubated ground raw SB and 160 degrees C extruded SB, respectively, and 81.9, 91.3, 89.7, and 89.4% for in situ residues of ground raw SB and 116, 138, and 160 degrees C extruded SB, respectively. Trypsin inhibitor activity was 17.61, 4.89, 4.08, and 1.56 mg/g fat-free DM for unincubated ground raw SB, 116, 138, and 160 degrees C extruded SB, respectively, and 3.62, .59, .55, and .21 mg/g fat-free DM for incubated ground raw SB, 116, 138, and 160 degrees C extruded SB, respectively. Heat treatment by roasting and extrusion improved AA digestibilities of SB, but there were no differences detected among the roasting or extrusion temperatures. Ruminal fermentation did not eliminate the negative effects of TI activity on intestinal digestibility of AA in whole SB but did reduce TI activity in ground SB.

Aminobacter aminovorans NADH:flavin oxidoreductase His140: a highly conserved residue critical for NADH binding and utilization.

PubMed

Russell, Thomas R; Tu, Shiao-Chun

2004-10-12

Homodimeric FRD(Aa) Class I is an NADH:flavin oxidoreductase from Aminobacter aminovorans. It is unusual because it contains an FMN cofactor but utilizes a sequential-ordered kinetic mechanism. Because little is known about NADH-specific flavin reductases in general and FRD(Aa) in particular, this study aimed to further explore FRD(Aa) by identifying the functionalities of a key residue. A sequence alignment of FRD(Aa) with several known and hypothetical flavoproteins in the same subfamily reveals within the flavin reductase active-site domain a conserved GDH motif, which is believed to be responsible for the enzyme and NADH interaction. Mutation of the His140 in this GDH motif to alanine reduced FRD(Aa) activity to <3%. An ultrafiltration assay and fluorescence quenching demonstrated that H140A FRD(Aa) binds FMN in the same 1:1 stoichiometric ratio as the wild-type enzyme, but with slightly weakened affinity (K(d) = 0.9 microM). Anaerobic stopped-flow studies were carried out using both the native and mutated FRD(Aa). Similar to the native enzyme, H140A FRD(Aa) was also able to reduce the FMN cofactor by NADH although much less efficiently. Kinetic analysis of anaerobic reduction measurements indicated that the His140 residue of FRD(Aa) was essential to NADH binding, as well as important for the reduction of the FMN cofactor. For the native enzyme, the cofactor reduction was followed by at least one slower step in the catalytic pathway.

Primary structure of the Aequorea victoria green-fluorescent protein.

PubMed

Prasher, D C; Eckenrode, V K; Ward, W W; Prendergast, F G; Cormier, M J

1992-02-15

Many cnidarians utilize green-fluorescent proteins (GFPs) as energy-transfer acceptors in bioluminescence. GFPs fluoresce in vivo upon receiving energy from either a luciferase-oxyluciferin excited-state complex or a Ca(2+)-activated phosphoprotein. These highly fluorescent proteins are unique due to the chemical nature of their chromophore, which is comprised of modified amino acid (aa) residues within the polypeptide. This report describes the cloning and sequencing of both cDNA and genomic clones of GFP from the cnidarian, Aequorea victoria. The gfp10 cDNA encodes a 238-aa-residue polypeptide with a calculated Mr of 26,888. Comparison of A. victoria GFP genomic clones shows three different restriction enzyme patterns which suggests that at least three different genes are present in the A. victoria population at Friday Harbor, Washington. The gfp gene encoded by the lambda GFP2 genomic clone is comprised of at least three exons spread over 2.6 kb. The nucleotide sequences of the cDNA and the gene will aid in the elucidation of structure-function relationships in this unique class of proteins.

A genetic analysis of an important hydrophobic interaction at the P22 tailspike protein N-terminal domain.

PubMed

Williams, Jeremie; Venkatesan, Karthikeya; Ayariga, Joseph Atia; Jackson, Doba; Wu, Hongzhuan; Villafane, Robert

2018-06-01

P22 bacteriophage has been studied extensively and has served as a model for many important processes such as in vivo protein folding, protein aggregation and protein-protein interactions. The trimeric tailspike protein (TSP) serves as the receptor-binding protein for the P22 bacteriophage to the bacterial host. The homotrimeric P22 tail consists of three chains of 666aa in which the first 108aa form a trimeric dome-like structure which is called the N-terminal domain (NTD) and is responsible for attachment of the tailspike protein to the rest of the phage particle structure in the phage assembly pathway. Knowledge of this interaction requires information on what amino acids are interacting in the interface and how the NTD structure is maintained. The first 23aa form the "stem peptide" which originates at the dome top and terminates at the dome bottom. It contains a hydrophobic valine patch (V8-V9-V10) located within the dome structure. It is hypothesized that the interaction between the hydrophobic valine patch located on stem peptide and the adjacent polypeptide is critical for the interchain interaction which should be important for the stability of the P22 TSP NTD itself. To test this hypothesis, each amino acid in the valine residues is substituted by an acid, a basic, and a hydrophobic amino acid. The results of such substitutions are presented as well as associated studies. The data strongly suggest that the valine patch is of critical importance in the hydrophobic interaction between stem peptide valine patch and an adjacent chain.

A novel amino acid substitution in a voltage-gated sodium channel is associated with knockdown resistance to permethrin in Aedes aegypti.

PubMed

Chang, Cheng; Shen, Wen-Kai; Wang, Tzu-Ting; Lin, Ying-Hsi; Hsu, Err-Lieh; Dai, Shu-Mei

2009-04-01

To identify pertinent mutations associated with knockdown resistance to permethrin, the entire coding sequence of the voltage-gated sodium channel gene Aa-para was sequenced and analyzed from a Per-R strain with 190-fold resistance to permethrin and two susceptible strains of Aedes aegypti. The longest transcript, a 6441bp open reading frame, encodes 2147 amino acid residues with an estimated molecular mass of 241kDa. A total of 33 exons were found in the Aa-para gene over 293kb of genomic DNA. Three previously unreported optional exons were identified. The first two exons, m and n, were located within the intracellular domain I/II, and the third, f', was found within the II/III linkers. The two mutually exclusive exons, d and l, were the only alternative exons in all the cDNA clones sequenced in this study. The most distinct finding was a novel amino acid substitution mutation, D1794Y, located within the extracellular linker between IVS5 and IVS6, which is concurrent with the known V1023G mutation in Aa-para of the Per-R strain. The high frequency and coexistence of the two mutations in the Per-R strain suggest that they might exert a synergistic effect to provide the knockdown resistance to permethrin. Furthermore, both cDNA and genomic DNA data from the same individual mosquitoes have demonstrated that RNA editing was not involved in amino acid substitutions of the Per-R strain.

Phospholipid sources for adrenic acid mobilization in RAW 264.7 macrophages. Comparison with arachidonic acid.

PubMed

Guijas, Carlos; Astudillo, Alma M; Gil-de-Gómez, Luis; Rubio, Julio M; Balboa, María A; Balsinde, Jesús

2012-11-01

Cells metabolize arachidonic acid (AA) to adrenic acid (AdA) via 2-carbon elongation reactions. Like AA, AdA can be converted into multiple oxygenated metabolites, with important roles in various physiological and pathophysiological processes. However, in contrast to AA, there is virtually no information on how the cells regulate the availability of free AdA for conversion into bioactive products. We have used a comparative lipidomic approach with both gas chromatography and liquid chromatography coupled to mass spectrometry to characterize changes in the levels of AA- and AdA-containing phospholipid species in RAW 264.7 macrophage-like cells. Incubation of the cells with AA results in an extensive conversion to AdA but both fatty acids do not compete with each other for esterification into phospholipids. AdA but not AA, shows preference for incorporation into phospholipids containing stearic acid at the sn-1 position. After stimulation of the cells with zymosan, both AA and AdA are released in large quantities, albeit AA is released to a greater extent. Finally, a variety of phosphatidylcholine and phosphatidylinositol molecular species contribute to AA; however, AdA is liberated exclusively from phosphatidylcholine species. Collectively, these results identify significant differences in the cellular utilization of AA and AdA by the macrophages, suggesting non-redundant biological actions for these two fatty acids. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioactive compounds and phenolic-linked functionality of powdered tropical fruit residues.

PubMed

Correia, Roberta T P; Borges, Kátia C; Medeiros, Maria F; Genovese, Maria I

2012-12-01

Tropical fruit residues consisting of seeds, peels and residual pulp generated as by-products of fruit processing industry were investigated for bioactive compounds, the in vitro antioxidant capacity as well as alpha-glucosidase and alpha-amylase inhibitory activities. Cyanidin, quercetin, ellagic acid (EA) and proanthocyanidins were found in acerola, jambolan, pitanga and cajá-umbu residue powders. Acerola powder had the highest phenolic content (8839.33 mg catechin equivalents (CE)/100 g) and also high-ascorbic acid (AA) concentration (2748.03 mg/100 g), followed by jambolan and pitanga. The greatest 1,1-Diphenyl-2-picrylhydrazyl (DPPH) inhibition was observed for jambolan (436.76 mmol Trolox eq/g) followed by pitanga (206.68 mmol Trolox eq/g) and acerola (192.60 mmol Trolox eq/g), while acerola had the highest ferric reducing antioxidant power (FRAP) assay result (7.87 mmol Trolox eq/g). All fruit powders exhibited enzymatic inhibition against alpha-amylase (IC50 ranging from 3.40 to 49.5 mg CE/mL) and alpha-glucosidase (IC50 ranging from 1.15 to 2.37 mg CE/mL). Therefore, acerola, jambolan and pitanga dried residues are promising natural ingredients for food and nutraceutical manufacturers, due to their rich bioactive compound content.

Flame Atmospheric Pressure Chemical Ionization Coupled with Negative Electrospray Ionization Mass Spectrometry for Ion Molecule Reactions

NASA Astrophysics Data System (ADS)

Cheng, Sy-Chyi; Bhat, Suhail Muzaffar; Shiea, Jentaie

2017-07-01

Flame atmospheric pressure chemical ionization (FAPCI) combined with negative electrospray ionization (ESI) mass spectrometry was developed to detect the ion/molecule reactions (IMRs) products between nitric acid (HNO3) and negatively charged amino acid, angiotensin I (AI) and angiotensin II (AII), and insulin ions. Nitrate and HNO3-nitrate ions were detected in the oxyacetylene flame, suggesting that a large quantity of nitric acid (HNO3) was produced in the flame. The HNO3 and negatively charged analyte ions produced by a negative ESI source were delivered into each arm of a Y-shaped stainless steel tube where they merged and reacted. The products were subsequently characterized with an ion trap mass analyzer attached to the exit of the Y-tube. HNO3 showed the strongest affinity to histidine and formed (Mhistidine-H+HNO3)- complex ions, whereas some amino acids did not react with HNO3 at all. Reactions between HNO3 and histidine residues in AI and AII resulted in the formation of dominant [MAI-H+(HNO3)]- and [MAII-H+(HNO3)]- ions. Results from analyses of AAs and insulin indicated that HNO3 could not only react with basic amino acid residues, but also with disulfide bonds to form [M-3H+(HNO3)n]3- complex ions. This approach is useful for obtaining information about the number of basic amino acid residues and disulfide bonds in peptides and proteins.

Flame Atmospheric Pressure Chemical Ionization Coupled with Negative Electrospray Ionization Mass Spectrometry for Ion Molecule Reactions.

PubMed

Cheng, Sy-Chyi; Bhat, Suhail Muzaffar; Shiea, Jentaie

2017-07-01

Flame atmospheric pressure chemical ionization (FAPCI) combined with negative electrospray ionization (ESI) mass spectrometry was developed to detect the ion/molecule reactions (IMRs) products between nitric acid (HNO 3 ) and negatively charged amino acid, angiotensin I (AI) and angiotensin II (AII), and insulin ions. Nitrate and HNO 3 -nitrate ions were detected in the oxyacetylene flame, suggesting that a large quantity of nitric acid (HNO 3 ) was produced in the flame. The HNO 3 and negatively charged analyte ions produced by a negative ESI source were delivered into each arm of a Y-shaped stainless steel tube where they merged and reacted. The products were subsequently characterized with an ion trap mass analyzer attached to the exit of the Y-tube. HNO 3 showed the strongest affinity to histidine and formed (M histidine -H+HNO 3 ) - complex ions, whereas some amino acids did not react with HNO 3 at all. Reactions between HNO 3 and histidine residues in AI and AII resulted in the formation of dominant [M AI -H+(HNO 3 )] - and [M AII -H+(HNO 3 )] - ions. Results from analyses of AAs and insulin indicated that HNO 3 could not only react with basic amino acid residues, but also with disulfide bonds to form [M-3H+(HNO 3 ) n ] 3- complex ions. This approach is useful for obtaining information about the number of basic amino acid residues and disulfide bonds in peptides and proteins. Graphical Abstract ᅟ.

Maintenance of coat protein N-terminal net charge and not primary sequence is essential for zucchini yellow mosaic virus systemic infectivity.

PubMed

Kimalov, Boaz; Gal-On, Amit; Stav, Ran; Belausov, Eduard; Arazi, Tzahi

2004-11-01

Zucchini yellow mosaic virus (ZYMV) surface exposed coat protein (CP) N-terminal domain (Nt) is 43 aa long and contains an equal number of positively and negatively charged amino acid residues (CP-Nt net charge = 0). A ZYMV-AGII truncation mutant lacking the first 20 aa of its CP-Nt (AGII-CP Delta 20; CP-Nt net charge = +2) was found to be systemically non-infectious even though AGII mutants harbouring larger CP-Nt deletions were previously demonstrated to be fully infectious. Nevertheless, AGII-CP Delta 20 infectivity was restored by fusion to its CP-Nt two Asp residues or a negatively charged Myc peptide, both predicted to neutralize CP-Nt net positive charge. To evaluate further the significance of CP-Nt net charge for AGII infectivity, a series of CP-Nt net charge mutants was generated and analysed for systemic infectivity of squash plants. AGII-CP(KKK) harbouring a CP-Nt amino fusion of three Lys residues (CP-Nt net charge = +3) was not systemically infectious. Addition of up to four Asp residues to CP-Nt did not abolish virus infectivity, although certain mutants were genetically unstable and had delayed infectivity. Addition of five negatively charged residues abolished infectivity (AGII-CP(DDDDD); CP-Nt net charge = -5) even though a recombinant CP(DDDDD) could assemble into potyviral-like particle in bacteria. Neutralization of CP-Nt net charge by fusing Asp or Lys residues recovered infectivity of AGII-CP(KKK) and AGII-CP(DDDDD). GFP-tagging of these mutants has demonstrated that both viruses have defective cell-to-cell movement. Together, these findings suggest that maintenance of CP-Nt net charge and not primary sequence is essential for ZYMV infectivity.

Streptococcus gordonii DL1 adhesin SspB V-region mediates coaggregation via receptor polysaccharide of Actinomyces oris T14V.

PubMed

Back, C R; Douglas, S K; Emerson, J E; Nobbs, A H; Jenkinson, H F

2015-10-01

Streptococcus gordonii SspA and SspB proteins, members of the antigen I/II (AgI/II) family of Streptococcus adhesins, mediate adherence to cysteine-rich scavenger glycoprotein gp340 and cells of other oral microbial species. In this article we investigated further the mechanism of coaggregation between S. gordonii DL1 and Actinomyces oris T14V. Previous mutational analysis of S. gordonii suggested that SspB was necessary for coaggregation with A. oris T14V. We have confirmed this by showing that Lactococcus lactis surrogate host cells expressing SspB coaggregated with A. oris T14V and PK606 cells, while L. lactis cells expressing SspA did not. Coaggregation occurred independently of expression of A. oris type 1 (FimP) or type 2 (FimA) fimbriae. Polysaccharide was prepared from cells of A. oris T14V and found to contain 1,4-, 4,6- and 3,4-linked glucose, 1,4-linked mannose, and 2,4-linked galactose residues. When immobilized onto plastic wells this polysaccharide supported binding of L. lactis expressing SspB, but not binding of L. lactis expressing other AgI/II family proteins. Purified recombinant NAVP region of SspB, comprising amino acid (aa) residues 41-847, bound A. oris polysaccharide but the C-domain (932-1470 aa residues) did not. A site-directed deletion of 29 aa residues (Δ691-718) close to the predicted binding cleft within the SspB V-region ablated binding of the NAVP region to polysaccharide. These results infer that the V-region head of SspB recognizes an actinomyces polysaccharide ligand, so further characterizing a lectin-like coaggregation mechanism occurring between two important primary colonizers. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Propylisopropylacetic acid (PIA), a constitutional isomer of valproic acid, uncompetitively inhibits arachidonic acid acylation by rat acyl-CoA synthetase 4: a potential drug for bipolar disorder

PubMed Central

Modi, Hiren R.; Basselin, Mireille; Taha, Ameer Y.; Li, Lei O.; Coleman, Rosalind A.; Bialer, Meir; Rapoport, Stanley I.

2013-01-01

Background Mood stabilizers used for treating bipolar disorder (BD) selectively downregulate arachidonic acid (AA) turnover (deacylation-reacylation) in brain phospholipids, when given chronically to rats. In vitro studies suggest that one of these, valproic acid (VPA), which is teratogenic, reduces AA turnover by inhibiting the brain acyl-CoA synthetase (Acsl)-4 mediated acylation of AA to AA-CoA. We tested whether non-teratogenic VPA analogues might also inhibit Acsl-4 catalyzed acylation, and thus have potential anti-BD action. Methods Rat Acsl4-flag protein was expressed in E. coli, and the ability of three VPA analogues, propylisopropylacetic acid (PIA), propylisopropylacetamide (PID) and N-methyl-2,2,3,3-tetramethylcyclopropanecarboxamide (MTMCD), and of sodium butyrate, to inhibit conversion of AA to AA-CoA by Acsl4 was quantified using Michaelis-Menten kinetics. Results Acsl4-mediated conversion of AA to AA-CoA in vitro was inhibited uncompetitively by PIA, with a Ki of 11.4 mM compared to a published Ki of 25 mM for VPA, while PID, MTMCD and sodium butyrate had no inhibitory effect. Conclusions PIA's ability to inhibit conversion of AA to AA-CoA by Acsl4 in vitro suggests that, like VPA, PIA may reduce AA turnover in brain phospholipids in unanesthetized rats, and if so, may be effective as a non-teratogenic mood stabilizer in BD patients. PMID:23354024

Intestinal digestibility of amino acids in rumen undegradable protein estimated using a precision-fed cecectomized rooster bioassay: I. Soybean meal and SoyPlus.

PubMed

Boucher, S E; Calsamiglia, S; Parsons, C M; Stein, H H; Stern, M D; Erickson, P S; Utterback, P L; Schwab, C G

2009-09-01

The objectives of this experiment were to measure intestinal digestibility of AA in rumen undegradable protein (RUP-AA) in soybean meal (SBM) and expeller SBM (SoyPlus, West Central, Ralston, IA; SP) and to determine if these feeds contain a constant protein fraction that is undegradable in the rumen and indigestible in the small intestine, as assumed in the French Institut National de la Recherche Agronomique (Paris, France) and Scandinavian AAT-PBV (AAT = AA absorbed from small intestine; PBV = protein balance in the rumen) models. Three samples of SBM and 3 samples of SP were obtained from the Feed Analysis Consortium Inc. (Savoy, IL). To obtain the RUP fraction, samples were ruminally incubated in situ for 16 h in 4 lactating cows, and the collected rumen undegraded residues (RUR) were pooled by sample. Subsamples of the intact feeds and RUR were crop intubated to 4 cecectomized roosters, and total excreta were collected for 48 h. Intact feeds, RUR, and excreta were analyzed for AA. Basal endogenous AA loss estimates were obtained from fasted birds and were used to calculate standardized digestibility of AA in the intact feeds and RUP-AA. Indigestibility coefficients of the intact feeds were calculated as (100 - % standardized AA digestibility), and indigestibility of the RUR was calculated as [(100 - % ruminal degradation of AA) x [(100 - % standardized RUP-AA digestibility)]/100]. Results indicated that standardized digestibility of feed-AA was similar to standardized digestibility of RUP-AA for SBM and SP samples and that standardized digestibility of individual AA differed within samples. Standardized feed-AA and RUP-AA digestibility values were lowest for Lys and Cys and highest for Trp and Met. Results also indicated that SBM and SP did not contain a constant protein fraction that was both undegradable in the rumen and indigestible in the small intestine. Indigestibility values of RUR were lower than in intact feeds, suggesting that SBM and SP contain a protein fraction that is indigestible in the intestine but partly degradable in the rumen, digestible in the intestine after ruminal incubation, or both.

Dietary Acrylamide and the Risks of Developing Cancer: Facts to Ponder.

PubMed

Kumar, Jaya; Das, Srijit; Teoh, Seong Lin

2018-01-01

Acrylamide (AA) is a water soluble white crystalline solid commonly used in industries. It was listed as an industrial chemical with potential carcinogenic properties. However to date, AA was used to produce polyacrylamide polymer, which was widely used as a coagulant in water treatment; additives during papermaking; grouting material for dams, tunnels, and other underground building constructions. AA in food could be formed during high-temperature cooking via several mechanisms, i.e., formation via acrylic acid which may be derived from the degradation of lipid, carbohydrates, or free amino acids; formation via the dehydration/decarboxylation of organic acids (malic acid, lactic acid, and citric acid); and direct formation from amino acids. The big debate is whether this compound is toxic to human beings or not. In the present review, we discuss the formation of AA in food products, its consumption, and possible link to the development of any cancers. We discuss the body enzymatic influence on AA and mechanism of action of AA on hormone, calcium signaling pathways, and cytoskeletal filaments. We also highlight the deleterious effects of AA on nervous system, reproductive system, immune system, and the liver. The present and future mitigation strategies are also discussed. The present review on AA may be beneficial for researchers, food industry, and also medical personnel.

Dietary Acrylamide and the Risks of Developing Cancer: Facts to Ponder

PubMed Central

Kumar, Jaya; Das, Srijit; Teoh, Seong Lin

2018-01-01

Acrylamide (AA) is a water soluble white crystalline solid commonly used in industries. It was listed as an industrial chemical with potential carcinogenic properties. However to date, AA was used to produce polyacrylamide polymer, which was widely used as a coagulant in water treatment; additives during papermaking; grouting material for dams, tunnels, and other underground building constructions. AA in food could be formed during high-temperature cooking via several mechanisms, i.e., formation via acrylic acid which may be derived from the degradation of lipid, carbohydrates, or free amino acids; formation via the dehydration/decarboxylation of organic acids (malic acid, lactic acid, and citric acid); and direct formation from amino acids. The big debate is whether this compound is toxic to human beings or not. In the present review, we discuss the formation of AA in food products, its consumption, and possible link to the development of any cancers. We discuss the body enzymatic influence on AA and mechanism of action of AA on hormone, calcium signaling pathways, and cytoskeletal filaments. We also highlight the deleterious effects of AA on nervous system, reproductive system, immune system, and the liver. The present and future mitigation strategies are also discussed. The present review on AA may be beneficial for researchers, food industry, and also medical personnel. PMID:29541638

Incomplete inhibition of platelet function as assessed by the platelet function analyzer (PFA-100) identifies a subset of cardiovascular patients with high residual platelet response while on aspirin.

PubMed

Crescente, M; Mezzasoma, A M; Del Pinto, M; Palmerini, F; Di Castelnuovo, A; Cerletti, C; De Gaetano, G; Gresele, P

2011-01-01

Sixty-six patients with a history of ischemic events (myocardial infarction, unstable angina, or stroke) on chronic aspirin therapy were studied by different platelet function tests: 37 patients had suffered a recurrent event while on aspirin and 29 were without recurrences. Based on results from light transmission aggregometry (LTA) induced by arachidonic acid (AA) and serum TxB(2) both COX-1-dependent methods, only one patient could be identified as aspirin "resistant". However, when methods only partially-dependent on platelet COX-1 activity were considered, the prevalence of aspirin non-responders ranged, according to the different tests, from 0 to 52%. No difference was observed between patients with recurrences and those without. Among patients with recurrent events, those with an incomplete inhibition of platelet function, as assessed by the PFA-100, had significantly higher residual serum TxB(2) (2.4 ± 2.4 ng/mL vs 0.4 ± 0.1 ng/mL, p = 0.03), residual LTA-AA (9.2 ± 10.6% vs 2.0 ± 1.6%, p = 0.008), LTA-Coll (49.3 ± 14.6% vs 10.2 ± 8.3%, p = 0.007) and LTA-ADP (50.9 ± 16.2% vs 34.3 ± 11.0%, p = 0.04). In conclusion, laboratory tests solely exploring the AA-mediated pathway of platelet function, while being the most appropriate to detect the effect of aspirin on its pharmacologic target (platelet COX-1), may fail to reveal the functional interactions between minimal residual TxA(2) and additional stimuli or primers potentially leading to aspirin-insensitive platelet aggregation. High residual platelet response in platelet function tests only partially dependent on COX-1 may reveal a condition of persistent platelet reactivity in a subset of aspirin-treated patients characterizing them as a subgroup at higher vascular risk.

The ratio of serum n-3 to n-6 polyunsaturated fatty acids is associated with diabetes mellitus in patients with prior myocardial infarction: a multicenter cross-sectional study.

PubMed

Takahashi, Masao; Ando, Jiro; Shimada, Kazunori; Nishizaki, Yuji; Tani, Shigemasa; Ogawa, Takayuki; Yamamoto, Masato; Nagao, Ken; Hirayama, Atsushi; Yoshimura, Michihiro; Daida, Hiroyuki; Nagai, Ryozo; Komuro, Issei

2017-01-26

In prior myocardial infarction (PMI) patients, diabetes mellitus (DM), dyslipidemia, and hypertension increase the risk of secondary cardiovascular events. Although a decreased ratio of serum eicosapentaenoic acid (EPA) to arachidonic acid (AA; EPA/AA) has been shown to significantly correlate with the onset of acute coronary syndrome, the associations between polyunsaturated fatty acid (PUFA) levels and coronary risk factors in PMI patients have not been evaluated thoroughly. This study aimed to assess the associations between PUFAs levels and the risk factors in PMI patients. We enrolled 1733 patients with known PUFA levels who were treated in five divisions of cardiology in a metropolitan area of Japan, including 303 patients with PMI. EPA/AA and docosahexaenoic acid (DHA) to AA level ratio (DHA/AA) in patients with and without PMI were analyzed according to presence of coronary risk factors. Diabetes patients with PMI had significantly lower EPA/AA and DHA/AA than diabetes patients without PMI (EPA/AA: P <0.01; DHA/AA: P =0.003), with no such differences in dyslipidemia and hypertension patients. In DM patients with high high-sensitivity C-reactive protein (hs-CRP) levels (>0.1 mg/dL), EPA/AA was low in individuals who also had PMI, whereas DHA/AA was not (EPA/AA, with PMI: 0.43 ± 0.24; without PMI: 0.53 ± 0.30, P < 0.05). Moreover, patients on statins had significantly lower DHA/AA ratios, whereas the EPA/AA ratio did not depend on statin use. Multiple regression analysis revealed that statin use in DM patients was associated with low DHA/AA but not EPA/AA. PMI patients with DM have low EPA/AA and DHA/AA. EPA/AA and DHA/AA are differently related to hs-CRP level in DM patients with PMI. Statin use can potentially affect DHA/AA but not EPA/AA, and therefore EPA/AA ratio is a better marker of assessment for cardiovascular events.

The influence of ochratoxin A on DNA adduct formation by the carcinogen aristolochic acid in rats.

PubMed

Stiborová, Marie; Bárta, František; Levová, Kateřina; Hodek, Petr; Frei, Eva; Arlt, Volker M; Schmeiser, Heinz H

2015-11-01

Exposure to the plant nephrotoxin and carcinogen aristolochic acid (AA) leads to the development of AA nephropathy, Balkan endemic nephropathy (BEN) and upper urothelial carcinoma (UUC) in humans. Beside AA, exposure to ochratoxin A (OTA) was linked to BEN. Although OTA was rejected as a factor for BEN/UUC, there is still no information whether the development of AA-induced BEN/UUC is influenced by OTA exposure. Therefore, we studied the influence of OTA on the genotoxicity of AA (AA-DNA adduct formation) in vivo. AA-DNA adducts were formed in liver and kidney of rats treated with AA or AA combined with OTA, but no OTA-related DNA adducts were detectable in rats treated with OTA alone or OTA combined with AA. Compared to rats treated with AA alone, AA-DNA adduct levels were 5.4- and 1.6-fold higher in liver and kidney, respectively, of rats treated with AA combined with OTA. Although AA and OTA induced quinone oxidoreductase (NQO1) activating AA to DNA adducts, their combined treatment did not lead to either higher NQO1 enzyme activity or higher AA-DNA adduct levels in ex vivo incubations. Oxidation of AA I (8-methoxy-6-nitrophenanthro[3,4-d]-1,3-dioxole-5-carboxylic acid) to its detoxification metabolite, 8-hydroxyaristolochic acid, was lower in microsomes from rats treated with AA and OTA, and this was paralleled by lower activities of cytochromes P450 1A1/2 and/or 2C11 in these microsomes. Our results indicate that a decrease in AA detoxification after combined exposure to AA and OTA leads to an increase in AA-DNA adduct formation in liver and kidney of rats.

Single amino acid insertions in extracellular loop 2 of Bombyx mori ABCC2 disrupt its receptor function for Bacillus thuringiensis Cry1Ab and Cry1Ac but not Cry1Aa toxins.

PubMed

Tanaka, Shiho; Miyamoto, Kazuhisa; Noda, Hiroaki; Endo, Haruka; Kikuta, Shingo; Sato, Ryoichi

2016-04-01

In a previous report, seven Cry1Ab-resistant strains were identified in the silkworm, Bombyx mori; these strains were shown to have a tyrosine insertion at position 234 in extracellular loop 2 of the ABC transporter C2 (BmABCC2). This insertion was confirmed to destroy the receptor function of BmABCC2 and confer the strains resistance against Cry1Ab and Cry1Ac. However, these strains were susceptible to Cry1Aa. In this report, we examined the mechanisms of the loss of receptor function of the transporter by expressing mutations in Sf9 cells. After replacement of one or two of the five amino acid residues in loop 2 of the susceptible BmABCC2 gene [BmABCC2_S] with alanine, cells still showed susceptibility, retaining the receptor function. Five mutants with single amino acid insertions at position 234 in BmABCC2 were also generated, resulting in loop 2 having six amino acids, which corresponds to replacing the tyrosine insertion in the resistant BmABCC2 gene [BmABCC2_R(+(234)Y)] with another amino acid. All five mutants exhibited loss of function against Cry1Ab and Cry1Ac. These results suggest that the amino acid sequence in loop 2 is less important than the loop size (five vs. six amino acids) or loop structure for Cry1Ab and Cry1Ac activity. Several domain-swapped mutant toxins were then generated among Cry1Aa, Cry1Ab, and Cry1Ac, which are composed of three domains. Swapped mutants containing domain II of Cry1Ab or Cry1Ac did not kill Sf9 cells expressing BmABCC2_R(+(234)Y), suggesting that domain II of the Cry toxin is related to the interaction with the receptor function of BmABCC2. This also suggests that different reactions against Bt-toxins in some B. mori strains, that is, Cry1Ab resistance or Cry1Aa susceptibility, are attributable to structural differences in domain II of Cry1A toxins. Copyright © 2016. Published by Elsevier Inc.

Crystal structure of salt-tolerant glutaminase from Micrococcus luteus K-3 in the presence and absence of its product L-glutamate and its activator Tris.

PubMed

Yoshimune, Kazuaki; Shirakihara, Yasuo; Wakayama, Mamoru; Yumoto, Isao

2010-02-01

Glutaminase from Micrococcus luteus K-3 [Micrococcus glutaminase (Mglu); 456 amino acid residues (aa); 48 kDa] is a salt-tolerant enzyme. Our previous study determined the structure of its major 42-kDa fragment. Here, using new crystallization conditions, we determined the structures of the intact enzyme in the presence and absence of its product L-glutamate and its activator Tris, which activates the enzyme by sixfold. With the exception of a 'lid' part (26-29 aa) and a few other short stretches, the structures were all very similar over the entire polypeptide chain. However, the presence of the ligands significantly reduced the length of the disordered regions: 41 aa in the unliganded structure (N), 21 aa for L-glutamate (G), 8 aa for Tris (T) and 6 aa for both L-glutamate and Tris (TG). L-glutamate was identified in both the G and TG structures, whereas Tris was only identified in the TG structure. Comparison of the glutamate-binding site between Mglu and salt-labile glutaminase (YbgJ) from Bacillus subtilis showed significantly smaller structural changes of the protein part in Mglu. A comparison of the substrate-binding pocket of Mglu, which is highly specific for L-glutamine, with that of Erwinia carotovora asparaginase, which has substrates other than L-glutamine, shows that Mglu has a larger substrate-binding pocket that prevents the binding of L-asparagine with proper interactions.

[Effect of citric acid stimulation on salivary alpha-amylase, total protein, salivary flow rate and pH value in Pi deficiency children].

PubMed

Yang, Ze-min; Chen, Long-hui; Lin, Jing; Zhang, Min; Yang, Xiao-rong; Chen, Wei-wen

2015-02-01

To compare the effect of citric acid stimulation on salivary alpha-amylase (sAA), total protein (TP), salivary flow rate, and pH value between Pi deficiency (PD) children and healthy children, thereby providing evidence for Pi controlling saliva theory. Twenty PD children were recruited, and 29 healthy children were also recruited at the same time. Saliva samples from all subjects were collected before and after citric acid stimulation. The sAA activity and amount, TP contents, salivary flow rate, and pH value were determined and compared. (1) Citric acid stimulation was able to significantly increase salivary flow rate, pH value, sAA activities, sAA specific activity and sAA amount (including glycosylated and non-glycosylated sAA amount) in healthy children (P<0.05), while it could markedly increase salivary flow rate, pH value, and glycosylated sAA levels in PD children (P<0.05); (2) Although there was no statistical difference in determined salivary indices between the two groups (P>0.05), salivary indices except salivary flow rate and glycosylated sAA levels decreased more in PD children. There was statistical difference in sAA activity ratio, sAA specific activity ratio, and the ratio of glycosylated sAA levels between PD children and healthy children (P<0.05). PD children had decreased response to citric acid stimulation.

Amino acid mutations in the caldesmon COOH-terminal functional domain increase force generation in bladder smooth muscle

PubMed Central

Deng, Maoxian; Boopathi, Ettickan; Hypolite, Joseph A.; Raabe, Tobias; Chang, Shaohua; Zderic, Stephen; Wein, Alan J.

2013-01-01

Caldesmon (CaD), a component of smooth muscle thin filaments, binds actin, tropomyosin, calmodulin, and myosin and inhibits actin-activated ATP hydrolysis by smooth muscle myosin. Internal deletions of the chicken CaD functional domain that spans from amino acids (aa) 718 to 731, which corresponds to aa 512–530 including the adjacent aa sequence in mouse CaD, lead to diminished CaD-induced inhibition of actin-activated ATP hydrolysis by myosin. Transgenic mice with mutations of five aa residues (Lys523 to Gln, Val524 to Leu, Ser526 to Thr, Pro527 to Cys, and Lys529 to Ser), which encompass the ATPase inhibitory determinants located in exon 12, were generated by homologous recombination. Homozygous (−/−) animals did not develop, but heterozygous (+/−) mice carrying the expected mutations in the CaD ATPase inhibitory domain (CaD mutant) matured and reproduced normally. The peak force produced in response to KCl and electrical field stimulation by the detrusor smooth muscle from the CaD mutant was high compared with that of the wild type. CaD mutant mice revealed nonvoiding contractions during bladder filling on awake cystometry, suggesting that the CaD ATPase inhibitory domain suppresses force generation during the filling phase and this suppression is partially released by mutations in 50% of CaD in heterozygous. Our data show for the first time a functional phenotype, at the intact smooth muscle tissue and in vivo organ levels, following mutation of a functional domain at the COOH-terminal region of CaD. PMID:23986516

Amino acid and hexosamine in the equatorial western Pacific: vertical fluxes and individual preservation through water column to surface sediments

NASA Astrophysics Data System (ADS)

Kawahata, H.; Gupta, L. P.; Ishizuka, T.

2002-12-01

Amino acids (AA) and hexosamines (HA) are major constituents for all living organisms, constituting important fractions of labile organic carbon and nitrogen. They usually decompose rapidly than bulk OM and must be expected to be closely linked to biogeochemical processes. In spite of such importance, our understanding of degradation processes of labile components is still limited. Therefore vertical fluxes and preservation of AA and HA from water column to surface sediments are investigated at the western equatorial Pacific. The settling particles were composed of fairly fresh AA, which could be derived from siliceous diatom with less amount of calcareous plankton. In contrast, AA were degraded in sediments and porewaters. Each AA showed highly variable preservation ratio from settling to sedimentary particles. Compared with glycine, the calculated preservation ratio was the lowest (0%) for cysteine, followed by phenylalanine (6%), tyrosine (17%), methionine (47%), leucine (60%), isoleucine (65%), proline (67%), valine (91%), serine (99%), arginine (107%), threonine (112%), alanine (115%), glutamic acid (114%), aspartic acid (150%), lysine (166%) and histidine (186%). Beta-alanine and gamma-aminobutyric acid were the least labile AA. Probably they are so difficult to degrade for bacteria to get biochemical energy that the degradation proceeds fairly slowly. In contrast, after burial, even most labile, aromatic and sulfur-containing AA, degrade at a rate similar to the other protein AA. In spite of complicated reactions, most of the AA showed first-order reaction kinetics during the degradation in the sediments. The decomposition rate constant k (kyr-1) in this study was 2-3 orders lower than those in coastal marine environments. Better preservation of HA over AA in the sediments was probably due to the general incorporation of HA into structural biopolymer matrices, such as bacterial cell-walls and chitinous material. Abundant glycine in the AA in the sediments is due to contribution from diatom cell-walls, bacterial peptidoglycan, and the degradation by bacterial activity. Dissolved combined AA (DCAA) showed enrichment in glutamic acid, glycine and threonine, and depletion in aspartic acid and alanine. Bacterial biomass and/or activity influences DCAA in porewaters more than AA in the sediments. Phenylalanine was abundant in the dissolved free AA (DFAA). Both aromatic and acidic AA are generally concentrated in diatom cell protoplasm, which is more rapidly degraded than cell-walls. Good correlation between aspartic acid and carbonate contents in the sediments and poor correlation in the settling particles indicates that aspartic acid is significantly controlled by the reaction or adsorption with carbonates during early diagenesis. Abundant occurrence of clay minerals in sediments would be responsible for the enhanced accumulation of basic AA and arginine. During diagenesis, bulk Corganic/N ratios are mainly controlled by more contribution of ammonium, which is incorporated into the lattice of clay minerals, not by the compositional change in AA. Microbial degradation continued to reduce AA and OM in the sediments, which has implications for appreciable under-estimates of paleoproductivity.

IgE binding to peanut allergens is inhibited by combined D-aspartic and D-glutamic acids

USDA-ARS?s Scientific Manuscript database

D-amino acids (D-aas) are reported to bind to IgE antibodies from people with allergy and asthma. The objectives of this study were to determine if D-aas bind or inhibit IgE binding to peanut allergens, and if they are more effective than L-amino acids (L-aas) in this respect. Several D-aa cocktails...

ARISTOLOCHIC ACID I METABOLISM IN THE ISOLATED PERFUSED RAT KIDNEY

PubMed Central

Priestap, Horacio A.; Torres, M. Cecilia; Rieger, Robert A.; Dickman, Kathleen G.; Freshwater, Tomoko; Taft, David R.; Barbieri, Manuel A.; Iden, Charles R.

2012-01-01

Aristolochic acids are natural nitro-compounds found globally in the plant genus Aristolochia that have been implicated in the severe illness in humans termed aristolochic acid nephropathy (AAN). Aristolochic acids undergo nitroreduction, among other metabolic reactions, and active intermediates arise that are carcinogenic. Previous experiments with rats showed that aristolochic acid I (AA-I), after oral administration or injection, is subjected to detoxication reactions to give aristolochic acid Ia, aristolactam Ia, aristolactam I and their glucuronide and sulfate conjugates that can be found in urine and faeces. Results obtained with whole rats do not clearly define the role of liver and kidney in such metabolic transformation. In this study, in order to determine the specific role of the kidney on the renal disposition of AA-I and to study the biotransformations suffered by AA-I in this organ, isolated kidneys of rats were perfused with AA-I. AA-I and metabolite concentrations were determined in perfusates and urines using HPLC procedures. The isolated perfused rat kidney model showed that AA-I distributes rapidly and extensively in kidney tissues by uptake from the peritubular capillaries and the tubules. It was also established that the kidney is able to metabolize AA-I into aristolochic acid Ia, aristolochic acid Ia O-sulfate, aristolactam Ia, aristolactam I and aristolactam Ia O-glucuronide. Rapid demethylation and sulfation of AA-I in the kidney generate aristolochic acid Ia and its sulfate conjugate that are voided to the urine. Reduction reactions to give the aristolactam metabolites occur to a slower rate. Renal clearances showed that filtered AA-I is reabsorbed at the tubules whereas the metabolites are secreted. The unconjugated metabolites produced in the renal tissues are transported to both urine and perfusate whereas the conjugated metabolites are almost exclusively secreted to the urine. PMID:22118289

The external amino acid signaling pathway promotes activation of Stp1 and Uga35/Dal81 transcription factors for induction of the AGP1 gene in Saccharomyces cerevisiae.

PubMed Central

Abdel-Sater, Fadi; Iraqui, Ismaïl; Urrestarazu, Antonio; André, Bruno

2004-01-01

Yeast cells respond to the presence of amino acids in their environment by inducing transcription of several amino acid permease genes including AGP1, BAP2, and BAP3. The signaling pathway responsible for this induction involves Ssy1, a permease-like sensor of external amino acids, and culminates with proteolytic cleavage and translocation to the nucleus of the zinc-finger proteins Stp1 and Stp2, the lack of which abolishes induction of BAP2 and BAP3. Here we show that Stp1-but not Stp2-plays an important role in AGP1 induction, although significant induction of AGP1 by amino acids persists in stp1 and stp1 stp2 mutants. This residual induction depends on the Uga35/Dal81 transcription factor, indicating that the external amino acid signaling pathway activates not only Stp1 and Stp2, but also another Uga35/Dal81-dependent transcriptional circuit. Analysis of the AGP1 gene's upstream region revealed that Stp1 and Uga35/Dal81 act synergistically through a 21-bp cis-acting sequence similar to the UAS(AA) element previously found in the BAP2 and BAP3 upstream regions. Although cells growing under poor nitrogen-supply conditions display much higher induction of AGP1 expression than cells growing under good nitrogen-supply conditions, the UAS(AA) itself is totally insensitive to nitrogen availability. Nitrogen-source control of AGP1 induction is mediated by the GATA factor Gln3, likely acting through adjacent 5'-GATA-3' sequences, to amplify the positive effect of UAS(AA). Our data indicate that Stp1 may act in combination with distinct sets of transcription factors, according to the gene context, to promote induction of transcription in response to external amino acids. The data also suggest that Uga35/Dal81 is yet another transcription factor under the control of the external amino acid sensing pathway. Finally, the data show that the TOR pathway mediating global nitrogen control of transcription does not interfere with the external amino acid signaling pathway. PMID:15126393

Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

NASA Astrophysics Data System (ADS)

Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

2015-11-01

Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

In vitro gastrointestinal digestion promotes the protective effect of blackberry extract against acrylamide-induced oxidative stress

NASA Astrophysics Data System (ADS)

Chen, Wei; Su, Hongming; Xu, Yang; Jin, Chao

2017-01-01

Acrylamide (AA)-induced toxicity has been associated with accumulation of excessive reactive oxygen species. The present study was therefore undertaken to investigate the protective effect of blackberry digests produced after (BBD) in vitro gastrointestinal (GI) digestion against AA-induced oxidative damage. The results indicated that the BBD (0.5 mg/mL) pretreatment significantly suppressed AA-induced intracellular ROS generation (56.6 ± 2.9% of AA treatment), mitochondrial membrane potential (MMP) decrease (297 ± 18% of AA treatment) and glutathione (GSH) depletion (307 ± 23% of AA treatment), thereby ameliorating cytotoxicity. Furthermore, LC/MS/MS analysis identified eight phenolic compounds with high contents in BBD, including ellagic acid, ellagic acid pentoside, ellagic acid glucuronoside, methyl-ellagic acid pentoside, methyl-ellagic acid glucuronoside, cyanidin glucoside, gallic acid and galloyl esters, as primary active compounds responsible for antioxidant action. Collectively, our study uncovered that the protective effect of blackberry was reserved after gastrointestinal digestion in combating exogenous pollutant-induced oxidative stress.

Identification of functional domains of the IR2 protein of equine herpesvirus 1 required for inhibition of viral gene expression and replication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Seong K., E-mail: skim1@lsuhsc.edu; Kim, Seongman; Dai Gan

2011-09-01

The equine herpesvirus 1 (EHV-1) negative regulatory IR2 protein (IR2P), an early 1,165-amino acid (aa) truncated form of the 1487-aa immediate-early protein (IEP), lacks the trans-activation domain essential for IEP activation functions but retains domains for binding DNA, TFIIB, and TBP and the nuclear localization signal. IR2P mutants of the N-terminal region which lack either DNA-binding activity or TFIIB-binding activity were unable to down-regulate EHV-1 promoters. In EHV-1-infected cells expressing full-length IR2P, transcription and protein expression of viral regulatory IE, early EICP0, IR4, and UL5, and late ETIF genes were dramatically inhibited. Viral DNA levels were reduced to 2.1% ofmore » control infected cells, but were vey weakly affected in cells that express the N-terminal 706 residues of IR2P. These results suggest that IR2P function requires the two N-terminal domains for binding DNA and TFIIB as well as the C-terminal residues 707 to 1116 containing the TBP-binding domain. - Highlights: > We examine the functional domains of IR2P that mediates negative regulation. > IR2P inhibits at the transcriptional level. > DNA-binding mutant or TFIIB-binding mutant fails to inhibit. > C-terminal aa 707 to 1116 are required for full inhibition. > Inhibition requires the DNA-binding domain, TFIIB-binding domain, and C-terminus.« less

Arachidonic Acid Stress Impacts Pneumococcal Fatty Acid Homeostasis

PubMed Central

Eijkelkamp, Bart A.; Begg, Stephanie L.; Pederick, Victoria G.; Trapetti, Claudia; Gregory, Melissa K.; Whittall, Jonathan J.; Paton, James C.; McDevitt, Christopher A.

2018-01-01

Free fatty acids hold dual roles during infection, serving to modulate the host immune response while also functioning directly as antimicrobials. Of particular importance are the long chain polyunsaturated fatty acids, which are not commonly found in bacterial organisms, that have been proposed to have antibacterial roles. Arachidonic acid (AA) is a highly abundant long chain polyunsaturated fatty acid and we examined its effect upon Streptococcus pneumoniae. Here, we observed that in a murine model of S. pneumoniae infection the concentration of AA significantly increases in the blood. The impact of AA stress upon the pathogen was then assessed by a combination of biochemical, biophysical and microbiological assays. In vitro bacterial growth and intra-macrophage survival assays revealed that AA has detrimental effects on pneumococcal fitness. Subsequent analyses demonstrated that AA exerts antimicrobial activity via insertion into the pneumococcal membrane, although this did not increase the susceptibility of the bacterium to antibiotic, oxidative or metal ion stress. Transcriptomic profiling showed that AA treatment also resulted in a dramatic down-regulation of the genes involved in fatty acid biosynthesis, in addition to impacts on other metabolic processes, such as carbon-source utilization. Hence, these data reveal that AA has two distinct mechanisms of perturbing the pneumococcal membrane composition. Collectively, this work provides a molecular basis for the antimicrobial contribution of AA to combat pneumococcal infections. PMID:29867785

Quantum chemical density functional theory studies on the molecular structure and vibrational spectra of Gallic acid imprinted polymers

NASA Astrophysics Data System (ADS)

Pardeshi, Sushma; Dhodapkar, Rita; Kumar, Anupama

2013-12-01

Gallic acid (GA) is known by its antioxidant, anticarcinogenic properties and scavenger activity against several types of harmful free radicals. Molecularly imprinted polymers (MIPs) are used in separation of a pure compound from complex matrices. A stable template-monomer complex generates the MIPs with the highest affinity and selectivity for the template. The quantum chemical computations based on density functional theory (DFT) was used on the template Gallic acid (GA), monomer acrylic acid (AA) and GA-AA complex to study the nature of interactions involved in the GA-AA complex. B3LYP/6-31+G(2d,2p) model chemistry was used to optimize their structures and frequency calculations. The effect of porogen acetonitrile (ACN) on complex formation was included by using polarizable continuum model (PCM). The results demonstrated the formation of a stable GA-AA complex through the intermolecular hydrogen bonding between carboxylic acid groups of GA and AA. The Mulliken atomic charge analysis and simulated vibrational spectra also supported the stable hydrogen bonding interaction between the carboxylic acid groups of GA and AA with minimal interference of porogen ACN. Further, simulations on GA-AA mole ratio revealed that 1:4 GA-AA was optimum for synthesis of MIP for GA.

Identification of functional domains of the IR2 protein of equine herpesvirus 1 required for inhibition of viral gene expression and replication

PubMed Central

Kim, Seong K.; Kim, Seongman; Dai, Gan; Zhang, Yunfei; Ahn, Byung C.; O'Callaghan, Dennis J.

2012-01-01

The equine herpesvirus 1 (EHV-1) negative regulatory IR2 protein (IR2P), an early 1,165-amino acid (aa) truncated form of the 1,487-aa immediate-early protein (IEP), lacks the trans-activation domain essential for IEP activation functions but retains domains for binding DNA, TFIIB, and TBP and the nuclear localization signal. IR2P mutants of the N-terminal region which lack either DNA-binding activity or TFIIB-binding activity were unable to down-regulate EHV-1 promoters. In EHV-1-infected cells expressing full-length IR2P, transcription and protein expression of viral regulatory IE, early EICP0, IR4, and UL5, and late ETIF genes were dramatically inhibited. Viral DNA levels were reduced to 2.1% of control infected cells, but were vey weakly affected in cells that express the N-terminal 706 residues of IR2P. These results suggest that IR2P function requires the two N-terminal domains for binding DNA and TFIIB as well as the C-terminal residues 707 to 1116 containing the TBP-binding domain. PMID:21794889

The ratio of serum eicosapentaenoic acid to arachidonic acid and risk of cancer death in a Japanese community: The Hisayama Study.

PubMed

Nagata, Masaharu; Hata, Jun; Hirakawa, Yoichiro; Mukai, Naoko; Yoshida, Daigo; Ohara, Tomoyuki; Kishimoto, Hiro; Kawano, Hiroyuki; Kitazono, Takanari; Kiyohara, Yutaka; Ninomiya, Toshiharu

2017-12-01

Whether the intake of eicosapentaenoic acid (EPA) or arachidonic acid (AA) affects the risk of cancer remains unclear, and the association between the serum EPA:AA ratio and cancer risk has not been fully evaluated in general populations. A total of 3098 community-dwelling subjects aged ≥40 years were followed up for 9.6 years (2002-2012). The levels of the serum EPA:AA ratio were categorized into quartiles (<0.29, 0.29-0.41, 0.42-0.60, and >0.60). The risk estimates were computed using a Cox proportional hazards model. The same analyses were conducted for the serum docosahexaenoic acid to arachidonic acid (DHA:AA) ratio and individual fatty acid concentrations. During the follow-up period, 121 subjects died of cancer. Age- and sex-adjusted cancer mortality increased with lower serum EPA:AA ratio levels (P trend<0.05). In the multivariable-adjusted analysis, the subjects in the first quartile of the serum EPA:AA ratio had a 1.93-fold (95% confidence interval, 1.15-3.22) greater risk of cancer death than those in the fourth quartile. Lower serum EPA concentrations were marginally associated with higher cancer mortality (P trend<0.11), but the serum DHA or AA concentrations and the serum DHA:AA ratio were not (all P trend>0.37). With regard to site-specific cancers, lower serum EPA:AA ratio was associated with a higher risk of death from liver cancer. However, no such associations were detected for deaths from other cancers. These findings suggest that decreased level of the serum EPA:AA ratio is a significant risk factor for cancer death in the general Japanese population. Copyright © 2017. Production and hosting by Elsevier B.V.

A targeted mass spectrometry-based approach for the identification and characterization of proteins containing α-aminoadipic and γ-glutamic semialdehyde residues

PubMed Central

Chavez, Juan D.; Bisson, William H.

2011-01-01

The site-specific identification of α-aminoadipic semialdehyde (AAS) and γ-glutamic semialdehyde (GGS) residues in proteins is reported. Semialdehydic protein modifications result from the metal-catalyzed oxidation of Lys or Arg and Pro residues, respectively. Most of the analytical methods for the analysis of protein carbonylation measure change to the global level of carbonylation and fail to provide details regarding protein identity, site, and chemical nature of the carbonylation. In this work, we used a targeted approach, which combines chemical labeling, enrichment, and tandem mass spectrometric analysis, for the site-specific identification of AAS and GGS sites in proteins. The approach is applied to in vitro oxidized glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and an untreated biological sample, namely cardiac mitochondrial proteins. The analysis of GAPDH resulted in the site-specific identification of two AAA and four GGS residues. Computational evaluation of the identified AAS and GGS sites in GAPDH indicated that these sites are located in flexible regions, show high solvent accessibility values, and are in proximity with possible metal ion binding sites. The targeted proteomic analysis of semialdehydic modifications in cardiac mitochondria yielded nine AAS modification sites which were unambiguously assigned to distinct lysine residues in the following proteins: ATP/ATP translocase isoforms 1 and 2, ubiquinol cytochrome-c reductase core protein 2, and ATP synthase α-subunit. PMID:20957471

Intestinal digestibility of amino acids in rumen-undegraded protein estimated using a precision-fed cecectomized rooster bioassay: II. Distillers dried grains with solubles and fish meal.

PubMed

Boucher, S E; Calsamiglia, S; Parsons, C M; Stein, H H; Stern, M D; Erickson, P S; Utterback, P L; Schwab, C G

2009-12-01

The objectives of this experiment were to measure intestinal digestibility of AA in the rumen-undegraded protein fraction (RUP-AA) of distillers dried grains with solubles (DDGS) and fish meal (FM) samples and to determine whether these feeds contain a constant protein fraction that is undegradable in the rumen and indigestible in the small intestine, as assumed in the French Institut National de la Recherche Agronomique (Paris, France) and Scandinavian AAT-PBV (AAT = AA absorbed from small intestine; PBV = protein balance in the rumen) models. Five sources of DDGS and 5 sources of FM were obtained from Feed Analysis Consortium, Inc. (Champaign, IL). To obtain the rumen-undegradable protein fraction, samples were ruminally incubated in situ for 16 h in 4 lactating cows, and the collected rumen-undegraded residues (RUR) were pooled by sample. Subsamples of the intact feeds and RUR were crop-intubated to 4 cecectomized roosters, and total excreta were collected for 48 h. Intact feeds, RUR, and excreta were analyzed for AA. Basal endogenous AA loss estimates were obtained from fasted birds and were used to calculate standardized digestibility of RUP-AA and AA in the intact feeds. Indigestibility coefficients of the intact feeds were calculated as (100 - % standardized AA digestibility), and indigestibility of the RUR was calculated as [(100 - % ruminal degradation of AA) x (100 - % standardized RUP-AA digestibility)/100]. Results indicate that standardized digestibility of feed-AA differs from RUP-AA for DDGS samples but not for FM samples, and that standardized digestibility of individual AA differs within samples. For the DDGS samples, standardized feed-AA and RUP-AA digestibility values were most often lowest for His and Lys and highest for Met and Trp. For FM samples, standardized feed-AA and RUP-AA digestibility values were most often lowest for His and highest for Trp. Results also indicate that DDGS and most FM samples do not contain a constant protein fraction that is both undegradable in the rumen and indigestible in the small intestine. Indigestibility values of RUR were lower than in intact feeds, suggesting that the feed ingredients used in this experiment contain a protein fraction that is indigestible in the intestine but partly degradable in the rumen or digestible in the intestine after rumen incubation, or both.

On the cellular metabolism of the click chemistry probe 19-alkyne arachidonic acid[S

PubMed Central

Robichaud, Philippe Pierre; Poirier, Samuel J.; Boudreau, Luc H.; Doiron, Jérémie A.; Barnett, David A.; Boilard, Eric; Surette, Marc E.

2016-01-01

Alkyne and azide analogs of natural compounds that can be coupled to sensitive tags by click chemistry are powerful tools to study biological processes. Arachidonic acid (AA) is a FA precursor to biologically active compounds. 19-Alkyne-AA (AA-alk) is a sensitive clickable AA analog; however, its use as a surrogate to study AA metabolism requires further evaluation. In this study, AA-alk metabolism was compared with that of AA in human cells. Jurkat cell uptake of AA was 2-fold greater than that of AA-alk, but significantly more AA-Alk was elongated to 22:4. AA and AA-alk incorporation into and remodeling between phospholipid (PL) classes was identical indicating equivalent CoA-independent AA-PL remodeling. Platelets stimulated in the pre­sence of AA-alk synthesized significantly less 12-lipoxygenase (12-LOX) and cyclooxygenase products than in the presence of AA. Ionophore-stimulated neutrophils produced significantly more 5-LOX products in the presence of AA-alk than AA. Neutrophils stimulated with only exogenous AA-alk produced significantly less 5-LOX products compared with AA, and leukotriene B4 (LTB4)-alk was 12-fold less potent at stimulating neutrophil migration than LTB4, collectively indicative of weaker leukotriene B4 receptor 1 agonist activity of LTB4-alk. Overall, these results suggest that the use of AA-alk as a surrogate for the study of AA metabolism should be carried out with caution. PMID:27538823

Effects of seasonings on the stability of ascorbic acid in a cooking model system.

PubMed

Kishida, Etsu; Maeda, Tomoko; Nishihama, Akiko; Kojo, Shosuke; Masuzawa, Yasuo

2004-12-01

The thermolability of ascorbic acid (AA) in aqueous solution at 100 degrees C was assessed in the presence of various seasonings commonly used in Japanese-style cooking. A model system approximated Japanese cooking with regard to the concentrations of AA and seasonings and the heating time. The decrease of AA in the reaction system of this experiment was a first-order reaction with respect to the concentration of AA loss. Although kinetic constants for AA loss decreased with increasing concentrations of AA (25-400 microg/mL), the absolute amounts degraded were almost the same for all AA concentrations, suggesting that dissolved oxygen is one of main factors affecting the stability of AA solutions during heating at 100 degrees C. When each seasoning was added to AA solution, salt stabilized AA and Japanese alcohol-containing admixtures, such as sake and sweet sake (mirin), did not have a significant effect on the stability. Conversely, soy sauce, miso (fermented soybean paste) and broth powder from skipjack accelerated the decrease of AA in a concentration-dependent manner. The kinetic study suggested that oxygen was rapidly consumed and AA loss accelerated by addition of soy sauce or miso to AA solution. Consequently it is likely that a reaction mechanism shifts from aerobic to anaerobic and the forward reactions proceed. Of the constituents of Japanese seasonings, not only iron but also amino acids are involved in the acceleration of AA degradation. The presence of amino acids should be taken into account when considering the levels of AA in soups.

Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults.

PubMed

Seah, Jowy Yi Hoong; Gay, Gibson Ming Wei; Su, Jin; Tai, E-Shyong; Yuan, Jian-Min; Koh, Woon-Puay; Ong, Choon Nam; van Dam, Rob M

2017-01-31

High arachidonic acid (AA; 20:4 n - 6) status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n - 6 polyunsaturated fatty acids (PUFAs) are based on the premise that endogenous conversion from linoleic acid (LA; 18:2 n - 6) is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25-80 years old) with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44-74 years old) from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy) and food sources of PUFA (fish, red meat, poultry, soy and cooking oils) in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3 n - 6), alpha-linolenic acid (ALA; 18:3 n - 3), eicosapentaenoic acid (EPA; 20:5 n - 3), and docosahexaenoic acid (DHA; 22:6 n - 3)) concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05) in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population.

Effects of Cooling Rate on Precipitate Evolution and Residual Stresses in Al-Si-Mn-Mg Casting Alloy

NASA Astrophysics Data System (ADS)

Lee, Eunkyung; Walde, Caitlin; Mishra, Brajendra

2018-07-01

The residual stresses with different heat treatment conditions have been measured and correlated with the microstructural behavior of AA365. 30 and 100 K/min cooling of AA365 inhibited the transformation of precipitates under 773 K, respectively. The alloy cooled at 30 and 100 K/min exhibited tensile residual stresses of 6.2 and 5.4 MPa, respectively, while the alloy cooled at 1 and 10 K/min showed compressive stresses of - 12.8 and - 10.3 MPa, respectively. The formation β', β″, and other intermetallic compounds affected the compressive residual stresses, and that the fracture of the brittle intermetallic phases could reduce the extent of residual stresses in the lattice through plastic deformation.

Effects of Cooling Rate on Precipitate Evolution and Residual Stresses in Al-Si-Mn-Mg Casting Alloy

NASA Astrophysics Data System (ADS)

Lee, Eunkyung; Walde, Caitlin; Mishra, Brajendra

2018-03-01

The residual stresses with different heat treatment conditions have been measured and correlated with the microstructural behavior of AA365. 30 and 100 K/min cooling of AA365 inhibited the transformation of precipitates under 773 K, respectively. The alloy cooled at 30 and 100 K/min exhibited tensile residual stresses of 6.2 and 5.4 MPa, respectively, while the alloy cooled at 1 and 10 K/min showed compressive stresses of - 12.8 and - 10.3 MPa, respectively. The formation β', β″, and other intermetallic compounds affected the compressive residual stresses, and that the fracture of the brittle intermetallic phases could reduce the extent of residual stresses in the lattice through plastic deformation.

Renal Liver-Type Fatty Acid Binding Protein (L-FABP) Attenuates Acute Kidney Injury in Aristolochic Acid Nephrotoxicity

PubMed Central

Matsui, Katsuomi; Kamijo-Ikemorif, Atsuko; Sugaya, Takeshi; Yasuda, Takashi; Kimura, Kenjiro

2011-01-01

Injection of aristolochic acid (AA) in mice causes AA-induced nephrotoxicity, in which oxidative stress contributes to development of tubulointerstitial damage (TID). Liver-type fatty acid binding protein (L-FABP) is expressed in human proximal tubules and has an endogenous antioxidative function. The renoprotection of renal L-FABP was examined in a model of AA-induced nephrotoxicity. Established human L-FABP (hL-FABP) transgenic (Tg) mice and wild-type (WT) mice were treated with AA for up to 5 days. Mice were sacrificed on days 1, 3, and 5 after the start of AA injection. Although mouse L-FABP was not expressed in proximal tubules of WT mice, hL-FABP was expressed in proximal tubules of Tg mice. The expression of renal hL-FABP was significantly increased in Tg mice administered AA (Tg-AA), compared with the control (saline-treated Tg mice). In WT-AA mice, there was high urinary excretion of Nε-(hexanoyl)-lysine, the production of heme oxygenase-1 and receptor for advanced glycation end products increased, and TID was provoked. In contrast, renal hL-FABP in Tg-AA mice suppressed production of Nε-(hexanoyl)lysine, heme oxygenase-1, and receptor for advanced glycation end products. Renal dysfunction was significantly milder in Tg-AA mice than in WT-AA mice. The degree of TID was significantly attenuated in Tg-AA mice, compared with WT-AA. In conclusion, renal hL-FABP reduced the oxidative stress in AA-induced nephrotoxicity and attenuated TID. PMID:21356355

Associations With Eicosapentaenoic Acid to Arachidonic Acid Ratio and Mortality in Hospitalized Heart Failure Patients.

PubMed

Watanabe, Shunsuke; Yoshihisa, Akiomi; Kanno, Yuki; Takiguchi, Mai; Yokokawa, Tetsuro; Sato, Akihiko; Miura, Shunsuke; Shimizu, Takeshi; Abe, Satoshi; Sato, Takamasa; Suzuki, Satoshi; Oikawa, Masayoshi; Sakamoto, Nobuo; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-Ichi; Takeishi, Yasuchika

2016-12-01

Intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) lowers the risk of atherosclerotic cardiovascular events, particularly ischemic heart disease. In addition, the ratio of eicosapentaenoic acid (EPA; n-3 PUFA) to arachidonic acid (AA; n-6 PUFA) has recently been recognized as a risk marker of cardiovascular disease. In contrast, the prognostic impact of the EPA/AA ratio on patients with heart failure (HF) remains unclear. A total of 577 consecutive patients admitted for HF were divided into 2 groups based on median of the EPA/AA ratio: low EPA/AA (EPA/AA <0.32 mg/dl, n = 291) and high EPA/AA (EPA/AA ≥0.32, n = 286) groups. We compared laboratory data and echocardiographic findings and followed cardiac mortality. Although body mass index, blood pressure, B-type natriuretic peptide, hemoglobin, estimated glomerular filtration rate, total protein, albumin, sodium, C-reactive protein, and left ventricular ejection fraction did not differ between the 2 groups, cardiac mortality was significantly higher in the low EPA/AA group than in the high EPA/AA group (12.7 vs 5.9%, log-rank P = .004). Multivariate Cox proportional hazard analysis revealed that the EPA/AA ratio was an independent predictor of cardiac mortality (hazard ratio 0.677, 95% confidence interval 0.453-0.983, P = .041) in patients with HF. The EPA/AA ratio was an independent predictor of cardiac mortality in patients with HF; therefore, the prognosis of patients with HF may be improved by taking appropriate management to control the EPA/AA balance. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Uncovering the Design Principle of Amino Acid-Derived Photoluminescent Biodots with Tailor-Made Structure-Properties and Applications for Cellular Bioimaging.

PubMed

Xu, Hesheng Victor; Zheng, Xin Ting; Zhao, Yanli; Tan, Yen Nee

2018-06-13

Natural amino acids possess side chains with different functional groups (R groups), which make them excellent precursors for programmable synthesis of biomolecule-derived nanodots (biodots) with desired properties. Herein, we report the first systematic study to uncover the material design rules of biodot synthesis from 20 natural α-amino acids via a green hydrothermal approach. The as-synthesized amino acid biodots (AA dots) are comprehensively characterized to establish a structure-property relationship between the amino acid precursors and the corresponding photoluminescent properties of AA dots. It was found that the amino acids with reactive R groups, including amine, hydroxyl, and carboxyl functional groups form unique C-O-C/C-OH and N-H bonds in the AA dots which stabilize the surface defects, giving rise to brightly luminescent AA dots. Furthermore, the AA dots were found to be amorphous and the length of the R group was observed to affect the final morphology (e.g., disclike nanostructure, nanowire, or nanomesh) of the AA dots, which in turn influence their photoluminescent properties. It is noteworthy to highlight that the hydroxyl-containing amino acids, that is, Ser and Thr, form the brightest AA dots with a quantum yield of 30.44% and 23.07%, respectively, and possess high photostability with negligible photobleaching upon continuous UV exposure for 3 h. Intriguingly, by selective mixing of Ser or Thr with another amino acid precursor, the resulting mixed AA dots could inherit unique properties such as improved photostability and significant red shift in their emission wavelength, producing enhanced green and red fluorescent intensity. Moreover, our cellular studies demonstrate that the as-synthesized AA dots display outstanding biocompatibility and excellent intracellular uptake, which are highly desirable for imaging applications. We envision that the material design rules discovered in this study will be broadly applicable for the rational selection of amino acid precursors in the tailored synthesis of biodots.

Cyclooxygenase Reaction Mechanism of PGHS ------- Evidence for a Reversible Transition between a Pentadienyl Radical and a New Tyrosyl Radical by Nitric Oxide Trapping

PubMed Central

Lü, Jian-Ming; Rogge, Corina E.; Wu, Gang; Kulmacz, Richard J.; van der Donk, Wilfred A.; Tsai, Ah-lim

2011-01-01

Incubation of prostaglandin H synthase-1 (PGHS-1) under anaerobic conditions with peroxide and arachidonic acid leads to two major radical species: a pentadienyl radical and a radical with a narrow EPR spectrum. The proportions of the two radicals are sensitive to temperature, favoring the narrow radical species at 22 °C. The EPR characteristics of this latter radical are somewhat similar to the previously reported narrow-singlet tyrosine radical NS1a and are insensitive to deuterium labeling of AA. To probe the origin and structure of this radical, we combined EPR analysis with nitric oxide (NO) trapping of tyrosine and substrate derived radicals for both PGHS-1 and -2. Formation of 3-nitrotyrosine in the proteins was analyzed by immunoblotting, whereas NO adducts to AA and AA metabolites were analyzed by mass spectrometry and by chromatography of 14C-labeled products. The results indicate that both nitrated tyrosine residues and NO-AA adducts formed upon NO trapping. The NO-AA adduct was predominantly an oxime at C11 of AA with three conjugated double bonds, as indicated by absorption at 275 nm and by mass spectral analysis. This adduct amounted to 10% and 20% of the heme concentration of PGHS-1 and -2, respectively. For PGHS-1, the yield of NO-AA adduct matched the yield of the narrow radical signal obtained in parallel EPR experiments. High frequency EPR characterization of this narrow radical, reported in an accompanying paper, supports assignment to a new tyrosyl radical, NS1c, rather than an AA-based radical. To reconcile the results from EPR and NO-trapping studies, we propose that the NS1c is in equilibrium with an AA pentadienyl radical, and that the latter reacts preferentially with NO. PMID:21403766

Synthesis and characterization of agricultural controllable humic acid superabsorbent.

PubMed

Gao, Lijuan; Wang, Shiqiang; Zhao, Xuefei

2013-12-01

Humic acid superabsorbent polymer (P(AA/AM-HA)) and superabsorbent polymer (P(AA/AM)) were synthesized by aqueous solution polymerization method using acrylic acid (AA), acrylamide (AM) and humic acid (HA) as raw material. The effects of N,N'-methylenebisacrylamide (MBA) crosslinking agent, potassium peroxydisulfate (KPS) initiator, reaction temperature, HA content, ratio of AA to AM, concentration of monomer and neutralization of AA on water absorption were investigated. Absorption and desorption ratios of nitrogen fertilizer and phosphate fertilizer were also investigated by determination of absorption and desorption ratio of NH4(+), PO4(3-) on P(AA/AM-HA) and P(AA/AM). The P(AA/AM-HA) and P(AA/AM) were characterized by Fourier translation infrared spectroscopy, biological photomicroscope and scanning electron microscopy (SEM). The optimal conditions obtained were as follows: the weight ratio of MBA to AA and AM was 0.003; the weight ratio of KPS to AA and AM was 0.008; the weight ratio of HA to AA was 0.1; the mole ratio of AM to AA is 0.1; the mole ratio of NaOH to AA is 0.9; the reaction temperature was 60°C. P(AA/AM-HA) synthesized under optimal conditions, has a good saline tolerance, its water absorbency in distilled water and 0.9 wt.% saline solution is 1180 g/g and 110 g/g, respectively. P(AA/AM-HA) achieves half saturation in 6.5 min. P(AA/AM-HA) is superior to P(AA/AM) on absorption of NH4(+), PO4(3-). The SEM micrograph of P(AA/AM-HA) shows a fine alveolate structure. The biological optical microscope micrograph of P(AA/AM-HA) shows a network structure. Graft polymerization between P(AA/AM) and HA was demonstrated by infrared spectrum. The P(AA/AM-HA) superabsorbent has better absorbing ability of water and fertilizer, electrolytic tolerance and fewer cost than P(AA/AM) superabsorbent. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Clinical implications of eicosapentaenoic acid/arachidonic acid ratio (EPA/AA) in adult patients with congenital heart disease.

PubMed

Kanoh, Miki; Inai, Kei; Shinohara, Tokuko; Tomimatsu, Hirofumi; Nakanishi, Toshio

2017-12-01

Recent studies showed that a low ratio between the levels of eicosapentaenoic acid and those of arachidonic acid (EPA/AA) is associated with higher incidence of coronary artery disease and poor prognosis of heart failure, arrhythmia, and cardiac sudden death. However, the clinical implications of EPA/AA in adult patients with congenital heart disease remain unclear. We aimed to assess the prognostic value of EPA/AA regarding cardiac events in adult patients with congenital heart disease. We measured the serum levels of eicosapentaenoic acid and arachidonic acid in 130 adult patients (median age, 31 years) stratified into two groups according to their EPA/AA (low, ≤0.22; high, >0.22). We prospectively analyzed the association between EPA/AA and incidence of cardiac events during a mean observation period of 15 months, expressed in terms of hazard ratio (HR) with 95% confidence interval (95% CI). In the subgroup of patients with biventricular circulation (2VC) (n = 76), we analyzed the same clinical endpoints. In our study population, EPA/AA was not associated with the incidence of arrhythmic events (HR, 1.52; 95% CI, 0.82-2.85; p = 0.19), but low EPA/AA was a predictor of heart failure hospitalization (HR, 2.83; 95% CI, 1.35-6.30; p < 0.01). Among patients with 2VC, an EPA/AA of ≤0.25 was associated with a significantly higher risk of arrhythmic events (HR, 2.55; 95% CI, 1.11-6.41; p = 0.03) and heart failure hospitalization (HR, 5.20; 95% CI, 1.78-18.1; p < 0.01). EPA/AA represents a useful predictor of cardiac events in adult patients with congenital heart disease.

Arachidonic Acid: An Evolutionarily Conserved Signaling Molecule Modulates Plant Stress Signaling Networks[C][W

PubMed Central

Savchenko, Tatyana; Walley, Justin W.; Chehab, E. Wassim; Xiao, Yanmei; Kaspi, Roy; Pye, Matthew F.; Mohamed, Maged E.; Lazarus, Colin M.; Bostock, Richard M.; Dehesh, Katayoon

2010-01-01

Fatty acid structure affects cellular activities through changes in membrane lipid composition and the generation of a diversity of bioactive derivatives. Eicosapolyenoic acids are released into plants upon infection by oomycete pathogens, suggesting they may elicit plant defenses. We exploited transgenic Arabidopsis thaliana plants (designated EP) producing eicosadienoic, eicosatrienoic, and arachidonic acid (AA), aimed at mimicking pathogen release of these compounds. We also examined their effect on biotic stress resistance by challenging EP plants with fungal, oomycete, and bacterial pathogens and an insect pest. EP plants exhibited enhanced resistance to all biotic challenges, except they were more susceptible to bacteria than the wild type. Levels of jasmonic acid (JA) were elevated and levels of salicylic acid (SA) were reduced in EP plants. Altered expression of JA and SA pathway genes in EP plants shows that eicosapolyenoic acids effectively modulate stress-responsive transcriptional networks. Exogenous application of various fatty acids to wild-type and JA-deficient mutants confirmed AA as the signaling molecule. Moreover, AA treatment elicited heightened expression of general stress-responsive genes. Importantly, tomato (Solanum lycopersicum) leaves treated with AA exhibited reduced susceptibility to Botrytis cinerea infection, confirming AA signaling in other plants. These studies support the role of AA, an ancient metazoan signaling molecule, in eliciting plant stress and defense signaling networks. PMID:20935246

Data on the effect of oral feeding of Arachidonic acid or Docosahexanoic acid on haematopoiesis in mice.

PubMed

Limbkar, Kedar; Dhenge, Ankita; Jadhav, Dipesh D; Thulasiram, Hirekodathakallu V; Kale, Vaijayanti; Limaye, Lalita

2017-10-01

Stem cells have peculiar property to self-renew and differentiate. It is important to control their fate in safe and effective ways for their therapeutic use. The mediators of essential polyunsaturated fatty acids (PUFAs) namely Arachidonic acid (AA) and Docosahexanoic acid (DHA) are known to play a role in haematopoiesis via various metabolic pathways [1]. However the direct effect of purified AA or DHA on haematopoiesis has not been well investigated yet. We have reported that oral administration of PUFAs enhanced haematopoiesis in mice [2]. Signaling Leukocyte Antigen Molecule (SLAM) (CD48 - CD150 + ) phenotype consists of pure population of haematopoietic stem cells (HSCs). Herein we observed higher percentage of SLAM (CD48 - CD150 + ) phenotype in the bone marrow (BM) cells of mice fed with AA or DHA compared to PBS fed control mice. Data from engraftment study depicts that BM from AA/DHA-fed mice showed higher absolute number of donor cells in recipient mice compared to control. The enhanced hematopoiesis observed in AA/DHA-fed mice was returned to normal when the mice were kept on normal diet for six weeks (after ten days of oral feeding). We confirmed GCMS (Gas Chromatography-Mass Spectroscopy) retention times of AA and DHA by co-injecting fatty acid extract from AA or DHA fed mice with purified AA or DHA standards respectively. Representative flow cytometry profile of Lin - Sca-1 + c-kit + (LSK) cells showed higher expression of CXCR4 protein and ligands of Wnt, Notch1 signaling in BM of AA/DHA-fed mice.

Reductive dechlorination of carbon tetrachloride using buffered alkaline ascorbic acid.

PubMed

Lin, Ya-Ting; Liang, Chenju

2015-10-01

Alkaline ascorbic acid (AA) was recently discovered as a novel in-situ chemical reduction (ISCR) reagent for remediating chlorinated solvents in the subsurface. For this ISCR process, the maintenance of an alkaline pH is essential. This study investigated the possibility of the reduction of carbon tetrachloride (CT) using alkaline AA solution buffered by phosphate and by NaOH. The results indicated that CT was reduced by AA, and chloroform (CF) was a major byproduct at a phosphate buffered pH of 12. However, CT was completely reduced by AA in 2M NaOH without CF formation. In the presence of iron/soil minerals, iron could be reduced by AA and Fe(2+) tends to precipitate on the mineral surface to accelerate CT degradation. A simultaneous transfer of hydrogenolysis and dichloroelimination would occur under phosphate buffered pH 12. This implies that a high alkaline environment is a crucial factor for maintaining the dominant pathway of two electron transfer from dianionic AA to dehydroascorbic acid, and to undergo dichloroelimination of CT. Moreover, threonic acid and oxalic acid were identified to be the major AA decomposition products in alkaline solutions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Role of ion channels and subcellular Ca2+ signaling in arachidonic acid-induced dilation of pressurized retinal arterioles.

PubMed

Kur, Joanna; McGahon, Mary K; Fernández, Jose A; Scholfield, C Norman; McGeown, J Graham; Curtis, Tim M

2014-05-02

To investigate the mechanisms responsible for the dilatation of rat retinal arterioles in response to arachidonic acid (AA). Changes in the diameter of isolated, pressurized rat retinal arterioles were measured in the presence of AA alone and following pre-incubation with pharmacologic agents inhibiting Ca(2+) sparks and oscillations and K(+) channels. Subcellular Ca(2+) signals were recorded in arteriolar myocytes using Fluo-4-based confocal imaging. The effects of AA on membrane currents of retinal arteriolar myocytes were studied using whole-cell perforated patch clamp recording. Arachidonic acid dilated pressurized retinal arterioles under conditions of myogenic tone. Eicosatetraynoic acid (ETYA) exerted a similar effect, but unlike AA, its effects were rapidly reversible. Arachidonic acid-induced dilation was associated with an inhibition of subcellular Ca(2+) signals. Interventions known to block Ca(2+) sparks and oscillations in retinal arterioles caused dilatation and inhibited AA-induced vasodilator responses. Arachidonic acid accelerated the rate of inactivation of the A-type Kv current and the voltage dependence of inactivation was shifted to more negative membrane potentials. It also enhanced voltage-activated and spontaneous large-conductance calcium-activated K(+) (BK) currents, but only at positive membrane potentials. Pharmacologic inhibition of A-type Kv and BK currents failed to block AA-induced vasodilator responses. Arachidonic acid suppressed L-type Ca(2+) currents. These results suggest that AA induces retinal arteriolar vasodilation by inhibiting subcellular Ca(2+)-signaling activity in retinal arteriolar myocytes, most likely through a mechanism involving the inhibition of L-type Ca(2+)-channel activity. Arachidonic acid actions on K(+) currents are inconsistent with a model in which K(+) channels contribute to the vasodilator effects of AA.

Affinity resins as new tools for identifying target proteins of ascorbic acid.

PubMed

Iwaoka, Yuji; Nishino, Kohei; Ishikawa, Takahiro; Ito, Hideyuki; Sawa, Yoshihiro; Tai, Akihiro

2018-02-12

l-Ascorbic acid (AA) has diverse physiological functions, but little is known about the functional mechanisms of AA. In this study, we synthesized two types of affinity resin on which AA is immobilized in a stable form to identify new AA-targeted proteins, which can provide important clues for elucidating unknown functional mechanisms of AA. To our knowledge, an affinity resin on which AA as a ligand is immobilized has not been prepared, because AA is very unstable and rapidly degraded in an aqueous solution. By using the affinity resins, cytochrome c (cyt c) was identified as an AA-targeted protein, and we showed that oxidized cyt c exhibits specific affinity for AA. These results suggest that two kinds of AA-affinity resin can be powerful tools to identify new target proteins of AA.

Absence of a Causal Relationship between Auxin-Induced Growth and Changes in the Content of Ascorbic and Dehydroascorbic Acids in Excised Plant Tissues 12

PubMed Central

Lin, C. Y.; Key, Joe L.

1967-01-01

The data reported indicate that the oxidation-reduction balance of the ascorbic acid system is not causally related to the auxin-regulation of cell elongation. There was no shift in the ascorbic acid (AA) to dehydroascorbic acid (DHA) ratio with growth-promoting concentration of auxin in several plant tissues. The AA to DHA ratio was experimentally increased without altering the growth rate. Inhibition of growth by supra-optimal auxin was associated with a decrease in the AA to DHA ratio. Since the AA to DHA ratio was lowered by EDTA treatment without altering growth, it seems unlikely that the decrease in the AA to DHA ratio related to the inhibition of growth by high levels of auxin. PMID:16656564

Portable electrochemical sensor based on 4-aminobenzoic acid-functionalized herringbone carbon nanotubes for the determination of ascorbic acid and uric acid in human fluids.

PubMed

Abellán-Llobregat, A; González-Gaitán, C; Vidal, L; Canals, A; Morallón, E

2018-06-30

A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 μM for both analytes, and sensitivities of (9.0 ± 0.4) A g -1 mM -1 and (8.8 ± 0.3) A g -1 mM -1 for AA and UA, respectively. Repeatability was studied at 50 μM for AA and UA, providing relative standard deviations (RSD) lower than 9%. Additions of glucose, dopamine and epinephrine did not interfere with the AA and UA determination. Furthermore, UA did not interfere with AA determination at 0.1 V, although AA additions increased the current recorded at 0.32 V. The method has been successfully applied to human urine, perspiration and serum samples, without significant matrix effects, which allows for the use of an external calibration and the analysis of all the matrices investigated. Copyright © 2018 Elsevier B.V. All rights reserved.

Dietary supplementation of branched-chain amino acids increases muscle net amino acid fluxes through elevating their substrate availability and intramuscular catabolism in young pigs.

PubMed

Zheng, Liufeng; Zuo, Fangrui; Zhao, Shengjun; He, Pingli; Wei, Hongkui; Xiang, Quanhang; Pang, Jiaman; Peng, Jian

2017-04-01

Branched-chain amino acids (BCAA) have been clearly demonstrated to have anabolic effects on muscle protein synthesis. However, little is known about their roles in the regulation of net AA fluxes across skeletal muscle in vivo. This study was aimed to investigate the effect and related mechanisms of dietary supplementation of BCAA on muscle net amino acid (AA) fluxes using the hindlimb flux model. In all fourteen 4-week-old barrows were fed reduced-protein diets with or without supplemental BCAA for 28 d. Pigs were implanted with carotid arterial, femoral arterial and venous catheters, and fed once hourly with intraarterial infusion of p-amino hippurate. Arterial and venous plasma and muscle samples were obtained for the measurement of AA, branched-chain α-keto acids (BCKA) and 3-methylhistidine (3-MH). Metabolomes of venous plasma were determined by HPLC-quadrupole time-of-flight-MS. BCAA-supplemented group showed elevated muscle net fluxes of total essential AA, non-essential AA and AA. As for individual AA, muscle net fluxes of each BCAA and their metabolites (alanine, glutamate and glutamine), along with those of histidine, methionine and several functional non-essential AA (glycine, proline and serine), were increased by BCAA supplementation. The elevated muscle net AA fluxes were associated with the increase in arterial and intramuscular concentrations of BCAA and venous metabolites including BCKA and free fatty acids, and were also related to the decrease in the intramuscular concentration of 3-MH. Correlation analysis indicated that muscle net AA fluxes are highly and positively correlated with arterial BCAA concentrations and muscle net BCKA production. In conclusion, supplementing BCAA to reduced-protein diet increases the arterial concentrations and intramuscular catabolism of BCAA, both of which would contribute to an increase of muscle net AA fluxes in young pigs.

Single tag for total carbohydrate analysis.

PubMed

Anumula, Kalyan Rao

2014-07-15

Anthranilic acid (2-aminobenzoic acid, 2-AA) has the remarkable property of reacting rapidly with every type of reducing carbohydrate. Reactivity of 2-AA with carbohydrates in aqueous solutions surpasses all other tags reported to date. This unique capability is attributed to the strategically located -COOH which accelerates Schiff base formation. Monosaccharides, oligosaccharides (N-, O-, and lipid linked and glycans in secretory fluids), glycosaminoglycans, and polysaccharides can be easily labeled with 2-AA. With 2-AA, labeling is simple in aqueous solutions containing proteins, peptides, buffer salts, and other ingredients (e.g., PNGase F, glycosidase, and transferase reaction mixtures). In contrast, other tags require relatively pure glycans for labeling in anhydrous dimethyl sulfoxide-acetic acid medium. Acidic conditions are known to cause desialylation, thus requiring a great deal of attention to sample preparation. Simpler labeling is achieved with 2-AA within 30-60 min in mild acetate-borate buffered solution. 2-AA provides the highest sensitivity and resolution in chromatographic methods for carbohydrate analysis in a simple manner. Additionally, 2-AA is uniquely qualified for quantitative analysis by mass spectrometry in the negative mode. Analyses of 2-AA-labeled carbohydrates by electrophoresis and other techniques have been reported. Examples cited here demonstrate that 2-AA is the universal tag for total carbohydrate analysis. Copyright © 2014 Elsevier Inc. All rights reserved.

Arachidonic acid is involved in the regulation of hCG induced steroidogenesis in rat Leydig cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Didolkar, A.K.; Sundaram, K.

1987-07-27

Phospholipase C (PLC), an enzyme involved in the hydrolysis of membrane phospholipid- phosphatidylinositol-bisphosphate to insositol triphosphate and diacylglycerol, and Phorbol 12, myristate 13, acetate (PMA) could significantly stimulate testosterone (T) secretion from Leydig cells. Arachidonic acid (AA) stimulated T secretion by about 2 fold. The steroidogenic effect of PLC and AA was biphasic. At low concentrations both PLC and AA augmented hCG induced T secretion, while at higher concentrations they inhibited steroid production. AA also had a biphasic effect on hCG induced cyclic AMP secretion. 5,8,11,14 Eicosatetrayenoic acid, a general inhibitor of AA metabolism, and Nordihydroguaiaretic acid, an inhibitor ofmore » the lipoxygenase pathway of AA metabolism, inhibited hCG induced T secretion while indomethacin, an inhibitor of cyclo-oxygenase pathway, had no effect on hCG induced T secretion. The authors conclude from these data that AA plays a role in the regulation of hCG induced steroidogenic responses in rat Leydig cells and that the metabolite(s) of AA that are involved are not cyclo-oxygenase products. 28 references, 4 figures, 2 tables.« less

Single mutations that redirect internal proton transfer in the ba3 oxidase from Thermus thermophilus

PubMed Central

Smirnova, Irina; Chang, Hsin-Yang; von Ballmoos, Christoph; Ädelroth, Pia; Gennis, Robert B.; Brzezinski, Peter

2014-01-01

The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound proton pump. Results from earlier studies have shown that with the aa3-type oxidases proton uptake to the catalytic site and “pump site” occur simultaneously. However, with the ba3 oxidase the pump site is loaded before proton transfer to the catalytic site because the proton transfer to the latter is slower than with the aa3 oxidases. In addition, the timing of formation and decay of catalytic intermediates is different in the two types of oxidases. In the present study, we have investigated two mutant ba3 CytcOs in which residues of the proton pathway leading to the catalytic site as well as the pump site were exchanged, Thr312Val and Tyr244Phe. Even though the ba3 CytcO uses only a single proton pathway for transfer of the substrate and “pumped” protons, the amino-acid residue substitutions had distinctly different effects on the kinetics of proton transfer to the catalytic site and the pump site, respectively. The results indicate that the rates of these reactions can be modified independently by replacement of single residues within the proton pathway. Furthermore, the data suggest that the Thr312Val and Tyr244Phe mutations interfere with a structural rearrangement in the proton pathway that is rate limiting for proton transfer to the catalytic site. PMID:24004023

Unique molecular architecture of silk fibroin in the waxmoth, Galleria mellonella.

PubMed

Zurovec, Michal; Sehnal, Frantisek

2002-06-21

Proteins of silk fibers are characterized by reiterations of amino acid repeats. Physical properties of the fiber are determined by the amino acid composition, the complexity of repetitive units, and arrangement of these units into higher order arrays. Except for very short motifs of 6-10 residues, the length of repetitive units and the number of these units concatenated in higher order assemblies vary in all spider and lepidopteran silks analyzed so far. This paper describes an exceptional silk protein represented by the 500-kDa heavy chain fibroin (H-fibroin) of the waxmoth, Galleria mellonella. Its non-repetitive N-terminal (175 residues) and C-terminal (60 residues) parts, the overall gene organization, and the nucleotide sequence around the TATA box show that it is homologous to the H-fibroins of other Lepidoptera. However, over 95% of the protein consists of highly ordered repetitive structures that are unmatched in other species. The repetitive region includes 11 assemblies AB(1)AB(1)AB(1)AB(2)(AB(2))AB(2) of remarkably conserved polypeptide repeats A (63 amino acid residues), B(1) (43 residues), and B(2) (18 residues). The repeats contain a high proportion of Gly (31.6%), Ala (23.8%), Ser (18.1%), and of residues with long hydrophobic side chains (16% for Leu, Ile, and Val combined). The presence of the GLGGLG and SSAASAA(AA) motifs suggests formation of pleated beta-sheets and their stacking into crystallites. Conspicuous conservation of the apolar sequence VIVI followed by DD or ED is interpreted as indicating the importance of hydrophobicity and electrostatic charge in H-fibroin cross-linking. The environment of G. mellonella larvae within bee cultures requires continuous production of silk that must be both strong and elastic. The spectacular arrangement of the repetitive H-fibroin region apparently evolved to meet these requirements.

Effects of alpha lipoic acid, ascorbic acid-6-palmitate, and fish oil on the glutathione, malonaldehyde, and fatty acids levels in erythrocytes of streptozotocin induced diabetic male rats.

PubMed

Yilmaz, Okkeş; Ozkan, Yusuf; Yildirim, Mehmet; Oztürk, A Ihsan; Erşan, Yasemin

2002-01-01

In this research, it has been aimed to evaluate the improvement effects of alpha lipoic acid (ALA), ascorbic acid-6-palmitate (AA6P), fish oil (FO), and their combination (COM) on some biochemical properties in erythrocytes of streptozotocin (STZ)-induced diabetic male rats. According to experimental results, glutathione (GSH) level in erythrocytes decreased in diabetes (P < 0.01), D + ALA, and D + AA6P groups (P < 0.001). Malonaldehyde (MA) level increased in diabetes (P < 0.05), D + FO, and D + COM groups (P < 0.001), but its level in D + AA6P and D + ALA groups was lower in diabetes group (P < 0.01). Total lipid level in diabetes and diabetes plus antioxidant administered groups were higher than control. Total cholesterol level was high in diabetes and D + ALA groups (P < 0.05), but its level reduced in D + FO compared to control and diabetes groups, P < 0.05, < 0.001, respectively. Total triglyceride (TTG) level was high in the D + ALA (P < 0.05) and D + COM (P < 0.001) groups. In contrast, TTG level in blood of diabetes group was higher than diabetes plus antioxidant and FO administered groups (P < 0.001). According to gas chromatography analysis results, while the palmitic acid raised in diabetes group (P < 0.05), stearic acid in D + FO, D + ALA, and diabetes groups was lower than control (P < 0.05), oleic acid reduced in D + COM and D + FO groups, but its level raised in D + AA6P and D + ALA groups (P < 0.01). As the linoleic acid (LA) elevated in ALA + D, D + AA6P, and diabetes groups, linolenic acid level in diabetes, D + AA6P, and D + FO groups was lower than control (P < 0.001). Arachidonic acid (AA) decreased in D + ALA, D+ AA6P, and diabetes groups (P < 0.01), but its level in D + COM and D + FO was higher than control (P < 0.05). Docosahexaenoic acid (DHA) increased in D + AA6P and D + COM (P < 0.05). While the total saturated fatty acid level raised in diabetes group, its level reduced in D + ALA and D + FO groups (P < 0.05). In contrast, total unsaturated fatty acid level in D + ALA and D + FO groups was higher than control (P < 0.05). In conclusion, present data have confirmed that the combination of the ALA, AA6P, and FO have improvement effects on the recycling of GSSG to reduced GSH in erythrocytes of diabetic rats, and in addition to this, oxidative stress was suppressed by ALA and AA6P, and unsaturated fatty acid degree was raised by the effects of ALA and FO. Copyright 2002 Wiley-Liss, Inc.

Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults

PubMed Central

Seah, Jowy Yi Hoong; Gay, Gibson Ming Wei; Su, Jin; Tai, E-Shyong; Yuan, Jian-Min; Koh, Woon-Puay; Ong, Choon Nam; van Dam, Rob M.

2017-01-01

High arachidonic acid (AA; 20:4n-6) status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n-6 polyunsaturated fatty acids (PUFAs) are based on the premise that endogenous conversion from linoleic acid (LA; 18:2n-6) is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25–80 years old) with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44–74 years old) from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy) and food sources of PUFA (fish, red meat, poultry, soy and cooking oils) in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3n-6), alpha-linolenic acid (ALA; 18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3)) concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05) in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population. PMID:28146136

Discovering amino acid patterns on binding sites in protein complexes

PubMed Central

Kuo, Huang-Cheng; Ong, Ping-Lin; Lin, Jung-Chang; Huang, Jen-Peng

2011-01-01

Discovering amino acid (AA) patterns on protein binding sites has recently become popular. We propose a method to discover the association relationship among AAs on binding sites. Such knowledge of binding sites is very helpful in predicting protein-protein interactions. In this paper, we focus on protein complexes which have protein-protein recognition. The association rule mining technique is used to discover geographically adjacent amino acids on a binding site of a protein complex. When mining, instead of treating all AAs of binding sites as a transaction, we geographically partition AAs of binding sites in a protein complex. AAs in a partition are treated as a transaction. For the partition process, AAs on a binding site are projected from three-dimensional to two-dimensional. And then, assisted with a circular grid, AAs on the binding site are placed into grid cells. A circular grid has ten rings: a central ring, the second ring with 6 sectors, the third ring with 12 sectors, and later rings are added to four sectors in order. As for the radius of each ring, we examined the complexes and found that 10Å is a suitable range, which can be set by the user. After placing these recognition complexes on the circular grid, we obtain mining records (i.e. transactions) from each sector. A sector is regarded as a record. Finally, we use the association rule to mine these records for frequent AA patterns. If the support of an AA pattern is larger than the predetermined minimum support (i.e. threshold), it is called a frequent pattern. With these discovered patterns, we offer the biologists a novel point of view, which will improve the prediction accuracy of protein-protein recognition. In our experiments, we produced the AA patterns by data mining. As a result, we found that arginine (arg) most frequently appears on the binding sites of two proteins in the recognition protein complexes, while cysteine (cys) appears the fewest. In addition, if we discriminate the shape of binding sites between concave and convex further, we discover that patterns {arg, glu, asp} and {arg, ser, asp} on the concave shape of binding sites in a protein more frequently (i.e. higher probability) make contact with {lys} or {arg} on the convex shape of binding sites in another protein. Thus, we can confidently achieve a rate of at least 78%. On the other hand {val, gly, lys} on the convex surface of binding sites in proteins is more frequently in contact with {asp} on the concave site of another protein, and the confidence achieved is over 81%. Applying data mining in biology can reveal more facts that may otherwise be ignored or not easily discovered by the naked eye. Furthermore, we can discover more relationships among AAs on binding sites by appropriately rotating these residues on binding sites from a three-dimension to two-dimension perspective. We designed a circular grid to deposit the data, which total to 463 records consisting of AAs. Then we used the association rules to mine these records for discovering relationships. The proposed method in this paper provides an insight into the characteristics of binding sites for recognition complexes. PMID:21464838

Arachidonic acid stimulates DNA synthesis in brown preadipocytes through the activation of protein kinase C and MAPK.

PubMed

Garcia, Bibian; Martinez-de-Mena, Raquel; Obregon, Maria-Jesus

2012-10-01

Arachidonic acid (AA) is a polyunsaturated fatty acid that stimulates the proliferation of many cellular types. We studied the mitogenic potential of AA in rat brown preadipocytes in culture and the signaling pathways involved. AA is a potent mitogen which induces 4-fold DNA synthesis in brown preadipocytes. The AA mitogenic effect increases by NE addition. AA also increases the mitogenic action of different growth factor combinations. Other unsaturated and saturated fatty acids do not stimulate DNA synthesis to the same extent as AA. We analyzed the role of PKC and MEK/MAPK signaling pathways. PKC inhibition by bisindolilmaleimide I (BIS) abolishes AA and phorbol ester stimulation of DNA synthesis and reduces the mitogenic activity of different growth factors in brown preadipocytes. Brown preadipocytes in culture express PKC α, δ, ε and ζ isoforms. Pretreatment with high doses of the phorbol ester PDBu, induces downregulation of PKCs ε and δ and reproduces the effect of BIS indicating that AA-dependent induction of DNA synthesis requires PKC activity. AA also activates MEK/MAPK pathway and the inhibition of MEK activity inhibits AA stimulation of DNA synthesis and brown adipocyte proliferation. Inhibition of PKC δ by rottlerin abolishes AA-dependent stimulation of DNA synthesis and MAPK activation, whereas PKC ε inhibition does not produce any effect. In conclusion, our results identify AA as a potent mitogen for brown adipocytes and demonstrate the involvement of the PDBu-sensitive PKC δ isoform and MEK/MAPK pathway in AA-induced proliferation of brown adipocytes. Increased proliferative activity might increase the thermogenic capacity of brown fat. Copyright © 2012 Elsevier B.V. All rights reserved.

Attenuated acute salivary α-amylase responses to gustatory stimulation with citric acid in thin children.

PubMed

Chen, Long Hui; Yang, Ze Min; Chen, Wei Wen; Lin, Jing; Zhang, Min; Yang, Xiao Rong; Zhao, Ling Bo

2015-04-14

Salivary α-amylase (sAA) is responsible for the 'pre-digestion' of starch in the oral cavity and accounts for up to 50 % of salivary protein in human saliva. An accumulating body of literature suggests that sAA is of nutritional importance; however, it is still not clear how sAA is related to individual's nutritional status. Although copy number variations (CNV) of the salivary amylase gene (AMY1) are associated with variation in sAA levels, a significant amount of sAA variation is not explained by AMY1 CNV. To measure sAA responses to gustatory stimulation with citric acid, we used sAA ratio (the ratio of stimulated sAA levels to those of resting sAA) and investigated acute sAA responses to citric acid in children with normal (Normal-BMI, n 22) and low (Low-BMI, n 21) BMI. The AMY1 gene copy number was determined by quantitative PCR. We, for the first time, demonstrated attenuated acute sAA responses (decreased sAA ratio) to gustatory stimulation in Low-BMI (thinness grade 3) children compared with the Normal-BMI children, which suggest that sAA responses to gustatory stimulation may be of nutritional importance. However, child's nutritional status was not directly related to their resting or stimulated sAA levels, and it was not associated with AMY1 gene copy number. Finally, AMY1 CNV might influence, but did not eventually determine, sAA levels in children.

Ascorbic acid deficiency aggravates stress-induced gastric mucosal lesions in genetically scorbutic ODS rats.

PubMed

Ohta, Y; Chiba, S; Imai, Y; Kamiya, Y; Arisawa, T; Kitagawa, A

2006-12-01

We examined whether ascorbic acid (AA) deficiency aggravates water immersion restraint stress (WIRS)-induced gastric mucosal lesions in genetically scorbutic ODS rats. ODS rats received scorbutic diet with either distilled water containing AA (1 g/l) or distilled water for 2 weeks. AA-deficient rats had 12% of gastric mucosal AA content in AA-sufficient rats. AA-deficient rats showed more severe gastric mucosal lesions than AA-sufficient rats at 1, 3 or 6 h after the onset of WIRS, although AA-deficient rats had a slight decrease in gastric mucosal AA content, while AA-sufficient rats had a large decrease in that content. AA-deficient rats had more decreased gastric mucosal nonprotein SH and vitamin E contents and increased gastric mucosal lipid peroxide content than AA-sufficient rats at 1, 3 or 6 h of WIRS. These results indicate that AA deficiency aggravates WIRS-induced gastric mucosal lesions in ODS rats by enhancing oxidative damage in the gastric mucosa.

Variant Amino Acid Residues Alter the Enzyme Activity of Peanut Type 2 Diacylglycerol Acyltransferases

PubMed Central

Zheng, Ling; Shockey, Jay; Bian, Fei; Chen, Gao; Shan, Lei; Li, Xinguo; Wan, Shubo; Peng, Zhenying

2017-01-01

Diacylglycerol acyltransferase (DGAT) catalyzes the final step in triacylglycerol (TAG) biosynthesis via the acyl-CoA-dependent acylation of diacylglycerol. This reaction is a major control point in the Kennedy pathway for biosynthesis of TAG, which is the most important form of stored metabolic energy in most oil-producing plants. In this study, Arachis hypogaea type 2 DGAT (AhDGAT2) genes were cloned from the peanut cultivar ‘Luhua 14.’ Sequence analysis of 11 different peanut cultivars revealed a gene family of 8 peanut DGAT2 genes (designated AhDGAT2a-h). Sequence alignments revealed 21 nucleotide differences between the eight ORFs, but only six differences result in changes to the predicted amino acid (AA) sequences. A representative full-length cDNA clone (AhDGAT2a) was characterized in detail. The biochemical effects of altering the AhDGAT2a sequence to include single variable AA residues were tested by mutagenesis and functional complementation assays in transgenic yeast systems. All six mutant variants retained enzyme activity and produced lipid droplets in vivo. The N6D and A26P mutants also displayed increased enzyme activity and/or total cellular fatty acid (FA) content. N6D mutant mainly increased the content of palmitoleic acid, and A26P mutant mainly increased the content of palmitic acid. The A26P mutant grew well both in the presence of oleic and C18:2, but the other mutants grew better in the presence of C18:2. AhDGAT2 is expressed in all peanut organs analyzed, with high transcript levels in leaves and flowers. These levels are comparable to that found in immature seeds, where DGAT2 expression is most abundant in other plants. Over-expression of AhDGAT2a in tobacco substantially increased the FA content of transformed tobacco seeds. Expression of AhDGAT2a also altered transcription levels of endogenous tobacco lipid metabolic genes in transgenic tobacco, apparently creating a larger carbon ‘sink’ that supports increased FA levels. PMID:29085382

Arachidonic Acid Enhances Reproduction in Daphnia magna and Mitigates Changes in Sex Ratios Induced by Pyriproxyfen

PubMed Central

Ginjupalli, Gautam K.; Gerard, Patrick D.; Baldwin, William S.

2016-01-01

Arachidonic acid (AA) is one of only two unsaturated fatty acids retained in the ovaries of crustaceans, and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. We hypothesized that as a key fatty acid, AA may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with AA indicate that it alters female/male sex ratios by increasing female production. This reproductive effect only occurred during a restricted P. subcapitata diet. Next, we tested whether enriching a poorer algal diet (C. vulgaris) with AA enhances overall reproduction and sex ratios. AA enrichment of a C. vulgaris diet also enhances fecundity at 1.0 and 4.0μM by 30–40% in the presence and absence of pyriproxyfen. This indicates that AA is crucial in reproduction regardless of environmental sex determination. Furthermore, our data indicates that P. subcapitata may provide a threshold concentration of AA needed for reproduction. Diet switch experiments from P. subcapitata to C. vulgaris mitigate some but not all of AA’s effects when compared to a C. vulgaris only diet, suggesting that some AA provided by P. subcapitata is retained. In summary, AA supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in AA may provide protection from some reproductive toxicants such as the juvenile hormone agonist, pyriproxyfen. PMID:25393616

Arachidonic and oleic acid exert distinct effects on the DNA methylome

PubMed Central

Silva-Martínez, Guillermo A.; Rodríguez-Ríos, Dalia; Alvarado-Caudillo, Yolanda; Vaquero, Alejandro; Esteller, Manel; Carmona, F. Javier; Moran, Sebastian; Nielsen, Finn C.; Wickström-Lindholm, Marie; Wrobel, Katarzyna; Wrobel, Kazimierz; Barbosa-Sabanero, Gloria; Zaina, Silvio; Lund, Gertrud

2016-01-01

ABSTRACT Abnormal fatty acid metabolism and availability are landmarks of metabolic diseases, which in turn are associated with aberrant DNA methylation profiles. To understand the role of fatty acids in disease epigenetics, we sought DNA methylation profiles specifically induced by arachidonic (AA) or oleic acid (OA) in cultured cells and compared those with published profiles of normal and diseased tissues. THP-1 monocytes were stimulated with AA or OA and analyzed using Infinium HumanMethylation450 BeadChip (Illumina) and Human Exon 1.0 ST array (Affymetrix). Data were corroborated in mouse embryonic fibroblasts. Comparisons with publicly available data were conducted by standard bioinformatics. AA and OA elicited a complex response marked by a general DNA hypermethylation and hypomethylation in the 1–200 μM range, respectively, with a maximal differential response at the 100 μM dose. The divergent response to AA and OA was prominent within the gene body of target genes, where it correlated positively with transcription. AA-induced DNA methylation profiles were similar to the corresponding profiles described for palmitic acid, atherosclerosis, diabetes, obesity, and autism, but relatively dissimilar from OA-induced profiles. Furthermore, human atherosclerosis grade-associated DNA methylation profiles were significantly enriched in AA-induced profiles. Biochemical evidence pointed to β-oxidation, PPAR-α, and sirtuin 1 as important mediators of AA-induced DNA methylation changes. In conclusion, AA and OA exert distinct effects on the DNA methylome. The observation that AA may contribute to shape the epigenome of important metabolic diseases, supports and expands current diet-based therapeutic and preventive efforts. PMID:27088456

Identification of Novel Placentally Expressed Aspartic Proteinase in Humans

PubMed Central

Majewska, Marta; Lipka, Aleksandra; Panasiewicz, Grzegorz; Gowkielewicz, Marek; Jozwik, Marcin; Majewski, Mariusz Krzysztof; Szafranska, Bozena

2017-01-01

This study presents pioneering data concerning the human pregnancy-associated glycoprotein-Like family, identified in the genome, of the term placental transcriptome and proteome. RNA-seq allowed the identification of 1364 bp hPAG-L/pep cDNA with at least 56.5% homology with other aspartic proteinases (APs). In silico analyses revealed 388 amino acids (aa) of full-length hPAG-L polypeptide precursor, with 15 aa-signal peptide, 47 aa-blocking peptide and 326 aa-mature protein, and two Asp residues (D), specific for a catalytic cleft of the APs (VVFDTGSSNLWV91-102 and AIVDTGTSLLTG274-285). Capillary sequencing identified 9330 bp of the hPAG-L gene (Gen Bank Acc. No. KX533473), composed of nine exons and eight introns. Heterologous Western blotting revealed the presence of one dominant 60 kDa isoform of the hPAG-L amongst cellular placental proteins. Detection with anti-pPAG-P and anti-Rec pPAG2 polyclonals allowed identification of the hPAG-L proteins located within regions of chorionic villi, especially within the syncytiotrophoblast of term singleton placentas. Our novel data extend the present knowledge about the human genome, as well as placental transcriptome and proteome during term pregnancy. Presumably, this may contribute to establishing a new diagnostic tool for examination of some disturbances during human pregnancy, as well as growing interest from both scientific and clinical perspectives. PMID:28594357

Identification of Novel Placentally Expressed Aspartic Proteinase in Humans.

PubMed

Majewska, Marta; Lipka, Aleksandra; Panasiewicz, Grzegorz; Gowkielewicz, Marek; Jozwik, Marcin; Majewski, Mariusz Krzysztof; Szafranska, Bozena

2017-06-08

This study presents pioneering data concerning the human pregnancy-associated glycoprotein-Like family, identified in the genome, of the term placental transcriptome and proteome. RNA-seq allowed the identification of 1364 bp hPAG-L/pep cDNA with at least 56.5% homology with other aspartic proteinases (APs). In silico analyses revealed 388 amino acids (aa) of full-length hPAG-L polypeptide precursor, with 15 aa-signal peptide, 47 aa-blocking peptide and 326 aa-mature protein, and two Asp residues (D), specific for a catalytic cleft of the APs (VVFDTGSSNLWV91-102 and AIVDTGTSLLTG274-285). Capillary sequencing identified 9330 bp of the hPAG-L gene (Gen Bank Acc. No. KX533473), composed of nine exons and eight introns. Heterologous Western blotting revealed the presence of one dominant 60 kDa isoform of the hPAG-L amongst cellular placental proteins. Detection with anti-pPAG-P and anti-Rec pPAG2 polyclonals allowed identification of the hPAG-L proteins located within regions of chorionic villi, especially within the syncytiotrophoblast of term singleton placentas. Our novel data extend the present knowledge about the human genome, as well as placental transcriptome and proteome during term pregnancy. Presumably, this may contribute to establishing a new diagnostic tool for examination of some disturbances during human pregnancy, as well as growing interest from both scientific and clinical perspectives.

Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

PubMed Central

Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk

2018-01-01

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563

Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Earnshaw, B.A.

1986-01-01

Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of /sup 14/C-2, 4-D. The embryo fraction had a lower concentration of /supmore » 14/C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected.« less

Dietary arachidonic acid in perinatal nutrition: a commentary.

PubMed

Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

2015-01-01

Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar levels in breast milk throughout the world, whereas the level of DHA is highly diet dependent. Autopsy studies show similar diet-dependent variation in brain DHA, whereas AA is little affected by intake. Early intake of DHA has been shown to affect visual development, but the effect of LCPUFA on neurodevelopment remains to be established. Few studies have found any functional difference between infants supplemented with DHA alone compared to DHA+AA, but some studies show neurodevelopmental advantages in breast-fed infants of mothers supplemented with n-3 LCPUFA alone. It also remains to be established whether the AA/DHA balance could affect allergic and inflammatory outcomes later in life. Disentangling effects of genetic variability and dietary intake on AA and DHA-status and on functional outcomes may be an important step in the process of determining whether AA-intake is of any physiological or clinical importance. However, based on the current evidence we hypothesize that dietary AA plays a minor role on growth and development relative to the impact of dietary DHA.

Amino Acid Medical Foods Provide a High Dietary Acid Load and Increase Urinary Excretion of Renal Net Acid, Calcium, and Magnesium Compared with Glycomacropeptide Medical Foods in Phenylketonuria

PubMed Central

Stroup, Bridget M.; Sawin, Emily A.; Murali, Sangita G.; Binkley, Neil; Hansen, Karen E.

2017-01-01

Background. Skeletal fragility is a complication of phenylketonuria (PKU). A diet containing amino acids compared with glycomacropeptide reduces bone size and strength in mice. Objective. We tested the hypothesis that amino acid medical foods (AA-MF) provide a high dietary acid load, subsequently increasing urinary excretion of renal net acid, calcium, and magnesium, compared to glycomacropeptide medical foods (GMP-MF). Design. In a crossover design, 8 participants with PKU (16–35 y) provided food records and 24-hr urine samples after consuming a low-Phe diet in combination with AA-MF and GMP-MF for 1–3 wks. We calculated potential renal acid load (PRAL) of AA-MF and GMP-MF and determined bone mineral density (BMD) measurements using dual X-ray absorptiometry. Results. AA-MF provided 1.5–2.5-fold higher PRAL and resulted in 3-fold greater renal net acid excretion compared to GMP-MF (p = 0.002). Dietary protein, calcium, and magnesium intake were similar. GMP-MF significantly reduced urinary excretion of calcium by 40% (p = 0.012) and magnesium by 30% (p = 0.029). Two participants had low BMD-for-age and trabecular bone scores, indicating microarchitectural degradation. Urinary calcium with AA-MF negatively correlated with L1–L4 BMD. Conclusion. Compared to GMP-MF, AA-MF increase dietary acid load, subsequently increasing urinary calcium and magnesium excretion, and likely contributing to skeletal fragility in PKU. The trial was registered at clinicaltrials.gov as NCT01428258. PMID:28546877

Uptake and conversion of D-amino acids in Arabidopsis thaliana.

PubMed

Gördes, Dirk; Kolukisaoglu, Üner; Thurow, Kerstin

2011-02-01

The D-enantiomers of proteinogenic amino acids fulfill essential functions in bacteria, fungi and animals. Just in the plant kingdom, the metabolism and role of D-amino acids (D-AAs) still remains unclear, although plants have to cope with significant amounts of these compounds from microbial decay in the rhizosphere. To fill this gap of knowledge, we tested the inhibitory effects of D-AAs on plant growth and established a method to quantitate 16 out of 19 proteinogenic amino acids and their D-enantiomers in plant tissue extracts. Therefore, the amino acids in the extracts were derivatized with Marfey's reagent and separated by HPLC-MS. We used two ecotypes (Col-0 and C24) and a mutant (lht1) of the model plant Arabidopsis thaliana to determine the influence and fate of exogenously applied D-AAs. All of them were found in high concentrations in the plant extracts after application, even in lht1, which points to additional transporters facilitating the import of D-AAs. The addition of particular amino acids (D-Trp, D-Phe, D-Met and D-His) led to the accumulation of the corresponding L-amino acid. In almost all cases, the application of a D-AA resulted in the accumulation of D-Ala and D-Glu. The presented results indicate that soil borne D-AAs can actively be taken up and metabolized via central metabolic routes.

Anger induced by interferon-alpha is moderated by ratio of arachidonic acid to omega-3 fatty acids.

PubMed

Lotrich, Francis E; Sears, Barry; McNamara, Robert K

2013-11-01

Anger worsens in some patients during interferon-alpha (IFN-α) therapy. Elevated anger has also been associated with lower long-chain omega-3 (LCn-3) fatty acid levels. We examined whether fatty acids could influence vulnerability to anger during IFN-α exposure. Plasma arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were determined prior to IFN-α therapy by mass spectroscopy. Repeated-measure analyses examined the relationship between AA/EPA+DHA and the subsequent development of labile anger and irritability in 82 subjects who prospectively completed the Anger, Irritability, and Assault Questionnaire (AIAQ) during the first eight weeks of IFN-α therapy. Prior to IFN-α therapy, AA/EPA+DHA did not correlate with either labile anger or irritability. Pre-treatment AA/EPA+DHA did correlate with the subsequent maximal increase in labile anger during IFN-α therapy (r=0.33; p=0.005). Over time, labile anger increased more in subjects with above median AA/EPA+DHA ratios (p<0.05). Of the 17 subjects ultimately requiring psychiatric intervention for anger, 14/17 had above-median AA/EPA+DHA ratios (p=0.009). There was also an interaction with the tumor necrosis factor-alpha (TNF-α) promoter polymorphism (A-308G), such that only those with both elevated AA/EPA+DHA and the A allele had increased labile anger (p=0.001). In an additional 18 subjects, we conversely observed that selective serotonin reuptake inhibitor treatment was associated with increased irritability during IFN-α therapy. LCn-3 fatty acid status may influence anger development during exposure to elevated inflammatory cytokines, and may interact with genetic risk for increased brain TNF-α. LCn-3 supplements may be one strategy for minimizing this adverse side effect of IFN-α. © 2013.

Amino acid supplementation alters bone metabolism during simulated weightlessness

NASA Technical Reports Server (NTRS)

Zwart, S. R.; Davis-Street, J. E.; Paddon-Jones, D.; Ferrando, A. A.; Wolfe, R. R.; Smith, S. M.

2005-01-01

High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group (Con, n = 6) and an amino acid-supplemented group (AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 (immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest (P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels (P < 0.05). Urinary NTX and DPD tended to be higher in the AA group (P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels (P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group (P < 0.05). During bed rest, urinary pH decreased (P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group.

Consequences of the Combined α-tocopherol, Ascorbic Acid and α-lipoic Acid on the Glutathione, Cholesterol and Fatty Acid Composition in Muscle and Liver of Diabetic Rats

PubMed Central

YILMAZ, Okkes; ERSAN, Yasemin; Dilek OZSAHIN, Ayse; Ihsan OZTURK, Ali; OZKAN, Yusuf

2013-01-01

Objective(s): Our objective was to evaluate the effects of a triple antioxidant combination [α-tocopherol (AT), ascorbic acid (AA) and α-lipoic acid (LA); AT+AA+LA] on the cholesterol and glutathione levels, and the fatty acid composition of liver and muscle tissues in diabetic rats. Materials and Methods: Forty-three Wistar rats were randomly divided into five groups. The first group was used as a control. The second, third and fourth groups received STZ (45 mg/kg) in citrate buffer. The fourth and fifth groups were injected with intraperitoneal (IP) 50 mg/kg DL-AT and 50 mg /kg DL-LA four times per week and received water-soluble vitamin C (50 mg/kg) in their drinking water for a period of six weeks. Results: Liver cholesterol levels in the AT+AA+LA group were lower than the control (P<0.05). Glutathione level was lower in D-2 (P<0.05) and were higher in D+AT+AA+LA and AT+AA+LA groups than the control groups (P≤ 0.05). The muscle cholesterol levels in the D-1 and D+AT+AA+LA groups were higher than the control group (P≤ 0.05). The levels of oleic acid were higher in the D-1 group and lower in the D-2 group (P<0.001). The arachidonic acid level in the D-1 and D-2 groups were lower (P<0.05), and higher in the D+AT+AA+LA group. Conclusion: Our results revealed that glutathione levels and the Stearoyl CoA Desaturase enzyme products in liver tissues of diabetic and non-diabetic rats were increased by triple antioxidant mixture. PMID:24298385

Consequences of the Combined α-tocopherol, Ascorbic Acid and α-lipoic Acid on the Glutathione, Cholesterol and Fatty Acid Composition in Muscle and Liver of Diabetic Rats.

PubMed

Yilmaz, Okkes; Ersan, Yasemin; Dilek Ozsahin, Ayse; Ihsan Ozturk, Ali; Ozkan, Yusuf

2013-02-01

Our objective was to evaluate the effects of a triple antioxidant combination [α-tocopherol (AT), ascorbic acid (AA) and α-lipoic acid (LA); AT+AA+LA] on the cholesterol and glutathione levels, and the fatty acid composition of liver and muscle tissues in diabetic rats. Forty-three Wistar rats were randomly divided into five groups. The first group was used as a control. The second, third and fourth groups received STZ (45 mg/kg) in citrate buffer. The fourth and fifth groups were injected with intraperitoneal (IP) 50 mg/kg DL-AT and 50 mg /kg DL-LA four times per week and received water-soluble vitamin C (50 mg/kg) in their drinking water for a period of six weeks. Liver cholesterol levels in the AT+AA+LA group were lower than the control (P<0.05). Glutathione level was lower in D-2 (P<0.05) and were higher in D+AT+AA+LA and AT+AA+LA groups than the control groups (P≤ 0.05). The muscle cholesterol levels in the D-1 and D+AT+AA+LA groups were higher than the control group (P≤ 0.05). The levels of oleic acid were higher in the D-1 group and lower in the D-2 group (P<0.001). The arachidonic acid level in the D-1 and D-2 groups were lower (P<0.05), and higher in the D+AT+AA+LA group. Our results revealed that glutathione levels and the Stearoyl CoA Desaturase enzyme products in liver tissues of diabetic and non-diabetic rats were increased by triple antioxidant mixture.

Ethylene signaling triggered by low concentrations of ascorbic acid regulates biomass accumulation in Arabidopsis thaliana.

PubMed

Caviglia, M; Mazorra Morales, L M; Concellón, A; Gergoff Grozeff, G E; Wilson, M; Foyer, C H; Bartoli, C G

2018-02-02

Ascorbic acid (AA) is a major redox buffer in plant cells. The role of ethylene in the redox signaling pathways that influence photosynthesis and growth was explored in two independent AA deficient Arabidopsis thaliana mutants (vtc2-1 and vtc2-4). Both mutants, which are defective in the AA biosynthesis gene GDP-L-galactose phosphorylase, produce higher amounts of ethylene than wt plants. In contrast to the wt, the inhibition of ethylene signaling increased leaf conductance, photosynthesis and dry weight in both vtc2 mutant lines. The AA-deficient mutants showed altered expression of genes encoding proteins involved in the synthesis/responses to phytohormones that control growth, particularly auxin, cytokinins, abscisic acid, brassinosterioids, ethylene and salicylic acid. These results demonstrate that AA deficiency modifies hormone signaling in plants, redox-ethylene interactions providing a regulatory node controlling shoot biomass accumulation. Copyright © 2018 Elsevier Inc. All rights reserved.

Structure of a Thermobifida fusca lytic polysaccharide monooxygenase and mutagenesis of key residues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruer-Zerhusen, Nathan; Alahuhta, Markus; Lunin, Vladimir V.

Auxiliary activity (AA) enzymes are produced by numerous bacterial and fungal species to assist in the degradation of biomass. These enzymes are abundant but have yet to be fully characterized. Here, we report the X-ray structure of Thermobifida fusca AA10A (TfAA10A), investigate mutational characterization of key surface residues near its active site, and explore the importance of the various domains of Thermobifida fusca AA10B (TfAA10B). The structure of TfAA10A is similar to other bacterial LPMOs (lytic polysaccharide monooxygenases), including signs of photo-reduction and a distorted active site, with mixed features showing both type I and II copper coordination. The pointmore » mutation experiments of TfAA10A show that Trp82 and Asn83 are needed for binding, but only Trp82 affects activity. The TfAA10B domain truncation mutants reveal that CBM2 is crucial for the binding of substrate, but that the X1 module does not affect binding or activity. In TfAA10A, Trp82 and Asn83 are needed for binding, but only Trp82 affects activity. The TfAA10B domain truncation mutants reveal that CBM2 is crucial for substrate binding, but that the X1 module does not affect binding or activity. The structure of TfAA10A is similar to other bacterial lytic polysaccharide monooxygenases with mixed features showing both type I and II copper coordination. The role of LPMOs and the variability of abundance in genomes are not fully explored. LPMOs likely perform initial attacks into crystalline cellulose to allow larger processive cellulases to bind and attack, but the precise nature of their synergistic behavior remains to be definitively characterized.« less

Structure of a Thermobifida fusca lytic polysaccharide monooxygenase and mutagenesis of key residues

DOE PAGES

Kruer-Zerhusen, Nathan; Alahuhta, Markus; Lunin, Vladimir V.; ...

2017-11-30

Auxiliary activity (AA) enzymes are produced by numerous bacterial and fungal species to assist in the degradation of biomass. These enzymes are abundant but have yet to be fully characterized. Here, we report the X-ray structure of Thermobifida fusca AA10A (TfAA10A), investigate mutational characterization of key surface residues near its active site, and explore the importance of the various domains of Thermobifida fusca AA10B (TfAA10B). The structure of TfAA10A is similar to other bacterial LPMOs (lytic polysaccharide monooxygenases), including signs of photo-reduction and a distorted active site, with mixed features showing both type I and II copper coordination. The pointmore » mutation experiments of TfAA10A show that Trp82 and Asn83 are needed for binding, but only Trp82 affects activity. The TfAA10B domain truncation mutants reveal that CBM2 is crucial for the binding of substrate, but that the X1 module does not affect binding or activity. In TfAA10A, Trp82 and Asn83 are needed for binding, but only Trp82 affects activity. The TfAA10B domain truncation mutants reveal that CBM2 is crucial for substrate binding, but that the X1 module does not affect binding or activity. The structure of TfAA10A is similar to other bacterial lytic polysaccharide monooxygenases with mixed features showing both type I and II copper coordination. The role of LPMOs and the variability of abundance in genomes are not fully explored. LPMOs likely perform initial attacks into crystalline cellulose to allow larger processive cellulases to bind and attack, but the precise nature of their synergistic behavior remains to be definitively characterized.« less

Fatty acid regulates gene expression and growth of human prostate cancer PC-3 cells

NASA Technical Reports Server (NTRS)

Hughes-Fulford, M.; Chen, Y.; Tjandrawinata, R. R.

2001-01-01

It has been proposed that the omega-6 fatty acids increase the rate of tumor growth. Here we test that hypothesis in the PC-3 human prostate tumor. We found that the essential fatty acids, linoleic acid (LA) and arachidonic acid (AA), and the AA metabolite PGE(2) stimulate tumor growth while oleic acid (OA) and the omega-3 fatty acid, eicosapentaenoic acid (EPA) inhibited growth. In examining the role of AA in growth response, we extended our studies to analyze changes in early gene expression induced by AA. We demonstrate that c-fos expression is increased within minutes of addition in a dose-dependent manner. Moreover, the immediate early gene cox-2 is also increased in the presence of AA in a dose-dependent manner, while the constitutive cox-1 message was not increased. Three hours after exposure to AA, the synthesis of PGE(2) via COX-2 was also increased. Previous studies have demonstrated that AA was primarily delivered by low density lipoprotein (LDL) via its receptor (LDLr). Since it is known that hepatomas, acute myelogenous leukemia and colorectal tumors lack normal cholesterol feedback, we examined the role of the LDLr in growth regulation of the PC-3 prostate cancer cells. Analysis of ldlr mRNA expression and LDLr function demonstrated that human PC-3 prostate cancer cells lack normal feedback regulation. While exogenous LDL caused a significant stimulation of cell growth and PGE(2) synthesis, no change was seen in regulation of the LDLr by LDL. Taken together, these data show that normal cholesterol feedback of ldlr message and protein is lost in prostate cancer. These data suggest that unregulated over-expression of LDLr in tumor cells would permit increased availability of AA, which induces immediate early genes c-fos and cox-2 within minutes of uptake.

Fatty acid regulates gene expression and growth of human prostate cancer PC-3 cells.

PubMed

Hughes-Fulford, M; Chen, Y; Tjandrawinata, R R

2001-05-01

It has been proposed that the omega-6 fatty acids increase the rate of tumor growth. Here we test that hypothesis in the PC-3 human prostate tumor. We found that the essential fatty acids, linoleic acid (LA) and arachidonic acid (AA), and the AA metabolite PGE(2) stimulate tumor growth while oleic acid (OA) and the omega-3 fatty acid, eicosapentaenoic acid (EPA) inhibited growth. In examining the role of AA in growth response, we extended our studies to analyze changes in early gene expression induced by AA. We demonstrate that c-fos expression is increased within minutes of addition in a dose-dependent manner. Moreover, the immediate early gene cox-2 is also increased in the presence of AA in a dose-dependent manner, while the constitutive cox-1 message was not increased. Three hours after exposure to AA, the synthesis of PGE(2) via COX-2 was also increased. Previous studies have demonstrated that AA was primarily delivered by low density lipoprotein (LDL) via its receptor (LDLr). Since it is known that hepatomas, acute myelogenous leukemia and colorectal tumors lack normal cholesterol feedback, we examined the role of the LDLr in growth regulation of the PC-3 prostate cancer cells. Analysis of ldlr mRNA expression and LDLr function demonstrated that human PC-3 prostate cancer cells lack normal feedback regulation. While exogenous LDL caused a significant stimulation of cell growth and PGE(2) synthesis, no change was seen in regulation of the LDLr by LDL. Taken together, these data show that normal cholesterol feedback of ldlr message and protein is lost in prostate cancer. These data suggest that unregulated over-expression of LDLr in tumor cells would permit increased availability of AA, which induces immediate early genes c-fos and cox-2 within minutes of uptake.

A feedback regulatory loop between G3P and lipid transfer proteins DIR1 and AZI1 mediates azelaic-acid-induced systemic immunity.

PubMed

Yu, Keshun; Soares, Juliana Moreira; Mandal, Mihir Kumar; Wang, Caixia; Chanda, Bidisha; Gifford, Andrew N; Fowler, Joanna S; Navarre, Duroy; Kachroo, Aardra; Kachroo, Pradeep

2013-04-25

Systemic acquired resistance (SAR), a highly desirable form of plant defense, provides broad-spectrum immunity against diverse pathogens. The recent identification of seemingly unrelated chemical inducers of SAR warrants an investigation of their mutual interrelationships. We show that SAR induced by the dicarboxylic acid azelaic acid (AA) requires the phosphorylated sugar derivative glycerol-3-phosphate (G3P). Pathogen inoculation induced the release of free unsaturated fatty acids (FAs) and thereby triggered AA accumulation, because these FAs serve as precursors for AA. AA accumulation in turn increased the levels of G3P, which is required for AA-conferred SAR. The lipid transfer proteins DIR1 and AZI1, both of which are required for G3P- and AA-induced SAR, were essential for G3P accumulation. Conversely, reduced G3P resulted in decreased AZI1 and DIR1 transcription. Our results demonstrate that an intricate feedback regulatory loop among G3P, DIR1, and AZI1 regulates SAR and that AA functions upstream of G3P in this pathway. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Degradation kinetics of the antioxidant additive ascorbic acid in packed table olives during storage at different temperatures.

PubMed

Montaño, A; Casado, F J; Rejano, L; Sanchez, A H; de Castro, A

2006-03-22

The kinetics of ascorbic acid (AA) loss during storage of packed table olives with two different levels of added AA was investigated. Three selected storage temperatures were assayed: 10 degrees C, ambient (20-24 degrees C), and 40 degrees C. The study was carried out in both pasteurized and unpasteurized product. The effect of pasteurization treatment alone on added AA was not significant. In the pasteurized product, in general AA degraded following a first-order kinetics. The activation energy calculated by using the Arrhenius model averaged 9 kcal/mol. For each storage temperature, the increase in initial AA concentration significantly decreased the AA degradation rate. In the unpasteurized product, AA was not detected after 20 days in samples stored at room temperature and AA degradation followed zero-order kinetics at 10 degrees C, whereas at 40 degrees C a second-order reaction showed the best fit. In both pasteurized and unpasteurized product, the low level of initial dehydroascorbic acid disappeared during storage. Furfural appeared to be formed during storage, mainly at 40 degrees C, following zero-order kinetics.

Amino acid adsorption on anatase (101) surface at vacuum and aqueous solution: a density functional study.

PubMed

Liu, Liuxie; Li, Kai; Chen, Xiao; Liang, Xiaoqin; Zheng, Yan; Li, Laicai

2018-03-29

The adsorption of 20 amino acids (AAs) on the (101) surface of anatase titanium dioxide (TiO 2 ) has been investigated under the scheme of density functional theory. Through the analysis of adsorption geometries, amino group and side chains of AAs have been identified as the major side to adsorb on TiO 2 , while the carboxyl group prefers to stay outside to avoid the repulsion between negatively charged oxygen from TiO 2 and AAs. On the surface, two-coordinated oxygen is the major site to stabilize AAs through O-H interactions. The above conclusion does not change when it is in the aqueous solution based on the calculations with AAs surrounded by explicit water molecules. The above knowledge is helpful in predicting how AAs and even peptides adsorb on inorganic materials. Graphical abstract The adsorption of 20 amino acids (AAs) on the (101) surface of anatase titanium dioxide (TiO 2 ) has been investigated under the scheme of density functional theory.

Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

PubMed

Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

2014-05-12

The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

Effect of insulin sensitizer therapy on amino acids and their metabolites.

PubMed

Irving, Brian A; Carter, Rickey E; Soop, Mattias; Weymiller, Audrey; Syed, Husnain; Karakelides, Helen; Bhagra, Sumit; Short, Kevin R; Tatpati, Laura; Barazzoni, Rocco; Nair, K Sreekumaran

2015-06-01

Prior studies have reported that elevated concentrations of several plasma amino acids (AA), particularly branched chain (BCAA) and aromatic AA predict the onset of type 2 diabetes. We sought to test the hypothesis that circulating BCAA, aromatic AA and related AA metabolites decline in response to the use of insulin sensitizing agents in overweight/obese adults with impaired fasting glucose or untreated diabetes. We performed a secondary analysis of a randomized, double-blind, placebo, controlled study conducted in twenty five overweight/obese (BMI ~30kg/m(2)) adults with impaired fasting glucose or untreated diabetes. Participants were randomized to three months of pioglitazone (45mg per day) plus metformin (1000mg twice per day, N=12 participants) or placebo (N=13). We measured insulin sensitivity by the euglycemic-hyperinsulinemic clamp and fasting concentrations of AA and AA metabolites using ultra-pressure liquid chromatography tandem mass spectrometry before and after the three-month intervention. Insulin sensitizer therapy that significantly enhanced insulin sensitivity reduced 9 out of 33 AA and AA metabolites measured compared to placebo treatment. Moreover, insulin sensitizer therapy significantly reduced three functionally clustered AA and metabolite pairs: i) phenylalanine/tyrosine, ii) citrulline/arginine, and iii) lysine/α-aminoadipic acid. Reductions in plasma concentrations of several AA and AA metabolites in response to three months of insulin sensitizer therapy support the concept that reduced insulin sensitivity alters AA and AA metabolites. Copyright © 2015 Elsevier Inc. All rights reserved.

Insight on the impacts of free amino acids and their metabolites on the immune system from a perspective of inborn errors of amino acid metabolism.

PubMed

Pakula, Malgorzata M; Maier, Thorsten J; Vorup-Jensen, Thomas

2017-06-01

Amino acids (AAs) support a broad range of functions in living organisms, including several that affect the immune system. The functions of the immune system are affected when free AAs are depleted or in excess because of external factors, such as starvation, or because of genetic factors, such as inborn errors of metabolism. Areas covered: In this review, we discuss the current insights into how free AAs affect immune responses. When possible, we make comparisons to known disease states resulting from inborn errors of metabolism, in which changed levels of AAs or AA metabolites provide insight into the impact of AAs on the human immune system in vivo. We also explore the literature describing how changes in AA levels might provide pharmaceutical targets for safe immunomodulatory treatment. Expert opinion: The impact of free AAs on the immune system is a neglected topic in most immunology textbooks. That neglect is undeserved, because free AAs have both direct and indirect effects on the immune system. Consistent choices of pre-clinical models and better strategies for creating formulations are required to gain clinical impact.

Determination of aristolochic acids by high-performance liquid chromatography with fluorescence detection.

PubMed

Wang, Yinan; Chan, Wan

2014-06-25

Nephrotoxic and carcinogenic aristolochic acids (AAs) are naturally occurring nitrophenanthrene carboxylic acids in the herbal genus Aristolochia. The misuse of AA-containing herbs in preparing slimming drugs has caused hundred of cases of kidney disease in Belgium women in a slimming regime in the early 1990s. Accumulating evidence also suggested that prolong dietary intake of AA-contaminated food is one of the major causes to the Balkan endemic nephropathy that was first observed in the late 1950s. Therefore, analytical methods of high sensitivity are extremely important for safeguarding human exposure to AA-containing herbal medicines, herbal remedies, and food composites. In this paper, we describe the development of a new high-performance liquid chromatography coupled fluorescence detector (HPLC-FLD) method for the sensitive determination of AAs. The method makes use of a novel cysteine-induced denitration reaction that "turns on" the fluorescence of AAs for fluorometric detections. Our results showed that the combination of cysteine-induced denitration and HPLC-FLD analysis allows for sensitive quantification of AA-I and AA-II at detection limits of 27.1 and 25.4 ng/g, respectively. The method was validated and has been successfully applied in quantifying AAs in Chinese herbal medicines.

Effects of unsaturated fatty acids on the kinetics of voltage‐gated proton channels heterologously expressed in cultured cells

PubMed Central

Kawanabe, Akira

2016-01-01

Key points Arachidonic acid (AA) greatly enhances the activity of the voltage‐gated proton (Hv) channel, although its mechanism of action and physiological function remain unclear.In the present study, we analysed the effects of AA on proton currents through Hv channels heterologously expressed in HEK293T cells.The dramatic increase in proton current amplitude elicited by AA was accompanied by accelerated activation kinetics and a leftward shift in the voltage‐dependence of activation.Mutagenesis studies suggest the two aforementioned effects of AA reflect two distinct structural mechanisms.Application of phospholipase A2, which liberates AA from phospholipids in the membrane, also enhances Hv channel activity, supporting the idea that AA modulates Hv channel activity within physiological contexts. Abstract Unsaturated fatty acids are key components of the biological membranes of all cells, and precursors of mediators for cell signalling. Arachidonic acid (AA) is an unsaturated fatty acid known to modulate the activities of various ion channels, including the voltage‐gated proton (Hv) channel, which supports the rapid production of reactive oxygen species (ROS) in phagocytes through regulation of pH and membrane potential. However, the molecular mechanisms and physiological functions of the effects of AA on Hv channels remain unclear. In the present study, we report an electrophysiological analysis of the effects of AA on the mouse Hv channel (mHv1) heterologously expressed in HEK293T cells. Application of AA to excised inside‐out patch membranes rapidly induced a robust increase in the amplitude of the proton current through mHv1. The current increase was accompanied by accelerated activation kinetics and a small leftward shift of the current–voltage relationship. In monomeric channels lacking the coiled‐coil region of the channel protein, the shift in the current–voltage relationship was diminished but activation and deactivation remained accelerated. Studies with several AA derivatives showed that double bonds and hydrophilic head groups are essential for the effect of AA, although charge was not important. The application of phospholipase A2 (PLA2), which generates AA from cell membrane phospholipids, stimulated mHv1 activity to a similar extent as direct application of ∼20 μm AA, suggesting that endogenous AA may regulate Hv channel activity. PMID:26563684

Bioavailability of particle-associated Se to the bivalve Potamocorbula amurensis

USGS Publications Warehouse

Schlekat, C.E.; Dowdle, P.R.; Lee, B.-G.; Luoma, S.N.; Oremland, R.S.

2000-01-01

Elemental selenium, Se(0), is a prevalent chemical form in sediments, but little is known about its bioavailability. We evaluated the bioavailability of two forms of Se(0) by generating radioisotopic 75Se(0) through bacterial dissimilatory reduction of 75SeO32- by pure bacterial cultures (SES) and by an anaerobic sediment microbial consortium (SED). A third form was generated by reducing 75SeO32- with ascorbic acid (AA). Speciation determinations showed that AA and SES were >90% Se(0), but SED showed a mixture of Se(0), selenoanions, and a residual fraction. Pulse-chase techniques were used to measure assimilation efficiencies (AE) of these particulate Se forms by the bivalve Potamocorbula amurensis. Mean AE values were 3 ?? 2% for AA, 7 ?? 1% for SES, and 28 ?? 15% for SED, showing that the bioavailability of reduced, particle-associated Se is dependent upon its origin. To determine if oxidative microbial processes increased Se transfer, SES 75Se(0) was incubated with an aerobic sediment microbial consortium. After 113 d of incubation, 36% of SES Se(0) was oxidized to SeO32-. Assimilation of total particulate Se was unaffected however (mean AE = 5.5%). The mean AE from the diatom Phaeodactylum tricornutum was 58 ?? 8%, verifying the importance of Se associated with biogenic particles. Speciation and AE results from SED suggest that selenoanion reduction in wetlands and estuaries produces biologically available reduced selenium.Elemental selenium, Se(0), is a prevalent chemical form in sediments, but little is known about its bioavailability. We evaluated the bioavailability of two forms of Se(0) by generating radioisotopic 75Se(0) through bacterial dissimilatory reduction of 75SeO32- by pure bacterial cultures (SES) and by an anaerobic sediment microbial consortium (SED). A third form was generated by reducing 75SeO32 with ascorbic acid (AA). Speciation determinations showed that AA and SES were > 90% Se(0), but SED showed a mixture of Se(0), selenoanions, and a residual fraction. Pulse-chase techniques were used to measure assimilation efficiencies (AE) of these particulate Se forms by the bivalve Potamocorbula amurensis. Mean AE values were 3 ?? 2% for AA, 7 ?? 1% for SES, and 28 ?? 15% for SED, showing that the bioavailability of reduced, particle-associated Se is dependent upon its origin. To determine if oxidative microbial processes increased Se transfer, SES 75Se(0) was incubated with an aerobic sediment microbial consortium. After 113 d of incubation, 36% of SES Se(0) was oxidized to SeO32-. Assimilation of total particulate Se was unaffected however (mean AE = 5.5%). The mean AE from the diatom Phaeodactylum tricornutum was 58 ?? 8%, verifying the importance of Se associated with biogenic particles. Speciation and AE results from SED suggest that selenoanion reduction in wetlands and estuaries produces biologically available reduced selenium.

Valnoctamide, which reduces rat brain arachidonic acid turnover, is a potential non-teratogenic valproate substitute to treat bipolar disorder.

PubMed

Modi, Hiren R; Ma, Kaizong; Chang, Lisa; Chen, Mei; Rapoport, Stanley I

2017-08-01

Valproic acid (VPA), used for treating bipolar disorder (BD), is teratogenic by inhibiting histone deacetylase. In unanaesthetized rats, chronic VPA, like other mood stabilizers, reduces arachidonic acid (AA) turnover in brain phospholipids, and inhibits AA activation to AA-CoA by recombinant acyl-CoA synthetase-4 (Acsl-4) in vitro. Valnoctamide (VCD), a non-teratogenic constitutional isomer of VPA amide, reported effective in BD, also inhibits recombinant Acsl-4 in vitro. VCD like VPA will reduce brain AA turnover in unanaesthetized rats. A therapeutically relevant (50mg/kg i.p.) dose of VCD or vehicle was administered daily for 30 days to male rats. AA turnover and related parameters were determined using our kinetic model, following intravenous [1- 14 C]AA in unanaesthetized rats for 10min, and measuring labeled and unlabeled lipids in plasma and high-energy microwaved brain. VCD, compared with vehicle, increased λ, the ratio of brain AA-CoA to unesterified plasma AA specific activities; and decreased turnover of AA in individual and total brain phospholipids. VCD's ability like VPA to reduce rat brain AA turnover and inhibit recombinant Acsl-4, and its efficacy in BD, suggest that VCD be further considered as a non-teratogenic VPA substitute for treating BD. Published by Elsevier B.V.

The impact of FADS genetic variants on ω6 polyunsaturated fatty acid metabolism in African Americans

PubMed Central

2011-01-01

Background Arachidonic acid (AA) is a long-chain omega-6 polyunsaturated fatty acid (PUFA) synthesized from the precursor dihomo-gamma-linolenic acid (DGLA) that plays a vital role in immunity and inflammation. Variants in the Fatty Acid Desaturase (FADS) family of genes on chromosome 11q have been shown to play a role in PUFA metabolism in populations of European and Asian ancestry; no work has been done in populations of African ancestry to date. Results In this study, we report that African Americans have significantly higher circulating levels of plasma AA (p = 1.35 × 10-48) and lower DGLA levels (p = 9.80 × 10-11) than European Americans. Tests for association in N = 329 individuals across 80 nucleotide polymorphisms (SNPs) in the Fatty Acid Desaturase (FADS) locus revealed significant association with AA, DGLA and the AA/DGLA ratio, a measure of enzymatic efficiency, in both racial groups (peak signal p = 2.85 × 10-16 in African Americans, 2.68 × 10-23 in European Americans). Ancestry-related differences were observed at an upstream marker previously associated with AA levels (rs174537), wherein, 79-82% of African Americans carry two copies of the G allele compared to only 42-45% of European Americans. Importantly, the allelic effect of the G allele, which is associated with enhanced conversion of DGLA to AA, on enzymatic efficiency was similar in both groups. Conclusions We conclude that the impact of FADS genetic variants on PUFA metabolism, specifically AA levels, is likely more pronounced in African Americans due to the larger proportion of individuals carrying the genotype associated with increased FADS1 enzymatic conversion of DGLA to AA. PMID:21599946

The 15N-leucine single-injection method allows for determining endogenous losses and true digestibility of amino acids in cecectomized roosters.

PubMed

Hu, Rujiu; Li, Jing; Soomro, Rab Nawaz; Wang, Fei; Feng, Yan; Yang, Xiaojun; Yao, Junhu

2017-01-01

This study was conducted to assess the influence of dietary protein content in poultry when using the 15N-leucine single-injection method to determine endogenous amino acid losses (EAALs) in poultry. Forty-eight cecectomized roosters (2.39 ± 0.23 kg) were randomly allocated to eight dietary treatments containing protein levels of 0, 3%, 6%, 9%, 12%, 15%, 18% and 21%. Each bird was precisely fed an experimental diet of 25 g/kg of body weight. After feeding, all roosters were subcutaneously injected with a 15N-leucine solution at a dose of 20 mg/kg of body weight. Blood was sampled 23 h after the injection, and excreta samples were continuously collected during the course of the 48-h experiment. The ratio of 15N-enrichment of leucine in crude mucin to free leucine in plasma ranged from 0.664 to 0.763 and remained relatively consistent (P > 0.05) across all treatments. The amino acid (AA) profiles of total endogenous AAs, except isoleucine, alanine, aspartic acid, cysteine, proline and serine, were not influenced (P > 0.05) by dietary protein contents. The predominant endogenous AAs in the excreta were glutamic acid, aspartic acid, threonine, serine and proline. The order of the relative proportions of these predominant AAs also remained relatively constant (P > 0.05). The endogenous losses of total AAs determined with the 15N-leucine single-injection method increased curvilinearly with the dietary protein contents. The true digestibility of most AAs and total AAs was independent of their respective dietary protein levels. Collectively, the 15N-leucine single-injection method is appropriate for determining EAALs and the true digestibility of AAs in poultry fed varying levels of protein-containing ingredients.

The 15N-leucine single-injection method allows for determining endogenous losses and true digestibility of amino acids in cecectomized roosters

PubMed Central

Hu, Rujiu; Li, Jing; Soomro, Rab Nawaz; Wang, Fei; Feng, Yan; Yang, Xiaojun

2017-01-01

This study was conducted to assess the influence of dietary protein content in poultry when using the 15N-leucine single-injection method to determine endogenous amino acid losses (EAALs) in poultry. Forty-eight cecectomized roosters (2.39 ± 0.23 kg) were randomly allocated to eight dietary treatments containing protein levels of 0, 3%, 6%, 9%, 12%, 15%, 18% and 21%. Each bird was precisely fed an experimental diet of 25 g/kg of body weight. After feeding, all roosters were subcutaneously injected with a 15N-leucine solution at a dose of 20 mg/kg of body weight. Blood was sampled 23 h after the injection, and excreta samples were continuously collected during the course of the 48-h experiment. The ratio of 15N-enrichment of leucine in crude mucin to free leucine in plasma ranged from 0.664 to 0.763 and remained relatively consistent (P > 0.05) across all treatments. The amino acid (AA) profiles of total endogenous AAs, except isoleucine, alanine, aspartic acid, cysteine, proline and serine, were not influenced (P > 0.05) by dietary protein contents. The predominant endogenous AAs in the excreta were glutamic acid, aspartic acid, threonine, serine and proline. The order of the relative proportions of these predominant AAs also remained relatively constant (P > 0.05). The endogenous losses of total AAs determined with the 15N-leucine single-injection method increased curvilinearly with the dietary protein contents. The true digestibility of most AAs and total AAs was independent of their respective dietary protein levels. Collectively, the 15N-leucine single-injection method is appropriate for determining EAALs and the true digestibility of AAs in poultry fed varying levels of protein-containing ingredients. PMID:29166671

Peptide-bacteria interactions using engineered surface-immobilized peptides from class IIa bacteriocins.

PubMed

Etayash, Hashem; Norman, Lana; Thundat, Thomas; Kaur, Kamaljit

2013-03-26

Specificity of the class IIa bacteriocin Leucocin A (LeuA), an antimicrobial peptide active against Gram-positive bacteria, including Listeria monocytogenes , is known to be dictated by the C-terminal amphipathic helical region, including the extended hairpin-like structure. However, its specificity when attached to a substrate has not been investigated. Exploiting properties of LeuA, we have synthesized two LeuA derivatives, which span the amphipathic helical region of the wild-type LeuA, consisting of 14- (14AA LeuA, CWGEAFSAGVHRLA) and 24-amino acid residues (24AA LeuA, CSVNWGEAFSAGVHRLANGGNGFW). The peptides were purified to >95% purity, as shown by analytical RP-HPLC and mass spectrometry. By including an N-terminal cysteine group, the tailored peptide fragments were readily immobilized at the gold interfaces. The resulting thickness and molecular orientation, determined by ellipsometry and grazing angle infrared spectroscopy, respectively, indicated that the peptides were covalently immobilized in a random helical orientation. The bacterial specificity of the anchored peptide fragments was tested against Gram-positive and Gram-negative bacteria. Our results showed that the adsorbed 14AA LeuA exhibited no specificity toward the bacterial strains, whereas the surface-immobilized 24AA LeuA displayed significant binding toward Gram-positive bacteria with various binding affinities from one strain to another. The 14AA LeuA did not show binding as this fragment is most likely too short in length for recognition by the membrane-bound receptor on the target bacterial cell membrane. These results support the potential use of class IIa bacteriocins as molecular recognition elements in biosensing platforms.

Amino acid specific stable nitrogen isotope values in avian tissues: Insights from captive American kestrels and wild herring gulls

USGS Publications Warehouse

Hebert, Craig E.; Popp, B.N.; Fernie, K.J.; Ka'apu-Lyons, C.; Rattner, Barnett A.; Wallsgrove, N.

2016-01-01

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) and 5.4 (red blood cells), lower than those reported for metazoan invertebrates. In a field study involving omnivorous herring gulls (Larus argentatus smithsonianus), egg AA isotopic patterns largely retained those observed in the laying female’s tissues (muscle, red blood cells, and liver). Realistic estimates of gull trophic position were obtained using bird Glu and Phe δ15N values combined with β values (difference in Glu and Phe δ15N in primary producers) for aquatic and terrestrial food webs. Egg fatty acids were used to weight β values for proportions of aquatic and terrestrial food in gull diets. This novel approach can be applied to generalist species that feed across ecosystem boundaries.

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Code of Federal Regulations, 2010 CFR

2010-07-01

... in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection... thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or cotton are exempt from the requirement of a...

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Code of Federal Regulations, 2011 CFR

2011-07-01

... in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection... thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or cotton are exempt from the requirement of a...

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Code of Federal Regulations, 2014 CFR

2014-07-01

... in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection... thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or cotton are exempt from the requirement of a...

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Code of Federal Regulations, 2012 CFR

2012-07-01

... in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection... thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or cotton are exempt from the requirement of a...

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Code of Federal Regulations, 2013 CFR

2013-07-01

... in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection... thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or cotton are exempt from the requirement of a...

Evaluation of the anxiolytic and antidepressant effects of asiatic acid, a compound from Gotu kola or Centella asiatica, in the male Sprague Dawley rat.

PubMed

Ceremuga, Tomás Eduardo; Valdivieso, Debra; Kenner, Catherine; Lucia, Amy; Lathrop, Keith; Stailey, Owen; Bailey, Heather; Criss, Jonathan; Linton, Jessica; Fried, Jordan; Taylor, Andrew; Padron, Gina; Johnson, Arthur Don

2015-04-01

Herbal medication use continues to rise and interactions with existing medications propose risks and may have significant effects and consequences on the administration of anesthesia. The purpose of this study was to investigate the anxiolytic and antidepressant effects of asiatic acid and its potential modulation of the γ-aminobutyric acid (GABAA) receptor. Fifty-five male Sprague Dawley rats were divided into 5 groups: vehicle (DMSO), asiatic acid (AA), midazolam, or a combination of flumazenil + AA or midazolam + AA, and injected intraperitoneally 30 minutes prior to testing. The rats were tested on the Elevated Plus Maze (EPM) and the Forced Swim Test (FST). Data were analyzed using a two-tailed multivariate analysis of variance (MANOVA). Significance was found regarding the ratio of open arm time, maximum speed, and time spent mobile in the AA group and the midazolam + AA group (P < .05). Flumazenil decreased the anxiolytic effects, suggesting that AA modulates the benzodiazepine site on the GABAA receptor. Further studies are recommended to determine the efficacy of prolonged treatment for anxiety and depression.

A novel and simple strategy for simultaneous determination of dopamine, uric acid and ascorbic acid based on the stacked graphene platelet nanofibers/ionic liquids/chitosan modified electrode.

PubMed

Niu, Xiuli; Yang, Wu; Guo, Hao; Ren, Jie; Yang, Fusheng; Gao, Jinzhang

2012-09-15

A promising electrochemical sensor for simultaneous determination of dopamine (DA), uric acid (UA) and ascorbic acid (AA) was fabricated based on the stacked graphene platelet nanofibers (SGNF)/ionic liquid (IL)/chitosan (CS) modified electrode. The SGNF/IL/CS modified electrode possessed excellent electrocatalytic activity towards the oxidation of DA, UA and AA with obvious reduction of over-potential and increased peak current, and the separations of oxidation peak potentials of DA-UA, DA-AA, and UA-AA were of 151, 213 and 364 mV, respectively. Under the optimum conditions, the linear range for the detection of DA, UA and AA were 0.05-240, 0.12-260, and 30-350 μM with the lowest detection limits of 0.05, 0.10 and 14.8 μM for DA, UA and AA, respectively. In addition, the electrochemical sensor showed high sensitivity, excellent selectivity, reproducibility and long-term stability. Copyright © 2012 Elsevier B.V. All rights reserved.

78 FR 58986 - Dry Cargo Residue Discharges in the Great Lakes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-25

...-AA89 Dry Cargo Residue Discharges in the Great Lakes AGENCY: Coast Guard, DHS. ACTION: Notice of... final rule to regulate discharges of dry cargo residue (DCR) in the Great Lakes. The Coast Guard... final rule to regulate discharges of dry cargo residue in the Great Lakes. In August 2008, the Coast...

Nonenzymatic template-directed synthesis on hairpin oligonucleotides. 3. Incorporation of adenosine and uridine residues

NASA Technical Reports Server (NTRS)

Wu, T.; Orgel, L. E.

1992-01-01

We have used [32P]-labeled hairpin oligonucleotides to study template-directed synthesis on templates containing one or more A or T residues within a run of C residues. When nucleoside-5'-phosphoro(2-methyl)imidazolides are used as substrates, isolated A and T residues function efficiently in facilitating the incorporation of U and A, respectively. The reactions are regiospecific, producing mainly 3'-5'-phosphodiester bonds. Pairs of consecutive non-C residues are copied much less efficiently. Limited synthesis of CA and AC sequences on templates containing TG and GT sequences was observed along with some synthesis of the AA sequences on templates containing TT sequences. The other dimer sequences investigated, AA, AG, GA, TA, and AT, could not be copied. If A is absent from the reaction mixture, misincorporation of G residues is a significant reaction on templates containing an isolated T residue or two consecutive T residues. However, if both A and G are present, A is incorporated to a much greater extent than G. We believe that wobble-pairing between T and G is responsible for misincorporation when only G is present.

A Novel Pathogenesis-Related Class 10 Protein Gly m 4l, Increases Resistance upon Phytophthora sojae Infection in Soybean (Glycine max [L.] Merr.)

PubMed Central

Fan, Sujie; Jiang, Liangyu; Wu, Junjiang; Dong, Lidong; Cheng, Qun; Xu, Pengfei; Zhang, Shuzhen

2015-01-01

Phytophthora root and stem rot of soybean, caused by Phytophthora sojae (P. sojae), is a destructive disease in many soybean planting regions worldwide. In a previous study, an expressed sequence tag (EST) homolog of the major allergen Pru ar 1 in apricot (Prunus armeniaca) was identified up-regulated in the highly resistant soybean ‘Suinong 10’ infected with P. sojae. Here, the full length of the EST was isolated using rapid amplification of cDNA ends (RACE). It showed the highest homolgy of 53.46% with Gly m 4 after comparison with the eight soybean allergen families reported and was named Gly m 4-like (Gly m 4l, GenBank accession no. HQ913577.1). The cDNA full length of Gly m 4l was 707 bp containing a 474 bp open reading frame encoding a polypeptide of 157 amino acids. Sequence analysis suggests that Gly m 4l contains a conserved ‘P-loop’ (phosphate-binding loop) motif at residues 47–55 aa and a Bet v 1 domain at residues 87–120 aa. The transcript abundance of Gly m 4l was significantly induced by P. sojae, salicylic acid (SA), NaCl, and also responded to methyl jasmonic acid (MeJA) and ethylene (ET). The recombinant Gly m 4l protein showed RNase activity and displayed directly antimicrobial activity that inhibited hyphal growth and reduced zoospore release in P. sojae. Further analyses showed that the RNase activity of the recombinant protein to degrading tRNA was significantly affected in the presence of zeatin. Over-expression of Gly m 4l in susceptible ‘Dongnong 50’ soybean showed enhanced resistance to P. sojae. These results indicated that Gly m 4l protein played an important role in the defense of soybean against P. sojae infection. PMID:26474489

The P9 peptide sidechain specificity of I-Ad.

PubMed

Bartnes, K; Li, X; Briand, J P; Travers, P J; Hannestad, K

1999-12-01

The murine MHC class II variant I-Ad confers susceptibility to herpes simplex virus (HSV)-induced keratitis and relative protection against type 1 diabetes mellitus. The association to these autoimmune diseases appears to be largely determined by the peptide sidechain specificity of the P9 pocket, which we therefore have analyzed in detail. Assessment of T-cell responses and I-Ad binding capacity of position 446-substituted analogs of an IgG2a allotype b (IgG2a(b)) heavy chain peptide demonstrates that engagement of the P9 pocket is crucial for effective peptide presentation. Sidechain size rather than charge decides the capacity to engage the P9 pocket. Thus, small, uncharged sidechains are accepted, whereas acidic and aromatic amino acids as well as lysine and arginine are disfavored. The specificity of the P9 pocket of I-Ad (serine beta57) is distinct from that of the diabetes-associated I-Ag7 (aspartic acid beta57), supporting the contention that the polymorphism at residue beta57 influences diabetes susceptibility via P9-specific effects on the repertoires of self peptides presented to T cells. Furthermore, the data rationalize the susceptibility to HSV-induced keratitis conferred by the a and the protection conferred by the b allotypes of the IgG2a heavy chain. Keratitogenic T cells, which cross-react with the viral UL6 protein and a corneal antigen, are silenced in IgG2a(b) mice because of antigenic mimicry with gamma2a(b) 435-451. Our finding that the lysine P9 residue of the corresponding gamma2a(a) allopeptide precludes high-affinity binding to I-Ad indicates that the susceptibility of IgG2a(a) mice reflects inefficient thymic presentation of autologous IgG2a and thus failure to purge the T-cell repertoire of the pathogenic clones.

Some distinguishable properties between acid-stable and neutral types of alpha-amylases from acid-producing koji.

PubMed

Suganuma, Toshihiko; Fujita, Kiyotaka; Kitahara, Kanefumi

2007-11-01

The highly humid climate of Japan facilitates the growth of various molds. Among these molds, Aspergillus oryzae is the most important and popular in Japan, and has been used as yellow-koji in producing many traditional fermented beverages and foods, such as Japanese sake, and soy sauce. Taka-amylase A (TAA), a major enzyme produced by the mold, is well known worldwide to be a leading enzyme for industrial utilization and academic study, since many extensive studies have been carried out with TAA. In southern Kyushu, the other koji's of citric acid-producing molds have often been used, such as in the production of a traditional distilled liquor of shochu. The koji molds black-koji and white-koji produce two types of alpha-amylase, namely, acid-stable (AA) and common neutral (NA). The latter enzyme is enzymatically and genetically similar to TAA. In this review, we investigate AA from three molds, Aspergillus niger, A. kawachii and A. awamori, and the yeast Cryptococcus sp. regarding the distinguishable properties between AA and NA. (i) The N-terminus amino acid sequences of AA determined by molecular cloning started with the sequence of L-S-A-, whereas those of NA started with A-T-P-. (ii) Most of the full sequences of AA were composed of, besides a core catalytic domain, an extra domain of a hinge region and a carbohydrate binding domain, which could be responsible for raw-starch-digestibility. The AA from A. niger has no exceptionally extra domain, similarly to NA. (iii) Simple methods for distinguishing AA from NA using CNP-alpha-G3 and G5 as substrates were developed by our group. (iv) The number of subsite in AA on the basis of its cleavage pattern of maltooligosaccharides was estimated to be five, which differs from that of TAA, 7-9. AA has many advantages in industrial applications, such as its acid-stability, thermostability, and raw-starch digesting properties.

Engineering posttranslational proofreading to discriminate nonstandard amino acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunjapur, Aditya M.; Stork, Devon A.; Kuru, Erkin

Accurate incorporation of nonstandard amino acids (nsAAs) is central for genetic code expansion to increase the chemical diversity of proteins. However, aminoacyl-tRNA synthetases are polyspecific and facilitate incorporation of multiple nsAAs. We investigated and repurposed a natural protein degradation pathway, the N-end rule pathway, to devise an innovative system for rapid assessment of the accuracy of nsAA incorporation. Using this tool to monitor incorporation of the nsAA biphenylalanine allowed the identification of tyrosyl-tRNA synthetase (TyrRS) variants with improved amino acid specificity. The evolved TyrRS variants enhanced our ability to contain unwanted proliferation of genetically modified organisms. In conclusion, this posttranslationalmore » proofreading system will aid the evolution of orthogonal translation systems for specific incorporation of diverse nsAAs.« less

Engineering posttranslational proofreading to discriminate nonstandard amino acids

DOE PAGES

Kunjapur, Aditya M.; Stork, Devon A.; Kuru, Erkin; ...

2018-01-04

Accurate incorporation of nonstandard amino acids (nsAAs) is central for genetic code expansion to increase the chemical diversity of proteins. However, aminoacyl-tRNA synthetases are polyspecific and facilitate incorporation of multiple nsAAs. We investigated and repurposed a natural protein degradation pathway, the N-end rule pathway, to devise an innovative system for rapid assessment of the accuracy of nsAA incorporation. Using this tool to monitor incorporation of the nsAA biphenylalanine allowed the identification of tyrosyl-tRNA synthetase (TyrRS) variants with improved amino acid specificity. The evolved TyrRS variants enhanced our ability to contain unwanted proliferation of genetically modified organisms. In conclusion, this posttranslationalmore » proofreading system will aid the evolution of orthogonal translation systems for specific incorporation of diverse nsAAs.« less

Developmental nephrotoxicity of aristolochic acid in a zebrafish model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Yu-Ju; Chen, Yau-Hung, E-mail: yauhung@mail.tku.edu.tw

2012-05-15

Aristolochic acid (AA) is a component of Aristolochia plant extracts which is used as a treatment for different pathologies and their toxicological effects have not been sufficiently studied. The aim of this study was to evaluate AA-induced nephrotoxicity in zebrafish embryos. After soaking zebrafish embryos in AA, the embryos displayed malformed kidney phenotypes, such as curved, cystic pronephric tubes, pronephric ducts, and cases of atrophic glomeruli. The percentages of embryos with malformed kidney phenotypes increased as the exposure dosages of AA increased. Furthermore, AA-treated embryos exhibited significantly reduced glomerular filtration rates (GFRs) in comparison with mock-control littermates (mock-control: 100 ±more » 2.24% vs. 10 ppm AA treatment for 3–5 h: 71.48 ± 18.84% ∼ 39.41 ± 15.88%), indicating that AA treatment not only caused morphological kidney changes but also induced renal failure. In addition to kidney malformations, AA-treated zebrafish embryos also exhibited deformed hearts, swollen pericardiums, impaired blood circulation and the accumulation(s) of red blood cells. Whole-mount in situ hybridization studies using cmlc2 and wt1b as riboprobes indicated that the kidney is more sensitive than the heart to AA damage. Real-time PCR showed that AA can up-regulate the expression of proinflammatory genes like TNFα, cox2 and mpo. These results support the following conclusions: (1) AA-induced renal failure is mediated by inflammation, which causes circulation dysfunction followed by serious heart malformation; and (2) the kidney is more sensitive than the heart to AA injury. -- Highlights: ► Zebrafish were used to evaluate aristolochic acid (AA)-induced nephrotoxicity. ► AA-treated zebrafish embryos exhibited deformed heart as well as malformed kidney. ► Kidney is more sensitive to AA injury than the heart.« less

Two Novel Motifs of Watermelon Silver Mottle Virus NSs Protein Are Responsible for RNA Silencing Suppression and Pathogenicity.

PubMed

Huang, Chung-Hao; Hsiao, Weng-Rong; Huang, Ching-Wen; Chen, Kuan-Chun; Lin, Shih-Shun; Chen, Tsung-Chi; Raja, Joseph A J; Wu, Hui-Wen; Yeh, Shyi-Dong

2015-01-01

The NSs protein of Watermelon silver mottle virus (WSMoV) is the RNA silencing suppressor and pathogenicity determinant. In this study, serial deletion and point-mutation mutagenesis of conserved regions (CR) of NSs protein were performed, and the silencing suppression function was analyzed through agroinfiltration in Nicotiana benthamiana plants. We found two amino acid (aa) residues, H113 and Y398, are novel functional residues for RNA silencing suppression. Our further analyses demonstrated that H113 at the common epitope (CE) ((109)KFTMHNQ(117)), which is highly conserved in Asia type tospoviruses, and the benzene ring of Y398 at the C-terminal β-sheet motif ((397)IYFL(400)) affect NSs mRNA stability and protein stability, respectively, and are thus critical for NSs RNA silencing suppression. Additionally, protein expression of other six deleted (ΔCR1-ΔCR6) and five point-mutated (Y15A, Y27A, G180A, R181A and R212A) mutants were hampered and their silencing suppression ability was abolished. The accumulation of the mutant mRNAs and proteins, except Y398A, could be rescued or enhanced by co-infiltration with potyviral suppressor HC-Pro. When assayed with the attenuated Zucchini yellow mosaic virus vector in squash plants, the recombinants carrying individual seven point-mutated NSs proteins displayed symptoms much milder than the recombinant carrying the wild type NSs protein, suggesting that these aa residues also affect viral pathogenicity by suppressing the host silencing mechanism.

Two Novel Motifs of Watermelon Silver Mottle Virus NSs Protein Are Responsible for RNA Silencing Suppression and Pathogenicity

PubMed Central

Huang, Chung-Hao; Hsiao, Weng-Rong; Huang, Ching-Wen; Chen, Kuan-Chun; Lin, Shih-Shun; Chen, Tsung-Chi; Raja, Joseph A. J.; Wu, Hui-Wen; Yeh, Shyi-Dong

2015-01-01

The NSs protein of Watermelon silver mottle virus (WSMoV) is the RNA silencing suppressor and pathogenicity determinant. In this study, serial deletion and point-mutation mutagenesis of conserved regions (CR) of NSs protein were performed, and the silencing suppression function was analyzed through agroinfiltration in Nicotiana benthamiana plants. We found two amino acid (aa) residues, H113 and Y398, are novel functional residues for RNA silencing suppression. Our further analyses demonstrated that H113 at the common epitope (CE) (109KFTMHNQ117), which is highly conserved in Asia type tospoviruses, and the benzene ring of Y398 at the C-terminal β-sheet motif (397IYFL400) affect NSs mRNA stability and protein stability, respectively, and are thus critical for NSs RNA silencing suppression. Additionally, protein expression of other six deleted (ΔCR1-ΔCR6) and five point-mutated (Y15A, Y27A, G180A, R181A and R212A) mutants were hampered and their silencing suppression ability was abolished. The accumulation of the mutant mRNAs and proteins, except Y398A, could be rescued or enhanced by co-infiltration with potyviral suppressor HC-Pro. When assayed with the attenuated Zucchini yellow mosaic virus vector in squash plants, the recombinants carrying individual seven point-mutated NSs proteins displayed symptoms much milder than the recombinant carrying the wild type NSs protein, suggesting that these aa residues also affect viral pathogenicity by suppressing the host silencing mechanism. PMID:25993336

Screening of Catalyst and Important Variable for The Esterification of Acrylic Acid with 2 Ethylhexanol

NASA Astrophysics Data System (ADS)

Ahmad, M. A. A.; Chin, S. Y.

2017-06-01

The global demand of 2-ethylhexyl acrylate (2EHA) market has witnessed a significant growth in the past few years and this growth is anticipated to increase in the coming years. 2EHA is one of the basic organic building blocks that mainly used in the production of coatings, adhesives, superabsorbents, thickeners and plastic additives. Homogenous acid-catalysed esterification of acrylic acid (AA) with 2-ethylhexanol (2EH) is commonly used for the production of 2EHA. The homogeneous catalysts such as sulfuric and para-toluene sulfonic acid have resulted the costly and complicated downstream process that generates acidic, corrosive and non-environmental friendly waste. Therefore, it is importance to develop a cheaper process that employing heterogeneous catalysts and alternative raw material from wastewater containing acrylic acid. In this research, the study for the esterification of AA with 2EH catalysed by ion-exchange resin was conducted. The best sulfonic acid functional cation-exchange resin among SK104, SK1B, PK208, PK216, PK228, RCP145, and RCP160 was screened. PK208 outperformed the other resins and it was used subsequently in the parametric studies. The effect of important parameters (initial concentration of acrylic acid (AA), temperature, molar ratio of reactant (AA and 2EH), catalyst loading, and polymerisation inhibitor loading) was studied using 2 factorial design to determine the significant parameters to the esterification. It was found that the initial concentration of AA and temperature were most significantly affecting the esterification of AA with 2EH.

Interaction between lysine 102 and aspartate 338 in the insect amino acid cotransporter KAAT1.

PubMed

Castagna, M; Soragna, A; Mari, S A; Santacroce, M; Betté, S; Mandela, P G; Rudnick, G; Peres, A; Sacchi, V F

2007-10-01

KAAT1 is a lepidopteran neutral amino acid transporter belonging to the NSS super family (SLC6), which has an unusual cation selectivity, being activated by K(+) and Li(+) in addition to Na(+). We have previously demonstrated that Asp338 is essential for KAAT1 activation by K(+) and for the coupling of amino acid and driver ion fluxes. By comparing sequences of NSS family members, site-directed mutagenesis, and expression in Xenopus laevis oocytes, we identified Lys102 as a residue likely to interact with Asp338. Compared with wild type, the single mutants K102V and D338E each showed altered leucine uptake and transport-associated currents in the presence of both Na(+) and K(+). However, in K102V/D338E double mutant, the K102V mutation reversed both the inhibition of Na(+)-dependent transport and the block in K(+)-dependent transport that characterize the D338E mutant. K(+)-dependent leucine currents were not observed in any mutants with D338E. In the presence of the oxidant Cu(II) (1,10-phenanthroline)(3), we observed specific and reversible inhibition of K102C/D338C mutant, but not of the corresponding single cysteine mutants, suggesting that these residues are sufficiently close to form a disulfide bond. Thus both structural and functional evidence suggests that these two residues interact. Similar results have been obtained mutating the bacterial transporter homolog TnaT. Asp338 corresponds to Asn286, a residue located in the Na(+) binding site in the recently solved crystal structure of the NSS transporter LeuT(Aa) (41). Our results suggest that Lys102, interacting with Asp338, could contribute to the spatial organization of KAAT1 cation binding site and permeation pathway.

Variation of amino acid sequences of serum amyloid a (SAA) and immunohistochemical analysis of amyloid a (AA) in Japanese domestic cats.

PubMed

Tei, Meina; Uchida, Kazuyuki; Chambers, James K; Watanabe, Ken-Ichi; Tamamoto, Takashi; Ohno, Koichi; Nakayama, Hiroyuki

2018-02-02

Amyloid A (AA) amyloidosis, a fatal systemic amyloid disease, occurs secondary to chronic inflammatory conditions in humans. Although persistently elevated serum amyloid A (SAA) levels are required for its pathogenesis, not all individuals with chronic inflammation necessarily develop AA amyloidosis. Furthermore, many diseases in cats are associated with the elevated production of SAA, whereas only a small number actually develop AA amyloidosis. We hypothesized that a genetic mutation in the SAA gene may strongly contribute to the pathogenesis of feline AA amyloidosis. In the present study, genomic DNA from four Japanese domestic cats (JDCs) with AA amyloidosis and from five without amyloidosis was analyzed using polymerase chain reaction (PCR) amplification and direct sequencing. We identified the novel variation combination of 45R-51A in the deduced amino acid sequences of four JDCs with amyloidosis and five without. However, there was no relationship between amino acid variations and the distribution of AA amyloid deposits, indicating that differences in SAA sequences do not contribute to the pathogenesis of AA amyloidosis. Immunohistochemical analysis using antisera against the three different parts of the feline SAA protein-i.e., the N-terminal, central, and C-terminal regions-revealed that feline AA contained the C-terminus, unlike human AA. These results indicate that the cleavage and degradation of the C-terminus are not essential for amyloid fibril formation in JDCs.

Effect of oral contraceptive agents on ascorbic acid metabolism in the rhesus monkey.

PubMed

Weininger, J; King, J C

1982-06-01

Ascorbic acid (AA) metabolism was studied in six sexually mature female rhesus monkeys with normal menstrual cycles before and during oral contraceptive administration. The animals were fed a commercial monkey stock diet (15% protein) containing no AA and given a 100 mg AA tablet daily throughout the study. After an initial adaptation period and a control period (total 8 months), combined-type oral contraceptive agents (OCAs) (50 micrograms mestranol and 1 mg norethindrone for 21 days each month) were administered to each monkey for 4 months. Serum copper and ceruloplasmin were significantly elevated during OCA treatment. There were no significant changes in plasma or leukocyte AA values during OCA use; however, urinary AA excretion decreased significantly. During the last month of the control period and the 3rd month of OCA treatment, 50 muCi of 1-14C-L-ascorbic acid were injected intravenously into each monkey. Urinary excretion of radioactivity, measured for 1 month, indicated a significantly faster AA turnover rate during the period of OCA use. These results suggest that women using OCAs may have an increased dietary requirement for AA.

Cooking methods employing natural anti-oxidant food additives effectively reduced concentration of nephrotoxic and carcinogenic aristolochic acids in contaminated food grains.

PubMed

Li, Weiwei; Chan, Chi-Kong; Wong, Yee-Lam; Chan, K K Jason; Chan, Ho Wai; Chan, Wan

2018-10-30

Emerging evidence suggests that aristolochic acids (AA) produced naturally by a common weed Aristolochia clematitis in the cultivation fields is contaminating the food products in Balkan Peninsula and acting as the etiological agent in the development of Balkan endemic nephropathy. In this study, we investigated the combined use of natural anti-oxidative "food additives" and different cooking methods to find a solution for the widespread contamination of AA in food products. The results indicated that the addition of healthy dietary supplements (such as cysteine, glutathione, ascorbic acid, citric acid and magnesium) during cooking, is a highly efficient method in lowering the concentration of AA in the final food products. Because previous observation indicated one of the toxicological mechanisms by which AA exert its toxicity is to induce oxidative stress in internal organs, it is anticipated that these added anti-oxidants will also help to attenuate the nephrotoxicity of AA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of ascorbic acid supplementation on male reproductive system during exposure to hypoxia

NASA Astrophysics Data System (ADS)

Havazhagan, G.; Riar, S. S.; Kain, A. K.; Bardhan, Jaya; Thomas, Pauline

1989-09-01

Two groups of male rats were exposed to simulated altitudes of 6060 m and 7576 m for 6 h/day for 7 days (intermittent exposure). In two additional groups of animals exposed to the same altitude, 100 mg of ascorbic acid (AA) was fed daily for 5 days prior to the exposure period and also during the exposure period. Rats that did not receive AA showed loss of body weight and weight of reproductive organs after exposure. Sex organs showed atrophy on histological examination and there was a deterioration in spermatozoal quality. There was an increase in alkaline and acid phosphatase, and decrease in protein, sialic acid and glyceryl phosphorylcholine content in various reproductive tissues after exposure. All the above changes in histology and biochemical composition could be partially prevented by AA supplementation. AA supplementation can therefore protect the male reproductive system from deleterious effects of hypoxia. The probable mechanism of action of AA is discussed.

Isolation and characterization of full-length putative alcohol dehydrogenase genes from polygonum minus

NASA Astrophysics Data System (ADS)

Hamid, Nur Athirah Abd; Ismail, Ismanizan

2013-11-01

Polygonum minus, locally named as Kesum is an aromatic herb which is high in secondary metabolite content. Alcohol dehydrogenase is an important enzyme that catalyzes the reversible oxidation of alcohol and aldehyde with the presence of NAD(P)(H) as co-factor. The main focus of this research is to identify the gene of ADH. The total RNA was extracted from leaves of P. minus which was treated with 150 μM Jasmonic acid. Full-length cDNA sequence of ADH was isolated via rapid amplification cDNA end (RACE). Subsequently, in silico analysis was conducted on the full-length cDNA sequence and PCR was done on genomic DNA to determine the exon and intron organization. Two sequences of ADH, designated as PmADH1 and PmADH2 were successfully isolated. Both sequences have ORF of 801 bp which encode 266 aa residues. Nucleotide sequence comparison of PmADH1 and PmADH2 indicated that both sequences are highly similar at the ORF region but divergent in the 3' untranslated regions (UTR). The amino acid is differ at the 107 residue; PmADH1 contains Gly (G) residue while PmADH2 contains Cys (C) residue. The intron-exon organization pattern of both sequences are also same, with 3 introns and 4 exons. Based on in silico analysis, both sequences contain "classical" short chain alcohol dehydrogenases/reductases ((c) SDRs) conserved domain. The results suggest that both sequences are the members of short chain alcohol dehydrogenase family.

Characterization of chiral amino acids from different milk origins using ultra-performance liquid chromatography coupled to ion-mobility mass spectrometry

NASA Astrophysics Data System (ADS)

Tian, He; Zheng, Nan; Li, Songli; Zhang, Yangdong; Zhao, Shengguo; Wen, Fang; Wang, Jiaqi

2017-04-01

Milk contains free amino acids (AAs) that play essential roles in maintaining the growth and health of infants, and D-AA isomers are increasingly being recognized as important signalling molecules. However, there are no studies of the different characteristics of chiral AA (C-AA) from different milk origins. Here, UPLC coupled to ion-mobility high-resolution MS (IM-HRMS) was employed to characterize 18 pairs of C-AAs in human, cow, yak, buffalo, goat, and camel milk. The results proved that milk origins can be differentiated based on the D- to L- AA ratio-based projection scores by principal component analysis. The present study gives a deeper understanding of the D- to L- AA ratio underlying the biological functions of different animal milks, and provide a new strategy for the study of AA metabolic pathways.

Analysis of the Cytotoxic Potential of Anisomelic Acid Isolated from Anisomeles malabarica

PubMed Central

Preethy, Christo Paul; Alshatwi, Ali Abdullah; Gunasekaran, Muthukumaran; Akbarsha, Mohammad Abdulkadher

2013-01-01

Anisomelic acid (AA), one of the major compounds in Anisomeles malabarica, was tested for its cytotoxicity and apoptosis-inducing potential in breast and cervical cancer cells. The MTT assay for cell viability indicated that AA is cytotoxic to all of the four cell lines tested in a dose- and duration-dependent manner. Acridine Orange & Ethidium Bromide (AO & EB) and Hoechst 33258 staining of AA-treated cells revealed typical apoptotic morphology such as condensed chromatin and formation of apoptotic bodies. The comet assay revealed DNA strand break(s), indicating that AA induces DNA damage which culminates in apoptosis. Thus, the study revealed the anti-proliferative and apoptosis-inducing properties of AA in both breast and cervical cancer cells. Therefore, anisomelic acid offers potential for application in breast and cervical cancer therapy. PMID:23833721

Comparison of long chain polyunsaturated fatty acid content in human milk in preterm and term deliveries and its correlation with mothers' diet.

PubMed

Iranpour, Ramin; Kelishadi, Roya; Babaie, Sharareh; Khosravi-Darani, Kianoush; Farajian, Sanam

2013-01-01

Human milk (HM) is the main food for infants, and phospholipids, especially long chain polyunsaturated fatty acids (LCPUFAs), play an essential role in the growth and brain development. This study was designed to evaluate the fatty acid composition in HM of mothers with preterm and full-term newborns and to determine the relationships of dietary intake of docosahexaenoic acid (DHA) and arachidonic acid (AA) of mothers and the content of these fatty acids in their milks. The AA and DHA of HM were determined by gas chromatography at the 3(rd) day after birth from mothers of 59 term and 58 preterm infants. Mothers were selected from those who delivered in Shahid Beheshti Hospital, a referral teaching hospital affiliated to Isfahan University of Medical Sciences, Isfahan, Iran. Dietary fat composition of mothers was examined by a food-frequency questionnaire. Total fat content, and DHA and AA levels of HM were compared in both groups. The correlation of dietary DHA and AA with DHA and AA of HM was determined in both groups. We found that maternal age, body mass index (BMI), and self-reported food-frequency questionnaire did not differ in the two groups. The mean AA (0.19 ± 0.10 mg/ml and 0.16 ± 0.09 mg/ml, respectively), DHA (0.10 ± 0.06 mg/ml and 0.08 ± 0.05 mg/ml, respectively), and total fat content (2.58 ± 2.16 g/dl and 2.06 ± 1.22 g/dl, respectively) of HM of mothers with preterm neonates were non-significantly higher than in mothers with term neonates. The percentage of DHA in the HM fat of preterm and term groups (0.45 ± 0.16% and 0.45 ± 0.18%, respectively) and the percentage of AA (0.85 ± 0.26% and 0.84 ± 0.20%, respectively) were comparable with worldwide standards. No correlations were documented between DHA and AA intake and DHA and AA content of HM in both groups. Although DHA and AA content of HM in preterm group was higher than in term group, this difference were not significant. In Isfahan, the percentage of DHA and AA was acceptable in the milk fat of mothers with term and preterm neonates.

Peroxisome proliferation activation receptor alpha modulation of Ca2+-regulated exocytosis via arachidonic acid in guinea-pig antral mucous cells.

PubMed

Sawabe, Yukinori; Shimamoto, Chikao; Sakai, Akiko; Kuwabara, Hiroko; Saad, Adel H; Nakano, Takashi; Takitani, Kimitaka; Tamai, Hiroshi; Mori, Hiroshi; Marunaka, Yoshinori; Nakahari, Takashi

2010-08-01

Indomethacin (IDM, 10 microm), not aspirin (ASA; 10 microm), enhanced the Ca(2+)-regulated exocytosis stimulated by 1 microm acetylcholine (ACh) in guinea-pig antral mucous cells. Indomethacin inhibits prostaglandin G/H (PGG/H) and 15R-hydroperoxy-eicosatetraenoic acid (15R-HPETE) production from arachidonic acid (AA), while ASA inhibits PGG/H production but accelerates 15R-HPETE production. This suggests that IDM accumulates AA. Arachidonic acid (2 microm) enhanced Ca(2+)-regulated exocytosis in antral mucous cells to a similar extent to IDM. Moreover, a stable analogue of AA, arachidonyltrifluoromethyl ketone (AACOCF(3)), also enhanced Ca(2+)-regulated exocytosis, indicating that AA, not products from AA, enhances Ca(2+)-regulated exocytosis. We hypothesized that AA activates peroxisome proliferation activation receptor alpha (PPARalpha), because AA is a natural ligand for PPARalpha. A PPARalpha agonist (WY14643; 1 microm) enhanced Ca(2+)-regulated exocytosis, and a PPARalpha blocker (MK886; 50 microm) abolished the enhancement of Ca(2+)-regulated exocytosis induced by AA, IDM, AACOCF(3) and WY14643. Western blotting and immunohistochemical examinations demonstrated that PPARalpha exists in antral mucous cells. Moreover, MK886 decreased the frequency of Ca(2+)-regulated exocytosis activated by 1 microm ACh or 2 microm thapsigargin alone by 25-30%. Thus, ACh stimulates AA accumulation via an [Ca(2+)](i) increase, which activates PPARalpha, leading to enhancement of Ca(2+)-regulated exocytosis in antral mucous cells. A novel autocrine mechanism mediated via PPARalpha enhances Ca(2+)-regulated exocytosis in guinea-pig antral mucous cells.

Prebiotic synthesis and degradation of amino acids by UV-irradiation at room temperature and 77K.

NASA Astrophysics Data System (ADS)

Mita, H.; Shimoyama, A.

Amino acids (AAs) were synthesized prebioticaly by UV irradiation to aqueous solution of amines and nitriles, and mixtures of graphite-ammonia-water (GAW mix.) at room temperature (RT, model of the primitive ocean) and 77 K (model of comet ice), using a Xe excimer lamp (max is 172 nm) and a low-pressure mercury lamp (max is 185/254 nm). Degradation of glycine and, degradation and racemization of aspartic acid were carried out by UV irradiation at RT. AAs in the irradiated samples were determined quantitatively by a gas chromatograph combined with a mass spectrometer after derivatized with HCl/2-propanol and trifluoroacetic anhydride. Maximum 16 hydrolyzed AAs from C2 to C6 were detected quantitatively. Amino acids have chiral center were nearly racemic. Therefore, those amino acids were not contaminants. In the most case, glycine was the most abundant AA and its concentration was 4.1 μmol/l from 1mmol/l acetonitrile solu. at RT for 3 h, 1 nmol/l from 100 mmol/l acetonitrile solu. at 77K for 1 h, 3.8?μmol/l from 10 mmol/l methylamine solu. at RT for 15 h, 278 μmol/l from 1 mol/l methylamine solu. At 77K for 4h, and 38.6 pmol/g-Carbon from GAW mix. at RT for 24 h. Maximum producing time of glycine from acetonitrile was 3 h and the shortest, that from GAW mix. was the longest among our experiments. Amount of glycine was decreased in gradually, after maximum producing time. Yields of glycine from acetonitrile and methylamine at 77K were lower than those at RT. Amounts of large AAs were lower than those of small AAs as glycine and alanine. Half-life time of glycine UV irradiation at RT was nearly 30 min. and similar to that of aspartic acid. Half-life time of racemization of aspartic acid was 2.1 h. It was able to confirm that a lot of AAs were synthesized by UV irradiation in the model experiments of primitive environments, even in simulated comet ice, from different starting materials. AA formation from developed material, as acetonitrile was more rapid and higher yield than that from primitive material as GAW mix. Degradation rate of AAs was faster than formation rate of AAs. Therefore, some protective systems are required for accumulation of AAs.

Amino acid repletion does not decrease muscle protein catabolism during hemodialysis.

PubMed

Raj, Dominic S C; Adeniyi, Oladipo; Dominic, Elizabeth A; Boivin, Michel A; McClelland, Sandra; Tzamaloukas, Antonios H; Morgan, Nancy; Gonzales, Lawrence; Wolfe, Robert; Ferrando, Arny

2007-06-01

Intradialytic protein catabolism is attributed to loss of amino acids in the dialysate. We investigated the effect of amino acid infusion during hemodialysis (HD) on muscle protein turnover and amino acid transport kinetics by using stable isotopes of phenylalanine, leucine, and lysine in eight patients with end-stage renal disease (ESRD). Subjects were studied at baseline (pre-HD), 2 h of HD without amino acid infusion (HD-O), and 2 h of HD with amino acid infusion (HD+AA). Amino acid depletion during HD-O augmented the outward transport of amino acids from muscle into the vein. Increased delivery of amino acids to the leg during HD+AA facilitated the transport of amino acids from the artery into the intracellular compartment. Increase in muscle protein breakdown was more than the increase in synthesis during HD-O (46.7 vs. 22.3%, P < 0.001). Net balance (nmol.min(-1).100 ml (-1)) was more negative during HD-O compared with pre-HD (-33.7 +/- 1.5 vs. -6.0 +/- 2.3, P < 0.001). Despite an abundant supply of amino acids, the net balance (-16.9 +/- 1.8) did not switch from net release to net uptake. HD+AA induced a proportional increase in muscle protein synthesis and catabolism. Branched chain amino acid catabolism increased significantly from baseline during HD-O and did not decrease during HD+AA. Protein synthesis efficiency, the fraction of amino acid in the intracellular pool that is utilized for muscle protein synthesis decreased from 42.1% pre-HD to 33.7 and 32.6% during HD-O and HD+AA, respectively (P < 0.01). Thus amino acid repletion during HD increased muscle protein synthesis but did not decrease muscle protein breakdown.

Combined α-tocopherol and ascorbic acid protects against smoke-induced lung squamous metaplasia in ferrets.

PubMed

Kim, Yuri; Chongviriyaphan, Nalinee; Liu, Chun; Russell, Robert M; Wang, Xiang-Dong

2012-01-01

Many epidemiological studies show the benefit of fruits and vegetables on reducing risk of lung cancer, the leading cause of cancer death in the United States. Previously, we demonstrated that cigarette smoke exposure (SM)-induced lung lesions in ferrets were prevented by a combination of low dose of β-carotene, α-tocopherol (AT), and ascorbic acid (AA). However, the role of a combination of AT and AA alone in the protective effect on lung carcinogenesis remains to be examined. In the present study, we investigated whether the combined AT (equivalent to ∼100 mg/day in the human) and AA (equivalent to ∼210 mg/day) supplementation prevents against SM (equivalent to 1.5 packs of cigarettes/day) induced lung squamous metaplasia in ferrets. Ferrets were treated for 6 weeks in the following three groups (9 ferrets/group): (i) Control (no SM, no AT+AA), (ii) SM alone, and (iii) SM+AT+AA. Results showed that SM significantly decreased concentrations of retinoic acid, AT, and reduced form of AA, not total AA, retinol and retinyl palmitate, in the lungs of ferrets. Combined AT+AA treatment partially restored the lowered concentrations of AT, reduced AA and retinoic acid in the lungs of SM-exposed ferrets to the levels in the control group. Furthermore, the combined AT+AA supplementation prevented SM-induced squamous metaplasia [0 positive/9 total ferrets (0%) vs. 5/8 (62%); p<0.05] and cyclin D1 expression (p<0.05) in the ferret lungs, in which both were positively correlated with expression of c-Jun expression. Although there were no significant differences in lung microsomal malondialdehyde (MDA) levels among the three groups, we found a positive correlation between MDA levels and cyclin D1, as well as c-Jun expressions in the lungs of ferrets. These data indicate that the combination of antioxidant AT+AA alone exerts protective effects against SM-induced lung lesions through inhibiting cyclin D1 expression and partially restoring retinoic acid levels to normal. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Growth and clinical variables in nitrogen-restricted piglets fed an adjusted essential amino acid mix: Effects using partially intact protein-based diets

USDA-ARS?s Scientific Manuscript database

Current recommendations for protein levels in infant formula ensure that growth matches or exceeds growth of breast-fed infants, but may provide a surplus of amino acids (AA). Recent studies in infants using AA-based formulas support specific adjustment of the essential AA (EAA) composition allowing...

In silico cloning and B/T cell epitope prediction of triosephosphate isomerase from Echinococcus granulosus.

PubMed

Wang, Fen; Ye, Bin

2016-10-01

Cystic echinococcosis is a worldwide zoonosis caused by Echinococcus granulosus. Because the methods of diagnosis and treatment for cystic echinococcosis were limited, it is still necessary to screen target proteins for the development of new anti-hydatidosis vaccine. In this study, the triosephosphate isomerase gene of E. granulosus was in silico cloned. The B cell and T cell epitopes were predicted by bioinformatics methods. The cDNA sequence of EgTIM was composition of 1094 base pairs, with an open reading frame of 753 base pairs. The deduced amino acid sequences were composed of 250 amino acids. Five cross-reactive epitopes, locating on 21aa-35aa, 43aa-57aa, 94aa-107aa, 115-129aa, and 164aa-183aa, could be expected to serve as candidate epitopes in the development of vaccine against E. granulosus. These results could provide bases for gene cloning, recombinant expression, and the designation of anti-hydatidosis vaccine.

Duplication of Drosophila melanogaster mitochondrial EF-Tu: pre-adaptation to T-arm truncation and exclusion of bulky aminoacyl residues.

PubMed

Sato, Aya; Suematsu, Takuma; Aihara, Koh-Ki; Kita, Kiyoshi; Suzuki, Tsutomu; Watanabe, Kimitsuna; Ohtsuki, Takashi; Watanabe, Yoh-Ichi

2017-03-07

Translation elongation factor Tu (EF-Tu) delivers aminoacyl-tRNA (aa-tRNA) to ribosomes in protein synthesis. EF-Tu generally recognizes aminoacyl moieties and acceptor- and T-stems of aa-tRNAs. However, nematode mitochondrial (mt) tRNAs frequently lack all or part of the T-arm that is recognized by canonical EF-Tu. We previously reported that two distinct EF-Tu species, EF-Tu1 and EF-Tu2, respectively, recognize mt tRNAs lacking T-arms and D-arms in the mitochondria of the chromadorean nematode Caenorhabditis elegans C. elegans EF-Tu2 specifically recognizes the seryl moiety of serylated D-armless tRNAs. Mitochondria of the enoplean nematode Trichinella possess three structural types of tRNAs: T-armless tRNAs, D-armless tRNAs, and cloverleaf tRNAs with a short T-arm. Trichinella mt EF-Tu1 binds to all three types and EF-Tu2 binds only to D-armless Ser-tRNAs, showing an evolutionary intermediate state from canonical EF-Tu to chromadorean nematode (e.g. C. elegans ) EF-Tu species. We report here that two EF-Tu species also participate in Drosophila melanogaster mitochondria. Both D. melanogaster EF-Tu1 and EF-Tu2 bound to cloverleaf and D-armless tRNAs. D. melanogaster EF-Tu1 has the ability to recognize T-armless tRNAs that do not evidently exist in D. melanogaster mitochondria, but do exist in related arthropod species. In addition, D. melanogaster EF-Tu2 preferentially bound to aa-tRNAs carrying small amino acids, but not to aa-tRNAs carrying bulky amino acids. These results suggest that the Drosophila mt translation system could be another intermediate state between the canonical and nematode mitochondria-type translation systems. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.

PubMed

Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

2016-01-01

Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy.

AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

PubMed Central

Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

2016-01-01

Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

Combined effect of selenium and ascorbic acid on alcohol induced hyperlipidemia in male guinea pigs.

PubMed

Asha, G S; Indira, M

2004-02-01

Alcoholics usually suffer from malnutrition and are especially deficient in micronutrients like vitamin C, selenium and Zn. In the present study, combined effects of selenium and ascorbic acid on alcohol-induced hyperlipidemia were studied in guinea pigs. Four groups of male guinea pigs were maintained for 45 days as follows: control (1 mg ascorbate (AA)/100 g body mass/day), ethanol (900 mg ethanol/100 g body mass + 1 mg AA/100 g body mass/day), selenium+ascorbic acid [(25 mg AA + 0.05 mg Se)/100 g body mass/day], ethanol+selenium+ascorbic acid [(25 mg AA + 0.05 mg Se + 900 mg ethanol)/100 g body mass/day]. Co-administration of selenium and ascorbic acid along with alcohol reduced the concentration of all lipids, as also evidenced from the decreased activities of hydroxymethylglutaryl-CoA reductase and enhanced activities of plasma lecithin cholesterol acyl transferase and lipoprotein lipase. Concentrations of bile acids were increased. We conclude that the supplementation of Se and ascorbic acid reduced alcohol induced hyperlipidemia, by decreased synthesis and increased catabolism.

Production of tag-free recombinant fusion protein encompassing promiscuous T cell epitope of tetanus toxoid and dog zona pellucida glycoprotein-3 for contraceptive vaccine development.

PubMed

Gupta, Neha; Shrestha, Abhinav; Panda, Amulya Kumar; Gupta, Satish Kumar

2013-07-01

Affinity tags can interfere in various physicochemical properties and immunogenicity of the recombinant proteins. In the present study, tag-free recombinant fusion protein encompassing promiscuous T cell epitope of tetanus toxoid [TT; amino acid (aa) residues 830-844] followed by dilysine linker and dog zona pellucida glycoprotein-3 (ZP3; aa residues 23-348) (TT-KK-ZP3) was expressed in Escherichia coli. The recombinant protein, expressed as inclusion bodies (IBs), was purified by isolation of IBs, processed to remove host cell proteins, followed by solubilization and refolding. A specific 39 kDa protein including ZP3 was identified by SDS-PAGE. CD spectra showed the presence of α-helices and β-sheets, and fluorescent spectroscopy revealed emission maxima of 265 A.U. at 339 nm for refolded protein and showed red shift in the presence of 6 M guanidine hydrochloride. Immunization of inbred FvB/J female mice with purified recombinant TT-KK-ZP3 (25 μg/animal) led to generation of high antibody titers against the recombinant protein. The antibodies reacted specifically with ZP matrix surrounding mouse oocytes. Immunized mice showed significant reduction in fertility as compared to the control group. The studies described herein provide a simple method to produce and purify tag-free recombinant protein for the development of a contraceptive vaccine.

Associations of cord blood fatty acids with lymphocyte proliferation, IL-13, and IFN-γ

PubMed Central

Gold, Diane R.; Willwerth, Ben M.; Tantisira, Kelan G.; Finn, Patricia W.; Schaub, Bianca; Perkins, David L.; Tzianabos, Arthur; Ly, Ngoc P.; Schroeter, Christian; Gibbons, Fiona; Campos, Hannia; Oken, Emily; Gillman, Matthew W.; Palmer, Lyle J.; Ryan, Louise M.; Weiss, Scott T.

2006-01-01

Background. N-3 and n-6 polyunsaturated fatty acids (PUFAs) have been hypothesized to have opposing influences on neonatal immune responses that might influence the risk of allergy or asthma. However, both n-3 eicosapentaenoic acid (EPA) and n-6 arachidonic acid (AA) are required for normal fetal development. Objective. We evaluated whether cord blood fatty acid levels were related to neonatal immune responses and whether n-3 and n-6 PUFA responses differed. Methods. We examined the relation of cord blood plasma n-3 and n-6 PUFAs (n = 192) to antigen- and mitogen-stimulated cord blood lymphocyte proliferation (n = 191) and cytokine (IL-13 and IFN-γ; n = 167) secretion in a US birth cohort. Results. Higher levels of n-6 linoleic acid were correlated with higher IL-13 levels in response to Bla g 2 (cockroach, P = .009) and Der f 1 (dust mite, P = .02). Higher n-3 EPA and n-6 AA levels were each correlated with reduced lymphocyte proliferation and IFN-γ levels in response to Bla g 2 and Der f 1 stimulation. Controlling for potential confounders, EPA and AA had similar independent effects on reduced allergen-stimulated IFN-γ levels. If neonates had either EPA or AA levels in the highest quartile, their Der f 1 IFN-γ levels were 90% lower (P = .0001) than those with both EPA and AA levels in the lowest 3 quartiles. Reduced AA/EPA ratio was associated with reduced allergen-stimulated IFN-γ level. Conclusion. Increased levels of fetal n-3 EPA and n-6 AA might have similar effects on attenuation of cord blood lymphocyte proliferation and IFN-γ secretion. Clinical implications. The implications of these findings for PMID:16630954

Temporal dynamics of amino and fatty acid composition in the razor clam Ensis siliqua (Mollusca: Bivalvia)

NASA Astrophysics Data System (ADS)

Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Luísa; Lopes, Vanessa M.; Narciso, Luis; Marques, António; Bandarra, Narcisa; Rosa, Rui

2014-12-01

Few studies have been conducted on the temporal dynamics of both amino acid (AA) and fatty acid (FA) profiles in marine bivalves. We investigated the seasonal variation of these compounds in the pod razor clam Ensis siliqua in relation to food availability, salinity, water temperature and reproductive cycle. AA content varied between 46.94 and 54.67 % dry weight (DW), and the AAs found in greater quantity were glutamic acid, glycine and aspartic acid. FA content varied between 34.02 and 87.94 mg g-1 DW and the FAs found in greater quantity were 16:0 and 22:6 n-3. Seasonal trends were observed for AAs and FAs. FAs increased with gametogenesis and decreased with spawning while AA content increased throughout spawning. The effect of increasing temperature and high food availability during the spawning season masked the loss of AAs resulting from gamete release. Still, a comparatively greater increase in the contents of glutamic acid and leucine with spawning indicate their possible involvement in a post-spawning gonad recovery mechanism. A post-spawning decrease in 14:0, 16:0, 16:1 n-7, 18:1 n-7 and 18:1 n-9 is indicative of the importance of these FAs in bivalve eggs. An increase in 18:3 n-3, 18:4 n-3, 20:1 n-9 and 20:2 n-6 during gametogenesis suggests their involvement in oocyte maturation. The FA 22:4 n-6, while increasing with spawning, appears to play a role in post-spawning gonad recovery. Salinity did not have an effect on the AA composition. None of the environmental parameters measured had an effect on FA composition.

Association between neurotrophin 4 and long-chain polyunsaturated fatty acid levels in mid-trimester amniotic fluid.

PubMed

Benn, Kiesha; Passos, Mariana; Jayaram, Aswathi; Harris, Mary; Bongiovanni, Ann Marie; Skupski, Daniel; Witkin, Steven S

2014-11-01

The omega-3 long-chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) and the omega-6 LCPUFA arachidonic acid (AA) are essential nervous system components that increase in concentration throughout gestation. The neurotrophins, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4) are small basic peptides crucial for fetal brain development. The DHA supplementation during pregnancy has been suggested to enhance neural development. We evaluated whether amniotic fluid DHA and AA concentrations correlated with intra-amniotic neurotrophin levels. Amniotic fluid, obtained at 15 to 19 weeks gestation from 62 women, was tested for BDNF, NGF, NT3, and NT4 by enzyme-linked immunosorbent assay. Concentrations of DHA and AA, and saturated and monounsaturated fatty acids, were determined by gas chromatography. Associations were analyzed by the Spearman rank correlation test. Median levels of AA and DHA were 2.3% and 1.3% of the total intra-amniotic fatty acids, respectively. Median neurotrophin levels (pg/mL) were 36.7 for NT3, 26.8 for BDNF, 5.2 for NT4, and 0.8 for NGF. Intra-amniotic NT4 and BDNF levels were correlated (P = .0016), while NT3 and NGF levels were unrelated to each other or to BDNF or NT4. Only NT4 was positively correlated with amniotic fluid DHA (P < .0001) and AA (P = .0003) concentrations. There were no associations between DHA, AA, or any neurotrophin and maternal age, gestational age at time of amniocentesis, amniocentesis indication, parity, or gestational age at delivery. Elevations in intra-amniotic NT4 with increasing levels of DHA and AA suggest that these LCPUFAs may specifically influence the extent of NT4-mediated fetal brain neurogenesis. © The Author(s) 2014.

Estimation of endogenous protein and amino acid ileal losses in weaned piglets by regression analysis using diets with graded levels of casein

PubMed Central

2013-01-01

Background Many studies have investigated endogenous loss of proteins and amino acids (AAs) at the ileal level in growing pigs. However, only a few studies have researched this subject in piglets. Knowledge regarding AA ileal digestibility in piglets would be helpful during the formulation of diets for weaning piglets, rather than just using coefficients obtained in growing pigs. Therefore, in this study, we sought to estimate endogenous protein and AA ileal losses in piglets. Furthermore, apparent and true ileal digestibility (AID and TID) of protein and AAs from casein were measured. Results The average flow of protein was 20.8 g/kg of dry matter intake (DMI). Basal protein loss, as estimated by regression, was 16.9 g/kg DMI. Glutamic acid, arginine, and aspartic acid (2.2, 1.4, and 1.2 g/kg DMI, respectively) were the AAs for which greater losses were seen. The AID of protein and AAs increased as the protein level in the diet increased. A higher increment in AID was observed between diets with 80 and160 g CP/kg of feed; this finding was mainly attributable to increases in glycine and arginine (46.1% and 18%, respectively). The TID of protein was 97.8, and the TID of AAs varied from 93.9 for histidine to 100.2 for phenylalanine. Conclusions The basal endogenous protein loss in piglets was 16.9 g/kg DMI. Endogenous protein was rich in glutamic acid, aspartic acid, and arginine, which represented 32.7% of endogenous protein loss in weaning piglets. The TID of casein was high and varied from 93.0 for histidine to 100.2 for phenylalanine. PMID:24053636

The Effect of Ascorbic Acid and Garlic Administration on Lead-Induced Neural Damage in Rat Offspring's Hippocampus.

PubMed

Sadeghi, Akram; Ebrahimzadeh Bideskan, Alireza; Alipour, Fatemeh; Fazel, Alireza; Haghir, Hossein

2013-02-01

The aim of this study was to investigate ascorbic acid and garlic protective effects on lead-induced neurotoxicity during rat hippocampus development. 90 pregnant wistar rats were divided randomly into nine groups: 1- Animals received leaded water (L). 2- Rats received leaded water and ascorbic acid (L+AA). 3- Animals received leaded water and garlic juice (L+G). 4-Animals received leaded water, ascorbic acid and garlic juice (L+G+AA). 5- Rats treated with ascorbic acid (AA). 6- Rats treated with garlic juice (G). 7- Rats treated with ascorbic acid and garlic juice (AA+G). 8- Rats treated with tap water plus 0.4 ml/l normal hydrogen chloride (HCl) and 0.5 mg/l Glucose (Sham). 9- Normal group (N). Leaded water (1500 ppm), garlic juice (1 ml/100g/day, gavage) and ascorbic acid (500 mg/kg/day, IP) were used. Finally, blood lead levels (BLL) were measured in both rats and their offspring. The rat offspring brain sections were stained using Toluidine Blue and photographed. Dark neurons (DNs) were counted to compare all groups. BLL significantly increased in L group compared to control and sham groups and decreased in L+G and L+AA groups in comparison to the L group (P<0.05). the number of DNs in the CA1, CA3, and DG of rat offspring hippocampus significantly increased in L group in comparison to control and sham groups (P<0.05) and decreased in L+G and L+AA groups compared to L group (P<0.05). Garlic juice and ascorbic acid administration during pregnancy and lactation may protect lead-induced neural damage in rat offspring hippocampus.

40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

Code of Federal Regulations, 2014 CFR

2014-07-01

... (40 CFR Part 63, Subpart A) to Subpart AA A Appendix A to Subpart AA of Part 63 Protection of... Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to Subpart AA of Part 63—Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA 40 CFR...

40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

Code of Federal Regulations, 2010 CFR

2010-07-01

... (40 CFR Part 63, Subpart A) to Subpart AA A Appendix A to Subpart AA of Part 63 Protection of... Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to Subpart AA of Part 63—Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA 40 CFR...

Analysis of protein glycation products by MALDI-TOF/MS.

PubMed

Kislinger, Thomas; Humeny, Andreas; Peich, Carlo C; Becker, Cord-Michael; Pischetsrieder, Monika

2005-06-01

Matrix-assisted laser desorption ionization-mass spectrometry with time-of-flight detection (MALDI-TOF/MS) is a promising tool to analyze advanced glycation end product (AGE)-modified proteins. The combination of soft ionization (MALDI) with time-of-flight mass detection allows analysis of peptides and proteins of a molecular mass up to 300 kDa with minimal sample workup. Because the direct structural analysis of intact AGE proteins is not possible due to the formation of broad and poorly resolved peaks, peptide mapping was introduced into the analysis of AGE proteins by MALDI-TOF/MS, allowing site-specific analysis of defined AGEs. When methylglyoxal-modified lysozyme was subjected to MALDI-TOF/MS peptide mapping, methylimidazolone and argpyrimidine attached to the arginine residue and carboxyethyl (CEL) bound to the lysine were detected on peptide(aa1-7) (KVFGRCE). In contrast, only one methylimidazolone was found on peptide(aa8-35) (LAAAMKRHGLDNYRGYSLGNWVCAAKFE) and peptide(aa120-129) (VQAWIRGCRL), respectively. The analysis of AGE protein, which had been incubated with glucose, revealed the presence of an Amadori product and a carboxymethyl residue (CML) on peptide(aa1-7) and peptide(aa8-35), as well as an imidazolone A on peptide(aa120-129). Furthermore, the early Maillard reaction of lysozyme, which had been glycated by seven different sugars, was monitored by MALDI-TOF/MS peptide mapping. Finally, this approach was successfully applied for site- and product-specific relative quantification of AGEs. For example, kinetics of CML and Amadori product formation on peptide(aa1-7), as well as imidazolone A formation on peptide(aa120-129), were determined.

Acid-Group-Content-Dependent Proton Conductivity Mechanisms at the Interlayer of Poly(N-dodecylacrylamide-co-acrylic acid) Copolymer Multilayer Nanosheet Films.

PubMed

Sato, Takuma; Tsukamoto, Mayu; Yamamoto, Shunsuke; Mitsuishi, Masaya; Miyashita, Tokuji; Nagano, Shusaku; Matsui, Jun

2017-11-14

The effect of the content of acid groups on the proton conductivity at the interlayer of polymer-nanosheet assemblies was investigated. For that purpose, amphiphilic poly(N-dodecylacrylamide-co-acrylic acid) copolymers [p(DDA/AA)] with varying contents of AA were synthesized by free radical polymerization. Surface pressure (π)-area (A) isotherms of these copolymers indicated that stable polymer monolayers are formed at the air/water interface for AA mole fraction (n) ≤ 0.49. In all cases, a uniform dispersion of the AA groups in the polymer monolayer was observed. Subsequently, polymer monolayers were transferred onto solid substrates using the Langmuir-Blodgett (LB) technique. X-ray diffraction (XRD) analyses of the multilayer films showed strong Bragg diffraction peaks, suggesting a highly uniform lamellar structure for the multilayer films. The proton conductivity of the multilayer films parallel to the direction of the layer planes were measured by impedance spectroscopy, which revealed that the conductivity increased with increasing values of n. Activation energies for proton conduction of ∼0.3 and 0.42 eV were observed for n ≥ 0.32 and n = 0.07, respectively. Interestingly, the proton conductivity of a multilayer film with n = 0.19 did not follow the Arrhenius equation. These results were interpreted in terms of the average distance between the AA groups (l AA ), and it was concluded that, for n ≥ 0.32, an advanced 2D hydrogen bonding network was formed, while for n = 0.07, l AA is too long to form such hydrogen bonding networks. The l AA for n = 0.19 is intermediate to these extremes, resulting in the formation of hydrogen bonding networks at low temperatures, and disruption of these networks at high temperatures due to thermally induced motion. These results indicate that a high proton conductivity with low activation energy can be achieved, even under weakly acidic conditions, by arranging the acid groups at an optimal distance.

Age Differences of Salivary Alpha-Amylase Levels of Basal and Acute Responses to Citric Acid Stimulation Between Chinese Children and Adults.

PubMed

Yang, Ze-Min; Chen, Long-Hui; Zhang, Min; Lin, Jing; Zhang, Jie; Chen, Wei-Wen; Yang, Xiao-Rong

2015-01-01

It remains unclear how salivary alpha-amylase (sAA) levels respond to mechanical stimuli in different age groups. In addition, the role played by the sAA gene (AMY1) copy number and protein expression (glycosylated and non-glycosylated) in sAA activity has also been rarely reported. In this study, we analyzed saliva samples collected before and after citric acid stimulation from 47 child and 47 adult Chinese subjects. We observed that adults had higher sAA activity and sAA glycosylated levels (glycosylated sAA amount/total sAA amount) in basal and stimulated saliva when compared with children, while no differences were found in total or glycosylated sAA amount between them. Interestingly, adults showed attenuated sAA activity levels increase over those of children after stimulation. Correlation analysis showed that total sAA amount, glycosylated sAA amount, and AMY1 copy number × total sAA amount were all positively correlated with sAA activity before and after stimulation in both groups. Interestingly, correlation r between sAA levels (glycosylated sAA amount and total sAA amount) and sAA activity decreased after stimulation in children, while adults showed an increase in correlation r. In addition, the correlation r between AMY1 copy number × total sAA amount and sAA activity was higher than that between AMY1 copy number, total sAA amount, and sAA activity, respectively. Taken together, our results suggest that total sAA amount, glycosylated sAA amount, and the positive interaction between AMY1 copy number and total sAA amount are crucial in influencing sAA activity before and after stimulation in children and adults.

Age Differences of Salivary Alpha-Amylase Levels of Basal and Acute Responses to Citric Acid Stimulation Between Chinese Children and Adults

PubMed Central

Yang, Ze-Min; Chen, Long-Hui; Zhang, Min; Lin, Jing; Zhang, Jie; Chen, Wei-Wen; Yang, Xiao-Rong

2015-01-01

It remains unclear how salivary alpha-amylase (sAA) levels respond to mechanical stimuli in different age groups. In addition, the role played by the sAA gene (AMY1) copy number and protein expression (glycosylated and non-glycosylated) in sAA activity has also been rarely reported. In this study, we analyzed saliva samples collected before and after citric acid stimulation from 47 child and 47 adult Chinese subjects. We observed that adults had higher sAA activity and sAA glycosylated levels (glycosylated sAA amount/total sAA amount) in basal and stimulated saliva when compared with children, while no differences were found in total or glycosylated sAA amount between them. Interestingly, adults showed attenuated sAA activity levels increase over those of children after stimulation. Correlation analysis showed that total sAA amount, glycosylated sAA amount, and AMY1 copy number × total sAA amount were all positively correlated with sAA activity before and after stimulation in both groups. Interestingly, correlation r between sAA levels (glycosylated sAA amount and total sAA amount) and sAA activity decreased after stimulation in children, while adults showed an increase in correlation r. In addition, the correlation r between AMY1 copy number × total sAA amount and sAA activity was higher than that between AMY1 copy number, total sAA amount, and sAA activity, respectively. Taken together, our results suggest that total sAA amount, glycosylated sAA amount, and the positive interaction between AMY1 copy number and total sAA amount are crucial in influencing sAA activity before and after stimulation in children and adults. PMID:26635626

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

PubMed Central

Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

2009-01-01

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations (AUC0-6h= 3237.0 and 181.8 pmol*h/L plasma respectively) relative to GT control (AUC0-6h = 1304.1 and 61.0 pmol*h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (∼51-53%) relative to EGCG and epicatechin gallate (ECG) (< 20%) and was modestly enhanced in GT+S and GT+S+AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P<0.05) higher from GT+S+AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea. PMID:20161530

IgE binding to peanut allergens is inhibited by combined D-aspartic and D-glutamic acids.

PubMed

Chung, Si-Yin; Reed, Shawndrika

2015-01-01

The objective of this study was to determine if D-amino acids (D-aas) bind and inhibit immunoglobulin E (IgE) binding to peanut allergens. D-aas such as D-Asp (aspartic acid), D-Glu (glutamic acid), combined D-[Asp/Glu] and others were each prepared in a cocktail of 9 other D-aas, along with L-amino acids (L-aas) and controls. Each sample was mixed with a pooled plasma from peanut-allergic donors, and tested by ELISA (enzyme-linked immunosorbent assay) and Western blots for IgE binding to peanut allergens. Results showed that D-[Asp/Glu] (4 mg/ml) inhibited IgE binding (75%) while D-Glu, D-Asp and other D-aas had no inhibitory effect. A higher inhibition was seen with D-[Asp/Glu] than with L-[Asp/Glu]. We concluded that IgE was specific for D-[Asp/Glu], not D-Asp or D-Glu, and that D-[Asp/Glu] was more reactive than was L-[Asp/Glu] in IgE inhibition. The finding indicates that D-[Asp/Glu] may have the potential for removing IgE or reducing IgE binding to peanut allergens in vitro. Published by Elsevier Ltd.

Co-induction of hepatic IGF-I and progranulin mRNA by growth hormone in tilapia, Oreochromis mossambiccus.

PubMed

Chen, Mark Hung-Chih; Li, Yen-Hsing; Chang, Yvonne; Hu, Shao-Yang; Gong, Hong-Yi; Lin, Gen-Hwa; Chen, Thomas T; Wu, Jen-Leih

2007-01-15

Like IGF-I, progranulin (pgrn) is a growth factor involved in tumorigenesis and wound healing. We report here the identification and characterization of pgrn cDNA in tilapia and the regulation of its expression by growth hormone (GH). The tilapia pgrn cDNA was cloned by RT-PCR amplification, using gene specific oligonucleotides as amplification primers. The cDNA contains an open reading frame encoding a peptide of 206 amino acid residues (aa) that contains a presumptive signal peptide (23 aa) and two repeat units of granulin (grn, 51 and 52 aa, respectively) franked by a GAP of 49 aa and the carboxyl terminus with 31 aa. The two predicted grn peptides are arranged in tandem repeats interrupted by a GAP peptide. RT-PCR analysis revealed that high levels of prgn mRNA were present in several tissues such as spleen, gastric cecum, intestine, fat tissue, gill, kidney, eye and pancreas, and lower levels in liver, muscle, heart, brain, skin and stomach. Administration of a single dose (500 ng/g body weight) of recombinant seabream growth hormone (rbGH) by intraperitoneal (ip) injection into one-month-old tilapia resulted in an obvious increase of IGF-I and pgrn mRNA (2.7-fold and 2.5-fold, respectively) in the liver at three hours post-GH treatment. The peptide levels of pgrn in the liver of GH-treated fish also were substantially induced over controls at 12h post-GH treatment as detected by western immuno-blot analysis. The co-induction of IGF-I and pgrn following GH treatment may suggest the involvement of pgrn in GH regulated growth in tilapia.

Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Tirouvanziam, Rabindra; Obukhanych, Tetyana V.; Laval, Julie; Aronov, Pavel A.; Libove, Robin; Banerjee, Arpita Goswami; Parker, Karen J.; O'Hara, Ruth; Herzenberg, Leonard A.; Herzenberg, Leonore A.; Hardan, Antonio Y.

2012-01-01

The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N = 27) and neuro-typically developing controls (N = 20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating…

Ascorbic acid, cognitive function, and Alzheimer’s disease: a current review and future direction

PubMed Central

Bowman, Gene L.

2013-01-01

This narrative review appraises the human and animal studies implicating ascorbic acid (AA) in normal cognitive function and Alzheimer’s disease. A research framework for how nutrition affects brain aging is proposed with emphasis on AA intake, status, metabolism, and transport into brain tissue. A final synopsis highlights areas for future research regarding AA nourishment and healthy brain aging. PMID:22419527

Blood fatty acid composition of pregnant and nonpregnant Korean women: red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus.

PubMed

Ghebremeskel, K; Min, Y; Crawford, M A; Nam, J H; Kim, A; Koo, J N; Suzuki, H

2000-05-01

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n = 40) and nonpregnant, nonlactating (n = 40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P < 0.05) and palmitic and oleic acids higher (P < 0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P < 0.05) and higher palmitic and oleic acids (P < 0.01). The reduction in DHA and total n-3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n-6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n-6 series and DPA/DTA ratio did not increase with the decrease of the n-3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n-3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.

The roles of AMY1 copies and protein expression in human salivary α-amylase activity.

PubMed

Yang, Ze-Min; Lin, Jing; Chen, Long-Hui; Zhang, Min; Chen, Wei-Wen; Yang, Xiao-Rong

2015-01-01

Salivary α-amylase (sAA) activity has been extensively investigated in nutrition and psychology. But few studies were performed to assess the role played by sAA gene (AMY1) copies and protein expression in basal and stimulus-induced sAA activity. The sAA activity, amount and AMY1 copy number were determined from 184 saliva samples pre- and post-citric acid stimulation. Our findings showed that citric acid could induce significant increase in sAA activity, total sAA amount, and glycosylated sAA amount, among which the glycosylated sAA amount had the largest response. The correlation analysis showed that AMY1 copy number, total sAA amount and AMY1 copy number×total sAA amount had significantly positive and successively increasing correlations with sAA activity in unstimulated and stimulated saliva, respectively, and furthermore, we observed higher correlations in unstimulated saliva when compared with the corresponding correlations in stimulated saliva. We also observed significant correlations between glycosylated sAA amount and sAA activity in unstimulated and stimulated saliva, respectively. Interestingly, the correlations were higher in stimulated saliva than in unstimulated saliva, and the correlations between glycosylated sAA amount and sAA activity were higher than that of between total sAA amount and sAA activity in stimulated saliva. Moreover, total sAA amount ratio and glycosylated sAA amount ratio showed significantly positive correlation with sAA activity ratio. AMY1 copy number had no correlation with sAA activity ratio. These findings suggested that AMY1 copy number and sAA amount played crucial roles in sAA activity; however, the roles were attenuated after stimulation due to fortified release of glycosylated sAA. Copyright © 2014 Elsevier Inc. All rights reserved.

High Protein Intake Does Not Prevent Low Plasma Levels of Conditionally Essential Amino Acids in Very Preterm Infants Receiving Parenteral Nutrition.

PubMed

Morgan, Colin; Burgess, Laura

2017-03-01

We have shown that increasing protein intake using a standardized, concentrated, added macronutrients parenteral (SCAMP) nutrition regimen improves head growth in very preterm infants (VPIs) compared with a control parenteral nutrition (PN) regimen. VPIs are at risk of conditionally essential amino acid (CEAA) deficiencies because of current neonatal PN amino acid (AA) formulations. We hypothesized that the SCAMP regimen would prevent low plasma levels of CEAAs. To compare the plasma AA profiles at approximately day 9 of life in VPIs receiving SCAMP vs a control PN regimen. VPIs (<29 weeks' gestation) were randomized to receive SCAMP (30% more PN AA) or a control regimen. Data were collected to measure parenteral and enteral protein, energy, and individual AA intake and the first plasma AA profile. Plasma profiles of the 20 individual protogenic AA levels were measured using ion exchange chromatography. Plasma AA profiles were obtained at median (interquartile range [IQR]) age of 9 (8-10) days in both SCAMP (n = 59) and control (n = 67) groups after randomizing 150 VPIs. Median (IQR) plasma levels of individual essential AAs were higher than the reference population mean (RPM) in both groups, especially for threonine. SCAMP infants had higher plasma levels of essential AAs than did the controls. Median (IQR) plasma levels of glutamine, arginine, and cysteine (CEAAs) were lower than the RPM in both groups. Plasma AA levels in PN-dependent VPIs indicate there is an imbalance in essential and CEAA provision in neonatal PN AA formulations that is not improved by increasing protein intake.

High-Molecular Compounds (Selected Articles).

DTIC Science & Technology

1987-08-24

Polymethacrylic Acid and Polyvinyl Alcohol, by I.F. Yefremov, E.B. D’yakonova, A.A. Spartakov, A.A. Trusov ._’ . Us’yarov...polyoctafluoroamyl methacrylate) was converted into polymethacrylic acid by hydrolysis in an alkaline medium. The poly acid was methylated by diazomethane...Institute im. Lensovet Submitted 25 Apr 66 In a low-concentrated aqueous solution of polymethacrylic acid (PHAK) and polyvinyl alcohol (PVS) mixed

Arachidonic acid-and docosahexaenoic acid-enriched formulas modulate antigen-specific T cell responses to influenza virus in neonatal piglets.

PubMed

Bassaganya-Riera, Josep; Guri, Amir J; Noble, Alexis M; Reynolds, Kathryn A; King, Jennifer; Wood, Cynthia M; Ashby, Michael; Rai, Deshanie; Hontecillas, Raquel

2007-03-01

Whereas the immunomodulatory effects of feeding either arachidonic acid (AA) or docosahexaenoic acid (DHA) separately have been previously investigated, little is known about the immunomodulatory efficacy of AA or DHA when they are fed in combination as infant formula ingredients. The objective of this study was to investigate the ability of AA- and DHA(AA/DHA)-enriched infant formula to modulate immune responses in the neonate in response to an inactivated influenza virus vaccine. Neonatal piglets (n = 48) were weaned on day 2 of age and distributed into 16 blocks of 3 littermate piglets each. Within each block, piglets were randomly assigned to a control formula, AA/DHA-enriched formula (0.63% AA and 0.34% DHA), or sow milk for 30 d. On day 9, 8 blocks of piglets were immunized with an inactivated influenza virus vaccine. On days 0, 9, 16, 23, and 30 after weaning, we measured influenza virus-specific T cell proliferation and phenotype of T subsets in peripheral blood. A delayed-type hypersensitivity reaction test was administered on day 28. Cytokine messenger RNA expression was determined by quantitative real time reverse transcriptase-polymerase chain reaction on day 30. The influenza virus-specific CD4(+) and CD8(+) T cell ex vivo lymphoproliferative responses were significantly lower on day 23 after immunization in piglets receiving dietary AA/DHA supplementation and sow milk than in those receiving the unsupplemented control formula. The immunomodulatory effects of AA/DHA-enriched formulas were consistent with up-regulation of interleukin 10 in peripheral blood mononuclear cells. Overall, it appears that the AA/DHA-enriched formula modulated antigen-specific T cell responses in part through an interleukin 10-dependent mechanism.

Commensal bacteria and essential amino acids control food choice behavior and reproduction

PubMed Central

Fioreze, Gabriela Tondolo; Anjos, Margarida; Baltazar, Célia; Elias, Ana Paula; Itskov, Pavel M.; Piper, Matthew D. W.

2017-01-01

Choosing the right nutrients to consume is essential to health and wellbeing across species. However, the factors that influence these decisions are poorly understood. This is particularly true for dietary proteins, which are important determinants of lifespan and reproduction. We show that in Drosophila melanogaster, essential amino acids (eAAs) and the concerted action of the commensal bacteria Acetobacter pomorum and Lactobacilli are critical modulators of food choice. Using a chemically defined diet, we show that the absence of any single eAA from the diet is sufficient to elicit specific appetites for amino acid (AA)-rich food. Furthermore, commensal bacteria buffer the animal from the lack of dietary eAAs: both increased yeast appetite and decreased reproduction induced by eAA deprivation are rescued by the presence of commensals. Surprisingly, these effects do not seem to be due to changes in AA titers, suggesting that gut bacteria act through a different mechanism to change behavior and reproduction. Thus, eAAs and commensal bacteria are potent modulators of feeding decisions and reproductive output. This demonstrates how the interaction of specific nutrients with the microbiome can shape behavioral decisions and life history traits. PMID:28441450

Commensal bacteria and essential amino acids control food choice behavior and reproduction.

PubMed

Leitão-Gonçalves, Ricardo; Carvalho-Santos, Zita; Francisco, Ana Patrícia; Fioreze, Gabriela Tondolo; Anjos, Margarida; Baltazar, Célia; Elias, Ana Paula; Itskov, Pavel M; Piper, Matthew D W; Ribeiro, Carlos

2017-04-01

Choosing the right nutrients to consume is essential to health and wellbeing across species. However, the factors that influence these decisions are poorly understood. This is particularly true for dietary proteins, which are important determinants of lifespan and reproduction. We show that in Drosophila melanogaster, essential amino acids (eAAs) and the concerted action of the commensal bacteria Acetobacter pomorum and Lactobacilli are critical modulators of food choice. Using a chemically defined diet, we show that the absence of any single eAA from the diet is sufficient to elicit specific appetites for amino acid (AA)-rich food. Furthermore, commensal bacteria buffer the animal from the lack of dietary eAAs: both increased yeast appetite and decreased reproduction induced by eAA deprivation are rescued by the presence of commensals. Surprisingly, these effects do not seem to be due to changes in AA titers, suggesting that gut bacteria act through a different mechanism to change behavior and reproduction. Thus, eAAs and commensal bacteria are potent modulators of feeding decisions and reproductive output. This demonstrates how the interaction of specific nutrients with the microbiome can shape behavioral decisions and life history traits.

Early amino acid administration in very preterm infants: Too little, too late or too much, too soon?

PubMed

Morgan, Colin

2013-03-09

Early postnatal growth failure is well described in very preterm infants. It reflects the nutritional deficits in protein and energy intake that accumulate in the first few weeks after birth. This coincides with the period of maximum parenteral nutrition (PN) dependency, so that protein intake is largely determined by intravenous amino acid (AA) administration. The contribution of PN manufacture, supply, formulation, prescribing and administration to the early postnatal nutritional deficit is discussed, focusing on total AA intake. The implications of postnatal deficits in AA and energy intake for growth are reviewed, with particular emphasis on early head/brain growth and long-term neurodevelopmental outcome. The rationale for maximising AA acid intake as soon as possible after birth is explained. This includes the benefits for very early postnatal nutritional intake and metabolic adaptation after birth. These benefits relate to total AA intake and so have to be interpreted with some caution, given the very limited evidence base surrounding the balance of individual AAs in neonatal PN formulations. This work mostly predates current nutritional recommendations and therefore may not provide a true reflection of individual AA utilisation in current clinical practice. Copyright © 2013. Published by Elsevier Ltd.

Synthesis and Biomedical Applications of Poly((meth)acrylic acid) Brushes.

PubMed

Qu, Zhenyuan; Xu, Hong; Gu, Hongchen

2015-07-15

Poly((meth)acrylic acid) (P(M)AA) brushes possess a number of distinctive properties that are particularly attractive for biomedical applications. This minireview summarizes recent advances in the synthesis and biomedical applications of P(M)AA brushes and brushes containing P(M)AA segments. First, we review different surface-initiated polymerization (SIP) methods, with a focus on recent progress in the surface-initiated controlled/living radical polymerization (SI-CLRP) techniques used to generate P(M)AA brushes with a tailored structure. Next, we discuss biomolecule immobilization methods for P(M)AA brushes, including physical adsorption, covalent binding, and affinity interactions. Finally, typical biomedical applications of P(M)AA brushes are reviewed, and their performance is discussed based on their unique properties. We conclude that P(M)AA brushes are promising biomaterials, and more potential biomedical applications are expected to emerge with the further development of synthetic techniques and increased understanding of their interactions with biological systems.

Prolonged infusion of amino acids increases leucine oxidation in fetal sheep

PubMed Central

Maliszewski, Anne M.; Gadhia, Monika M.; O'Meara, Meghan C.; Thorn, Stephanie R.; Rozance, Paul J.

2012-01-01

Maternal high-protein supplements designed to increase birth weight have not been successful. We recently showed that maternal amino acid infusion into pregnant sheep resulted in competitive inhibition of amino acid transport across the placenta and did not increase fetal protein accretion rates. To bypass placental transport, singleton fetal sheep were intravenously infused with an amino acid mixture (AA, n = 8) or saline [control (Con), n = 10] for ∼12 days during late gestation. Fetal leucine oxidation rate increased in the AA group (3.1 ± 0.5 vs. 1.4 ± 0.6 μmol·min−1·kg−1, P < 0.05). Fetal protein accretion (2.6 ± 0.5 and 2.2 ± 0.6 μmol·min−1·kg−1 in AA and Con, respectively), synthesis (6.2 ± 0.8 and 7.0 ± 0.9 μmol·min−1·kg−1 in AA and Con, respectively), and degradation (3.6 ± 0.6 and 4.5 ± 1.0 μmol·min−1·kg−1 in AA and Con, respectively) rates were similar between groups. Net fetal glucose uptake decreased in the AA group (2.8 ± 0.4 vs. 3.9 ± 0.1 mg·kg−1·min−1, P < 0.05). The glucose-O2 quotient also decreased over time in the AA group (P < 0.05). Fetal insulin and IGF-I concentrations did not change. Fetal glucagon increased in the AA group (119 ± 24 vs. 59 ± 9 pg/ml, P < 0.05), and norepinephrine (NE) also tended to increase in the AA group (785 ± 181 vs. 419 ± 76 pg/ml, P = 0.06). Net fetal glucose uptake rates were inversely proportional to fetal glucagon (r2 = 0.38, P < 0.05), cortisol (r2 = 0.31, P < 0.05), and NE (r2 = 0.59, P < 0.05) concentrations. Expressions of components in the mammalian target of rapamycin signaling pathway in fetal skeletal muscle were similar between groups. In summary, prolonged infusion of amino acids directly into normally growing fetal sheep increased leucine oxidation. Amino acid-stimulated increases in fetal glucagon, cortisol, and NE may contribute to a shift in substrate oxidation by the fetus from glucose to amino acids. PMID:22454287

Omega-3 and Omega-6 Polyunsaturated Fatty Acid Levels and Correlations with Symptoms in Children with Attention Deficit Hyperactivity Disorder, Autistic Spectrum Disorder and Typically Developing Controls

PubMed Central

Niyonsenga, Theophile; Duff, Jacques

2016-01-01

Background There is evidence that children with Attention Deficit Hyperactivity Disorder (ADHD) and Autistic Spectrum Disorder (ASD) have lower omega-3 polyunsaturated fatty acid (n-3 PUFA) levels compared with controls and conflicting evidence regarding omega-6 (n-6) PUFA levels. Objectives This study investigated whether erythrocyte n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were lower and n-6 PUFA arachidonic acid (AA) higher in children with ADHD, ASD and controls, and whether lower n-3 and higher n-6 PUFAs correlated with poorer scores on the Australian Twin Behaviour Rating Scale (ATBRS; ADHD symptoms) and Test of Variable Attention (TOVA) in children with ADHD, and Childhood Autism Rating Scale (CARS) in children with ASD. Methods Assessments and blood samples of 565 children aged 3–17 years with ADHD (n = 401), ASD (n = 85) or controls (n = 79) were analysed. One-way ANOVAs with Tukey’s post-hoc analysis investigated differences in PUFA levels between groups and Pearson’s correlations investigated correlations between PUFA levels and ATBRS, TOVA and CARS scores. Results Children with ADHD and ASD had lower DHA, EPA and AA, higher AA/EPA ratio and lower n-3/n-6 than controls (P<0.001 except AA between ADHD and controls: P = 0.047). Children with ASD had lower DHA, EPA and AA than children with ADHD (P<0.001 for all comparisons). ATBRS scores correlated negatively with EPA (r = -.294, P<0.001), DHA (r = -.424, P<0.001), n-3/n-6 (r = -.477, P<0.001) and positively with AA/EPA (r = .222, P <.01). TOVA scores correlated positively with DHA (r = .610, P<0.001), EPA (r = .418, P<0.001) AA (r = .199, P<0.001), and n-3/n-6 (r = .509, P<0.001) and negatively with AA/EPA (r = -.243, P<0.001). CARS scores correlated significantly with DHA (r = .328, P = 0.002), EPA (r = -.225, P = 0.038) and AA (r = .251, P = 0.021). Conclusions Children with ADHD and ASD had low levels of EPA, DHA and AA and high ratio of n-6/n-3 PUFAs and these correlated significantly with symptoms. Future research should further investigate abnormal fatty acid metabolism in these disorders. PMID:27232999

Omega-3 and Omega-6 Polyunsaturated Fatty Acid Levels and Correlations with Symptoms in Children with Attention Deficit Hyperactivity Disorder, Autistic Spectrum Disorder and Typically Developing Controls.

PubMed

Parletta, Natalie; Niyonsenga, Theophile; Duff, Jacques

2016-01-01

There is evidence that children with Attention Deficit Hyperactivity Disorder (ADHD) and Autistic Spectrum Disorder (ASD) have lower omega-3 polyunsaturated fatty acid (n-3 PUFA) levels compared with controls and conflicting evidence regarding omega-6 (n-6) PUFA levels. This study investigated whether erythrocyte n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were lower and n-6 PUFA arachidonic acid (AA) higher in children with ADHD, ASD and controls, and whether lower n-3 and higher n-6 PUFAs correlated with poorer scores on the Australian Twin Behaviour Rating Scale (ATBRS; ADHD symptoms) and Test of Variable Attention (TOVA) in children with ADHD, and Childhood Autism Rating Scale (CARS) in children with ASD. Assessments and blood samples of 565 children aged 3-17 years with ADHD (n = 401), ASD (n = 85) or controls (n = 79) were analysed. One-way ANOVAs with Tukey's post-hoc analysis investigated differences in PUFA levels between groups and Pearson's correlations investigated correlations between PUFA levels and ATBRS, TOVA and CARS scores. Children with ADHD and ASD had lower DHA, EPA and AA, higher AA/EPA ratio and lower n-3/n-6 than controls (P<0.001 except AA between ADHD and controls: P = 0.047). Children with ASD had lower DHA, EPA and AA than children with ADHD (P<0.001 for all comparisons). ATBRS scores correlated negatively with EPA (r = -.294, P<0.001), DHA (r = -.424, P<0.001), n-3/n-6 (r = -.477, P<0.001) and positively with AA/EPA (r = .222, P <.01). TOVA scores correlated positively with DHA (r = .610, P<0.001), EPA (r = .418, P<0.001) AA (r = .199, P<0.001), and n-3/n-6 (r = .509, P<0.001) and negatively with AA/EPA (r = -.243, P<0.001). CARS scores correlated significantly with DHA (r = .328, P = 0.002), EPA (r = -.225, P = 0.038) and AA (r = .251, P = 0.021). Children with ADHD and ASD had low levels of EPA, DHA and AA and high ratio of n-6/n-3 PUFAs and these correlated significantly with symptoms. Future research should further investigate abnormal fatty acid metabolism in these disorders.

Versatility of acyl-acyl carrier protein synthetases

DOE PAGES

Beld, Joris; Finzel, Kara; Burkart, Michael D.

2014-10-09

The acyl carrier protein (ACP) requires posttranslational modification with a 4'-phosphopantetheine arm for activity, and this thiol-terminated modification carries cargo between enzymes in ACP-dependent metabolic pathways. In this paper, we show that acyl-ACP synthetases (AasSs) from different organisms are able to load even, odd, and unnatural fatty acids onto E. coli ACP in vitro. Vibrio harveyi AasS not only shows promiscuity for the acid substrate, but also is active upon various alternate carrier proteins. AasS activity also extends to functional activation in living organisms. We show that exogenously supplied carboxylic acids are loaded onto ACP and extended by the E.more » coli fatty acid synthase, including unnatural fatty acid analogs. These analogs are further integrated into cellular lipids. Finally, in vitro characterization of four different adenylate-forming enzymes allowed us to disambiguate CoA-ligases and AasSs, and further in vivo studies show the potential for functional application in other organisms.« less

Preparation and characterization of poly(acrylic acid)-hydroxyethyl cellulose graft copolymer.

PubMed

Abdel-Halim, E S

2012-10-01

Poly(acrylic acid) hydroxyethyl cellulose [poly(AA)-HEC] graft copolymer was prepared by polymerizing acrylic acid (AA) with hydroxyethyl cellulose (HEC) using potassium bromate/thiourea dioxide (KBrO(3)/TUD) as redox initiation system. The polymerization reaction was carried out under a variety of conditions including concentrations of AA, KBrO(3) and TUD, material to liquor ratio and polymerization temperature. The polymerization reaction was monitored by withdrawing samples from the reaction medium and measuring the total conversion. The rheological properties of the poly(AA)-HEC graft copolymer were investigated. The total conversion and rheological properties of the graft copolymer depended on the ratio of KBrO(3) to TUD and on acrylic acid concentration as well as temperature and material to liquor ratio. Optimum conditions of the graft copolymer preparation were 30 mmol KBrO(3) and 30 mmol TUD/100g HEC, 100% AA (based on weight of HEC), duration 2h at temperature 50 °C using a material to liquor ratio of 1:10. Copyright © 2012. Published by Elsevier Ltd.

Eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio as an associated factor of high risk plaque on coronary computed tomography in patients without coronary artery disease.

PubMed

Nagahara, Yasuomi; Motoyama, Sadako; Sarai, Masayoshi; Ito, Hajime; Kawai, Hideki; Takakuwa, Yoko; Miyagi, Meiko; Shibata, Daisuke; Takahashi, Hiroshi; Naruse, Hiroyuki; Ishii, Junichi; Ozaki, Yukio

2016-07-01

Coronary computed tomography angiography (CCTA)-verified high risk plaque (HRP) characteristics including positive remodeling and low attenuation plaque have been associated with acute coronary syndromes. Several studies reported that the n-3 polyunsaturated fatty acids have been associated with cardiovascular events. However, the relationship between serum eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio and CCTA-verified HRP in patients without known coronary artery disease (CAD) is unclear. We aimed at investigating the relation between EPA/AA and CCTA-verified HRP in patients without known CAD. We included 193 patients undergoing CCTA without known CAD (65.5 ± 12.0 years, 55.0% male). No patient has been treated with EPA. The relation of coronary risk factors, lipid profile, high-sensitivity C-reactive protein, coronary artery calcification score (CACS), number of vessel disease, plaque burden, and EPA/AA with the presence of HRP was evaluated by logistic regression analysis. Incremental value of EPA/AA to predict HRP was also analyzed by C-index, NRI, and IDI. A Cox proportional hazards model was used to estimate the time to cardiovascular event. HRP was observed in 37 (19%) patients. Multivariable logistic regression analysis revealed that current smoking (OR 2.58; p=0.046), number of vessel disease (OR 1.87; p=0.031), and EPA/AA ratio (OR 0.65; p=0.0006) were independent associated factors of HRP on CCTA. Although the addition of EPA/AA to the baseline model did not significantly improve C-index, both NRI (0.60, p=0.0049) and IDI (0.054, p=0.0072) were significantly improved. Patients with HRP had significantly higher rate of events compared with patients without HRP (14% vs. 3%, Logrank p=0.0004). On multivariable Cox hazard analysis, baseline EPA/AA ratio was an independent predictor (HR 0.57, p=0.047). Low EPA/AA was an associated factor of HRP on CCTA in patients without CAD. In addition to conventional coronary risk factors and CACS, EPA/AA and CCTA might be useful for risk stratification of CAD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Molecular basis of the evolution of alternative tyrosine biosynthetic routes in plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schenck, Craig A.; Holland, Cynthia K.; Schneider, Matthew R.

L-Tyrosine (Tyr) is essential for protein synthesis and is a precursor of numerous specialized metabolites crucial for plant and human health. Tyr can be synthesized via two alternative routes by different key regulatory TyrA family enzymes, prephenate dehydrogenase (PDH, also known as TyrAp) or arogenate dehydrogenase (ADH, also known as TyrAa), representing a unique divergence of primary metabolic pathways. The molecular foundation underlying the evolution of these alternative Tyr pathways is currently unknown. Here we characterized recently diverged plant PDH and ADH enzymes, obtained the X-ray crystal structure of soybean PDH, and identified a single amino acid residue that definesmore » TyrA substrate specificity and regulation. Structures of mutated PDHs co-crystallized with Tyr indicate that substitutions of Asn222 confer ADH activity and Tyr sensitivity. Reciprocal mutagenesis of the corresponding residue in divergent plant ADHs further introduced PDH activity and relaxed Tyr sensitivity, highlighting the critical role of this residue in TyrA substrate specificity that underlies the evolution of alternative Tyr biosynthetic pathways in plants.« less

Disinfection of wastewater with peracetic acid: a review.

PubMed

Kitis, Mehmet

2004-03-01

Peracetic acid is a strong disinfectant with a wide spectrum of antimicrobial activity. Due to its bactericidal, virucidal, fungicidal, and sporicidal effectiveness as demonstrated in various industries, the use of peracetic acid as a disinfectant for wastewater effluents has been drawing more attention in recent years. The desirable attributes of peracetic acid for wastewater disinfection are the ease of implementing treatment (without the need for expensive capital investment), broad spectrum of activity even in the presence of heterogeneous organic matter, absence of persistent toxic or mutagenic residuals or by-products, no quenching requirement (i.e., no dechlorination), small dependence on pH, short contact time, and effectiveness for primary and secondary effluents. Major disadvantages associated with peracetic acid disinfection are the increases of organic content in the effluent due to acetic acid (AA) and thus in the potential microbial regrowth (acetic acid is already present in the mixture and is also formed after peracetic acid decomposition). Another drawback to the use of peracetic acid is its high cost, which is partly due to limited production capacity worldwide. However, if the demand for peracetic acid increases, especially from the wastewater industry, the future mass production capacity might also be increased, thus lowering the cost. In such a case, in addition to having environmental advantages, peracetic acid may also become cost-competitive with chlorine.

Leucine and methionine deficiency induce catabolism through non-overlapping mechanisms in rainbow trout (Oncorhynchus mykiss) primary myoblasts

USDA-ARS?s Scientific Manuscript database

Amino acids (AA) have anabolic effects on protein accretion in muscle. In fish it is unknown if this anabolic response is directly attributed to a single AA or a specific AA profile. Therefore, our experimental objective was to determine if AAs or AA profiles regulate protein turnover and growth-r...

The role of amino acids in hydroxyapatite mineralization

PubMed Central

2016-01-01

Polar and charged amino acids (AAs) are heavily expressed in non-collagenous proteins (NCPs), and are involved in hydroxyapatite (HA) mineralization in bone. Here, we review what is known on the effect of single AAs on HA precipitation. Negatively charged AAs, such as aspartic acid, glutamic acid (Glu) and phosphoserine are largely expressed in NCPs and play a critical role in controlling HA nucleation and growth. Positively charged ones such as arginine (Arg) or lysine (Lys) are heavily involved in HA nucleation within extracellular matrix proteins such as collagen. Glu, Arg and Lys intake can also increase bone mineral density by stimulating growth hormone production. In vitro studies suggest that the role of AAs in controlling HA precipitation is affected by their mobility. While dissolved AAs are able to inhibit HA precipitation and growth by chelating Ca2+ and PO43− ions or binding to nuclei of calcium phosphate and preventing their further growth, AAs bound to surfaces can promote HA precipitation by attracting Ca2+ and PO43− ions and increasing the local supersaturation. Overall, the effect of AAs on HA precipitation is worth being investigated more, especially under conditions closer to the physiological ones, where the presence of other factors such as collagen, mineralization inhibitors, and cells heavily influences HA precipitation. A deeper understanding of the role of AAs in HA mineralization will increase our fundamental knowledge related to bone formation, and could lead to new therapies to improve bone regeneration in damaged tissues or cure pathological diseases caused by excessive mineralization in tissues such as cartilage, blood vessels and cardiac valves. PMID:27707904

Phenolic profiles and their contribution to the antioxidant activity of selected chickpea genotypes from Mexico and ICRISAT collections.

PubMed

Quintero-Soto, Maria F; Saracho-Peña, Ana G; Chavez-Ontiveros, Jeanett; Garzon-Tiznado, Jose A; Pineda-Hidalgo, Karen V; Delgado-Vargas, Francisco; Lopez-Valenzuela, Jose A

2018-06-01

Chickpea (Cicer arietinum L.) genotypes, nine kabuli from Mexico and 9 desi from other countries, were investigated for their phenolic profiles and antioxidant activity (AA). Phenolics in methanol extracts (ME) were analyzed by ultra-performance liquid chromatography coupled to diode array detection and mass spectrometry (UPLC-DAD-MS), whereas the AA was measured as Trolox equivalents (TE) by ABTS, DPPH and FRAP methods. Twenty phenolic compounds were identified in the ME and their levels showed a great variability among the chickpea genotypes. Phenolic acids and flavonoids were the most abundant compounds in kabuli and desi genotypes, respectively. The AA values (μmol TE/ 100 g dw) by ABTS (278-2417), DPPH (52-1650), and FRAP (41-1181) were mainly associated with the content of sinapic acid hexoside, gallic acid, myricetin, quercetin, catechin, and isorhamnetin, suggesting they are the main compounds responsible for the AA. The sum of the AA obtained for standards of these compounds evaluated at the concentration found in the extracts accounted for 34.3, 69.8, and 47.0% of the AA in the extract by ABTS, DPPH, and FRAP, respectively. In the AA by DPPH, most of the mixtures of these compounds resulted in synergistic interactions. Three desi genotypes with black seeds (ICC 4418, ICC 6306, and ICC 3761) showed the highest AA and flavonoids content, whereas the most promising kabuli genotypes were Surutato 77, Bco. Sin. 92, and Blanoro that showed the highest values of phenolic acids. These genotypes represent good sources of antioxidants for the improvement of nutraceutical properties in chickpea.

Carboxylator: incorporating solvent-accessible surface area for identifying protein carboxylation sites

NASA Astrophysics Data System (ADS)

Lu, Cheng-Tsung; Chen, Shu-An; Bretaña, Neil Arvin; Cheng, Tzu-Hsiu; Lee, Tzong-Yi

2011-10-01

In proteins, glutamate (Glu) residues are transformed into γ-carboxyglutamate (Gla) residues in a process called carboxylation. The process of protein carboxylation catalyzed by γ-glutamyl carboxylase is deemed to be important due to its involvement in biological processes such as blood clotting cascade and bone growth. There is an increasing interest within the scientific community to identify protein carboxylation sites. However, experimental identification of carboxylation sites via mass spectrometry-based methods is observed to be expensive, time-consuming, and labor-intensive. Thus, we were motivated to design a computational method for identifying protein carboxylation sites. This work aims to investigate the protein carboxylation by considering the composition of amino acids that surround modification sites. With the implication of a modified residue prefers to be accessible on the surface of a protein, the solvent-accessible surface area (ASA) around carboxylation sites is also investigated. Radial basis function network is then employed to build a predictive model using various features for identifying carboxylation sites. Based on a five-fold cross-validation evaluation, a predictive model trained using the combined features of amino acid sequence (AA20D), amino acid composition, and ASA, yields the highest accuracy at 0.874. Furthermore, an independent test done involving data not included in the cross-validation process indicates that in silico identification is a feasible means of preliminary analysis. Additionally, the predictive method presented in this work is implemented as Carboxylator (http://csb.cse.yzu.edu.tw/Carboxylator/), a web-based tool for identifying carboxylated proteins with modification sites in order to help users in investigating γ-glutamyl carboxylation.

Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid.

PubMed

Mallesha, Malledevaru; Manjunatha, Revanasiddappa; Nethravathi, C; Suresh, Gurukar Shivappa; Rajamathi, Michael; Melo, Jose Savio; Venkatesha, Thimmappa Venkatarangaiah

2011-06-01

Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The behavior of FGGE towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been investigated by CV, differential pulse voltammetry (DPV) and chronoamperommetry (CA). The FGGE showed excellent catalytic activity towards electrochemical oxidation of AA, DA and UA compared to that of the bare graphite electrode. The electrochemical oxidation signals of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 193mv, 172mv and 264mV between AA-DA, DA-UA and AA-UA respectively in CV studies and the corresponding peak potential separations in DPV mode are 204mv, 141mv and 345mv. The FGGE is successfully used for the simultaneous detection of AA, DA and UA in their ternary mixture and DA in serum and pharmaceutical samples. The excellent electrocatalytic behavior of FGGE may lead to new applications in electrochemical analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

Protein Restriction with Amino Acid-Balanced Diets Shrinks Circulating Pool Size of Amino Acid by Decreasing Expression of Specific Transporters in the Small Intestine

PubMed Central

Luo, Min; Zhang, Xin; Sun, Wen Juan; Jiao, Ning; Li, De Fa; Yin, Jing Dong

2016-01-01

Dietary protein restriction is not only beneficial to health and longevity in humans, but also protects against air pollution and minimizes feeding cost in livestock production. However, its impact on amino acid (AA) absorption and metabolism is not quite understood. Therefore, the study aimed to explore the effect of protein restriction on nitrogen balance, circulating AA pool size, and AA absorption using a pig model. In Exp.1, 72 gilts weighting 29.9 ± 1.5 kg were allocated to 1 of the 3 diets containing 14, 16, or 18% CP for a 28-d trial. Growth (n = 24), nitrogen balance (n = 6), and the expression of small intestinal AA and peptide transporters (n = 6) were evaluated. In Exp.2, 12 barrows weighting 22.7 ± 1.3 kg were surgically fitted with catheters in the portal and jejunal veins as well as the carotid artery and assigned to a diet containing 14 or 18% CP. A series of blood samples were collected before and after feeding for determining the pool size of circulating AA and AA absorption in the portal vein, respectively. Protein restriction did not sacrifice body weight gain and protein retention, since nitrogen digestibility was increased as dietary protein content reduced. However, the pool size of circulating AA except for lysine and threonine, and most AA flux through the portal vein were reduced in pigs fed the low protein diet. Meanwhile, the expression of peptide transporter 1 (PepT-1) was stimulated, but the expression of the neutral and cationic AA transporter systems was depressed. These results evidenced that protein restriction with essential AA-balanced diets, decreased AA absorption and reduced circulating AA pool size. Increased expression of small intestinal peptide transporter PepT-1 could not compensate for the depressed expression of jejunal AA transporters for AA absorption. PMID:27611307

Hydrocortisone selectively inhibits IgE-dependent arachidonic acid release from rat peritoneal mast cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heiman, A.S.; Crews, F.T.

Purified rat mst cells were used to study the effects of antiinflammatory steroids on the release of (1-14C)-arachidonic acid ((1-14C)AA) and metabolites. Mast cell were incubated overnight with glucocorticoids, (1-14C)AA incorporated into cellular phospholipids and the release of (1-14C)AA, and metabolites determined using a variety of secretagogues. Release of (1-14C)AA and metabolites by concanavalin A, the antigen ovalbumin and anti-immunoglobulin E antibody was markedly reduced by glucocorticoid treatment. Neither the total incorporation of (1-14C)AA nor the distribution into phospholipids was altered by hydrocortisone pretreatment. Glucocorticoid pretreatment did not alter (1-14C)AA release stimulated by somatostatin, compound 48/80, or the calcium ionophore,more » A23187. These data indicate that antiinflammatory steroids selectively inhibit immunoglobulin dependent release of arachidonic acid from rat mast cells. These findings question the role of lipomodulin and macrocortin as general phospholipase inhibitors and suggest that they may be restricted to immunoglobulin stimuli.« less

Acetic acid in aged vinegar affects molecular targets for thrombus disease management.

PubMed

Jing, Li; Yanyan, Zhang; Junfeng, Fan

2015-08-01

To elucidate the mechanism underlying the action of dietary vinegar on antithrombotic activity, acetic acid, the main acidic component of dietary vinegar, was used to determine antiplatelet and fibrinolytic activity. The results revealed that acetic acid significantly inhibits adenosine diphosphate (ADP)-, collagen-, thrombin-, and arachidonic acid (AA)-induced platelet aggregation. Acetic acid (2.00 mM) reduced AA-induced platelet aggregation to approximately 36.82 ± 1.31%, and vinegar (0.12 mL L(-1)) reduced the platelet aggregation induced by AA to 30.25 ± 1.34%. Further studies revealed that acetic acid exerts its effects by inhibiting cyclooxygenase-1 and the formation of thromboxane-A2. Organic acids including acetic acid, formic acid, lactic acid, citric acid, and malic acid also showed fibrinolytic activity; specifically, the fibrinolytic activity of acetic acid amounted to 1.866 IU urokinase per mL. Acetic acid exerted its fibrinolytic activity by activating plasminogen during fibrin crossing, thus leading to crosslinked fibrin degradation by the activated plasmin. These results suggest that organic acids in dietary vinegar play important roles in the prevention and cure of cardiovascular diseases.

A Novel Glucosylation Reaction on Anthocyanins Catalyzed by Acyl-Glucose–Dependent Glucosyltransferase in the Petals of Carnation and Delphinium[C][W

PubMed Central

Matsuba, Yuki; Sasaki, Nobuhiro; Tera, Masayuki; Okamura, Masachika; Abe, Yutaka; Okamoto, Emi; Nakamura, Haruka; Funabashi, Hisakage; Takatsu, Makoto; Saito, Mikako; Matsuoka, Hideaki; Nagasawa, Kazuo; Ozeki, Yoshihiro

2010-01-01

Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose–dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose–dependent glucosyltransferases. PMID:20971893

Analysis of novel high-molecular-weight prolamins from Leymus multicaulis (Kar. et Kir.) Tzvelev and L. chinensis (Trin. ex Bunge) Tzvelev.

PubMed

Hu, Xinkun; Dai, Shoufen; Song, Zhongping; Xu, Dongyang; Wen, Zhaojin; Wei, Yuming; Liu, Dengcai; Zheng, Youliang; Yan, Zehong

2018-06-01

Nine novel high-molecular-weight prolamins (HMW-prolamins) were isolated from Leymus multicaulis and L. chinensis. Based on the structure of the repetitive domains, all nine genes were classified as D-hordeins but not high-molecular-weight glutenin subunits (HMW-GSs) that have been previously isolated in Leymus spp. Four genes, Lmul 1.2, 2.4, 2.7, and Lchi 2.5 were verified by bacterial expression, whereas the other five sequences (1.3 types) were classified as pseudogenes. The four Leymus D-hordein proteins had longer N-termini than those of Hordeum spp. [116/118 vs. 110 amino acid (AA) residues], whereas three (Lmul 1.2, 2.4, and 2.7) contained shorter N-termini than those of the Ps. juncea (116 vs. 118 AA residues). Furthermore, Lmul 1.2 was identified as the smallest D-hordein, and Lmul 1.2 and 2.7 had an additional cysteines. Phylogenetic analysis supported that the nine D-hordeins of Leymus formed two independent clades, with all the 1.3 types clustered with Ps. juncea Ns 1.3, whereas the others were clustered together with the D-hordeins from Hordeum and Ps. juncea and the HMW-GSs from Leymus. Within the clade of four D-hordein genes and HMW-GSs, the HMW-GSs of Leymus formed a separated branch that served as an intermediate between the D-hordeins of Ps. juncea and Leymus. These novel D-hordeins may be potentially utilized in the improvement of food processing properties particularly those relating to extra cysteine residues. The findings of the present study also provide basic information for understanding the HMW-prolamins among Triticeae species, as well as expand the sources of D-hordeins from Hordeum to Leymus.

Functional relevance of three proopiomelanocortin (POMC) genes in darkening camouflage, blind-side hypermelanosis, and appetite of Paralichthys olivaceus.

PubMed

Kang, Duk-Young; Kim, Hyo-Chan

2015-01-01

To determine whether proopiomelanocortin (POMC) genes are involved in darkening color camouflage, blind-side hypermelanosis, and appetite in flatfish, we isolated and cloned three POMC genes from the pituitary of the olive flounder (Paralichthys olivaceus) and compared their amino acid (aa) structures to those of POMC genes from other animals. Next, we examined the relationship of these pituitary POMC genes to camouflage color change, blind-side hypermelanosis, and appetite by quantifying mRNA expression. Olive flounder (of)-POMC1, 2, and 3 cDNAs consisted of 648-bp, 582-bp, and 693-bp open reading frames (ORF) encoding 216 aa, 194 aa, and 231 aa residues, respectively. Structurally, the three of-POMC cDNAs consisted of seven peptides (signal peptide, N-POMC, α-MSH, CLIP, N-β-LPH, β-MSH and β-END [or END-like peptide]) that are similar to those of other fish POMC cDNAs. α-MSH encoded a protein composed of 13 aa and β-MSH encoded a protein composed of 17 aa. The three POMC genes were predominantly expressed in the pituitary gland, but they were also expressed in a variety of tissues, including brain, eye, kidney, heart, testis, and skin. of-POMC2 exhibited the highest expression, while of-POMC3 displayed the lowest expression. The relative levels of of-POMC1 and 3 mRNAs were not influenced by background color and feeding (or fasting), but the relative level of of-POMC2 mRNA significantly increased in response to a dark background and fasting. The relative levels of of-POMC1 and 2 mRNAs were significantly higher in hypermelanic fish; however, we did not determine a direct anorexigenic or orexigenic relationship for the three POMC genes. These results indicate that pituitary POMC genes are related to darkening color change and the differentiation of pigment cells, but they are not directly related to appetite. Copyright © 2014 Elsevier Inc. All rights reserved.

How human IgGs against myelin basic protein (MBP) recognize oligopeptides and MBP.

PubMed

Belov, Sergey; Buneva, Valentina N; Nevinsky, Georgy A

2017-10-01

Myelin basic protein (MBP) is a major protein of myelin-proteolipid shell of axons, and it plays an important role in pathogenesis of multiple sclerosis. In the literature, there are no data on how antibodies recognize different protein antigens including MBP. A stepwise increase in ligand complexity was used to estimate the relative contributions of virtually every amino acid residue (AA) of a specific 12-mer LSRFSWGAEGQK oligopeptide corresponding to immunodominant sequence of MBP to the light chains and to intact anti-MBP IgGs from sera of patients with multiple sclerosis. It was shown that the minimal ligands of the light chains of IgGs are many different free AAs (K d  = 0.51-0.016 M), and each free AA interacts with the specific subsite of the light chain intended for recognition of this AA in specific LSRFSW oligopeptide. A gradual transition from Leu to LSRFSWGAEGQK leads to an increase in the affinity from 10 -1 to 2.3 × 10 -4  M because of additive interactions of the light chain with 6 AAs of this oligopeptide and then the affinity reaches plateau. The contributions of 6 various AAs to the affinity of the oligopeptide are different (K d , M): 0.71 (S), 0.44 (R), 0.14 (F), 0.17 (S), and 0.62 (W). Affinity of nonspecific oligopeptides to the light chains of IgGs is significantly lower. Intact MBP interacts with both light and heavy chains of IgGs demonstrating 192-fold higher affinity than the specific oligopeptide. It is a first quantitative analysis of the mechanism of proteins recognition by antibodies. The thermodynamic model was constructed to describe the interactions of IgGs with MBP. The data obtained can be very useful for understanding how antibodies against many different proteins can recognize these proteins. Copyright © 2017 John Wiley & Sons, Ltd.

Measurements and Modeling of Stress in Precipitation-Hardened Aluminum Alloy AA2618 during Gleeble Interrupted Quenching and Constrained Cooling

NASA Astrophysics Data System (ADS)

Chobaut, Nicolas; Carron, Denis; Saelzle, Peter; Drezet, Jean-Marie

2016-11-01

Solutionizing and quenching are the key steps in the fabrication of heat-treatable aluminum parts such as AA2618 compressor impellers for turbochargers as they highly impact the mechanical characteristics of the product. In particular, quenching induces residual stresses that can cause unacceptable distortions during machining and unfavorable stresses in service. Predicting and controlling stress generation during quenching of large AA2618 forgings are therefore of particular interest. Since possible precipitation during quenching may affect the local yield strength of the material and thus impact the level of macroscale residual stresses, consideration of this phenomenon is required. A material model accounting for precipitation in a simple but realistic way is presented. Instead of modeling precipitation that occurs during quenching, the model parameters are identified using a limited number of tensile tests achieved after representative interrupted cooling paths in a Gleeble machine. This material model is presented, calibrated, and validated against constrained coolings in a Gleeble blocked-jaws configuration. Applications of this model are FE computations of stress generation during quenching of large AA2618 forgings for compressor impellers.

Ascorbic Acid and the Brain: Rationale for the Use against Cognitive Decline

PubMed Central

Harrison, Fiona E.; Bowman, Gene L.; Polidori, Maria Cristina

2014-01-01

This review is focused upon the role of ascorbic acid (AA, vitamin C) in the promotion of healthy brain aging. Particular attention is attributed to the biochemistry and neuronal metabolism interface, transport across tissues, animal models that are useful for this area of research, and the human studies that implicate AA in the continuum between normal cognitive aging and age-related cognitive decline up to Alzheimer’s disease. Vascular risk factors and comorbidity relationships with cognitive decline and AA are discussed to facilitate strategies for advancing AA research in the area of brain health and neurodegeneration. PMID:24763117

Determination and stereochemistry of proteinogenic and non-proteinogenic amino acids in Saudi Arabian date fruits.

PubMed

Ali, Hatem Salama Mohamed; Alhaj, Omar Amin; Al-Khalifa, Abdulrahman Saleh; Brückner, Hans

2014-09-01

Whereas an abundance of literature is available on the occurrence of common proteinogenic amino acids (AAs) in edible fruits of the date palm (Phoenix dactylifera L.), recent reports on non-proteinogenic (non-coded) AAs and amino components are scarce. With emphasis on these components we have analyzed total hydrolysates of twelve cultivars of date fruits using automated ion-exchange chromatography, HPLC employing a fluorescent aminoquinolyl label, and GC-MS of total hydrolysates using the chiral stationary phases Chirasil(®)-L-Val and Lipodex(®) E. Besides common proteinogenic AAs, relatively large amounts of the following non-proteinogenic amino acids were detected: (2S,5R)-5-hydroxypipecolic acid (1.4-4.0 g/kg dry matter, DM), 1-aminocyclopropane-1-carboxylic acid (1.3-2.6 g/kg DM), γ-amino-n-butyric acid (0.5-1.2 g/kg DM), (2S,4R)-4-hydroxyproline (130-230 mg/kg DM), L-pipecolic acid (40-140 mg/kg DM), and 2-aminoethanol (40-160 mg/kg DM) as well as low or trace amounts (<70 mg/kg DM) of L-ornithine, 5-hydroxylysine, β-alanine, and in some samples (<20 mg/kg DM) of (S)-β-aminoisobutyric acid and (<10 mg/kg DM) L-allo-isoleucine. In one date fruit, traces of α-aminoadipic acid could be determined. Enantiomeric analysis of 6 M DCl/D2O hydrolysates of AAs using chiral capillary gas chromatography-mass spectrometry revealed the presence of very low amounts of D-Ala, D-Asp, D-Glu, D-Ser and D-Phe (1.2-0.4%, relative to the corresponding L-enantiomers), besides traces (0.2-1%) of other D-AAs. The possible relevance of non-proteinogenic amino acids in date fruits is briefly addressed.

A combination of additives can synergically decrease acrylamide content in gingerbread without compromising sensory quality.

PubMed

Komprda, Tomáš; Pridal, Antonin; Mikulíková, Renata; Svoboda, Zdeněk; Cwiková, Olga; Nedomová, Šárka; Sýkora, Vladimír

2017-02-01

The present study tested whether replacement of the leavening agent ammonium carbonate by sodium hydrogen carbonate in combination with calcium cation and acidifying agent will synergically decrease acrylamide (AA) content in gingerbread. The type of leavening agent and the presence of Ca 2+ and citric acid accounted for 33.6%, 13.2% and 53.2% of the explained variability of the AA content, respectively (P < 0.01). The AA content in gingerbread produced with (NH 4 ) 2 CO 3 alone was 186.5 µg kg -1 . Irrespective of other tested additives, NaHCO 3 decreased (P < 0.05) AA content to 42% compared to (NH 4 ) 2 CO 3 . Combination of NaHCO 3 + CaCl 2 + citric acid in dough reduced (P < 0.05) AA content below the limit of detection (25 µg kg -1 ). The AA content in gingerbread (y; µg kg -1 ) decreased with an increasing number of additives used (x) according to the equation y = 158.8 - 47.94x (r 2 = 0.42; P < 0.0001). A comprehensive sensory analysis did not indicate any significant deterioration (P > 0.05) in the organoleptic quality of gingerbread produced using calcium cation and citric acid. The present study demonstrates that the combination of additives NaHCO 3 /Ca 2+ /citric acid synergically decreases AA content in gingerbread without compromising the sensory quality. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?

PubMed Central

2011-01-01

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis. PMID:21375761

Ligand-independent activation of EphA2 by arachidonic acid induces metastasis-like behaviour in prostate cancer cells

PubMed Central

Tawadros, T; Brown, M D; Hart, C A; Clarke, N W

2012-01-01

Background: High intake of omega-6 polyunsaturated fatty acids (PUFA) has been associated with clinical progression in prostate cancer (CaP). This study investigates the signalling mechanism by which the omega-6 PUFA arachidonic acid (AA) induces prostatic cellular migration to bone marrow stroma. Methods: Western blot analysis of the PC-3, PC3-GFP, DU 145 and LNCaP cells or their lipid raft (LR) components post AA stimulation was conducted in association with assays for adhesion and invasion through the bone marrow endothelial monolayers. Results: Arachidonic acid increased transendothelial migration of PC3-GFP cells (adhesion 37%±0.08, P=0.0124; transmigration 270%±0.145, P=0.0008). Akt, Src and focal adhesion kinase (FAK) pathways were induced by AA and integrally involved in transendothelial migration. LR were critical in AA uptake and induced Akt activity. Ephrin receptor A2 (EphA2), localised in LR, is expressed in DU 145 and PC-3 cells. Arachidonic acid induced a rapid increase of EphA2 Akt-dependent/ligand-independent activation, while knockdown of the EphrinA1 ligand decreased AA induced transendothelial migration, with an associated decrease in Src and FAK activity. Arachidonic acid activated Akt in EphA2− LNCaP cells but failed to induce BMEC transendothelial invasion. Conclusion: Arachidonic acid induced stimulation of EphA2 in vitro is associated fundamentally with CaP epithelial migration across the endothelial barrier. PMID:23037715

Different Fatty Acids Compete with Arachidonic Acid for Binding to the Allosteric or Catalytic Subunits of Cyclooxygenases to Regulate Prostanoid Synthesis*

PubMed Central

Dong, Liang; Zou, Hechang; Yuan, Chong; Hong, Yu H.; Kuklev, Dmitry V.; Smith, William L.

2016-01-01

Prostaglandin endoperoxide H synthases (PGHSs), also called cyclooxygenases (COXs), convert arachidonic acid (AA) to PGH2. PGHS-1 and PGHS-2 are conformational heterodimers, each composed of an (Eallo) and a catalytic (Ecat) monomer. Previous studies suggested that the binding to Eallo of saturated or monounsaturated fatty acids (FAs) that are not COX substrates differentially regulate PGHS-1 versus PGHS-2. Here, we substantiate and expand this concept to include polyunsaturated FAs known to modulate COX activities. Non-substrate FAs like palmitic acid bind Eallo of PGHSs stimulating human (hu) PGHS-2 but inhibiting huPGHS-1. We find the maximal effects of non-substrate FAs on both huPGHSs occurring at the same physiologically relevant FA/AA ratio of ∼20. This inverse allosteric regulation likely underlies the ability of PGHS-2 to operate at low AA concentrations, when PGHS-1 is effectively latent. Unlike FAs tested previously, we observe that C-22 FAs, including ω-3 fish oil FAs, have higher affinities for Ecat than Eallo subunits of PGHSs. Curiously, C-20 ω-3 eicosapentaenoate preferentially binds Ecat of huPGHS-1 but Eallo of huPGHS-2. PGE2 production decreases 50% when fish oil consumption produces tissue EPA/AA ratios of ≥0.2. However, 50% inhibition of huPGHS-1 itself is only seen with ω-3 FA/AA ratios of ≥5.0. This suggests that fish oil-enriched diets disfavor AA oxygenation by altering the composition of the FA pool in which PGHS-1 functions. The distinctive binding specificities of PGHS subunits permit different combinations of non-esterified FAs, which can be manipulated dietarily, to regulate AA binding to Eallo and/or Ecat thereby controlling COX activities. PMID:26703471

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

PubMed

Hasegawa, Tomoka; Li, Minqi; Hara, Kuniko; Sasaki, Muneteru; Tabata, Chihiro; de Freitas, Paulo Henrique Luiz; Hongo, Hiromi; Suzuki, Reiko; Kobayashi, Masatoshi; Inoue, Kiichiro; Yamamoto, Tsuneyuki; Oohata, Noboru; Oda, Kimimitsu; Akiyama, Yasuhiro; Amizuka, Norio

2011-08-01

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Compound-specific amino acid δ15N patterns in marine algae: Tracer potential for cyanobacterial vs. eukaryotic organic nitrogen sources in the ocean

NASA Astrophysics Data System (ADS)

McCarthy, Matthew D.; Lehman, Jennifer; Kudela, Raphael

2013-02-01

Stable nitrogen isotopic analysis of individual amino acids (δ15N-AA) has unique potential to elucidate the complexities of food webs, track heterotrophic transformations, and understand diagenesis of organic nitrogen (ON). While δ15N-AA patterns of autotrophs have been shown to be generally similar, prior work has also suggested that differences may exist between cyanobacteria and eukaryotic algae. However, δ15N-AA patterns in differing oceanic algal groups have never been closely examined. The overarching goals of this study were first to establish a more quantitative understanding of algal δ15N-AA patterns, and second to examine whether δ15N-AA patterns have potential as a new tracer for distinguishing prokaryotic vs. eukaryotic N sources. We measured δ15N-AA from prokaryotic and eukaryotic phytoplankton cultures and used a complementary set of statistical approaches (simple normalization, regression-derived fractionation factors, and multivariate analyses) to test for variations. A generally similar δ15N-AA pattern was confirmed for all algae, however significant AA-specific variation was also consistently identified between the two groups. The relative δ15N fractionation of Glx (glutamine + glutamic acid combined) vs. total proteinaceous N appeared substantially different, which we hypothesize could be related to differing enzymatic forms. In addition, the several other AA (most notably glycine and leucine) appeared to have strong biomarker potential. Finally, we observed that overall patterns of δ15N values in algae correspond well with the Trophic vs. Source-AA division now commonly used to describe variable AA δ15N changes with trophic transfer, suggesting a common mechanistic basis. Overall, these results show that autotrophic δ15N-AA patterns can differ between major algal evolutionary groupings for many AA. The statistically significant multivariate results represent a first approach for testing ideas about relative eukaryotic vs. prokaryotic ON sources in the sea.

Risk of secondary lymphedema in breast cancer survivors is related to serum phospholipid fatty acid desaturation.

PubMed

Ryu, Eunjung; Yim, Seung Yun; Do, Hyun Ju; Lim, Jae-Young; Yang, Eun Joo; Shin, Min-Jeong; Lee, Seung-Min

2016-09-01

Secondary lymphedema is a common irreversible side effect of breast cancer surgery. We investigated if risk of secondary lymphedema in breast cancer survivors was related to changes in serum phospholipid fatty acid composition. Study subjects were voluntarily recruited into the following three groups: breast cancer survivors who had sentinel lymph node biopsy without lymphedema (SLNB), those who had auxillary lymph node dissection without lymphedema (ALND), and those who had ALND with lymphedema (ALND + LE). Body mass index (BMI), serum lipid profiles, bioimpedance data with single-frequency bioimpedance analysis (SFBIA), and serum phospholipid compositions were analyzed and compared among the groups. BMI, serum total cholesterol (total-C), and low-density lipoprotein cholesterol (LDL-C) and SFBIA ratios increased only in the ALND + LE. High polyunsaturated fatty acids (PUFAs) and high C20:4 to C18:2 n-6 PUFAs (arachidonic acid [AA]/linoleic acid [LA]) was detected in the ALND and ALND + LE groups compared to SLNB. The ALND + LE group showed increased activity indices for delta 6 desaturase (D6D) and D5D and increased ratio of AA to eicosapentaenoic acid (AA/EPA) compared to the ALND and SLNB groups. Correlation and regression analysis indicated that D6D, D5D, and AA/EPA were associated with SFBIA ratios. We demonstrated that breast cancer survivors with lymphedema had elevated total PUFAs, fatty acid desaturase activity indices, and AA/EPA in serum phospholipids. Our findings suggested that desaturation extent of fatty acid composition might be related to the risk of secondary lymphedema in breast cancer survivors.

Amino Acid Intakes Are Inversely Associated with Arterial Stiffness and Central Blood Pressure in Women.

PubMed

Jennings, Amy; MacGregor, Alex; Welch, Ailsa; Chowienczyk, Phil; Spector, Tim; Cassidy, Aedín

2015-09-01

Although data suggest that intakes of total protein and specific amino acids (AAs) reduce blood pressure, data on other cardiovascular disease risk factors are limited. We examined associations between intakes of AAs with known mechanistic links to cardiovascular health and direct measures of arterial stiffness, central blood pressure, and atherosclerosis. In a cross-sectional study of 1898 female twins aged 18-75 y from the TwinsUK registry, intakes of 7 cardioprotective AAs (arginine, cysteine, glutamic acid, glycine, histidine, leucine, and tyrosine) were calculated from food-frequency questionnaires. Direct measures of arterial stiffness and atherosclerosis included central systolic blood pressure (cSBP), mean arterial pressure (MAP), augmentation index (AI), pulse wave velocity (PWV), and intima-media thickness (IMT). ANCOVA was used to assess the associations between endpoints of arterial stiffness and intake (per quintile), adjusting for potential confounders. In multivariable analyses, higher intakes of total protein and 7 potentially cardioprotective AAs were associated with lower cSBP, MAP, and PWV. Higher intakes of glutamic acid, leucine, and tyrosine were most strongly associated with PWV, with respective differences of -0.4 ± 0.2 m/s (P-trend = 0.02), -0.4 ± 0.2 m/s (P-trend = 0.03), and -0.4 ± 0.2 m/s (P-trend = 0.03), comparing extreme quintiles. There was a significant interaction between AA intakes and protein source, and higher intakes of AAs from vegetable sources were associated with lower central blood pressure and AI. Higher intakes of glutamic acid, leucine, and tyrosine from animal sources were associated with lower PWV. These data provide evidence to suggest that intakes of several AAs are associated with cardiovascular benefits beyond blood pressure reduction in healthy women. The magnitude of the observed associations was similar to those previously reported for other lifestyle factors. Increasing intakes of these AAs could be an important and readily achievable way to reduce cardiovascular disease risk.

[Effect of phospholipids containing omega-3 fatty acids on structural changes of microsomal lipids in cell membranes of functionally different cells].

PubMed

Datsenko, Z M; Volkov, H L; Kryvenko, O M; Nechytaĭlo, L O; Shovkun, S A; Khmel', T O; Perederiĭ, O F

2002-01-01

As a result of the experimental researches conducted it has been shown that administration of some normal animal marine phospholipids (PL) including in their structure omega-3 polyunsaturated fatty acids (PUFA) provides for quantitative changes of individual PL, fatty acids (FA) content and quantity in general and individual PL of liver, heart, brain and gonads microsomes. While estimating general microsomal PL fraction FA content under the action of PL omega-3 PUFA FA concentration change, unsaturation index (omega 6/omega 3) and relation of arachidonic acid to docosahexenic (AA/DHA) decrease have been identified. The decrease of AA/DHA relationship occurs due to AA and DHA quantitative changes. In the case of AA increase in some tissues there is observed the decrease of docosapentaenic acid and increase of DHA and eucosapentaenic (EPA) acidds. As a result of studying FA content in the individual PL composition it has been identified that certain PL classes characteristic for some tissues respond by changes of some certain FA. The relationship omega 6/omega 3 has been shown as decreasing in phosphatidilcholine (PC) all tissues microsomes (liver, gonads, heart, brain), in phosphatidilethanolamine (PEA) of liver and cardiac microsomes, in phosphatidilserine (PS) this relationship relationship decreases in the liver, brain and heart, for phosphatidilinositole (PI) the changes take place in liver, gonads, brain. Simultaneously, the decrease of AA/DHA relationship in the individual PL decrease of AA and increase of EPA and DHA depend on the tested tissues. The marine phospholipids might be supposed to render their effect on AA metabolism resulting in AA/DHA relationship in PEA and PS relationship displays itself as specific and depends on the tissues functions. The preference of PEA and PS use by certain tissues microsomes could be explained by their membrane protective capability.

Selection of the Strain Lactobacillus acidophilus ATCC 43121 and Its Application to Brewers' Spent Grain Conversion into Lactic Acid

PubMed Central

Liguori, Rossana; Soccol, Carlos Ricardo; Vandenberghe, Luciana Porto de Souza; Woiciechowski, Adenise Lorenci; Ionata, Elena; Marcolongo, Loredana; Faraco, Vincenza

2015-01-01

Six Lactobacillus strains were analyzed to select a bacterium for conversion of brewers' spent grain (BSG) into lactic acid. Among the investigated strains, L. acidophilus ATCC 43121 showed the highest yield of lactic acid production (16.1 g/L after 48 hours) when grown in a synthetic medium. It was then analyzed for its ability to grow on the hydrolysates obtained from BSG after acid-alkaline (AAT) or aqueous ammonia soaking (AAS) pretreatment. The lactic acid production by L. acidophilus ATCC 43121 through fermentation of the hydrolysate from AAS treated BSG was 96% higher than that from the AAT treated one, although similar yields of lactic acid per consumed glucose were achieved due to a higher (46%) glucose consumption by L. acidophilus ATCC 43121 in the AAS BSG hydrolysate. It is worth noting that adding yeast extract to the BSG hydrolysates increased both the yield of lactic acid per substrate consumed and the volumetric productivity. The best results were obtained by fermentation of AAS BSG hydrolysate supplemented by yeast extract, in which the strain produced 22.16 g/L of lactic acid (yield of 0.61 g/g), 27% higher than the value (17.49 g/L) obtained in the absence of a nitrogen source. PMID:26640784

Effects of dimethylaminoethanol and compound amino acid on D-galactose induced skin aging model of rat.

PubMed

Liu, Su; Chen, Zhenyu; Cai, Xia; Sun, Ying; Zhao, Cailing; Liu, Fangjun; Liu, Dalie

2014-01-01

A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE) and compound amino acid (AA) in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat.

Effects of Dimethylaminoethanol and Compound Amino Acid on D-Galactose Induced Skin Aging Model of Rat

PubMed Central

Liu, Su; Chen, Zhenyu; Cai, Xia; Sun, Ying; Zhao, Cailing

2014-01-01

A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE) and compound amino acid (AA) in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat. PMID:25133239

Distinct functional domains within the acidic cluster of tegument protein pp28 required for trafficking and cytoplasmic envelopment of human cytomegalovirus.

PubMed

Seo, Jun-Young; Jeon, Hyejin; Hong, Sookyung; Britt, William J

2016-10-01

Human cytomegalovirus UL99-encoded tegument protein pp28 contains a 16 aa acidic cluster that is required for pp28 trafficking to the assembly compartment (AC) and the virus assembly. However, functional signals within the acidic cluster of pp28 remain undefined. Here, we demonstrated that an acidic cluster rather than specific sorting signals was required for trafficking to the AC. Recombinant viruses with chimeric pp28 proteins expressing non-native acidic clusters exhibited delayed viral growth kinetics and decreased production of infectious virus, indicating that the native acidic cluster of pp28 was essential for wild-type virus assembly. These results suggested that the acidic cluster of pp28 has distinct functional domains required for trafficking and for efficient virus assembly. The first half (aa 44-50) of the acidic cluster was sufficient for pp28 trafficking, whereas the native acidic cluster consisting of aa 51-59 was required for the assembly of wild-type levels of infectious virus.

Enhancement of neurite outgrowth in PC12 cells stimulated with cyclic AMP and NGF by 6-acylated ascorbic acid 2-O-alpha-glucosides (6-Acyl-AA-2G), novel lipophilic ascorbate derivatives.

PubMed

Zhou, Xiaohua; Tai, Akihiro; Yamamoto, Itaru

2003-03-01

It has been shown that ascorbate (AsA) and its stable derivative, ascorbic acid 2-O-alpha-glucoside (AA-2G), do not elicit neurite outgrowth in PC12 cells. However, these ascorbates are synergistically enhanced by both dibutyryl cyclic AMP (Bt(2)cAMP)- and nerve growth factor (NGF)-induced neurite outgrowth in this model. In the present study, the effects of a series of novel lipophilic ascorbate derivatives, 6-acylated ascorbic acid 2-O-alpha-glucosides (6-Acyl-AA-2G), on neurite outgrowth induced by Bt(2)cAMP and NGF were examined in PC12 cells. We found that all the tested acylated ascorbate derivatives enhanced neurite formation induced by both agents in a dose-dependent manner. Of the 6-Acyl-AA-2G derivatives, 6-octanoyl ascorbic acid 2-O-alpha-glucoside (6-Octa-AA-2G) enhanced the Bt(2)cAMP-induced phosphorylated MAPK p44 and p42 expression. A alpha-glucosidase inhibitor, castanospermine, completely abrogated the promotion of neurite outgrowth and MAPK expression by 6-Octa-AA-2G. Addition of 6-Octa-AA-2G (0.5 mM) to PC12 cells caused a rapid and significant increase in intracellular AsA content, which reached a maximum and was maintained from 12 to 24 h after the culture. These findings suggest that 6-Acyl-AA-2G is rapidly hydrolyzed to AsA within the cell and enhances neurite differentiation through the interaction with the inducer-activated MAPK pathway.

Maternal nutritional determinants of colostrum fatty acids in the EDEN mother-child cohort.

PubMed

Armand, Martine; Bernard, Jonathan Y; Forhan, Anne; Heude, Barbara; Charles, Marie-Aline

2017-10-21

Programming of infant development and later health may depend on early-milk polyunsaturated fatty acids (PUFA) contents, that are very variable between women for reasons not well elucidated. Indeed, a high n-6/n-3 PUFA in milk was associated with higher adiposity, arterial pressure and lower psychomotor scores in childhood. We aimed to explore the respective contribution of several maternal and perinatal factors to the variability of linoleic (LA), α-linolenic (ALA), arachidonic (AA), and docosahexaenoic (DHA) acid levels in early milk. Fatty acids of 934 colostrum samples from the EDEN mother-child cohort were analyzed by gas chromatography. The dietary intakes during the last trimester of pregnancy were estimated using a quantitative food frequency questionnaire. Relationship between milk PUFA and dietary fatty acids, and other maternal or pregnancy variables were analyzed by multiple linear regression. The means (±SD) of colostrum LA, ALA, AA and DHA levels were, respectively, 9.85 ± 1.85, 0.65 ± 0.22, 0.86 ± 0.16, and 0.64 ± 0.19% of total fatty acids. Obese mothers colostrum contained the highest level of LA and AA and the lowest level of ALA and DHA. Colostrum LA, AA and DHA levels were higher in primiparous women. Mother's age was positively associated with colostrum AA and DHA. Dietary n-6 PUFA were associated with higher LA and lower DHA levels in colostrum, while dietary n-3 PUFA were related to higher LA and lower AA levels. Contrary to what was observed for DHA, AA level in colostrum was not related to its dietary intake. High dietary AA/DHA and total n-6/n-3 ratios were critical for the content of DHA in colostrum lipids. Our study brings new insights in the understanding of the main maternal factors involved in PUFA levels variability in early milk. These data are important to consider for dietary counseling for women prior to and during pregnancy. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

A Conserved Epitope Mapped with a Monoclonal Antibody against the VP3 Protein of Goose Parvovirus by Using Peptide Screening and Phage Display Approaches.

PubMed

Li, Chenxi; Liu, Hongyu; Li, Jinzhe; Liu, Dafei; Meng, Runze; Zhang, Qingshan; Shaozhou, Wulin; Bai, Xiaofei; Zhang, Tingting; Liu, Ming; Zhang, Yun

2016-01-01

Waterfowl parvovirus (WPV) infection causes high mortality and morbidity in both geese (Anser anser) and Muscovy ducks (Cairina moschata), resulting in significant losses to the waterfowl industries. The VP3 protein of WPV is a major structural protein that induces neutralizing antibodies in the waterfowl. However, B-cell epitopes on the VP3 protein of WPV have not been characterized. To understand the antigenic determinants of the VP3 protein, we used the monoclonal antibody (mAb) 4A6 to screen a set of eight partially expressed overlapping peptides spanning VP3. Using western blotting and an enzyme-linked immunosorbent assay (ELISA), we localized the VP3 epitope between amino acids (aa) 57 and 112. To identify the essential epitope residues, a phage library displaying 12-mer random peptides was screened with mAb 4A6. Phage clone peptides displayed a consensus sequence of YxRFHxH that mimicked the sequence 82Y/FNRFHCH88, which corresponded to amino acid residues 82 to 88 of VP3 protein of WPVs. mAb 4A6 binding to biotinylated fragments corresponding to amino acid residues 82 to 88 of the VP3 protein verified that the 82FxRFHxH88 was the VP3 epitope and that amino acids 82F is necessary to retain maximal binding to mAb 4A6. Parvovirus-positive goose and duck sera reacted with the epitope peptide by dot blotting assay, revealing the importance of these amino acids of the epitope in antibody-epitope binding reactivity. We identified the motif FxRFHxH as a VP3-specific B-cell epitope that is recognized by the neutralizing mAb 4A6. This finding might be valuable in understanding of the antigenic topology of VP3 of WPV.

Arachidonic acid enhances intracellular [Ca2+]i increase and mitochondrial depolarization induced by glutamate in cerebellar granule cells.

PubMed

Surin, A M; Bolshakov, A P; Mikhailova, M M; Sorokina, E G; Senilova, Ya E; Pinelis, V G; Khodorov, B I

2006-08-01

Maturation of primary neuronal cultures is accompanied by an increase in the proportion of cells that exhibit biphasic increase in free cytoplasmic Ca2+ ([Ca2+]i) followed by synchronic decrease in electrical potential difference across the inner mitochondrial membrane (DeltaPsim) in response to stimulation of glutamate receptors. In the present study we have examined whether the appearance of the second phase of [Ca2+]i change can be attributed to arachidonic acid (AA) release in response to the effect of glutamate (Glu) on neurons. Using primary culture of rat cerebellar granule cells we have investigated the effect of AA (1-20 microM) on [Ca2+]i, DeltaPsim, and [ATP] and changes in these parameters induced by neurotoxic concentrations of Glu (100 microM, 10-40 min). At =10 microM, AA caused insignificant decrease in DeltaPsim without any influence on [Ca2+]i. The mitochondrial ATPase inhibitor oligomycin enhanced AA-induced decrease in DeltaPsim; this suggests that AA may inhibit mitochondrial respiration. Addition of AA during the treatment with Glu resulted in more pronounced augmentation of [Ca2+]i and the decrease in DeltaPsim than the changes in these parameters observed during independent action of AA; removal of Glu did not abolish these changes. An inhibitor of the cyclooxygenase and lipoxygenase pathways of AA metabolism, 5,8,11,14-eicosatetraynoic acid, increased the proportion of neurons characterized by Glu-induced biphasic increase in [Ca2+]i and the decrease in DeltaPsim. Palmitic acid (30 microM) did not increase the percentage of neurons exhibiting biphasic response to Glu. Co-administration of AA and Glu caused 2-3 times more pronounced decrease in ATP concentrations than that observed during the independent effect of AA and Glu. The data suggest that AA may influence the functional state of mitochondria, and these changes may promote biphasic [Ca2+]i and DeltaPsim responses of neurons to the neurotoxic effect of Glu.

Nutraceutical properties of cumin residue generated from Ayurvedic industries using cell line models.

PubMed

Arun, K B; Aswathi, U; Venugopal, V V; Madhavankutty, T S; Nisha, P

2016-10-01

Spent cumin (SC), generated from Ayurvedic industry, was evaluated for its nutraceutical potential in terms of antioxidant, antidiabetic and anticancer properties, and compared with that of the raw cumin (RC). SC and RC seeds were extracted with ethyl acetate (E) and methanol (M). SCM (methanol extract) were rich in p-coumaric acid, ferulic acid, ellagic acid and cinnamic acid (6.4445, 5.8286, 2.1519, 4.3085 mg/g dry extract). SCM reduced Fe 2+ ion (89.68 µM AA/g dry weight), scavenged DPPH radical (IC 50 -238.6 µg/mL), better α-amylase inhibition (IC 50 -337.22 µg/mL) and glucose uptake activity in 30.7% of L6 cells. SCM inhibited viability, retarded migration area up to 41.02%, arrested cell cycle at S phase and induced apoptosis in 2.45% of HT29 colon cancer cells. The results indicated that dietary interventions using nutraceutical food formulation made out of SC can play a significant role in the prevention and management of degenerative diseases.

Inactivating mutations in MFSD2A, required for omega-3 fatty acid transport in brain, cause a lethal microcephaly syndrome.

PubMed

Guemez-Gamboa, Alicia; Nguyen, Long N; Yang, Hongbo; Zaki, Maha S; Kara, Majdi; Ben-Omran, Tawfeg; Akizu, Naiara; Rosti, Rasim Ozgur; Rosti, Basak; Scott, Eric; Schroth, Jana; Copeland, Brett; Vaux, Keith K; Cazenave-Gassiot, Amaury; Quek, Debra Q Y; Wong, Bernice H; Tan, Bryan C; Wenk, Markus R; Gunel, Murat; Gabriel, Stacey; Chi, Neil C; Silver, David L; Gleeson, Joseph G

2015-07-01

Docosahexanoic acid (DHA) is the most abundant omega-3 fatty acid in brain, and, although it is considered essential, deficiency has not been linked to disease. Despite the large mass of DHA in phospholipids, the brain does not synthesize it. DHA is imported across the blood-brain barrier (BBB) through the major facilitator superfamily domain-containing 2a (MFSD2A) protein. MFSD2A transports DHA as well as other fatty acids in the form of lysophosphatidylcholine (LPC). We identify two families displaying MFSD2A mutations in conserved residues. Affected individuals exhibited a lethal microcephaly syndrome linked to inadequate uptake of LPC lipids. The MFSD2A mutations impaired transport activity in a cell-based assay. Moreover, when expressed in mfsd2aa-morphant zebrafish, mutants failed to rescue microcephaly, BBB breakdown and lethality. Our results establish a link between transport of DHA and LPCs by MFSD2A and human brain growth and function, presenting the first evidence of monogenic disease related to transport of DHA in humans.

A Novel Concept of Amino Acid Supplementation to Improve the Growth of Young Malnourished Male Rats.

PubMed

Furuta, Chie; Murakami, Hitoshi

2018-01-01

This study was aimed at understanding the relationship between plasma amino acids and protein malnutrition and at determining whether amino acid supplementation associated with malnutrition and growth improves linear growth in growing rats. Body length and plasma amino acids were measured in young male rats that were fed the following diet for 3 weeks, mimicking a low and imbalanced protein diets based on maize, a major staple consumed in developing countries: a 70% calorically restricted cornmeal-based diet (C), C + micronutrients (CM), CM + casein (CMC), CM + soy protein (CMS) or CMS + 0.3% lysine. A correlation analysis of linear growth and plasma amino acids indicated that lysine, tryptophan, branched-chain amino acids, methionine, and phenylalanine significantly correlated with body length. Supplementation with these 5 amino acids (AA1) significantly improved the body length in rats compared to CMC treatment whereas, nitrogen-balanced amino acid supplemented controls (AA2) did not (CM +1.2 ± 0.2, CMC +2.7 ± 0.3, CMS +2.1 ± 0.3, AA1 +2.8 ± 0.2, and AA2 +2.5 ± 0.3 cm). With securing proper amino acid balance, supplementing growth-related amino acids is more effective in improving linear growth in malnourished growing male rats. Analysis of the correlation between plasma amino acids and growth represents a powerful tool to determine candidate amino acids for supplementation to prevent malnutrition. This technology is adaptable to children in developing countries. © 2018 S. Karger AG, Basel.

Interference of nitrite and nitrogen dioxide on mercury and selenium determination by chemical vapor generation atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Nunes, Dayana Lopes; dos Santos, Eliane Pereira; Barin, Juliano Smanioto; Mortari, Sergio Roberto; Dressler, Valderi Luiz; de Moraes Flores, Érico Marlon

2005-06-01

In this study, a systematic investigation was performed concerning the interference of nitrogen oxides on the determination of selenium and mercury by hydride generation atomic absorption spectrometry (HG AAS) and cold vapor atomic absorption spectrometry (CV AAS). The effect of nitrate, nitrite and NO 2 dissolved in the condensed phase was evaluated. No effect of NO 3- on Se and Hg determination was observed up to 100 mg of sodium nitrate added to the reaction vessel. The Se signal was reduced by about 80% upon the addition of 6.8 mg NO 2-. For Hg, no interference of nitrite was observed up to 20 mg of NO 2-. A complete suppression of the Se signal was observed when gaseous NO 2 was introduced into analytical solutions. For Hg, a signal decrease between 8 and 13% occurred. For Se, bubbling argon or heating the solution was not able to recover the original absorbance values, whereas Hg signals were recovered with these procedures. When gaseous NO 2 was passed directly into the atomizer, Se signals decreased similarly to when NO 2 was bubbled in analytical solutions. The addition of urea, hydroxylamine hydrochloride and sulfamic acid (SA) was investigated to reduce the NO 2 effect in sample digests containing residual NO 2, but only SA was effective in reducing the interference. Based on the results, it is possible to propose the use of SA to prevent interferences in Se and Hg determinations by HG AAS and CV AAS, respectively.

Valine Supplementation in a Reduced Protein Diet Regulates Growth Performance Partially through Modulation of Plasma Amino Acids Profile, Metabolic Responses, Endocrine, and Neural Factors in Piglets.

PubMed

Zhang, Xiaoya; Liu, Xutong; Jia, Hongmin; He, Pingli; Mao, Xiangbing; Qiao, Shiyan; Zeng, Xiangfang

2018-03-28

The objective of this study was to investigate whether valine (Val) supplementation in a reduced protein (RP) diet regulates growth performance associated with the changes in plasma amino acids (AAs) profile, metabolism, endocrine, and neural system in piglets. Piglets or piglets with a catheter in the precaval vein were randomly assigned to two treatments, including two RP diets with standardized ileal digestible (SID) Val:Lysine (Lys) ratio of 0.45 and 0.65, respectively. The results indicated that piglets in the higher Val:Lys ratio treatment had higher average daily feed intake (ADFI) ( P < 0.001), average daily gain (ADG) ( P = 0.001), feed conversion ratio (FCR) ( P = 0.004), lower plasma urea nitrogen ( P = 0.032), expression of gastric cholecystokinin (CCK), and hypothalamic pro-opiomelanocortin (POMC). Plasma AAs profiles including postprandial plasma essential AAs (EAAs) profile and in serum, muscle, and liver involved in metabolism of AAs and fatty acids were significantly different between two treatments. In conclusion, Val influenced growth performance associated with metabolism of AAs and fatty acids and both endocrine and neural system in piglets.

Uptake and Accumulation of Nephrotoxic and Carcinogenic Aristolochic Acids in Food Crops Grown in Aristolochia clematitis-Contaminated Soil and Water.

PubMed

Li, Weiwei; Hu, Qin; Chan, Wan

2016-01-13

Emerging evidence has suggested aristolochic acids (AAs) are linked to the development of Balkan endemic nephropathy (BEN), a chronic renal disease affecting numerous farmers living in the Balkan peninsula. However, the pathway by which AAs enter the human food chain and cause kidney disease remains poorly understood. Using our previously developed analytical method with high sensitivity and selectivity (Chan, W.; Lee, K. C.; Liu, N.; Cai, Z. J. Chromatogr. A 2007, 1164, 113-119), we quantified AAs in lettuce, tomato, and spring onion grown in AA-contaminated soil and culture medium. Our study revealed that AAs were being taken up from the soil and bioaccumulated in food crops in a time- and dose-dependent manner. To the best of our knowledge, this study is the first to identify one of the possible pathways by which AAs enter our food chain to cause chronic food poisoning. Results also demonstrated that AAs were resistant to the microbial activity of the soil/water.

Gabapentin’s minimal action on markers of rat brain arachidonic acid metabolism agrees with its inefficacy against bipolar disorder

PubMed Central

Reese, Edmund A.; Cheon, Yewon; Ramadan, Epolia; Kim, Hyung-Wook; Chang, Lisa; Rao, Jagadeesh S.; Rapoport, Stanley I.; Taha, Ameer Y.

2012-01-01

In rats, FDA-approved mood stabilizers used for treating bipolar disorder (BD) selectively downregulate brain markers of the arachidonic acid (AA) cascade, which are upregulated in postmortem BD brain. Phase III clinical trials show that gabapentin (GBP) is ineffective in treating BD. We hypothesized that GBP would not alter the rat brain AA cascade. Chronic GBP (10 mg/kg body weight, injected i.p. for 30 days) compared to saline vehicle did not significantly alter brain expression or activity of AA-selective cytosolic phospholipase A2 (cPLA2) IVA or secretory (s) PLA2 IIA, activity of cyclooxygenase-2, or prostaglandin or thromboxane concentrations. Plasma AA concentration was unaffected. These results, taken with evidence of an upregulated AA cascade in the BD brain and that approved mood stabilizers downregulate rat brain AA cascade, support the hypothesis that effective anti-BD drugs act by targeting the AA cascade, and suggest that the rat model might be used for drug screening PMID:22841517

Ruminal degradation and intestinal digestibility of protein and amino acids in high-protein feedstuffs commonly used in dairy diets.

PubMed

Paz, H A; Klopfenstein, T J; Hostetler, D; Fernando, S C; Castillo-Lopez, E; Kononoff, P J

2014-10-01

A study was conducted to determine the rumen degradation and intestinal digestibility of crude protein (CP) and AA, and AA composition of the rumen-undegradable protein (RUP) from 3 sources of blood meal (BM1, BM2, and BM3), canola meal (CM), low-fat distillers dried grains with solubles (LFDG), soybean meal (SBM), and expeller soybean meal (ESBM). Two Holstein cows fitted with ruminal and proximal duodenal cannulas were used for in situ incubation of 16h and for the mobile bag technique. To correct for bacterial contamination of the RUP, 2 methods were used: purines and DNA as bacterial markers. Ruminal degradations of CP were 85.3, 29.8, 40.7, 75.7, 76.9, 68.8, and 37.0 ± 3.93% for BM1, BM2, BM3, CM, LFDG, SBM, and ESBM, respectively. Ruminal degradation of both total essential AA and nonessential AA followed a similar pattern to that of CP across feedstuffs. Based on the ratio of AA concentration in the RUP to AA concentration in the original feedstuff, ruminal incubation decreased (ratio <1) the concentrations of His, Lys, and Trp, and increased (ratio >1) the concentrations of Ile and Met across feedstuffs. Compared with purines, the use of DNA as bacterial marker resulted in a higher estimate of bacterial CP contamination for CM and lower estimates for LFDG and ESBM. Intestinal digestibility of RUP could not be estimated for BM1, BM3, and SBM due to insufficient recovery of residue. For the remaining feedstuffs, intestinal digestibility of RUP was highest for ESBM, followed by BM2 and LFDG, and lowest for CM: 98.8, 87.9, 89.7, and 72.4 ± 1.40%, respectively. Intestinal absorbable dietary protein was higher for BM2 compared with CM and LFDG, at 61.7, 17.9, and 20.7 ± 2.73% CP, respectively. As prices fluctuate, intestinal absorbable protein or AA may be used as a tool to aid in the selection among feedstuffs with different protein quality. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula

USDA-ARS?s Scientific Manuscript database

Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA c...

Active biopolymer film based on carboxymethyl cellulose and ascorbic acid for food preservation

NASA Astrophysics Data System (ADS)

Halim, Al Luqman Abdul; Kamari, Azlan

2017-05-01

In the present study, an active biopolymer film based on carboxymethyl cellulose (CMC) and ascorbic acid (AA) was synthesised at an incorporation rate of 15% (w/w). Several analytical instruments such as Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetry Analyser (TGA), UV-Visible Spectrophotometer (UV-Vis), Scanning Electron Microscope (SEM) and Universal Testing Machine were used to characterise the physical and chemical properties of CMC-AA film. The addition of AA significantly reduced elongation at break (322%) and tensile strength (10 MPa) of CMC-AA film. However, CMC-AA film shows a better antimicrobial property against two bacteria, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to CMC film. The CMC-AA film was able to preserve cherry tomato with low weight loss and browning index. Overall, results from this study highlight the feasibility of CSAA film for food preservation.

Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene.

PubMed

Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia; Lu, Xiaoquan; Zhou, Xibin

2014-05-01

A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π-π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2-12.9 mM, 0.5-110 μM, and 10-1000 μM, with the detection limits (S/N=3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Differences in Arachidonic Acid Levels and Fatty Acid Desaturase (FADS) Gene Variants in African Americans and European Americans with Diabetes/Metabolic Syndrome

PubMed Central

Sergeant, Susan; Hugenschmidt, Christina E.; Rudock, Megan E.; Ziegler, Julie T.; Ivester, Priscilla; Ainsworth, Hannah C.; Vaidya, Dhananjay; Case, L. Douglas; Langefeld, Carl D.; Freedman, Barry I.; Bowden, Donald W.; Mathias, Rasika A.; Chilton, Floyd H.

2012-01-01

Over the past 50 years, increases in dietary n-6 polyunsaturated fatty acids (PUFAs), such as linoleic acid, have been hypothesized to cause or exacerbate chronic inflammatory diseases. This study examines an individual’s innate capacity to synthesize n-6-long chain PUFAs (LC-PUFAs), with respect to the fatty acid desaturase (FADS) locus in Americans of African and European descent with diabetes/metabolic syndrome. Compared to European Americans (EAm), African Americans (AfAm) exhibited markedly higher serum levels of arachidonic acid (AA) (EAm 7.9±2.1; AfAm 9.8±1.9 % of total fatty acids, mean ± sd; p<2.29×10−9) and the AA to n-6-precursor fatty acid ratio, which estimates FADS1 activity (EAm 5.4±2.2, AfAm 6.9±2.2; p=1.44×10−5). Seven single nucleotide polymorphisms (SNP) mapping to the FADS locus revealed strong association with AA, eicosapentaenoic acid (EPA) and dihomogamma-linolenic acid (DGLA) in the EAm. Importantly, EAm homozygous for the minor allele (T) had significantly lower AA levels (TT: 6.3±1.0; GG: 8.5±2.1; p=3.0×10−5) and AA/DGLA ratios (TT: 3.4±0.8; GG: 6.5±2.3; p=2.2×10−7) but higher DGLA levels (TT: 1.9±0.4; GG: 1.4±0.4; p=3.3×10−7) compared to those homozygous for the major allele (GG). Allele frequency patterns suggest that the GG genotype at rs174537 (associated with higher circulating levels of AA) is much higher in AfAm (0.81) compared to EAm (0.46). Similarly, marked differences in rs174537 genotypic frequencies were observed in HapMap populations. These data suggest that there are likely important differences in the capacity of different populations to synthesize LC-PUFAs. These differences may provide a genetic mechanism contributing to health disparities between populations of African and European descent. PMID:21733300

Cloning of a growth hormone from a primitive bony fish and its phylogenetic relationships.

PubMed

Rubin, D A; Dores, R M

1994-07-01

Growth hormone (GH), prolactin, and their relatives constitute a multigene family which is considered to have evolved from a common ancestor. The structural and functional domains of GH appear to be highly conserved among vertebrates. In order to investigate the phylogenetic relationships among GHs in the Actinopterygii and Sarcopterygii, we have cloned and sequenced GH from the pituitary of the primitive bony fish, Amia calva. Bony fishes (teleosts) and Amia (Halecomorphi) are purported sister-groups within the Neoptergii, hence studies on this perspective group of fish can provide insights into the evolution of GH. The deduced amino acid (aa) sequence from A. calva GH (amGH) cDNA revealed that the mature GH consists of 190 residues. Phylogenetic comparisons with GH aa sequences from blue shark, sturgeon, four teleosts (eel, carp, porgy, flounder), and two sarcopterygians (African lungfish and bullfrog) indicated, in the most parsimonious cladogram, that amGH clusters as the sister-group to the teleosts, that sturgeon is the sister-group to the Neopterygii, and that the African lungfish and bullfrog are in the same clade.

Rapid microwave-assisted acid extraction of southern pine waste wood to remove metals from chromated copper arsenate (CCA) treatment

Treesearch

Chung-Yun Hse; Todd F. Shupe; Bin Yu

2013-01-01

Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated by extraction in a microwave reactor with binary combinations of acetic acid (AA), oxalic acid (OxA), and phosphoric acid (PhA). Use of OxA was not successful, as insoluble copper oxalate complexes impeded copper removal. The combination of OxA and AA also had...

A New Model to Study the Role of Arachidonic Acid in Colon Cancer Pathophysiology.

PubMed

Fan, Yang-Yi; Callaway, Evelyn; M Monk, Jennifer; S Goldsby, Jennifer; Yang, Peiying; Vincent, Logan; S Chapkin, Robert

2016-09-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA)-derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression, and metastasis. We have recently developed a novel Fads1 knockout mouse model that allows for the investigation of AA-dependent eicosanoid deficiency without the complication of essential fatty acid deficiency. Interestingly, the survival rate of Fads1-null mice is severely compromised after 2 months on a semi-purified AA-free diet, which precludes long-term chemoprevention studies. Therefore, in this study, dietary AA levels were titrated to determine the minimal level required for survival, while maintaining a distinct AA-deficient phenotype. Null mice supplemented with AA (0.1%, 0.4%, 0.6%, 2.0%, w/w) in the diet exhibited a dose-dependent increase (P < 0.05) in AA, PGE2, 6-keto PGF1α, TXB2, and EdU-positive proliferative cells in the colon. In subsequent experiments, null mice supplemented with 0.6% AA diet were injected with a colon-specific carcinogen (azoxymethane) in order to assess cancer susceptibility. Null mice exhibited significantly (P < 0.05) reduced levels/multiplicity of aberrant crypt foci (ACF) as compared with wild-type sibling littermate control mice. These data indicate that (i) basal/minimal dietary AA supplementation (0.6%) expands the utility of the Fads1-null mouse model for long-term cancer prevention studies and (ii) that AA content in the colonic epithelium modulates colon cancer risk. Cancer Prev Res; 9(9); 750-7. ©2016 AACR. ©2016 American Association for Cancer Research.

Dynamics of the active site loops in catalyzing aminoacylation reaction in seryl and histidyl tRNA synthetases.

PubMed

Dutta, Saheb; Kundu, Soumya; Saha, Amrita; Nandi, Nilashis

2018-03-01

Aminoacylation reaction is the first step of protein biosynthesis. The catalytic reorganization at the active site of aminoacyl tRNA synthetases (aaRSs) is driven by the loop motions. There remain lacunae of understanding concerning the catalytic loop dynamics in aaRSs. We analyzed the functional loop dynamics in seryl tRNA synthetase from Methanopyrus kandleri ( mk SerRS) and histidyl tRNA synthetases from Thermus thermophilus ( tt HisRS), respectively, using molecular dynamics. Results confirm that the motif 2 loop and other active site loops are flexible spots within the catalytic domain. Catalytic residues of the loops form a network of interaction with the substrates to form a reactive state. The loops undergo transitions between closed state and open state and the relaxation of the constituent residues occurs in femtosecond to nanosecond time scale. Order parameters are higher for constituent catalytic residues which form a specific network of interaction with the substrates to form a reactive state compared to the Gly residues within the loop. The development of interaction is supported from mutation studies where the catalytic domain with mutated loop exhibits unfavorable binding energy with the substrates. During the open-close motion of the loops, the catalytic residues make relaxation by ultrafast librational motion as well as fast diffusive motion and subsequently relax rather slowly via slower diffusive motion. The Gly residues act as a hinge to facilitate the loop closing and opening by their faster relaxation behavior. The role of bound water is analyzed by comparing implicit solvent-based and explicit solvent-based simulations. Loops fail to form catalytically competent geometry in absence of water. The present result, for the first time reveals the nature of the active site loop dynamics in aaRS and their influence on catalysis.

Prediction protein structural classes with pseudo-amino acid composition: approximate entropy and hydrophobicity pattern.

PubMed

Zhang, Tong-Liang; Ding, Yong-Sheng; Chou, Kuo-Chen

2008-01-07

Compared with the conventional amino acid (AA) composition, the pseudo-amino acid (PseAA) composition as originally introduced for protein subcellular location prediction can incorporate much more information of a protein sequence, so as to remarkably enhance the power of using a discrete model to predict various attributes of a protein. In this study, based on the concept of PseAA composition, the approximate entropy and hydrophobicity pattern of a protein sequence are used to characterize the PseAA components. Also, the immune genetic algorithm (IGA) is applied to search the optimal weight factors in generating the PseAA composition. Thus, for a given protein sequence sample, a 27-D (dimensional) PseAA composition is generated as its descriptor. The fuzzy K nearest neighbors (FKNN) classifier is adopted as the prediction engine. The results thus obtained in predicting protein structural classification are quite encouraging, indicating that the current approach may also be used to improve the prediction quality of other protein attributes, or at least can play a complimentary role to the existing methods in the relevant areas. Our algorithm is written in Matlab that is available by contacting the corresponding author.

Chlamydia trachomatis Scavenges Host Fatty Acids for Phospholipid Synthesis via an Acyl-Acyl Carrier Protein Synthetase*

PubMed Central

Yao, Jiangwei; Dodson, V. Joshua; Frank, Matthew W.; Rock, Charles O.

2015-01-01

The obligate intracellular parasite Chlamydia trachomatis has a reduced genome but relies on de novo fatty acid and phospholipid biosynthesis to produce its membrane phospholipids. Lipidomic analyses showed that 8% of the phospholipid molecular species synthesized by C. trachomatis contained oleic acid, an abundant host fatty acid that cannot be made by the bacterium. Mass tracing experiments showed that isotopically labeled palmitic, myristic, and lauric acids added to the medium were incorporated into C. trachomatis-derived phospholipid molecular species. HeLa cells did not elongate lauric acid, but infected HeLa cell cultures elongated laurate to myristate and palmitate. The elongated fatty acids were incorporated exclusively into C. trachomatis-produced phospholipid molecular species. C. trachomatis has adjacent genes encoding the separate domains of the bifunctional acyl-acyl carrier protein (ACP) synthetase/2-acylglycerolphosphoethanolamine acyltransferase gene (aas) of Escherichia coli. The CT775 gene encodes an acyltransferase (LpaT) that selectively transfers fatty acids from acyl-ACP to the 1-position of 2-acyl-glycerophospholipids. The CT776 gene encodes an acyl-ACP synthetase (AasC) with a substrate preference for palmitic compared with oleic acid in vitro. Exogenous fatty acids were elongated and incorporated into phospholipids by Escherichia coli-expressing AasC, illustrating its function as an acyl-ACP synthetase in vivo. These data point to an AasC-dependent pathway in C. trachomatis that selectively scavenges host saturated fatty acids to be used for the de novo synthesis of its membrane constituents. PMID:26195634

An alanine residue in human parainfluenza virus type 3 phosphoprotein is critical for restricting excessive N0-P interaction and maintaining N solubility.

PubMed

Zhang, Shengwei; Cheng, Qi; Luo, Chenxi; Yin, Lei; Qin, Yali; Chen, Mingzhou

2018-05-01

The phosphoprotein (P) of human parainfluenza virus type 3 (HPIV3) plays a pivotal role in viral RNA synthesis, which interacts with the nucleoprotein (N) to form a soluble N 0 -P complex (N 0 , free of RNAs) to prevent the nonspecific RNA binding and illegitimate aggregation of N. Functional regions within P have been studied intensively. However, the precise site (s) within P directly involved in N 0 -P interaction still remains unclear. In this study, using a series of deleted and truncated mutants of P of HPIV3, we demonstrate that amino-terminal 40 amino acids (aa) of P restrict and regulate N 0 -P interaction. Furthermore, using in vivo HPIV3 minigenome replicon assay, we identify a critical P mutant (P A28P ) located in amino-terminal 40 aa, which fails to support RNA synthesis of HPIV3 minigenome replicon. Although P A28P maintains an enhanced N-P interaction, it is unable to form N 0 -P complex and keep N soluble, thus, resulting in aggregation and functional abolishment of N-P complex. Moreover, we found that recombinant HPIV3 with mutation of A28P in P failed to be rescued. Taken together, we identified a residue within the extreme amino-terminus of P, which plays a critical role in restricting the excessively N-P interaction and keeping a functional N 0 -P complex formation. Copyright © 2018 Elsevier Inc. All rights reserved.

Ruminal bacteria and protozoa composition, digestibility, and amino acid profile determined by multiple hydrolysis times.

PubMed

Fessenden, S W; Hackmann, T J; Ross, D A; Foskolos, A; Van Amburgh, M E

2017-09-01

Microbial samples from 4 independent experiments in lactating dairy cattle were obtained and analyzed for nutrient composition, AA digestibility, and AA profile after multiple hydrolysis times ranging from 2 to 168 h. Similar bacterial and protozoal isolation techniques were used for all isolations. Omasal bacteria and protozoa samples were analyzed for AA digestibility using a new in vitro technique. Multiple time point hydrolysis and least squares nonlinear regression were used to determine the AA content of omasal bacteria and protozoa, and equivalency comparisons were made against single time point hydrolysis. Formalin was used in 1 experiment, which negatively affected AA digestibility and likely limited the complete release of AA during acid hydrolysis. The mean AA digestibility was 87.8 and 81.6% for non-formalin-treated bacteria and protozoa, respectively. Preservation of microbe samples in formalin likely decreased recovery of several individual AA. Results from the multiple time point hydrolysis indicated that Ile, Val, and Met hydrolyzed at a slower rate compared with other essential AA. Singe time point hydrolysis was found to be nonequivalent to multiple time point hydrolysis when considering biologically important changes in estimated microbial AA profiles. Several AA, including Met, Ile, and Val, were underpredicted using AA determination after a single 24-h hydrolysis. Models for predicting postruminal supply of AA might need to consider potential bias present in postruminal AA flow literature when AA determinations are performed after single time point hydrolysis and when using formalin as a preservative for microbial samples. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Risk control of traditional Chinese medicines containing aristolochis acids (AAs) based on influencing factors of content of AAs].

PubMed

Tian, Jing-Zhuo; Liang, Ai-Hua; Liu, Jing; Zhang, Bo-Li

2017-12-01

Aristolochic acids (AAs) widely exist in such plants as Aristolochia and Asarum. The renal toxicity of AAs as well as its carcinogenicity to urinary system have been widely known. In 2003 and 2004, China prohibited the use of Aristolochiae Radix, Aristolochiae Manshuriensis Caulis and Aristolochiae Fangchi Radix, and required administering other AAs-containing medicines in accordance with the regulations for prescription drugs. In this paper, we retrieved literatures on the content determination of AAs in recent 10 years in China. It suggested that the AAs content is lower in Asarum herb, especially in its roots and rhizomes, and most of which do not show detectable amount of AA-I. Some of traditional Chinese medicines show fairly small amount of detectable AA-I. The AAs content in Aristolochia herb (including Fructus Aristolochiae, kaempfer dutchmanspipe root) is relatively high; however, there are fewer literatures for studying the content determination of AAs in Chinese patent medicines. There were many factors affecting AAs content, including the parts used, origins, processing methods, extraction process. It suggested that we should pay attention to the toxicity of Chinese medicines containing AAs and use these decoction pieces and traditional Chinese medicines cautiously. In addition, basic studies for the origins, processing methods and extraction process of Chinese patent medicines containing AAs, as well as supervision and detection of AAs content in traditional Chinese medicinal materials, decoction pieces and Chinese patent medicines shall be strengthened for reducing medication risk and guaranteeing clinical medication safety. Copyright© by the Chinese Pharmaceutical Association.

Anacardic acid from brazilian cashew nut trees reduces dentine erosion.

PubMed

Silveira, Cintia; Oliveira, Flávia; Dos Santos, Maria Lucilia; de Freitas, Thiago; Imparato, José Carlos; Magalhães, Ana Carolina

2014-01-01

The aim of this study was to analyze the effect of solutions containing saturated anacardic acid (AA) on dentine erosion in vitro. AA was chemically isolated from natural cashew nutshell liquid obtained by continuous extraction in a Soxhlet extractor and was fully saturated by catalytic hydrogenation. Matrix metalloproteinase 2 (MMP-2) activity, when exposed to buffers containing 100 µmol/l AA, was analyzed using zymography. Bovine root samples were subjected to erosive demineralization (Sprite Zero™, 4 × 90 s/day) and remineralization with artificial saliva between the erosive cycles for 5 days. The samples were treated as follows, after the first and the last acid exposure (1 min; n = 12/group): (1) 100 µmol/l epigallocatechin-3-gallate (EGCG) (positive control); (2) 0.05% NaF; (3) 100 µmol/l saturated AA; (4) saturated AA and EGCG; (5) saturated AA, EGCG and NaF; (6) untreated (negative control). Dentine erosion was measured using a contact profilometer. Two dentine samples from each group were analyzed using scanning electron microscopy. Saturated AA reduced the activity of MMP-2. ANOVA and Tukey's test revealed that all treatments significantly reduced dentine loss compared to the negative control (6.03 ± 0.98 µm). Solutions containing saturated AA (1.97 ± 1.02 µm) showed the greatest reduction in dentine erosion compared to the NaF (3.93 ± 1.54 µm) and EGCG (3.79 ± 0.83 µm) solutions. Therefore, it may be concluded that AA significantly reduces dentine erosion in vitro, possibly by acting as an MMP-2 inhibitor.

Effects of blanching, acidification, or addition of EDTA on vitamin C and β-carotene stability during mango purée preparation.

PubMed

Guiamba, Isabel R F; Svanberg, Ulf

2016-09-01

The impact of acidification with citric acid, addition of EDTA or water blanching at high temperature, and short time (HTST) conducted at 90°C for 4 min, on the retention of vitamin C (L-AA and DHAA) and β-carotene was studied in mango purée 30 min after crushing. HTST blanching prior to matrix disruption into purée resulted in complete inactivation of polyphenol oxidase (PPO) and minor residual activity (8%) of ascorbic acid oxidase (AAO). The retention of total vitamin C was 100% in blanched purées and in purée with EDTA and about 90% in purées at pH 3.9 and 5.0. Acidification, blanching, and addition of EDTA preserved vitamin C mainly as L-AA, while complete conversion into DHAA was observed in purée at pH 5.0. The retention of all-trans-β-carotene was between 65 and 72%, with the highest value in purée with EDTA and the lowest value in purée of blanched mango. The ratio of 13-cis-β-carotene in fresh mango was 8.2 ± 0.5% that increased significantly after blanching and in purée at pH 5.0.

Conserved Tryptophan Motifs in the Large Tegument Protein pUL36 Are Required for Efficient Secondary Envelopment of Herpes Simplex Virus Capsids

PubMed Central

Ivanova, Lyudmila; Buch, Anna; Döhner, Katinka; Pohlmann, Anja; Binz, Anne; Prank, Ute; Sandbaumhüter, Malte

2016-01-01

ABSTRACT Herpes simplex virus (HSV) replicates in the skin and mucous membranes, and initiates lytic or latent infections in sensory neurons. Assembly of progeny virions depends on the essential large tegument protein pUL36 of 3,164 amino acid residues that links the capsids to the tegument proteins pUL37 and VP16. Of the 32 tryptophans of HSV-1-pUL36, the tryptophan-acidic motifs 1766WD1767 and 1862WE1863 are conserved in all HSV-1 and HSV-2 isolates. Here, we characterized the role of these motifs in the HSV life cycle since the rare tryptophans often have unique roles in protein function due to their large hydrophobic surface. The infectivity of the mutants HSV-1(17+)Lox-pUL36-WD/AA-WE/AA and HSV-1(17+)Lox-CheVP26-pUL36-WD/AA-WE/AA, in which the capsid has been tagged with the fluorescent protein Cherry, was significantly reduced. Quantitative electron microscopy shows that there were a larger number of cytosolic capsids and fewer enveloped virions compared to their respective parental strains, indicating a severe impairment in secondary capsid envelopment. The capsids of the mutant viruses accumulated in the perinuclear region around the microtubule-organizing center and were not dispersed to the cell periphery but still acquired the inner tegument proteins pUL36 and pUL37. Furthermore, cytoplasmic capsids colocalized with tegument protein VP16 and, to some extent, with tegument protein VP22 but not with the envelope glycoprotein gD. These results indicate that the unique conserved tryptophan-acidic motifs in the central region of pUL36 are required for efficient targeting of progeny capsids to the membranes of secondary capsid envelopment and for efficient virion assembly. IMPORTANCE Herpesvirus infections give rise to severe animal and human diseases, especially in young, immunocompromised, and elderly individuals. The structural hallmark of herpesvirus virions is the tegument, which contains evolutionarily conserved proteins that are essential for several stages of the herpesvirus life cycle. Here we characterized two conserved tryptophan-acidic motifs in the central region of the large tegument protein pUL36 of herpes simplex virus. When we mutated these motifs, secondary envelopment of cytosolic capsids and the production of infectious particles were severely impaired. Our data suggest that pUL36 and its homologs in other herpesviruses, and in particular such tryptophan-acidic motifs, could provide attractive targets for the development of novel drugs to prevent herpesvirus assembly and spread. PMID:27009950

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy.

PubMed

Yarla, Nagendra Sastry; Bishayee, Anupam; Sethi, Gautam; Reddanna, Pallu; Kalle, Arunasree M; Dhananjaya, Bhadrapura Lakkappa; Dowluru, Kaladhar S V G K; Chintala, Ramakrishna; Duddukuri, Govinda Rao

2016-10-01

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A 2 s (PLA 2 s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA 2 s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plasma Amino Acid Abnormalities in Chronic Heart Failure. Mechanisms, Potential Risks and Targets in Human Myocardium Metabolism

PubMed Central

Aquilani, Roberto; La Rovere, Maria Teresa; Corbellini, Daniela; Pasini, Evasio; Verri, Manuela; Barbieri, Annalisa; Condino, Anna Maria; Boschi, Federica

2017-01-01

The goal of this study was to measure arterial amino acid levels in patients with chronic heart failure (CHF), and relate them to left ventricular function and disease severity. Amino acids (AAs) play a crucial role for heart protein-energy metabolism. In heart failure, arterial AAs, which are the major determinant of AA uptake by the myocardium, are rarely measured. Forty-one subjects with clinically stable CHF (New York Heart Association (NYHA) class II to IV) were analyzed. After overnight fasting, blood samples from the radial artery were taken to measure AA concentrations. Calorie (KcalI), protein-, fat-, carbohydrate-intake, resting energy expenditure (REE), total daily energy expenditure (REE × 1.3), and cardiac right catheterization variables were all measured. Eight matched controls were compared for all measurements, with the exception of cardiac catheterization. Compared with controls, CHF patients had reduced arterial AA levels, of which both their number and reduced rates are related to Heart Failure (HF) severity. Arterial aspartic acid correlated with stroke volume index (r = 0.6263; p < 0.0001) and cardiac index (r = 0.4243; p = 0.0028). The value of arterial aspartic acid (µmol/L) multiplied by the cardiac index was associated with left ventricular ejection fraction (r = 0.3765; p = 0.0076). All NYHA groups had adequate protein intake (≥1.1 g/kg/day) and inadequate calorie intake (KcalI < REE × 1.3) was found only in class IV patients. This study showed that CHF patients had reduced arterial AA levels directly related to clinical disease severity and left ventricular dysfunction. PMID:29140312

Arachidonic acid, but not its metabolites, is essential for FcγR-stimulated intracellular killing of Staphylococcus aureus by human monocytes

PubMed Central

Zheng, L; Zomerdijk, T P L; Van Den Barselaar, M T; Geertsma, M F; Van Furth, R; Nibbering, P H

1999-01-01

Since arachidonic acid (AA) production by phospholipase A2 (PLA2) is essential for the Fcγ receptor (FcγR)-mediated respiratory burst and phagocytosis of opsonized erythrocytes by monocytes and macrophages, we focused in this study on the role of AA and its metabolites in the FcγR-stimulated intracellular killing of Staphylococcus aureus by human monocytes. The results revealed that the PLA2 inhibitors, but not inhibitors of cyclo-oxygenase and lipoxygenase, markedly suppressed the FcγR-mediated killing process. The production of O−2 by monocytes upon FcγR cross-linking was inhibited by 4-bromophenacyl bromide in a dose-dependent fashion, indicating that inhibition of PLA2 activity impairs the oxygen-dependent bactericidal mechanisms of monocytes, which could be partially restored by addition of exogenous AA and docosahexaenoic acid, but not myristic acid. These polyunsaturated fatty acids, but not myristic acid, stimulated the intracellular killing of S. aureus by monocytes, although not as effectively as FcγR cross-linking. Furthermore, FcγR cross-linking stimulated the release of AA from monocytes. Studies with selective inhibitors revealed that the FcγR-mediated activation of PLA2 is dependent on Ca2+ and tyrosine kinase activity. Together these results indicate a key role for PLA2/AA, but not its major metabolites, in mediating the FcγR-stimulated intracellular killing of S. aureus by monocytes. PMID:10233682

The effects of centrally injected arachidonic acid on respiratory system: Involvement of cyclooxygenase to thromboxane signaling pathway.

PubMed

Erkan, Leman Gizem; Guvenc, Gokcen; Altinbas, Burcin; Niaz, Nasir; Yalcin, Murat

2016-05-01

Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Spraque Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA2 signaling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

Modulating the gut flora alters amino acid metabolism in neonatal pigs

USDA-ARS?s Scientific Manuscript database

Intestinal microbes consume and produce amino acids (AA). This may impact intestinal threonine (THR) metabolism necessary for adequate gut function. We hypothesized that modulating the gut flora results in an alteration of intestinal THR utilization and hence whole body AA metabolism. Neonatal pigs ...

ASCORBID ACID IS DECREASED IN INDUCED SPUTUM OF MILD ASTHMATICS

EPA Science Inventory

ABSTRACT
Evidence suggests that the antioxidant ascorbic acid (AA), plays an essential role in defending against oxidant attack in the airways. Decreased levels of AA have been reported in asthmatics but not at the site directly proximal to asthma pathology, i.e. the bronchial...

Ascorbic acid, but not dehydroascorbic acid increases intracellular vitamin C content to decrease Hypoxia Inducible Factor -1 alpha activity and reduce malignant potential in human melanoma.

PubMed

Fischer, Adam P; Miles, Sarah L

2017-02-01

Accumulation of hypoxia inducible factor-1 alpha (HIF-1α) in malignant tissue is known to contribute to oncogenic progression and is inversely associated with patient survival. Ascorbic acid (AA) depletion in malignant tissue may contribute to aberrant normoxic activity of HIF-1α. While AA supplementation has been shown to attenuate HIF-1α function in malignant melanoma, the use of dehydroascorbic acid (DHA) as a therapeutic means to increase intracellular AA and modulate HIF-1α function is yet to be evaluated. Here we compared the ability of AA and DHA to increase intracellular vitamin C content and decrease the malignant potential of human melanoma by reducing the activity of HIF-1α. HIF-1α protein accumulation was evaluated by western blot and transcriptional activity was evaluated by reporter gene assay using a HIF-1 HRE-luciferase plasmid. Protein expressions and subcellular localizations of vitamin C transporters were evaluated by western blot and confocal imaging. Intracellular vitamin C content following AA, ascorbate 2-phosphate (A2P), or DHA supplementation was determined using a vitamin C assay. Malignant potential was accessed using a 3D spheroid Matrigel invasion assay. Data was analyzed by One or Two-way ANOVA with Tukey's multiple comparisons test as appropriate with p<0.05 considered significant. Melanoma cells expressed both sodium dependent vitamin C (SVCT) and glucose (GLUT) transporters for AA and DHA transport respectively, however advanced melanomas responded favorably to AA, but not DHA. Physiological glucose conditions significantly impaired intracellular vitamin C accumulation following DHA treatment. Consequently, A2P and AA, but not DHA treated cells demonstrated lower HIF-1α protein expression and activity, and reduced malignant potential. The ability of AA to regulate HIF-1α was dependent on SVCT2 function and SVCT2 was not significantly inhibited at pH representative of the tumor microenvironment. The use of ascorbic acid as an adjuvant cancer therapy remains under investigated. While AA and A2P were capable of modulating HIF-1α protein accumulation/activity, DHA supplementation resulted in minimal intracellular vitamin C activity with decreased ability to inhibit HIF-1α activity and malignant potential in advanced melanoma. Restoring AA dependent regulation of HIF-1α in malignant cells may prove beneficial in reducing chemotherapy resistance and improving treatment outcomes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Variation in plasma amino acid concentrations during a cycling competition.

PubMed

Medelli, J; Lounana, J; Hill, D

2003-06-01

The variations in plasma concentrations of 24 amino acids (AAs) were measured, taking into account modifications in plasma volume, in 7 male subjects, professional cyclists, during the first 2 stages (EI and EII) of the competition "4 Days of Dunkirk 1999". Blood samples were taken before the start and at the end of each stage. At the end of EI a significant reduction (p<0.02) in alpha-aminobutyric acid was observed (-38%) and a significant increase (Wilcoxon 0.01

Amino acid metabolism in dairy cows and their regulation in milk synthesis.

PubMed

Wang, Feiran; Shi, Haitao; Wang, Shuxiang; Wang, Yajing; Cao, Zhijun; Li, Shengli

2018-06-10

Reducing dietary crude protein (CP) and supplementing with certain amino acids (AAs) has been known as a potential solution to improve nitrogen (N) efficiency in dairy production. Thus understanding how AAs are utilized in various sites along the gut is critical. AA flow from the intestine to portal-drained viscera (PDV) and liver then to the mammary gland was elaborated in this article. Recoveries in individual AA in PDV and liver seem to share similar AA pattern with input: output ratio in mammary gland, which subdivides essential AA (EAA) into two groups, lysine (Lys) and branched-chain AA (BCAA) in group 1, input: output ratio > 1; methionine (Met), histidine (His), phenylalanine (Phe) etc. in group 2, input: output ratio close to 1. AAs in the mammary gland are either utilized for milk protein synthesis or retained as body tissue, or catabolized. The fractional removal of AAs and the number and activity of AA transporters together contribute to the ability of AAs going through mammary cells. Mammalian target of rapamycin (mTOR) pathway is closely related to milk protein synthesis and provides alternatives for AA regulation of milk protein synthesis, which connects AA with lactose synthesis via α-lactalbumin (gene: LALBA) and links with milk fat synthesis via sterol regulatory element-binding transcription protein 1 (SREBP1) and peroxisome proliferator-activated receptor (PPAR). Overall, AA flow across various tissues reveal AA metabolism and utilization in dairy cows on one hand. While the function of AA in the biosynthesis of milk protein, fat and lactose at both transcriptional and posttranscriptional level from another angle provides the possibility for us to regulate them for higher efficiency. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The h-region of twin-arginine signal peptides supports productive binding of bacterial Tat precursor proteins to the TatBC receptor complex.

PubMed

Ulfig, Agnes; Fröbel, Julia; Lausberg, Frank; Blümmel, Anne-Sophie; Heide, Anna Katharina; Müller, Matthias; Freudl, Roland

2017-06-30

The twin-arginine translocation (Tat) pathway transports folded proteins across bacterial membranes. Tat precursor proteins possess a conserved twin-arginine (RR) motif in their signal peptides that is involved in their binding to the Tat translocase, but some facets of this interaction remain unclear. Here, we investigated the role of the hydrophobic (h-) region of the Escherichia coli trimethylamine N -oxide reductase (TorA) signal peptide in TatBC receptor binding in vivo and in vitro We show that besides the RR motif, a minimal, functional h-region in the signal peptide is required for Tat-dependent export in Escherichia coli Furthermore, we identified mutations in the h-region that synergistically suppressed the export defect of a TorA[KQ]-30aa-MalE Tat reporter protein in which the RR motif was replaced with a lysine-glutamine pair. Strikingly, all suppressor mutations increased the hydrophobicity of the h-region. By systematically replacing a neutral residue in the h-region with various amino acids, we detected a positive correlation between the hydrophobicity of the h-region and the translocation efficiency of the resulting reporter variants. In vitro cross-linking of residues located in the periplasmically-oriented part of the TatBC receptor to TorA[KQ]-30aa-MalE reporter variants harboring a more hydrophobic h-region in their signal peptides confirmed that unlike in TorA[KQ]-30aa-MalE with an unaltered h-region, the mutated reporters moved deep into the TatBC-binding cavity. Our results clearly indicate that, besides the Tat motif, the h-region of the Tat signal peptides is another important binding determinant that significantly contributes to the productive interaction of Tat precursor proteins with the TatBC receptor complex. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Evaluating Force Fields for the Computational Prediction of Ionized Arginine and Lysine Side-Chains Partitioning into Lipid Bilayers and Octanol.

PubMed

Sun, Delin; Forsman, Jan; Woodward, Clifford E

2015-04-14

Abundant peptides and proteins containing arginine (Arg) and lysine (Lys) amino acids can apparently permeate cell membranes with ease. However, the mechanisms by which these peptides and proteins succeed in traversing the free energy barrier imposed by cell membranes remain largely unestablished. Precise thermodynamic studies (both theoretical and experimental) on the interactions of Arg and Lys residues with model lipid bilayers can provide valuable clues to the efficacy of these cationic peptides and proteins. We have carried out molecular dynamics simulations to calculate the interactions of ionized Arg and Lys side-chains with the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayer for 10 widely used lipid/protein force fields: CHARMM36/CHARMM36, SLIPID/AMBER99SB-ILDN, OPLS-AA/OPLS-AA, Berger/OPLS-AA, Berger/GROMOS87, Berger/GROMOS53A6, GROMOS53A6/GROMOS53A6, nonpolarizable MARTINI, polarizable MARTINI, and BMW MARTINI. We performed umbrella sampling simulations to obtain the potential of mean force for Arg and Lys side-chains partitioning from water to the bilayer interior. We found significant differences between the force fields, both for the interactions between side-chains and bilayer surface, as well as the free energy cost for placing the side-chain at the center of the bilayer. These simulation results were compared with the Wimley-White interfacial scale. We also calculated the free energy cost for transferring ionized Arg and Lys side-chains from water to both dry and wet octanol. Our simulations reveal rapid diffusion of water molecules into octanol whereby the equilibrium mole fraction of water in the wet octanol phase was ∼25%. Surprisingly, our free energy calculations found that the high water content in wet octanol lowered the water-to-octanol partitioning free energies for cationic residues by only 0.6 to 0.7 kcal/mol.

Determination of trace amino acids in human serum by a selective and sensitive pre-column derivatization method using HPLC-FLD-MS/MS and derivatization optimization by response surface methodology.

PubMed

Li, Guoliang; Cui, Yanyan; You, Jinmao; Zhao, Xianen; Sun, Zhiwei; Xia, Lian; Suo, Yourui; Wang, Xiao

2011-04-01

Analysis of trace amino acids (AA) in physiological fluids has received more attention, because the analysis of these compounds could provide fundamental and important information for medical, biological, and clinical researches. More accurate method for the determination of those compounds is highly desirable and valuable. In the present study, we developed a selective and sensitive method for trace AA determination in biological samples using 2-[2-(7H-dibenzo [a,g]carbazol-7-yl)-ethoxy] ethyl chloroformate (DBCEC) as labeling reagent by HPLC-FLD-MS/MS. Response surface methodology (RSM) was first employed to optimize the derivatization reaction between DBCEC and AA. Compared with traditional single-factor design, RSM was capable of lessening laborious, time and reagents consumption. The complete derivatization can be achieved within 6.3 min at room temperature. In conjunction with a gradient elution, a baseline resolution of 20 AA containing acidic, neutral, and basic AA was achieved on a reversed-phase Hypersil BDS C(18) column. This method showed excellent reproducibility and correlation coefficient, and offered the exciting detection limits of 0.19-1.17 fmol/μL. The developed method was successfully applied to determinate AA in human serum. The sensitive and prognostic index of serum AA for liver diseases has also been discussed.

Amino acid utilization and body composition of growing pigs fed processed soybean meal or rapeseed meal with or without amino acid supplementation.

PubMed

Hulshof, T G; van der Poel, A F B; Hendriks, W H; Bikker, P

2017-07-01

Feed ingredients used in swine diets are often processed to improve nutritional value. However, (over-)processing may result in chemical reactions with amino acids (AAs) that decrease their ileal digestibility. This study aimed to determine effects of (over-)processing of soybean meal (SBM) and rapeseed meal (RSM) on post-absorptive utilization of ileal digestible AAs for retention and on body AA composition of growing pigs. Soybean meal and RSM were processed by secondary toasting in the presence of lignosulfonate to obtain processed soybean meal (pSBM) and processed rapeseed meal (pRSM). Four diets contained SBM, pSBM, RSM or pRSM as sole protein source. Two additional diets contained pSBM or pRSM and were supplemented with crystalline AA to similar standardized ileal digestible (SID) AA level as the SBM or RSM diet. These diets were used to verify that processing affected AA retention by affecting ileal AA digestibility rather than post-absorptive AA utilization. The SID AA levels of the protein sources were determined in a previous study. In total, 59 pigs were used (initial BW of 15.6±0.7 kg) of which five were used to determine initial body composition at the start of the experiment. In total, 54 pigs were fed one of six experimental diets and were slaughtered at a BW of 40 kg. The organ fraction (i.e. empty organs plus blood) and carcass were analyzed separately for N and AA content. Post-absorptive AA utilization was calculated from AA retention and SID AA intake. An interaction between diet type, comprising effects of processing and supplementing crystalline AA, and protein source was observed for CP content in the organ fraction, carcass and empty body and for nutrient retention. Processing reduced CP content and nutrient retention more for SBM than for RSM. Moreover, processing reduced (P<0.001) the lysine content in the organ fraction for both protein sources. Supplementing crystalline AA ameliorated the effect of processing on these variables. Thus, the data indicated that processing affected retention by reducing digestibility. Correcting AA retention for SID AA intake was, therefore, expected to result in similar post-absorptive AA utilization which was observed for the RSM diets. However, post-absorptive AA utilization was lower for the pSBM diet than for the SBM diet which might be related to an imbalanced post-absorptive AA supply. In conclusion, processing negatively affected nutrient retention for both protein sources and post-absorptive utilization of SID AA for retention for SBM. Effects of processing were compensated by supplementing crystalline AA.

Metabolomic profiling of amino acids and beta-cell function relative to insulin sensitivity in youth

USDA-ARS?s Scientific Manuscript database

In longitudinal studies of adults, elevated amino acid (AA) concentrations predicted future type 2 diabetes mellitus (T2DM). The aim of the present investigation was to examine whether increased plasma AA concentrations are associated with impaired beta-cell function relative to insulin sensitivity ...

Amino acids, independent of insulin, attenuate skeletal muscle autophagy in neonatal pigs during endotoxemia

USDA-ARS?s Scientific Manuscript database

Sepsis induces loss of skeletal muscle mass by activating the ubiquitin proteasome (UPS) and autophagy systems. Although muscle protein synthesis in healthy neonatal piglets is responsive to amino acids (AA) stimulation, it is not known if AA can prevent the activation of muscle protein degradation ...

Significance of Brain Tissue Oxygenation and the Arachidonic Acid Cascade in Stroke

PubMed Central

Rink, Cameron

2011-01-01

Abstract The significance of the hypoxia component of stroke injury is highlighted by hypermetabolic brain tissue enriched with arachidonic acid (AA), a 22:6n-3 polyunsaturated fatty acid. In an ischemic stroke environment in which cerebral blood flow is arrested, oxygen-starved brain tissue initiates the rapid cleavage of AA from the membrane phospholipid bilayer. Once free, AA undergoes both enzyme-independent and enzyme-mediated oxidative metabolism, resulting in the formation of number of biologically active metabolites which themselves contribute to pathological stroke outcomes. This review is intended to examine two divergent roles of molecular dioxygen in brain tissue as (1) a substrate for life-sustaining homeostatic metabolism of glucose and (2) a substrate for pathogenic metabolism of AA under conditions of stroke. Recent developments in research concerning supplemental oxygen therapy as an intervention to correct the hypoxic component of stroke injury are discussed. Antioxid. Redox Signal. 14, 1889–1903. PMID:20673202

Prescription profile of potentially aristolochic acid containing Chinese herbal products: an analysis of National Health Insurance data in Taiwan between 1997 and 2003.

PubMed

Hsieh, Shu-Ching; Lin, I-Hsin; Tseng, Wei-Lum; Lee, Chang-Hsing; Wang, Jung-Der

2008-10-23

Some Chinese herbal products (CHPs) may contain aristolochic acid (AA) or may be adulterated by the herbs suspected of containing AA which is nephrotoxic and carcinogenic. This study aims to identify the risk and the prescription profile of AA-containing CHPs (AA-CHPs) in Taiwan. A longitudinal analysis was conducted on a randomly sampled cohort of 200,000 patients using the data from the National Health Insurance (NHI) in Taiwan between 1997 and 2003. During the 7-year study period, 78,644 patients were prescribed with AA-CHPs; most patients were females, or middle-aged, or both. A total of 526,867 prescriptions were made to use 1,218 licensed AA-CHPs. Over 85% of the AA-exposed patients took less than 60 g of AA-herbs; however, about 7% were exposed to a cumulated dose of over 100 g of Radix et Rhizoma Asari (Xixin), Caulis Akebiae (Mutong) or Fructus Aristolochiae (Madouling). Patients of respiratory and musculoskeletal diseases received most of the AA-CHP prescriptions. The most frequently prescribed AA-CHPs Shujing Huoxie Tang, Chuanqiong Chadiao San and Longdan Xiegan Tang, containing Radix Stephaniae Tetrandrae, Radix et Rhizoma Asari and Caulis Akebiae, respectively. About one-third of people in Taiwan have been prescribed with AA-CHPs between 1997 and 2003. Although the cumulated doses were not large, further actions should be carried out to ensure the safe use of AA-CHPs.

Prescription profile of potentially aristolochic acid containing Chinese herbal products: an analysis of National Health Insurance data in Taiwan between 1997 and 2003

PubMed Central

Hsieh, Shu-Ching; Lin, I-Hsin; Tseng, Wei-Lum; Lee, Chang-Hsing; Wang, Jung-Der

2008-01-01

Background Some Chinese herbal products (CHPs) may contain aristolochic acid (AA) or may be adulterated by the herbs suspected of containing AA which is nephrotoxic and carcinogenic. This study aims to identify the risk and the prescription profile of AA-containing CHPs (AA-CHPs) in Taiwan. Methods A longitudinal analysis was conducted on a randomly sampled cohort of 200,000 patients using the data from the National Health Insurance (NHI) in Taiwan between 1997 and 2003. Results During the 7-year study period, 78,644 patients were prescribed with AA-CHPs; most patients were females, or middle-aged, or both. A total of 526,867 prescriptions were made to use 1,218 licensed AA-CHPs. Over 85% of the AA-exposed patients took less than 60 g of AA-herbs; however, about 7% were exposed to a cumulated dose of over 100 g of Radix et Rhizoma Asari (Xixin), Caulis Akebiae (Mutong) or Fructus Aristolochiae (Madouling). Patients of respiratory and musculoskeletal diseases received most of the AA-CHP prescriptions. The most frequently prescribed AA-CHPs Shujing Huoxie Tang, Chuanqiong Chadiao San and Longdan Xiegan Tang, containing Radix Stephaniae Tetrandrae, Radix et Rhizoma Asari and Caulis Akebiae, respectively. Conclusion About one-third of people in Taiwan have been prescribed with AA-CHPs between 1997 and 2003. Although the cumulated doses were not large, further actions should be carried out to ensure the safe use of AA-CHPs. PMID:18945373

Effects of arachidonic acid intake on inflammatory reactions in dextran sodium sulphate-induced colitis in rats.

PubMed

Naito, Yukiko; Ji, Xu; Tachibana, Shigehiro; Aoki, Satoko; Furuya, Mami; Tazura, Yoshiyuki; Miyazawa, Daisuke; Harauma, Akiko; Moriguchi, Toru; Nagata, Tomoko; Iwai, Naoharu; Ohara, Naoki

2015-09-14

The aim of this study was to investigate the effects of the administration of oral arachidonic acid (AA) in rats with or without dextran sulphate sodium (DSS)-induced inflammatory bowel disease. Male Wistar rats were administered AA at 0, 5, 35 or 240 mg/kg daily by gavage for 8 weeks. Inflammatory bowel disease was induced by replacing drinking water with 3 % DSS solution during the last 7 d of the AA dosing period. These animals passed loose stools, diarrhoea and red-stained faeces. Cyclo-oxygenase-2 concentration and myeloperoxidase activity in the colonic tissue were significantly increased in the animals given AA at 240 mg/kg compared with the animals given AA at 0 mg/kg. Thromboxane B2 concentration in the medium of cultured colonic mucosae isolated from these groups was found to be dose-dependently increased by AA, and the increase was significant at 35 and 240 mg/kg. Leukotriene B4 concentration was also significantly increased and saturated at 5 mg/kg. In addition, AA at 240 mg/kg promoted DSS-induced colonic mucosal oedema with macrophage infiltration. In contrast, administration of AA for 8 weeks, even at 240 mg/kg, showed no effects on the normal rats. These results suggest that in rats with bowel disease AA metabolism is affected by oral AA, even at 5 mg/kg per d, and that excessive AA may aggravate inflammation, whereas AA shows no effects in rats without inflammatory bowel disease.

Chiral capillary electrophoresis with UV-excited fluorescence detection for the enantioselective analysis of 9-fluorenylmethoxycarbonyl-derivatized amino acids.

PubMed

Prior, Amir; Coliva, Giulia; de Jong, Gerhardus J; Somsen, Govert W

2018-05-29

The potential of capillary electrophoresis (CE) with ultraviolet (UV)-excited fluorescence detection for sensitive chiral analysis of amino acids (AAs) was investigated. DL-AAs were derivatized with 9-fluorenylmethoxycarbonyl chloride (FMOC)-Cl to allow their fluorescence detection and enhance enantioseparation. Fluorescence detection was achieved employing optical fibers, leading UV excitation light (< 300 nm) from a Xe-Hg lamp to the capillary window, and fluorescence emission to a spectrograph equipped with a charge-coupled device (CCD). Signal averaging over time and emission wavelength intervals was carried out to improve the signal-to-noise ratio of the FMOC-AAs. A background electrolyte (BGE) of 40 mM sodium tetraborate (pH 9.5), containing 15% isopropanol (v/v), 30 mM sodium dodecyl sulfate (SDS), and 30 mM β-cyclodextrin (β-CD), was found optimal for AA chemo- and enantioseparation. Enantioresolutions of 1.0 or higher were achieved for 16 proteinogenic DL-AAs. Limits of detection (LODs) were in the 10-100-nM range (injected concentration) for the D-AA enantiomers, except for FMOC-D-tryptophan (536 nM) which showed intramolecular fluorescence quenching. Linearity (R 2  > 0.997) and repeatability for peak height (relative standard deviations (RSDs) < 7.0%; n = 5) and electrophoretic mobility (RSDs < 0.6%; n = 5) of individual AA enantiomers were established for chiral analysis of DL-AA mixtures. The applicability of the method was investigated by the analysis of cerebrospinal fluid (CSF). Next to L-AAs, endogenous levels of D-glutamine and D-aspartic acid could be measured in CSF revealing enantiomeric ratios of 0.35 and 19.6%, respectively. This indicates the method's potential for the analysis of low concentrations of D-AAs in presence of abundant L-AAs.

Growth and development in preterm infants fed long-chain polyunsaturated fatty acids: a prospective, randomized controlled trial.

PubMed

O'Connor, D L; Hall, R; Adamkin, D; Auestad, N; Castillo, M; Connor, W E; Connor, S L; Fitzgerald, K; Groh-Wargo, S; Hartmann, E E; Jacobs, J; Janowsky, J; Lucas, A; Margeson, D; Mena, P; Neuringer, M; Nesin, M; Singer, L; Stephenson, T; Szabo, J; Zemon, V

2001-08-01

A randomized, masked, controlled trial was conducted to assess effects of supplementing premature infant formulas with oils containing the long-chain polyunsaturated fatty acids, arachidonic acid (AA; 20:4 n6), and docosahexaenoic acid (DHA; 22:6 n3) on growth, visual acuity, and multiple indices of development. Infants (N = 470) with birth weights 750 to 1800 g were assigned within 72 hours of the first enteral feeding to 1 of 3 formula groups with or without long-chain polyunsaturated fatty acids: 1) control (N = 144), 2) AA+DHA from fish/fungal oil (N = 140), and 3) AA+DHA from egg-derived triglyceride (egg-TG)/fish oil (N = 143). Infants were fed human milk and/or Similac Special Care with or without 0.42% AA and 0.26% DHA to term corrected age (CA), then fed human milk or NeoSure with or without 0.42% AA and 0.16% DHA to 12 months' CA. Infants fed exclusively human milk to term CA (EHM-T; N = 43) served as a reference. Visual acuity measured by acuity cards at 2, 4, and 6 months' CA was not different among groups. Visual acuity measured by swept-parameter visual-evoked potentials in a subgroup from 3 sites (45 control, 50 AA+DHA [fish/fungal]; 39 AA+DHA [egg-TG/fish]; and 23 EHM-T) was better in both the AA+DHA (fish/fungal; least square [LS] means [cycle/degree] +/- standard error [SE; octaves] 11.4 +/- 0.1) and AA+DHA (egg-TG/fish; 12.5 +/- 0.1) than control (8.4 +/- 0.1) and closer to that of the EHM-T group (16.0 +/- 0.2) at 6 months' CA. Visual acuity improved from 4 to 6 months' CA in all but the control group. Scores on the Fagan test of novelty preference were greater in AA+DHA (egg-TG/fish; LS means +/- SE, 59.4 +/- 7.7) than AA+DHA (fish/fungal; 57.0 +/- 7.5) and control (57.5 +/- 7.4) at 6 months' CA, but not at 9 months' CA. There were no differences in the Bayley Mental Development Index at 12 months' CA. However, the Bayley motor development index was higher for AA+DHA (fish/fungal; LS means +/- SE, 90.6 +/- 4.4) than control (81.8 +/- 4.3) for infants

Activity of Aristolochia bracteolata against Moraxella catarrhalis

PubMed Central

Khedr, Amgad I. M.; Abd AlGadir, Haidar; Takeshita, Satoshi; Shah, Mohammad Monir; Ichinose, Yoshio; Maki, Toshihide

2014-01-01

A bioassay-guided fractionation of methanol extract of Aristolochia bracteolata whole plant was carried out in order to evaluate its antimicrobial activity and to identify the active compounds in this extract. Antibacterial and antifungal activities of methanol extract against gram-positive, gram-negative, and fungal strains were investigated by the agar disk diffusion method. Among the strains tested, Moraxella catarrhalis and sea urchin-derived Bacillus sp. showed the highest sensitivity towards the methanol extract and hence they are used as test organisms for the bioassay-guided fractionation. From this extract, aristolochic acid 1 (AA-1) has been isolated and has showed the greatest antibacterial activity against both standard strain and clinical isolates of Moraxella catarrhalis with equal minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 25 and 50 μg/mL. Modification of the AA-1 to AA-1 methyl ester completely abolished the antibacterial activity of the compound and the piperonylic acid moiety of AA-1 which suggested that the coexistence of phenanthrene ring and free carboxylic acid is essential for AA-1 antibacterial activity. PMID:26904734

Immunoglobulin from Antarctic fish species of Rajidae family.

PubMed

Coscia, Maria Rosaria; Cocca, Ennio; Giacomelli, Stefano; Cuccaro, Fausta; Oreste, Umberto

2012-03-01

Immunoglobulins (Ig) of Chondroichthyes have been extensively studied in sharks; in contrast, in skates investigations on Ig remain scarce and fragmentary despite the high occurrence of skates in all of the major oceans of the world. To focus on Rajidae Igμ, the most abundant heavy chain isotype, we have chosen the Antarctic species Bathyraja eatonii, Bathyraja albomaculata, Bathyraja brachyurops, and Amblyraja georgiana which live at high latitudes in the Southern Ocean, and at very low temperatures. We prepared mRNA from the spleen of individuals of each species and performed RT-PCR experiments using two oligonucleotides designed on the alignment of various elasmobranch Igμ heavy chain sequences available in GenBank. The PCR products, about 1400-nt long, were cloned and sequenced. Nucleotide sequence identities calculated for the constant region domains ranged from 88.5% to 97.5% between species, and from 91.1% to 99.7% within species. In a distance tree, including also Raja erinacea sequences, two major branches were obtained, one containing Arhynchobatinae sequences, the other one Rajinae sequences. Four presumptive D gene segments were identified in the region of the VH/D/JH recombination; two different D segments were often found in the same sequence. Moreover, 5-15 genomic fragments of different lengths, carrying the gene locus encoding Igμ chain were revealed by Southern blotting analysis. B. eatonii amino acid sequences were analyzed for the positional diversity by Shannon entropy analysis, showing CH4 as the most conserved domain, and CH3 as the most variable one. B. eatonii CDR3 region length varied between 11 and 15 amino acid residues; the mean length (13.4 aa) was greater than that of Leucoraja eglanteria sequences (7.7 aa). An alignment of representative sequences of Antarctic species and R. erinacea showed that more cysteine residues not involved in the intradomain disulfide bridges were present in Antarctic species. Copyright © 2011 Elsevier B.V. All rights reserved.

Toward Radiocarbon Measurement of Individual Amino Acids in Marine Dissolved Organic Matter (DOM): Δ14C Blank Quantification for an HPLC Purification Method.

NASA Astrophysics Data System (ADS)

Bour, A. L.; Broek, T.; Walker, B. D.; Mccarthy, M. D.

2014-12-01

The presence of much of the marine dissolved organic nitrogen (DON) pool as uncharacterized, biologically recalcitrant molecules is a central mystery in the marine nitrogen cycle. Radiocarbon (Δ14C) isotopic measurements have been perhaps the most important data constraining the cycling of dissolved organic matter (DOM), but little Δ14C data specific to DON is available. Amino acids (AAs) are the major component of DON that can be isolated on a molecular level. Δ14C measurements for the operational "protein-like" fraction of DOM in the deep ocean indicate that this compound class has radiocarbon ages greater than several ocean mixing cycles, suggesting remarkable preservation of labile AAs exported from the surface. However, it is possible that the previously defined operational "protein-like" fraction may also contain non-AA material. Radiocarbon measurement of purified individual AAs would provide a more direct and reliable proxy for DON Δ14C age and cycling rate. We present here Δ14C blank characterization of an AA purification method based on HPLC, with on-line fraction collection. This method allows the recovery of unmodified AAs, but accurate measurement of small AA samples that can be extracted from DOM requires a system with extremely low Δ 14C blanks. Here we assess the impact of HPLC purification on the Δ14C age of known amino acids standards. Individual AA standards with contrasting (modern vs. dead) and well- characterized Δ14C ages were processed in a range of sample sizes. The eluted peaks were collected and dried, and measurement of their post-chromatography Δ14C content allowed for determination of the Δ14C blank by method of additions. The same protocol was applied to a mixture of six AA standards, to evaluate tailing effects in consecutive AA peaks of contrasting Δ14C age. AA standards were selected to include both Δ14C modern and dead AAs that elute both early and late in the chromatographic solvent program. We discuss implications for future Δ14C analysis of AAs purified from DOM by this method.

Organic N cycling in Arctic ecosystems: Quantifying root uptake kinetics and temporal variability of soil amino acids.

NASA Astrophysics Data System (ADS)

Homyak, P. M.; Iverson, S. L.; Slessarev, E.; Marchus, K.; Schimel, J.

2017-12-01

Arctic ecosystems are undergoing shifts in plant community composition with increased warming. How these changes may alter ecosystem function is not well constrained, owing in part to uncertainties on how plant-soil feedbacks influence nutrient cycling. For nitrogen (N), in particular, understanding how these feedbacks may alter cycling rates is challenging because i) Arctic plants take up organic N (i.e., amino acids; AA) when inorganic N is limiting, yet ii) it has never been quantified, for any plant species growing in the wild, how much of its N demand is actually met by taking up AA. To advance fundamental understanding of plant-soil feedbacks as the Arctic warms, we are integrating field measurements of AA availability in N-limited tussock tundra (E. vaginatum) and a comparably less N-limited birch shrub tundra (Betula nana and Salix spp.) with a root uptake model. We used soil microdialysis to determine available AA concentrations in the soil solution and potential rates of AA diffusion and mass flow to roots at the Toolik Field Station in Alaska. These measurements are being combined with AA root uptake kinetic experiments using E. vaginatum to establish actual AA root uptake rates. We found that in the early growing season (June), total AA concentrations in the soil solution averaged 104 µg N L-1 and were similar to NH4+ across sites. In the late growing season (August), AA were the dominant form of N averaging 75 µg N L-1 while NH4+ decreased to 13 µg N L-1. In the early growing season AA diffusion rates in the soil averaged 200 ng N cm-2 s-1 and declined to 150 ng N cm-2 s-1 in the late growing season. Lysine, serine, and arginine were the most abundant AA and differences in the N status of sites did not affect total AA concentrations. Amino acids made up at least half of the N diffusing through the soil solution, suggesting they can subsidize the N demand of arctic plants. Ongoing field experiments at Toolik will be used to constrain actual AA root uptake rates.

Removal of Pb(II) from aqueous solutions using waste textiles/poly(acrylic acid) composite synthesized by radical polymerization technique.

PubMed

Zhou, Tao; Xia, Fafa; Deng, Yue; Zhao, Youcai

2018-05-01

Waste textiles (WTs) are the inevitable outcome of human activity and should be separated and recycled in view of sustainable development. In this work, WT was modified through grafting with acrylic acid (AA) via radical polymerization process using ceric ammonium nitrate (CAN) as an initiator and microwave and/or UV irradiation as energy supply. The acrylic acid-grafted waste textiles (WT-g-AA) thus obtained was then used as an adsorbent to remove Pb(II) from Pb(II)-containing wastewater. The effects of pH, initial concentrations of Pb(II) and adsorbent dose were investigated, and around 95% Pb(II) can be removed from the aqueous solution containing 10mg/L at pH6.0-8.0. The experimental adsorption isotherm data was fitted to the Langmuir model with maximum adsorption capacity of 35.7mg Pb/g WT-g-AA. The Pb-absorbed WT-g-AA was stripped using dilute nitric acid solution and the adsorption capacity of Pb-free material decreased from 95.4% (cycle 1) to 91.1% (cycle 3). It was considered that the WT-g-AA adsorption for Pb(II) may be realized through the ion-exchange mechanism between COOH and Pb(II). The promising results manifested that WT-g-AA powder was an efficient, eco-friendly and reusable adsorbent for the removal of Pb(II) from wastewater. Copyright © 2017. Published by Elsevier B.V.

Altered Arachidonate Distribution in Macrophages from Caveolin-1 Null Mice Leading to Reduced Eicosanoid Synthesis*

PubMed Central

Astudillo, Alma M.; Pérez-Chacón, Gema; Meana, Clara; Balgoma, David; Pol, Albert; del Pozo, Miguel A.; Balboa, María A.; Balsinde, Jesús

2011-01-01

In this work we have studied the effect of caveolin-1 deficiency on the mechanisms that regulate free arachidonic acid (AA) availability. The results presented here demonstrate that macrophages from caveolin-1-deficient mice exhibit elevated fatty acid incorporation and remodeling and a constitutively increased CoA-independent transacylase activity. Mass spectrometry-based lipidomic analyses reveal stable alterations in the profile of AA distribution among phospholipids, manifested by reduced levels of AA in choline glycerophospholipids but elevated levels in ethanolamine glycerophospholipids and phosphatidylinositol. Furthermore, macrophages from caveolin-1 null mice show decreased AA mobilization and prostaglandin E2 and LTB4 production upon cell stimulation. Collectively, these results provide insight into the role of caveolin-1 in AA homeostasis and suggest an important role for this protein in the eicosanoid biosynthetic response. PMID:21852231

Sensitive electrochemical sensors for simultaneous determination of ascorbic acid, dopamine, and uric acid based on Au@Pd-reduced graphene oxide nanocomposites.

PubMed

Jiang, Jingjing; Du, Xuezhong

2014-10-07

Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the concentrations of AA, DA, and UA, the linear response ranges were 1-800, 0.1-100, and 0.1-350 μM with detection limits of 0.28, 0.024, and 0.02 μM (S/N = 3), respectively. The fabricated sensors were further applied to the detection of AA, DA, and UA in urine samples. The Au@Pd-RGO nanocomposites have promising applications in highly sensitive and selective electrochemical sensing.

Novel graphene flowers modified carbon fibers for simultaneous determination of ascorbic acid, dopamine and uric acid.

PubMed

Du, Jiao; Yue, Ruirui; Ren, Fangfang; Yao, Zhangquan; Jiang, Fengxing; Yang, Ping; Du, Yukou

2014-03-15

A novel and sensitive carbon fiber electrode (CFE) modified by graphene flowers was prepared and used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). SEM images showed that beautiful and layer-petal graphene flowers homogeneously bloomed on the surface of CFE. Moreover, sharp and obvious oxidation peaks were found at the obtained electrode when compared with CFE and glassy carbon electrode (GCE) for the oxidation of AA, DA and UA. Also, the linear calibration plots for AA, DA and UA were observed, respectively, in the ranges of 45.4-1489.23 μM, 0.7-45.21 μM and 3.78-183.87 μM in the individual detection of each component. By simultaneously changing the concentrations of AA, DA and UA, their oxidation peaks appeared at -0.05 V, 0.16 V and 2.6 V, and the good linear responses ranges were 73.52-2305.53 μM, 1.36-125.69 μM and 3.98-371.49 μM, respectively. In addition, the obtained electrode showed satisfactory results when applied to the determination of AA, DA and UA in urine and serum samples. © 2013 Elsevier B.V. All rights reserved.

Overoxidized polyimidazole/graphene oxide copolymer modified electrode for the simultaneous determination of ascorbic acid, dopamine, uric acid, guanine and adenine.

PubMed

Liu, Xiaofang; Zhang, Ling; Wei, Shaping; Chen, Shihong; Ou, Xin; Lu, Qiyi

2014-07-15

In the present work, a novel strategy based on overoxidized polyimidazole (PImox) and graphene oxide (GO) copolymer modified electrode was proposed for the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA), guanine (G) and adenine (A). The copolymer was characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effects between PImox and GO, the proposed electrode exhibited excellent electrochemical catalytic activities and high selectivity and sensitivity toward the oxidation of AA, DA, UA, G and A. The peak separations between AA and DA, AA and UA, UA and G, and G and A were 140 mV, 200 mV, 380 mV and 300 mV, respectively. The linear response ranges for AA, DA, UA, G and A were 75-2275 μM, 12-278 μM, 3.6-249.6 μM, 3.3-103.3 μM and 9.6-215 μM, respectively, and corresponding detection limits were 18 μM, 0.63 μM, 0.59 μM, 0.48 μM and 1.28 μM. Copyright © 2014 Elsevier B.V. All rights reserved.

Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats.

PubMed

Mandal, Tapas K; Parvin, Nargish; Mondal, Santanu; Saxena, Vijaylaxmi; Saxena, Ashok K; Sarkar, Sabyasachi; Saha, Mitali

2012-04-01

Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions. © 2011 Blackwell Verlag GmbH.

Simultaneous determination of ascorbic acid, dopamine and uric acid by a novel electrochemical sensor based on N2/Ar RF plasma assisted graphene nanosheets/graphene nanoribbons.

PubMed

Jothi, Lavanya; Neogi, Sudarsan; Jaganathan, Saravana Kumar; Nageswaran, Gomathi

2018-05-15

A novel nitrogen/argon (N 2 /Ar) radio frequency (RF) plasma functionalized graphene nanosheet/graphene nanoribbon (GS/GNR) hybrid material (N 2 /Ar/GS/GNR) was developed for simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Various nitrogen mites introduced into GS/GNR hybrid structure was evidenced by a detailed microscopic, spectroscopic and surface area analysis. Owing to the unique structure and properties originating from the enhanced surface area, nitrogen functional groups and defects introduced on both the basal and edges, N 2 /Ar/GS/GNR/GCE showed high electrocatalytic activity for the electrochemical oxidations of AA, DA, and UA with the respective lowest detection limits of 5.3, 2.5 and 5.7 nM and peak-to-peak separation potential (ΔE P ) (vs Ag/AgCl) in DPV of 220, 152 and 372 mV for AA/DA, DA/UA and AA/UA respectively. Moreover, the selectivity, stability, repeatability and excellent performance in real time application of the fabricated N 2 /Ar/GS/GNR/GCE electrode suggests that it can be considered as a potential electrode material for simultaneous detection of AA, DA, and UA. Copyright © 2018 Elsevier B.V. All rights reserved.

Ascorbic Acid Intake and Oxalate Synthesis

PubMed Central

Knight, John; Madduma-Liyanage, Kumudu; Mobley, James A.; Assimos, Dean G.; Holmes, Ross P.

2016-01-01

In humans approximately 60 mg of ascorbic acid (AA) breaks down in the body each day and has to be replaced by a dietary intake of 70 mg in females and 90 mg in males to maintain optimal health and AA homeostasis. The breakdown of AA is non-enzymatic and results in oxalate formation. The exact amount of oxalate formed has been difficult to ascertain primarily due to the limited availability of healthy human tissue for such research and the difficulty in measuring AA and its breakdown products. The breakdown of 60 mg of AA to oxalate could potentially result in the formation of up to 30 mg oxalate per day. This exceeds our estimates of the endogenous production of 10 – 25 mg oxalate per day, indicating that degradative pathways that do not form oxalate exist. In this review we examine what is known about the pathways of AA metabolism and how oxalate forms. We further identify how gaps in our knowledge may be filled to more precisely determine the contribution of AA breakdown to oxalate production in humans. The use of stable isotopes of AA to directly assess the conversion of vitamin to oxalate should help fill this void. PMID:27002809

Combination of azelaic acid 5% and erythromycin 2% in the treatment of acne vulgaris.

PubMed

Pazoki-Toroudi, Hamidreza; Nassiri-Kashani, Mansour; Tabatabaie, Hossein; Ajami, Marjan; Habibey, Rouhollah; Shizarpour, Mohammad; Babakoohi, Shahab; Rahshenas, Makan; Firooz, Alireza

2010-05-01

Acne vulgaris is a common problem, particularly among adolescents, which is usually resistant to monotherapy. We evaluated the efficacy and safety of a combination of azelaic acid (AA) 5% and erythromycin 2% gel (AzE) compared with AA 20% or erythromycin 2% gels in facial acne vulgaris. We conducted a 12-week, multicenter, randomized double-blind study on 147 patients with mild-to-moderate acne vulgaris. Four treatment group were determined (placebo, erythromycin, AA and AzE) and followed in 4-week intervals for 12 weeks, except the placebo group which was changed to routine treatment after 4 weeks. The combination of AA 5% and erythromycin 2% gel significantly reduced the number of papules, pustules and comedones compared with placebo (p < 0.001), erythromycin 2% (p < 0.01) or AA 20% (p < 0.05). The incidence of adverse effects observed in patients treated with AzE (27%) was less than that with erythromycin 2% (54%) and AA 20% (45%). The combination of AA 5% and erythromycin 2% produced more potent therapeutic effects in comparison with erythromycin 2% or AA 20% alone, and with fewer side effects.

Amino Acids Inhibitory Effects and Mechanism on 2-Amino-1-Methyl-6-Phenylimidazo [4,5-b]Pyridine (PhIP) Formation in the Maillard Reaction Model Systems.

PubMed

Linghu, Ziyi; Karim, Faris; Smith, J Scott

2017-12-01

This study was to investigate the inhibitory effects of amino acids (AAs) on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) and to evaluate the inhibition mechanism of PhIP in Maillard model systems. Different AAs were individually added into model systems heat-treated at 180 °C/1 h. The PhIP, phenylacetaldehyde (PheAce), and pyrazines derivatives were determined using HPLC and GC-MS. AAs significantly reduced (P < 0.05) PhIP levels in a dose-dependent response, ranking as: Trp = Lys > Pro > Leu > Met > Val > Ile > Thr > Phe > Asp, at the highest molar ratio. The PheAce content was gradually reduced with increasing AAs levels, suggesting that AAs may inhibit PhIP formation through scavenging the available PheAce. A correlation between PhIP inhibition and PheAce-scavenging activity of AAs was observed when PheAce and AAs were heated. The variety and quantity of pyrazines formed are highly depending on the type of AAs. © 2017 Institute of Food Technologists®.

Risk assessment of plant food supplements and other herbal products containing aristolochic acids using the margin of exposure (MOE) approach.

PubMed

Abdullah, Rozaini; Diaz, Leolean Nyle; Wesseling, Sebastiaan; Rietjens, Ivonne M C M

2017-02-01

After the incidences of induction of aristolochic acid nephropathy after consumption of herbal weight loss preparations that accidentally contained aristolochic acids (AAs), several countries defined national restrictions on the presence of AAs in food, including plant food supplements (PFS) and herbal products. This study investigates whether the risks associated with exposure to AAs via PFS and herbal products are at present indeed negligible. Data reported in literature on AA levels in PFS and other herbal products and also obtained from a new series of PFS in the present study were used to calculate the estimated daily intakes (EDIs) and corresponding margins of exposure (MOEs). Available literature data revealed that 206 out of 573 samples were found to contain aristolochic acid I (AAI) and/or aristolochic acid II (AAII). The results obtained from recently collected PFS revealed that both AAI and AAII were detected in three out of 18 analysed PFS at levels up to 594.8 and 235.3 µg g -1 , respectively, being in line with the levels reported in literature. The EDIs resulting from intake of these PFS resulted in MOEs that were generally below 10,000, corroborating the priority for risk management. Although these results refer to PFS collected by targeted sampling strategies, the data reveal that AA-containing PFS are still freely available. When considering that the use of these samples may be limited to shorter periods of time, the EDIs might be lower, but MOE values would still be lower than 10,000 for more than 50% of the AA-containing PFS and herbal products. In conclusion, the presence of AAs in PFS and herbal products even several years after instalment of the legal restrictions still raises concern, especially for people who frequently use the respective PFS and herbal products.

Evolutionary Limitation and Opportunities for Developing tRNA Synthetase Inhibitors with 5-Binding-Mode Classification

PubMed Central

Fang, Pengfei; Guo, Min

2015-01-01

Aminoacyl-tRNA synthetases (aaRSs) are enzymes that catalyze the transfer of amino acids to their cognate tRNAs as building blocks for translation. Each of the aaRS families plays a pivotal role in protein biosynthesis and is indispensable for cell growth and survival. In addition, aaRSs in higher species have evolved important non-translational functions. These translational and non-translational functions of aaRS are attractive for developing antibacterial, antifungal, and antiparasitic agents and for treating other human diseases. The interplay between amino acids, tRNA, ATP, EF-Tu and non-canonical binding partners, had shaped each family with distinct pattern of key sites for regulation, with characters varying among species across the path of evolution. These sporadic variations in the aaRSs offer great opportunity to target these essential enzymes for therapy. Up to this day, growing numbers of aaRS inhibitors have been discovered and developed. Here, we summarize the latest developments and structural studies of aaRS inhibitors, and classify them with distinct binding modes into five categories. PMID:26670257

Evaluation of the antioxidant effect of ganghwayakssuk (Artemisia princeps Pamp.) extract alone and in combination with ascorbic acid in raw chicken patties.

PubMed

Hwang, K E; Kim, H W; Choi, Y S; Lee, S Y; Yeo, E J; Ham, Y K; Choi, S M; Lee, M A; Kim, C J

2013-12-01

We investigated the inhibition of lipid oxidation of raw chicken patties by the antioxidants ascorbic acid (Aa), ganghwayakssuk extracts (GE), and their combination (Aa + GE). All antioxidant combinations were effective at delaying lipid oxidation compared with the control or Aa. A combination of Aa + GE (0.05% Aa + 0.2% GE) was the most effective for delaying lipid oxidation (TBA reactive substances, conjugated dienes, and peroxide formation). The color values of all samples were significantly affected by adding GE. Additionally, the redness, color difference, and hue values of all treatments, except for Aa, were lower than those of the control as the amount of GE increased. The total viable bacterial counts of samples with GE 0.2 and Aa + GE 0.2 were significantly affected during storage (P < 0.05). The results suggest that adding an antioxidant combination reduced the oxidative stress and microbial growth of raw chicken patties stored for 12 d under normal refrigeration temperature, which may extend the shelf life of chicken patties.

Breakfast with glycomacropeptide compared with amino acids suppresses plasma ghrelin levels in individuals with phenylketonuria

PubMed Central

MacLeod, Erin L.; Clayton, Murray K.; van Calcar, Sandra C.; Ney, Denise M.

2010-01-01

Phenylketonuria (PKU) requires a lifelong low-phenylalanine (phe) diet where protein needs are met by consumption of a phe-free amino acid (AA) formula; complaints of persistent hunger are common. Foods made with glycomacropeptide (GMP), an intact protein that contains minimal phe and may promote satiety, provide an alternative to AA formula. The objective was to assess the ability of a GMP breakfast to promote satiety and affect plasma concentrations of AAs, insulin, and the appetite stimulating hormone ghrelin in those with PKU, when compared to an AA-based breakfast. Eleven PKU subjects (8 adults and 3 boys ages 11–14) served as their own controls in an inpatient metabolic study with two 4-day treatments: an AA-based diet followed by a diet replacing all AA formula with GMP foods. Plasma concentrations of AAs, insulin and ghrelin were obtained before and/or 180 minutes after breakfast. Satiety was assessed using a visual analog scale before, immediately after and 180 minutes after breakfast. Postprandial ghrelin concentration was significantly lower (p=0.03) with GMP compared to an AA-based breakfast, with no difference in fasting ghrelin. Lower postprandial ghrelin concentrations were associated with greater feelings of fullness 180 minutes after breakfast suggesting greater satiety with GMP compared to AAs. Postprandial concentrations of insulin and total plasma AAs were higher after a GMP breakfast compared to an AA-based breakfast consistent with slower absorption of AAs from GMP. These results show sustained ghrelin suppression, and suggest greater satiety with ingestion of a meal containing GMP compared with AAs. PMID:20466571

Beneficial effects of garlic on learning and memory deficits and brain tissue damages induced by lead exposure during juvenile rat growth is comparable to the effect of ascorbic acid.

PubMed

Ghasemi, Simagol; Hosseini, Mahmoud; Feizpour, Azadeh; Alipour, Fatemeh; Sadeghi, Akram; Vafaee, Farzaneh; Mohammadpour, Toktam; Soukhtanloo, Mohammad; Ebrahimzadeh Bideskan, Alireza; Beheshti, Farimah

2017-04-01

The neuroprotective effects of both garlic and ascorbic acid (AA) have been documented. In this study the effects of garlic and ascorbic acid on memory deficits and brain tissue oxidative damages induced by lead exposure was investigated. The juvenile rats were divided and treated: (1) Control, (2) Lead (lead acetate in drinking water, 8 weeks), (3) Lead - Ascorbic Acid (Lead-AA), (4)  Lead - Garlic (100 mg/kg, daily, gavage) (Lead-Gar). In Morris water maze (MWM), the escape latency and traveled path in the Lead group were significantly higher while, the time spent in the target quadrant (Q1) was lower than Control. Both Lead-Gar and Lead-AA groups spent more times in Q1than to lead group. There were no significant differences in swimming speed between the groups. In passive avoidance (PA) test, the time latency for entering the dark compartment by Lead group was lower than Control. Treatment of the animals by AA and garlic significantly increased the time latency. In Lead group, the total thiol concentration in brain tissues was significantly lower while, MDA was higher than Control. Treatment by both garlic and AA increased total thiol concentrations and decreased MDA. Both garlic and AA decreased the lead content of brain tissues. It is suggested that treatment with garlic attenuates the learning and memory impairments due to lead exposure during juvenile rat growth which is comparable to AA. The possible mechanism may be due to its protective effects against brain tissues oxidative damage as well the lowering effects of brain lead content.

Differential effects of military training on fat-free mass and plasma amino acid adaptations in men and women.

PubMed

Margolis, Lee M; Pasiakos, Stefan M; Karl, J Philip; Rood, Jennifer C; Cable, Sonya J; Williams, Kelly W; Young, Andrew J; McClung, James P

2012-12-18

Fat-free mass (FFM) adaptations to physical training may differ between sexes based on disparities in fitness level, dietary intake, and levels of plasma amino acids (AA). This investigation aimed to determine FFM and plasma AA responses to military training, examine whether adaptations differ between male and female recruits, and explore potential associations between FFM and AA responses to training. Body composition and plasma AA levels were assessed in US Army recruits (n = 209, 118 males, 91 females) before (baseline) and every three weeks during basic combat training (BCT), a 10-week military training course. Body weight decreased in men but remained stable in women during BCT (sex-by-time interaction, P < 0.05). Fifty-eight percent of recruits gained FFM during BCT, with more (P < 0.05) females (88%) gaining FFM than males (36%). Total plasma AA increased (P < 0.05) during BCT, with greater (P < 0.05) increases observed in females (17%) then in males (4%). Essential amino acids (EAA) and branched-chain amino acids (BCAA) were increased (P < 0.05) in females but did not change in males (sex-by-time interaction, P < 0.05). Independent of sex, changes in EAA (r = 0.34) and BCAA (r = 0.27) from baseline were associated with changes in FFM (P < 0.05); greater (P < 0.05) increases in AA concentrations were observed for those who gained FFM. Increases in FFM and plasma AA suggest that BCT elicits a more pronounced anabolic response in women compared to men, which may reflect sex-specific differences in the relative intensity of the combined training and physiological stimulus associated with BCT.

[Nephrotoxicity of Aristolochia manshuriensis and aristolochic acids in mice].

PubMed

Ding, Xiao-shuang; Liang, Ai-hua; Wang, Jin-hua; Xiao, Yong-qing; Wu, Zi-lun; Li, Chun-ying; Li, Li; He, Rong; Hui, Lian-qiang; Liu, Bao-yan

2005-07-01

The acute toxic effects of Aristolochia manshuriensis (GMT) and the total aristolochic acids (TA) were compared in mice with aristolochic acid A (AA) as the dose standard. The dose relationship of the renal toxicity induced by Aristolochia manshuriensis was determined. A single dose of GMT extract or TA was given intragastrically to mice at different doses. LD50 values, the blood levels of BUN, Cr and ALT were measured. A histomorphological study was also performed in livers and kidneys of mice. LD50 value of GMT extract was 4.4 g x kg(-1) which was equivalent to 40 mg x kg(-1) as calculated by the content of AA in GMT extract, and this value was comparable with LD50 obtained from TA given intragastrically in mice (equivalent to 33 mg x kg(-1) of AA for male and 37 mg x kg(-1) for female). GMT extract caused a significant increase in blood BUN and Cr and an obvious morphological change in kidney in a dose-dependent manner at doses of AA 4.5 mg x kg(-1) and above. Liver damage, characterized by both an increase in blood level of AST and histomorphological change, was observed at doses of AA 25 mg x kg(-1) and above. All changes were in proportion to the doses of AA. GMT causes both renal and liver toxicity. The dose leading to nephrotoxicity is much lower than that inducing hepatatoxicity. Aristolochic acids existed in GMT are the main toxic components to cause renal toxicity which is a crucial cause to result in death. The lethality and nephrotoxicity of GMT is in proportion to the doses of AA.

Differential Effects of Military Training on Fat-Free Mass and Plasma Amino Acid Adaptations in Men and Women

PubMed Central

Margolis, Lee M.; Pasiakos, Stefan M.; Karl, J. Philip; Rood, Jennifer C.; Cable, Sonya J.; Williams, Kelly W.; Young, Andrew J.; McClung, James P.

2012-01-01

Fat-free mass (FFM) adaptations to physical training may differ between sexes based on disparities in fitness level, dietary intake, and levels of plasma amino acids (AA). This investigation aimed to determine FFM and plasma AA responses to military training, examine whether adaptations differ between male and female recruits, and explore potential associations between FFM and AA responses to training. Body composition and plasma AA levels were assessed in US Army recruits (n = 209, 118 males, 91 females) before (baseline) and every three weeks during basic combat training (BCT), a 10-week military training course. Body weight decreased in men but remained stable in women during BCT (sex-by-time interaction, P < 0.05). Fifty-eight percent of recruits gained FFM during BCT, with more (P < 0.05) females (88%) gaining FFM than males (36%). Total plasma AA increased (P < 0.05) during BCT, with greater (P < 0.05) increases observed in females (17%) then in males (4%). Essential amino acids (EAA) and branched-chain amino acids (BCAA) were increased (P < 0.05) in females but did not change in males (sex-by-time interaction, P < 0.05). Independent of sex, changes in EAA (r = 0.34) and BCAA (r = 0.27) from baseline were associated with changes in FFM (P < 0.05); greater (P < 0.05) increases in AA concentrations were observed for those who gained FFM. Increases in FFM and plasma AA suggest that BCT elicits a more pronounced anabolic response in women compared to men, which may reflect sex-specific differences in the relative intensity of the combined training and physiological stimulus associated with BCT. PMID:23250145

SVCT-2 determines the sensitivity to ascorbate-induced cell death in cholangiocarcinoma cell lines and patient derived xenografts.

PubMed

Wang, Changzheng; Lv, Hongwei; Yang, Wen; Li, Ting; Fang, Tian; Lv, Guishuai; Han, Qin; Dong, Liwei; Jiang, Tianyi; Jiang, Beige; Yang, Guangshun; Wang, Hongyang

2017-07-10

Cholangiocarcinoma (CC) is a devastating malignancy with late diagnosis and poor response to conventional chemotherapy. Recent studies have revealed anti-cancer effect of vitamin C (l-ascorbic acid, ascorbate) in several types of cancer. However, the effect of l-ascorbic acid (AA) in CC remains elusive. Herein, we demonstrated that AA induced cytotoxicity in CC cells by generating intracellular reactive oxygen species (ROS), and subsequently DNA damage, ATP depletion, mTOR pathway inhibition. Moreover, AA worked synergistically with chemotherapeutic agent cisplatin to impair CC cells growth both in vitro and in vivo. Intriguingly, sodium-dependent vitamin C transporter 2 (SVCT-2) expression was inversely correlated with IC50 values of AA. Knockdown of SVCT-2 dramatically alleviated DNA damage, ATP depletion, and inhibition of mTOR pathway induced by AA. Furthermore, SVCT-2 knockdown endowed CC cells with the resistance to AA treatment. Finally, the inhibitory effects of AA were further confirmed in patient-derived CC xenograft models. Thus, our results unravel therapeutic potential of AA alone or in combination with cisplatin for CC. SVCT2 expression level may serve as a positive outcome predictor for AA treatment in CC. Copyright © 2017 Elsevier B.V. All rights reserved.

Arachidonic acid induces macrophage cell cycle arrest through the JNK signaling pathway.

PubMed

Shen, Ziying; Ma, Yunqing; Ji, Zhonghao; Hao, Yang; Yan, Xuan; Zhong, Yuan; Tang, Xiaochun; Ren, Wenzhi

2018-02-09

Arachidonic acid (AA) has potent pro-apoptotic effects on cancer cells at a low concentration and on macrophages at a very high concentration. However, the effects of AA on the macrophage cell cycle and related signaling pathways have not been fully investigated. Herein we aim to observe the effect of AA on macrophages cell cycle. AA exposure reduced the viability and number of macrophages in a dose- and time-dependent manner. The reduction in RAW264.7 cell viability was not caused by apoptosis, as indicated by caspase-3 and activated caspase-3 detection. Further research illustrated that AA exposure induced RAW264.7 cell cycle arrested at S phase, and some cell cycle-regulated proteins were altered accordingly. Moreover, JNK signaling was stimulated by AA, and the stimulation was partially reversed by a JNK signaling inhibitor in accordance with cell cycle-related factors. In addition, nuclear and total Foxo1/3a and phosphorylated Foxo1/3a were elevated by AA in a dose- and time-dependent manner, and this elevation was suppressed by the JNK signaling inhibitor. Our study demonstrated that AA inhibits macrophage viability by inducing S phase cell cycle arrest. The JNK signaling pathway and the downstream FoxO transcription factors are involved in AA-induced RAW264.7 cell cycle arrest.

Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS).

PubMed

Mathai, John K; Liu, Yanhong; Stein, Hans H

2017-02-01

An experiment was conducted to compare values for digestible indispensable amino acid scores (DIAAS) for four animal proteins and four plant proteins with values calculated as recommended for protein digestibility-corrected amino acid scores (PDCAAS), but determined in pigs instead of in rats. Values for standardised total tract digestibility (STTD) of crude protein (CP) and standardised ileal digestibility (SID) of amino acids (AA) were calculated for whey protein isolate (WPI), whey protein concentrate (WPC), milk protein concentrate (MPC), skimmed milk powder (SMP), pea protein concentrate (PPC), soya protein isolate (SPI), soya flour and whole-grain wheat. The PDCAAS-like values were calculated using the STTD of CP to estimate AA digestibility and values for DIAAS were calculated from values for SID of AA. Results indicated that values for SID of most indispensable AA in WPI, WPC and MPC were greater (P<0·05) than for SMP, PPC, SPI, soya flour and wheat. With the exception of arginine and tryptophan, the SID of all indispensable AA in SPI was greater (P<0·05) than in soya flour, and with the exception of threonine, the SID of all indispensable AA in wheat was less (P<0·05) than in all other ingredients. If the same scoring pattern for children between 6 and 36 months was used to calculate PDCAAS-like values and DIAAS, PDCAAS-like values were greater (P<0·05) than DIAAS values for SMP, PPC, SPI, soya flour and wheat indicating that PDCAAS-like values estimated in pigs may overestimate the quality of these proteins.

Raman spectroscopy and capillary zone electrophoresis for the analysis of degradation processes in commercial effervescent tablets containing acetylsalicylic acid and ascorbic acid.

PubMed

Neuberger, Sabine; Jooß, Kevin; Flottmann, Dirk; Scriba, Gerhard; Neusüß, Christian

2017-02-05

In order to ensure the stability of pharmaceutical products appropriate manufacturing and storage conditions are required. In general, the degradation of active pharmaceutical ingredients (APIs) and subsequent formation of degradation products affect the pharmaceutical quality. Thus, a fast and effective detection and characterization of these substances is mandatory. Here, the applicability of Raman spectroscopy and CZE for the characterization of the degradation of effervescent tablets containing acetylsalicylic acid (ASA) and ascorbic acid (AA) was evaluated. Therefore, a degradation study was performed analyzing tablets from two different manufacturers at varying conditions (relative humidity (RH) 33%, 52% and 75% at 30°C). Raman spectroscopy combined with principal component analysis could be successfully applied for the fast and easy discrimination of non-degraded and degraded effervescent tablets after a storage period of approximately 24h (RH 52%). Nevertheless, a clear identification or quantification of APIs and degradation products within the analyzed tablets was not possible, i.a. due to missing reference materials. CZE-UV enabled the quantification of the APIs (ASA, AA) and related degradation products (salicylic acid (SA); semi-quantitative also mono- and diacetylated AA) within the complex tablet mixtures. The higher the RH, the faster the degradation of ASA and AA as well as the formation of the degradation products. Mono- and diacetylated AA are major primary degradation products of AA for the applied effervescent tablets. A significant degradation of the APIs was detected earlier by CZE (6-12h, RH 52%) than by Raman spectroscopy. Summarized, Raman spectroscopy is well-suited as quick test to detect degradation of these tablets and CZE can be utilized for further detailed characterization and quantification of specific APIs and related degradation products. Copyright © 2016 Elsevier B.V. All rights reserved.

Polyunsaturated Fatty Acid (PUFA) Status in Pregnant Women: Associations with Sleep Quality, Inflammation, and Length of Gestation

PubMed Central

Christian, Lisa M.; Blair, Lisa M.; Porter, Kyle; Lower, Mary; Cole, Rachel M.; Belury, Martha A.

2016-01-01

Mechanistic pathways linking maternal polyunsaturated fatty acid (PUFA) status with gestational length are poorly delineated. This study examined whether inflammation and sleep quality serve as mediators, focusing on the antiinflammatory ω-3 docosahexaenoic acid (DHA; 22:6n3) and proinflammatory ω-6 arachidonic acid (AA; 20:4n6). Pregnant women (n = 135) provided a blood sample and completed the Pittsburgh Sleep Quality Index (PSQI) at 20–27 weeks gestation. Red blood cell (RBC) fatty acid levels were determined by gas chromatography and serum inflammatory markers [interleukin (IL)-6, IL-8, tumor necrosis factor-α, IL-1β, and C-reactive protein] by electrochemiluminescence using high sensitivity kits. Both higher serum IL-8 (95% CI = 0.10,3.84) and poor sleep (95% CI = 0.03,0.28) served as significant mediators linking lower DHA:AA ratios with shorter gestation. Further, a serial mediation model moving from the DHA:AA ratio → sleep → IL-8 → length of gestation was statistically significant (95% CI = 0.02, 0.79). These relationships remained after adjusting for depressive symptoms, age, BMI, income, race, and smoking. No interactions with race were observed in relation to length of gestation as a continuous variable. However, a significant interaction between race and the DHA:AA ratio in predicting preterm birth was observed (p = 0.049); among African Americans only, odds of preterm birth decreased as DHA:AA increased (p = 0.048). These data support a role for both inflammatory pathways and sleep quality in linking less optimal RBC PUFA status with shorter gestation in African American and European American women and suggest that African-Americans have greater risk for preterm birth in the context of a low DHA:AA ratio. PMID:26859301

Amino acid-assisted synthesis of zinc oxide nanostructures

NASA Astrophysics Data System (ADS)

Singh, Baljinder; Moudgil, Lovika; Singh, Gurinder; Kaura, Aman

2018-05-01

In this manuscript we have used experimental approach that can provide a fundamental knowledge about the role played by biomolecules in designing the shape of nanostructure (NS) at a microscopic level. The three different amino acids (AAs) - Arginine (Arg), Aspartic acid (Asp) and Histidine (His) coated Zinc oxide (ZnO) NSs to explain the growth mechanism of nanoparticles of different shapes. Based on the experimental methodology we propose that AA-ZnO (Asp and Arg) nanomaterials could form of rod like configuration and His-ZnO NPs could form tablet like configuration. The synthesized samples are characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Results reveal that AAs are responsible for formation of different NSs

Sensitive electrochemical sensors for simultaneous determination of ascorbic acid, dopamine, and uric acid based on Au@Pd-reduced graphene oxide nanocomposites

NASA Astrophysics Data System (ADS)

Jiang, Jingjing; Du, Xuezhong

2014-09-01

Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the concentrations of AA, DA, and UA, the linear response ranges were 1-800, 0.1-100, and 0.1-350 μM with detection limits of 0.28, 0.024, and 0.02 μM (S/N = 3), respectively. The fabricated sensors were further applied to the detection of AA, DA, and UA in urine samples. The Au@Pd-RGO nanocomposites have promising applications in highly sensitive and selective electrochemical sensing.Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the concentrations of AA, DA, and UA, the linear response ranges were 1-800, 0.1-100, and 0.1-350 μM with detection limits of 0.28, 0.024, and 0.02 μM (S/N = 3), respectively. The fabricated sensors were further applied to the detection of AA, DA, and UA in urine samples. The Au@Pd-RGO nanocomposites have promising applications in highly sensitive and selective electrochemical sensing. Electronic supplementary information (ESI) available: pH optimization, comparison of sensor performances, interference experiments, and detection in urine samples. See DOI: 10.1039/c4nr01774a

The selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

PubMed

Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

2014-01-01

Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu. © 2014 American Institute of Chemical Engineers.

Omega-3 and omega-6 polyunsaturated fatty acids enhance arsenic trioxide efficacy in arsenic trioxide-resistant leukemic and solid tumor cells.

PubMed

Wirtitsch, Melanie; Roth, Erich; Bachleitner-Hofmann, Thomas; Wessner, Barbara; Sturlan, Sanda

2009-01-01

Recently we showed that the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) sensitizes arsenic trioxide (As2O3)-resistant tumor cells to a clinically achievable concentration (1 microM) of As2O3 via a reactive oxygen species (ROS)-dependent mechanism. The aim of the present study was to evaluate, whether this combined effect of As2O3 and DHA is also applicable to other PUFAs [i.e., eicospentaenoic acid (EPA), arachidonic acid (AA), and gamma-linolenic acid (GLA)]. Fourteen tumor cell lines were incubated with As2O3 (1 microM), PUFA (25-100 microM), or the combination thereof (+/- vitamin E). Cell viability (colorimetric), apoptosis (bivariate annexin V/propidium iodide staining, detection of hypodiploid DNA), and thiobarbituric acid reactive substances (TBARS) were evaluated. Twelve of 14 As2O3-resistant cell lines tested were resistant to PUFA monotherapy. However, combined treatment with As2O3 and either PUFA significantly reduced cell viability in a dose-dependent manner with AA being the most potent As2O3 enhancer. The combined cytotoxic effect of As2O3/AA treatment was due to induction of apoptosis, preceded by increased intracellular TBARS and was abolished by the antioxidant vitamin E. Importantly, the combined effect of As2O3 and AA was selectively toxic for malignant cells because no cytotoxic effect was observed in normal skin fibroblasts and human microvascular endothelial cells. In conclusion, our study shows that also other PUFAs than DHA-and in particular the omega-6-PUFA AA--can be used as effective modulators of tumor cell chemosensitivity to clinically achievable concentrations of As2O3. Enhanced lipid peroxidation most likely constitutes the key mechanism for the combined effect.

Effects of Histidine Supplementation on Global Serum and Urine 1H NMR-based Metabolomics and Serum Amino Acid Profiles in Obese Women from a Randomized Controlled Study.

PubMed

Du, Shanshan; Sun, Shuhong; Liu, Liyan; Zhang, Qiao; Guo, Fuchuan; Li, Chunlong; Feng, Rennan; Sun, Changhao

2017-06-02

The aim of current study was to investigate the metabolic changes associated with histidine supplementation in serum and urine metabolic signatures and serum amino acid (AA) profiles. Serum and urine 1 H NMR-based metabolomics and serum AA profiles were employed in 32 and 37 obese women with metabolic syndrome (MetS) intervened with placebo or histidine for 12 weeks. Multivariable statistical analysis were conducted to define characteristic metabolites. In serum 1 H NMR metabolic profiles, increases in histidine, glutamine, aspartate, glycine, choline, and trimethylamine-N-oxide (TMAO) were observed; meanwhile, decreases in cholesterol, triglycerides, fatty acids and unsaturated lipids, acetone, and α/β-glucose were exhibited after histidine supplement. In urine 1 H NMR metabolic profiles, citrate, creatinine/creatine, methylguanidine, and betaine + TMAO were higher, while hippurate was lower in histidine supplement group. In serum AA profiles, 10 AAs changed after histidine supplementation, including increased histidine, glycine, alanine, lysine, asparagine, and tyrosine and decreased leucine, isoleucine, ornithine, and citrulline. The study showed a systemic metabolic response in serum and urine metabolomics and AA profiles to histidine supplementation, showing significantly changed metabolism in AAs, lipid, and glucose in obese women with MetS.

Ferulic acid with ascorbic acid synergistically extenuates the mitochondrial dysfunction during beta-adrenergic catecholamine induced cardiotoxicity in rats.

PubMed

Yogeeta, Surinder Kumar; Raghavendran, Hanumantha Rao Balaji; Gnanapragasam, Arunachalam; Subhashini, Rajakannu; Devaki, Thiruvengadam

2006-10-27

Disruption of mitochondria and free radical mediated tissue injury have been reported during cardiotoxicity induced by isoproterenol (ISO), a beta-adrenergic catecholamine. The present study was designed to investigate the effect of the combination of ferulic acid (FA) and ascorbic acid (AA) on the mitochondrial damage in ISO induced cardiotoxicity. Induction of rats with ISO (150 mg/kg b.wt., i.p.) for 2 days resulted in a significant decrease in the activities of respiratory chain enzymes (NADH dehydrogenase and cytochrome c-oxidase), tricarboxylic acid cycle enzymes (isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, alpha-ketoglutarate dehydrogenase), mitochondrial antioxidants (GPx, GST, SOD, CAT, GSH), cytochromes (b, c, c1, aa3) and in the level of mitochondrial phospholipids. A marked elevation in mitochondrial lipid peroxidation, mitochondrial levels of cholesterol, triglycerides and free fatty acids were also observed in ISO intoxicated rats. Pre-co-treatment with the combination of FA (20 mg/kg b.wt.) and AA (80 mg/kg b.wt.) orally for 6 days significantly enhanced the attenuation of these functional abnormalities and restored normal mitochondrial function when compared to individual drug treated groups. Mitigation of ISO induced biochemical and morphological changes in mitochondria were more pronounced with a combination of FA and AA rather than the individual drug treated groups. Transmission electron microscopic observations also correlated with these biochemical parameters. Hence, these findings demonstrate the synergistic ameliorative potential of FA and AA on mitochondrial function during beta-adrenergic catecholamine induced cardiotoxicity and associated oxidative stress in rats.

Protection of ascorbic acid from copper(II)-catalyzed oxidative degradation in the presence of flavonoids: quercetin, catechin and morin.

PubMed

Beker, Bilge Yildoğan; Sönmezoğlu, Inci; Imer, Filiz; Apak, Reşat

2011-08-01

Protection of ascorbic acid (AA) (vitamin C) from Cu(II)-catalyzed autoxidation is an important aspect of antioxidant chemistry. The autoxidation of AA in the absence and presence of Cu(II) ions was investigated in aerated solution at room temperature and I = 0.1 ionic strength (KNO(3)); the effects of three different flavonoids of similar structure (quercetin, morin and catechin) and their mixtures on the AA system were studied. The concentration of unoxidized AA remaining in solution was measured with the modified cupric ion reducing antioxidant capacity spectrophotometric method. The Cu(II)-catalyzed oxidation at pH 4.5 followed first-order kinetics with respect to AA concentration. Catalytic autoxidation of AA was inhibited to a greater extent by stable quercetin and morin complexes of Cu(II) than by catechin complex. The inhibitive effectiveness order of mixtures gives information about possible synergistic or antagonistic combinations of flavonoid antioxidants, which should be further confirmed with other antioxidant tests.

Comparison of the nucleotide and amino acid sequences of the RsrI and EcoRI restriction endonucleases.

PubMed

Stephenson, F H; Ballard, B T; Boyer, H W; Rosenberg, J M; Greene, P J

1989-12-21

The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.

Functional amino acids in nutrition and health.

PubMed

Wu, Guoyao

2013-09-01

The recent years have witnessed growing interest in biochemistry, physiology and nutrition of amino acids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).

Methionine and Choline Supply during the Periparturient Period Alter Plasma Amino Acid and One-Carbon Metabolism Profiles to Various Extents: Potential Role in Hepatic Metabolism and Antioxidant Status.

PubMed

Zhou, Zheng; Vailati-Riboni, Mario; Luchini, Daniel N; Loor, Juan J

2016-12-29

The objective of this study was to profile plasma amino acids (AA) and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET) or rumen-protected choline (CHOL). Forty cows were fed from -21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine) were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status.

Expression of Renal Aquaporins in Aristolochic Acid I and Aristolactam I-Induced Nephrotoxicity.

PubMed

Li, Ji; Zhang, Liang; Jiang, ZhenZhou; He, XiuQin; Zhang, LuYong; Xu, Ming

2016-01-01

Exposure to aristolochic acid (AA) can cause AA nephropathy, which is characterized by extensive proximal tubular damage and polyuria. To test the hypothesis that polyuria might be induced by altered regulation of aquaporins (AQPs) in the kidney, different doses of AA-I or aristolactam I (AL-I) were administered intraperitoneally to Sprague-Dawley rats, and urine, blood, and kidney samples were analyzed. In addition, AQP1, AQP2, AQP4 and AQP6 expression in the kidney were determined. The results showed dose-dependent proximal tubular damage and polyuria in the AA-I- and AL-I-treated groups, and the nephrotoxicity of AL-I was higher than that of AA-I. The expression of renal AQP1, AQP2 and AQP4, but not AQP6 were significantly inhibited by AA-I and AL-I. Comparison of the inhibition potencies of AA-I and AL-I showed that AL-I was a stronger inhibitor of AQP1 expression than AA-I, while there was no difference in their effects on AQP2 and AQP4. These results suggested that AA induced renal damage and polyuria were associated with a specific decrease in the expression of renal AQP1 AQP2 and AQP4, and AL-I showed higher nephrotoxicity than AA-I, which might be attributable to the differences in their inhibition of AQP1. © 2016 S. Karger AG, Basel.

Methionine and Choline Supply during the Periparturient Period Alter Plasma Amino Acid and One-Carbon Metabolism Profiles to Various Extents: Potential Role in Hepatic Metabolism and Antioxidant Status

PubMed Central

Zhou, Zheng; Vailati-Riboni, Mario; Luchini, Daniel N.; Loor, Juan J.

2016-01-01

The objective of this study was to profile plasma amino acids (AA) and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET) or rumen-protected choline (CHOL). Forty cows were fed from −21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine) were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status. PMID:28036059

Prevention of alcoholic fatty liver and mitochondrial dysfunction in the rat by long-chain polyunsaturated fatty acids

PubMed Central

Song, Byoung-Joon; Moon, Kwan-Hoon; Olsson, Nils U.; Salem, Norman

2008-01-01

Background/Aims We reported that reduced dietary intake of polyunsaturated fatty acids (PUFA) such as arachidonic (AA,20:4n6, omega-6) and docosahexaenoic (DHA,22:6n3, omega-3) acids led to alcohol-induced fatty liver and fibrosis. This study was aimed at studying the mechanisms by which a DHA/AA-supplemented diet prevents alcohol-induced fatty liver. Methods Male Long-Evans rats were fed an ethanol or control liquid-diet with or without DHA/AA for 9 weeks. Plasma transaminase levels, liver histology, oxidative/nitrosative stress markers, and activities of oxidatively-modified mitochondrial proteins were evaluated. Results Chronic alcohol administration increased the degree of fatty liver but fatty liver decreased significantly in rats fed the alcohol-DHA/AA-supplemented diet. Alcohol exposure increased oxidative/nitrosative stress with elevated levels of ethanol-inducible CYP2E1, nitric oxide synthase, nitrite and mitochondrial hydrogen peroxide. However, these increments were normalized in rats fed the alcohol-DHA/AA-supplemented diet. The number of oxidatively-modified mitochondrial proteins was markedly increased following alcohol exposure but significantly reduced in rats fed the alcohol-DHA/AA-supplemented diet. The suppressed activities of mitochondrial aldehyde dehydrogenase, ATP synthase, and 3-ketoacyl-CoA thiolase in ethanol-exposed rats were also recovered in animals fed the ethanol-DHA/AA-supplemented diet. Conclusions Addition of DHA/AA prevents alcohol-induced fatty liver and mitochondrial dysfunction in an animal model by protecting various mitochondrial enzymes most likely through reducing oxidative/nitrosative stress. PMID:18571270

AaCAT1 of the Yellow Fever Mosquito, Aedes aegypti

PubMed Central

Hansen, Immo A.; Boudko, Dmitri Y.; Shiao, Shin-Hong; Voronov, Dmitri A.; Meleshkevitch, Ella A.; Drake, Lisa L.; Aguirre, Sarah E.; Fox, Jeffrey M.; Attardo, Geoffrey M.; Raikhel, Alexander S.

2011-01-01

Insect yolk protein precursor gene expression is regulated by nutritional and endocrine signals. A surge of amino acids in the hemolymph of blood-fed female mosquitoes activates a nutrient signaling system in the fat bodies, which subsequently derepresses yolk protein precursor genes and makes them responsive to activation by steroid hormones. Orphan transporters of the SLC7 family were identified as essential upstream components of the nutrient signaling system in the fat body of fruit flies and the yellow fever mosquito, Aedes aegypti. However, the transport function of these proteins was unknown. We report expression and functional characterization of AaCAT1, cloned from the fat body of A. aegypti. Expression of AaCAT1 transcript and protein undergoes dynamic changes during postembryonic development of the mosquito. Transcript expression was especially high in the third and fourth larval stages; however, the AaCAT1 protein was detected only in pupa and adult stages. Functional expression and analysis of AaCAT1 in Xenopus oocytes revealed that it acts as a sodium-independent cationic amino acid transporter, with unique selectivity to l-histidine at neutral pH (K0.5l-His = 0.34 ± 0.07 mm, pH 7.2). Acidification to pH 6.2 dramatically increases AaCAT1-specific His+-induced current. RNAi-mediated silencing of AaCAT1 reduces egg yield of subsequent ovipositions. Our data show that AaCAT1 has notable differences in its transport mechanism when compared with related mammalian cationic amino acid transporters. It may execute histidine-specific transport and signaling in mosquito tissues. PMID:21262963

Contribution of Fermentation Yeast to Final Amino Acid Profile in DDGS

USDA-ARS?s Scientific Manuscript database

One major factor affecting DDGS quality and market values is amino acid (AA) composition. DDGS proteins come from corn and yeast. Yet, the effect of fermentation yeast on DDGS protein quantity and quality (AA profile) has not been well documented. Based on literature review, there are at least 4 met...

77 FR 63813 - Agency Information Collection Activities: Request for Comments on Thirty-Seven Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-17

... Phosphoric Acid Manufacturing and Phosphate Fertilizers Production (40 CFR Part 63, Subparts AA and BB). ICR... September 30, 2013. (33) Docket ID Number: EPA-HQ-OECA-2012-0686. Title: NESHAP for Organic Liquids... Acid Manufacturing and Phosphate Fertilizers Production (40 CFR Part 63, Subparts AA and BB); Learia...

Advances in the application of amino acid nitrogen isotopic analysis in ecological and biogeochemical studies

USDA-ARS?s Scientific Manuscript database

Compound-specific isotopic analysis of amino acids (CSIA-AA) has emerged in the last decade as a powerful approach for tracing the origins and fate of nitrogen in ecological and biogeochemical studies. This approach is based on the empirical knowledge that source AAs (i.e., phenylalanine), fractiona...

Amino Acid Transport Associated to Cluster of Differentiation 98 Heavy Chain (CD98hc) Is at the Cross-road of Oxidative Stress and Amino Acid Availability.

PubMed

de la Ballina, Laura R; Cano-Crespo, Sara; González-Muñoz, Elena; Bial, Susanna; Estrach, Soline; Cailleteau, Laurence; Tissot, Floriane; Daniel, Hannelore; Zorzano, Antonio; Ginsberg, Mark H; Palacín, Manuel; Féral, Chloé C

2016-04-29

CD98hc functions as an amino acid (AA) transporter (together with another subunit) and integrin signaling enhancer. It is overexpressed in highly proliferative cells in both physiological and pathological conditions. CD98hc deletion induces strong impairment of cell proliferation in vivo and in vitro Here, we investigate CD98hc-associated AA transport in cell survival and proliferation. By using chimeric versions of CD98hc, the two functions of the protein can be uncoupled. Although recovering the CD98hc AA transport capacity restores the in vivo and in vitro proliferation of CD98hc-null cells, reconstitution of the integrin signaling function of CD98hc is unable to restore in vitro proliferation of those cells. CD98hc-associated transporters (i.e. xCT, LAT1, and y(+)LAT2 in wild-type cells) are crucial to control reactive oxygen species and intracellular AA levels, thus sustaining cell survival and proliferation. Moreover, in CD98hc-null cells the deficiency of CD98hc/xCT cannot be compensated, leading to cell death by ferroptosis. Supplementation of culture media with β-mercaptoethanol rescues CD98hc-deficient cell survival. Under such conditions null cells show oxidative stress and intracellular AA imbalance and, consequently, limited proliferation. CD98hc-null cells also present reduced intracellular levels of branched-chain and aromatic amino acids (BCAAs and ARO AAs, respectively) and induced expression of peptide transporter 1 (PEPT1). Interestingly, external supply of dipeptides containing BCAAs and ARO AAs rescues cell proliferation and compensates for impaired uptake of CD98hc/LAT1 and CD98hc/y(+)LAT2. Our data establish CD98hc as a master protective gene at the cross-road of redox control and AA availability, making it a relevant therapeutic target in cancer. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Preparation of poly(acrylamide-co-acrylic acid)-grafted gum and its flocculation and biodegradation studies.

PubMed

Mittal, H; Mishra, Shivani B; Mishra, A K; Kaith, B S; Jindal, R; Kalia, S

2013-10-15

Biodegradation studies of Gum ghatti (Gg) and acrylamide-co-acrylic acid based flocculants [Gg-cl-poly(AAm-co-AA)] have been reported using the soil composting method. Gg-cl-poly(AAm-co-AA) was found to degrade 89.76% within 60 days. The progress of biodegradation at each stage was monitored through FT-IR and SEM. Polymer was synthesized under pressure using potassium persulphate-ascorbic acid as a redox initiator and N,N'-methylene-bis-acrylamide as a crosslinker. Synthesized polymer was found to show pH, temperature and ionic strength of the cations dependent swelling behavior. Gg-cl-poly(AAm-co-AA) was utilized for the selective absorption of saline from different petroleum fraction-saline emulsions. The flocculation efficiency of the polymer was studied as a function of polymer dose, temperature and pH of the solution. Gg-cl-poly(AAm-co-AA) showed maximum flocculation efficiency with 20 mol L(-1) polymer dose in acidic medium at 50 °C. Copyright © 2013. Published by Elsevier Ltd.

Comparison of the contents of various antioxidants of sea buckthorn berries using CE.

PubMed

Gorbatsova, Jelena; Lõugas, Tiina; Vokk, Raivo; Kaljurand, Mihkel

2007-11-01

The increased interest in sea buckthorn (Hippophae rhamnoides L.) made it possible to investigate the antioxidant content in it. To address this issue, the presence of following antioxidant compounds were analyzed: trans-resveratrol, catechin, myricetin, quercetin, p-coumaric acid, caffeic acid, L-ascorbic acid (AA), and gallic acid (linear range of 50-150 micromol/L) in six different varieties of sea buckthorn berries extracts (sea buckthorn varieties: "Trofimovskaja (TR)," "Podarok Sadu (PS)," and "Avgustinka (AV),") received from two local Estonian companies. Trans-Resveratrol, catechin, AA, myricetin, and quercetin were found in extracts of sea buckthorn. Moreover, AA, myricetin, and quercetin contents were quantified. The biggest average AA content was found in TR (740 mg/100 g of dried berries, respectively). Furthermore, the same varieties gave the biggest quercetin content 116 mg/100 g of dried berries, respectively. For analysis, CZE was used and the results were partly validated by HPLC. Statistically no big differences in levels of antioxidants were consistently found in different varieties of sea buckthorn extracts investigated in this work.

Amino acid nitrogen isotopic fractionation patterns as indicators of heterotrophy in plankton, particulate, and dissolved organic matter

NASA Astrophysics Data System (ADS)

McCarthy, Matthew D.; Benner, Ronald; Lee, Cindy; Fogel, Marilyn L.

2007-10-01

Bulk nitrogen (N) isotope signatures have long been used to investigate organic N source and food web structure in aquatic ecosystems. This paper explores the use of compound-specific δ 15N patterns of amino acids (δ 15N-AA) as a new tool to examine source and processing history in non-living marine organic matter. We measured δ 15N-AA distributions in plankton tows, sinking particulate organic matter (POM), and ultrafiltered dissolved organic matter (UDOM) in the central Pacific Ocean. δ 15N-AA patterns in eukaryotic algae and mixed plankton tows closely resemble those previously reported in culture. δ 15N differences between individual amino acids (AA) strongly suggest that the sharply divergent δ 15N enrichment for different AA with trophic transfer, as first reported by [McClelland, J.W. and Montoya, J.P. (2002) Trophic relationships and the nitrogen isotopic composition of amino acids. Ecology83, 2173-2180], is a general phenomenon. In addition, differences in δ 15N of individual AA indicative of trophic transfers are clearly preserved in sinking POM, along with additional changes that may indicate subsequent microbial reworking after incorporation into particles. We propose two internally normalized δ 15N proxies that track heterotrophic processes in detrital organic matter. Both are based on isotopic signatures in multiple AA, chosen to minimize potential problems associated with any single compound in degraded materials. A trophic level indicator (ΔTr) is derived from the δ 15N difference between selected groups of AA based on their relative enrichment with trophic transfer. We propose that a corresponding measure of the variance within a sub-group of AA (designated Σ V) may indicate total AA resynthesis, and be strongly tied to heterotrophic microbial reworking in detrital materials. Together, we hypothesize that ΔTr and Σ V define a two dimensional trophic "space", which may simultaneously express relative extent of eukaryotic and bacterial heterotrophic processing. In the equatorial Pacific, ΔTr indicates an average of 1.5-2 trophic transfers between phytoplankton and sinking POM at all depths and locations. The Σ V parameter suggests that substantial variation may exist in bacterial heterotrophic processing between differing regions and time periods. In dissolved material δ 15N-AA patterns appear unrelated to those in POM. In contrast to POM, δ 15N-AA signatures in UDOM show no clear changes with depth, and suggest that dissolved AA preserved throughout the oceanic water column have undergone few, if any, trophic transfers. Together these data suggest a sharp divide between processing histories, and possibly sources, of particulate vs. dissolved AA.

Bolus oral or continuous intestinal amino acids reduce hypothermia during anesthesia in rats.

PubMed

Imoto, Akinobu; Yokoyama, Takeshi; Suwa, Kunio; Yamasaki, Fumiyasu; Yatabe, Tomoaki; Yokoyama, Reiko; Yamashita, Koichi; Selldén, Eva

2010-01-01

We hypothesized that, with oral or intestinal administration of amino acids (AA), we may reduce hypothermia during general anesthesia as effectively as with intravenous AA. We, therefore, examined the effect of bolus oral and continuous intestinal AA in preventing hypothermia in rats. Male Wistar rats were anesthetized with sevoflurane for induction and with propofol for maintenance. In the first experiment, 30 min before anesthesia, rats received one bolus 42 mL/kg of AA solution (100 g/L) or saline orally. Then for the next 3 h during anesthesia, they received 14 mL/kg/h of AA and/or saline intravenously. They were in 4 groups: I-A/A, both AA; I-A/S, oral AA and intravenous saline; I-S/A, oral saline and intravenous AA; I-S/S, both saline. In the second experiment, rats received 14 mL/kg/h duodenal AA and/or saline for 2 h. They were in 3 groups: II-A/S, duodenal AA and intravenous saline; II-S/A, duodenal saline and intravenous AA; II-S/S, both saline. Core body temperature was measured rectally. After the second experiment, serum electrolytes were examined. In both experiments, rectal temperature decreased in all groups during anesthesia. However, the decrease in rectal temperature was significantly less in groups receiving AA than in groups receiving only saline. In the second experiment, although there was no significant difference in the decrease in body temperature between II-A/S and II-S/A, Na(+) concentration was significantly lower in II-S/A. In conclusion, AA, administered orally or intestinally, tended to keep the body temperature stable during anesthesia without disturbing electrolyte balance. These results suggest that oral or enteral AA may be useful for prevention of hypothermia in patients.

Ascorbic acid transported by sodium-dependent vitamin C transporter 2 stimulates steroidogenesis in human choriocarcinoma cells.

PubMed

Wu, Ximei; Iguchi, Takuma; Itoh, Norio; Okamoto, Kousuke; Takagi, Tatsuya; Tanaka, Keiichi; Nakanishi, Tsuyoshi

2008-01-01

Reduced vitamin C [ascorbic acid (AA)], which is taken up into cells by sodium-dependent vitamin C transporter (SVCT) 1 and 2, is believed to be important for hormone synthesis, but its role in generating placental steroids needed to maintain pregnancy and fetal development is not clear. To determine the steroidogenic effect of AA and the role of SVCT2 in AA-induced steroidogenesis, we tested the effects of AA treatment and SVCT2 knockdown on steroidogenesis in human choriocarcinoma cell lines. AA treatment of JEG-3, BeWo, and JAR cells for 48-h dose dependently increased progesterone and estradiol levels. In JEG-3 cells, AA increased the mRNA expression of P450 cholesterol side-chain cleavage enzyme, 3beta-hydroxysteroid dehydrogenase type 1, and aromatase, key enzymes for steroidogenesis. Stable knockdown of SVCT2 in JEG-3 cells by retrovirally mediated RNA interference decreased the maximal velocity of AA uptake by approximately 50%, but apparent affinity values were not affected. SVCT2 knockdown in JEG-3 cells significantly suppressed the AA-induced mRNA expression of placental P450 cholesterol side-chain cleavage enzyme, 3beta-hydroxysteroid dehydrogenase type 1, and aromatase. This suppression of the AA-induced mRNA expression of steroidogenic enzymes subsequently decreased progesterone and estradiol production. In addition, inhibition of MAPK kinase-ERK signaling, which is a major pathway for AA-regulated gene expression, failed to affect AA-induced steroidogenesis. Our observations indicate that SVCT2-mediated AA uptake into cells is necessary for AA-induced steroidogenesis in human choriocarcinoma cell, but MAPK kinase-ERK signaling is not involved in AA-induced steroidogenesis.

β-Cell lipotoxicity in response to free fatty acid elevation in prepubertal youth: African American versus Caucasian contrast.

PubMed

Michaliszyn, Sara F; Bonadonna, Riccardo C; Sjaarda, Lindsey A; Lee, Sojung; Farchoukh, Lama; Arslanian, Silva A

2013-08-01

Prepubertal African American (AA) youth compared with their Caucasian (C) peers have higher insulin secretion, which correlates positively with free fatty acid (FFA) concentration. In our continued efforts to explain the racial disparity in insulinemia, and because FFAs modulate insulin secretion, we hypothesized that AA youth would have a greater response to FFA-induced β-cell insulin secretion than C youth. We compared the short-term effects of FFA elevation on fasting and glucose-stimulated C-peptide-modeled insulin secretion in prepubertal normal-weight AA versus C peers during a 2-h hyperglycemic clamp (12.5 mmol/L) on two occasions: 1) infusion of normal saline and 2) infusion of 20% intralipid (IL). During IL infusion, insulin sensitivity (IS) declined comparably in AA and C youth. Glucose sensitivity of first- and second-phase insulin secretion showed a significant condition × race interaction being higher in AA youth. Disposition index, β-cell function relative to IS, declined with IL infusion in AA and C youth, with a significantly greater decrease in Cs compared with AAs. In conclusion, AA and C prepubertal youth both demonstrated a decline in β-cell function relative to IS during IL infusion, indicative of acute lipotoxicity. The greater decline in C youth compared with AAs may suggest that C youth are more susceptible to β-cell lipotoxicity than AA youth, or alternatively, that AA youth are hypersensitive to FFA stimulation of β-cell insulin secretion, consistent with our theory.

Rapid quantification of underivatized amino acids in plasma by hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass-spectrometry.

PubMed

Prinsen, Hubertus C M T; Schiebergen-Bronkhorst, B G M; Roeleveld, M W; Jans, J J M; de Sain-van der Velden, M G M; Visser, G; van Hasselt, P M; Verhoeven-Duif, N M

2016-09-01

Amino acidopathies are a class of inborn errors of metabolism (IEM) that can be diagnosed by analysis of amino acids (AA) in plasma. Current strategies for AA analysis include cation exchange HPLC with post-column ninhydrin derivatization, GC-MS, and LC-MS/MS-related methods. Major drawbacks of the current methods are time-consuming procedures, derivative problems, problems with retention, and MS-sensitivity. The use of hydrophilic interaction liquid chromatography (HILIC) columns is an ideal separation mode for hydrophilic compounds like AA. Here we report a HILIC-method for analysis of 36 underivatized AA in plasma to detect defects in AA metabolism that overcomes the major drawbacks of other methods. A rapid, sensitive, and specific method was developed for the analysis of AA in plasma without derivatization using HILIC coupled with tandem mass-spectrometry (Xevo TQ, Waters). Excellent separation of 36 AA (24 quantitative/12 qualitative) in plasma was achieved on an Acquity BEH Amide column (2.1×100 mm, 1.7 μm) in a single MS run of 18 min. Plasma of patients with a known IEM in AA metabolism was analyzed and all patients were correctly identified. The reported method analyzes 36 AA in plasma within 18 min and provides baseline separation of isomeric AA such as leucine and isoleucine. No separation was obtained for isoleucine and allo-isoleucine. The method is applicable to study defects in AA metabolism in plasma.

Effect of cultivar and variety on phenolic compounds and antioxidant activity of cherry wine.

PubMed

Xiao, Zuobing; Fang, Lingling; Niu, Yunwei; Yu, Haiyan

2015-11-01

To compare the influence of cultivar and variety on the phenolic compounds and antioxidant activity (AA) of cherry wines, total phenolic (TP), total flavonoid (TF), total anthocyanin (TA), total tannin (TT), five individual phenolic acids, and AA were determined. An ultra-performance liquid chromatography tandem mass spectrometry (HPLC-DAD/ESI-MS) method was developed for the determination of gallic acid (GAE), p-hydroxybenzoic acid (PHB), chlorogenic acid (CHL), vanillic acid (VAN), and caffeic acid (CAF). A principal component analysis (PCA) and a cluster analysis (CA) were used to analyze differences related to cultivar and variety. The TP, TF, TA, TT, and AA of samples sourced from the Shandong province of China were higher than those from the Jiangsu province. The PCA and CA results showed that phenolic compounds in cherry wines were closely related to cultivar and variety and that cultivar had more influence on the phenolic compounds of cherry wines than variety. Copyright © 2015 Elsevier Ltd. All rights reserved.

Free radical grafting of gallic acid (GA) on cellulose nanocrystals (CNCS) and evaluation of antioxidant reinforced gellan gum films

NASA Astrophysics Data System (ADS)

Criado, P.; Fraschini, C.; Salmieri, S.; Becher, D.; Safrany, A.; Lacroix, M.

2016-01-01

Antiradical properties were introduced on cellulose nanocrystals (CNCs) by redox pair (RP) initiator and γ-radiation treatments. Different procedures were tested on CNC, first a 2 h reaction of hydrogen peroxide (H2O2)/ascorbic acid (AA) was performed on CNC solution. γ-Radiation treatment at 20 kGy dose was then applied and immediately after GA was reacted during 24 h with the pretreated CNCs, giving CNC-H2O2-AA-γ-GA. The formation of new carboxylic acids and carbonyl groups were characterized by FT-IR at 1650 and 1730 cm-1 respectively. Carboxylic acid functionalities were also analyzed by conductometric titration where an increase from 49 to 134 mmol COOH kg-1 was found from native to irradiated CNCs. A similar increase in the carboxylic acid content (132 mmol kg-1) was observed for CNC-H2O2-AA-γ-GA, showing the highest radical scavenging properties (8 mM Trolox eq/mg CNC). Thermogravimetric analysis confirmed the structural changes onto CNC. Film packaging containing 20% of CNC-H2O2-AA-γ-GA was then added to a gellan-based film packaging. A significant improvement (p<0.05) of the tensile strength (TS), the tensile modulus (TM) and the elongation at break (EB) and water vapor permeability reduction was observed when CNC-H2O2-AA-γ-GA was added to the film packaging formulation.

Functional Interaction Map of Lyssavirus Phosphoprotein: Identification of the Minimal Transcription Domains

PubMed Central

Jacob, Yves; Real, Eléonore; Tordo, Noël

2001-01-01

Lyssaviruses, the causative agents of rabies encephalitis, are distributed in seven genotypes. The phylogenetically distant rabies virus (PV strain, genotype 1) and Mokola virus (genotype 3) were used to develop a strategy to identify functional homologous interactive domains from two proteins (P and N) which participate in the viral ribonucleoprotein (RNP) transcription-replication complex. This strategy combined two-hybrid and green fluorescent protein–reverse two-hybrid assays in Saccharomyces cerevisiae to analyze protein-protein interactions and a reverse genetic assay in mammalian cells to study the transcriptional activity of the reconstituted RNP complex. Lyssavirus P proteins contain two N-binding domains (N-BDs), a strong one encompassing amino acid (aa) 176 to the C terminus and a weak one in the 189 N-terminal aa. The N-terminal portion of P (aa 52 to 189) also contains a homomultimerization site. Here we demonstrate that N-P interactions, although weaker, are maintained between proteins of the different genotypes. A minimal transcriptional module of the P protein was obtained by fusing the first 60 N-terminal aa containing the L protein binding site to the C-terminal strong N-BD. Random mutation of the strong N-BD on P protein identified three highly conserved K residues crucial for N-P interaction. Their mutagenesis in full-length P induced a transcriptionally defective RNP. The analysis of homologous interactive domains presented here and previously reported dissections of the P protein allowed us to propose a model of the functional interaction network of the lyssavirus P protein. This model underscores the central role of P at the interface between L protein and N-RNA template. PMID:11559793

Plant Proteins Are Smaller Because They Are Encoded by Fewer Exons than Animal Proteins.

PubMed

Ramírez-Sánchez, Obed; Pérez-Rodríguez, Paulino; Delaye, Luis; Tiessen, Axel

2016-12-01

Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylogenetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa), average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ∼81aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ∼10 exons of small size [∼176 nucleotides (nt)]. Streptophyta have on average only ∼5.7 exons of medium size (∼230nt). Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400nt). Among subcellular compartments, membrane proteins are the largest (∼520aa), whereas the smallest proteins correspond to the gene ontology group of ribosome (∼240aa). Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ∼34% more but ∼20% smaller proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes. Copyright © 2016 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

Sufficient protein quality of food aid varies with the physiologic status of recipients

USDA-ARS?s Scientific Manuscript database

Protein quality scores use the amino acid (AA) requirements of a healthy North American child. AA requirements vary with physiologic status. We estimated AA requirements for healthy North American children, children with environmental enteric dysfunction, children recovering from wasting, and childr...

The Effects of Applied Stress and Sensitization on the Passive Film Stability of Al-Mg Alloys

DTIC Science & Technology

2013-06-01

and residual tensile and compressive stresses impact the passive layer film and the material’s electrochemistry. Sample plates of AA5083 were...electrochemistry. Sample plates of AA5083 were sensitized to different levels to promote the formation of intergranular β phase (Al3Mg2). The...41  A.  MATERIAL PROCESSING: FABRICATION AND APPLIED STRESSES OF TEST SAMPLES

Sex Differences in Omega-3 and -6 Fatty Acids and Health Status Among Young Adults With Acute Myocardial Infarction: Results From the VIRGO Study.

PubMed

Lu, Yuan; Ding, Qinglan; Xu, Xiao; Spatz, Erica S; Dreyer, Rachel P; D'Onofrio, Gail; Caulfield, Michael; Nasir, Khurram; Spertus, John A; Krumholz, Harlan M

2018-05-30

Young women (aged ≤55 years) with acute myocardial infarction (AMI) have poorer health status outcomes than similarly aged men. Low omega-3 fatty acids (FAs) have been implicated as risk factors for cardiovascular outcomes in AMI patients, but it is not clear whether young women have similar or different post-AMI omega-3 FA profiles compared with young men. We assessed the sex differences in post-AMI omega-3 FAs and the associations of these biomarkers with patient-reported outcomes (symptom, functioning status, and quality of life) at 12-month follow-up, using data from 2985 US adults with AMI aged 18 to 55 years enrolled in the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young Acute Myocardial Infarction Patients) study. Biomarkers including eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid (AA), eicosapentaenoic acid/AA ratio, omega-3/omega-6 ratio, and omega-3 index were measured 1 month after AMI. Overall, the omega-3 FAs and AA were similar in young men and women with AMI. In both unadjusted and adjusted analysis (controlling for age, sex, race, smoking, hypertension, diabetes mellitus, body mass index, and health status score at 1 month), omega-3 FAs and AA were not significantly associated with 12-month health status scores using the Bonferroni corrected statistical threshold. We found no evidence of sex differences in omega-3 FAs and AA in young men and women 1 month after AMI. Omega-3 FAs and AA at 1-month after AMI were generally not associated with 12-month patient-reported health status after adjusting for patient demographic, clinical characteristics, and the corresponding 1-month health status score. © 2018 The Authors and Quest Diagnostics Inc. Published on behalf of the American Heart Association, Inc., by Wiley.

Vitamin-C delivery from CoCr alloy surfaces using polymer-free and polymer-based platforms for cardiovascular stent applications.

PubMed

Thiruppathi, Eagappanath; Mani, Gopinath

2014-06-03

Antiproliferative drugs such as paclitaxel and sirolimus are delivered from stents to inhibit the growth of smooth muscle cells (SMCs) for preventing neointimal hyperplasia. However, these drugs delay the growth of endothelial cells (ECs) as well and cause late stent thrombosis. We recently demonstrated the use of Vitamin-C (l-ascorbic acid, l-AA) over paclitaxel and sirolimus for inhibiting SMCs growth and promoting EC growth simultaneously. In this study, we have investigated the delivery of l-AA from CoCr alloy surfaces for potential use in stents. A polymer-free phosphoric acid (PA) platform and a polymer-based poly(lactic-co-glycolic acid) (PLGA) platform were used for coating l-AA onto CoCr surfaces. For the PA platform, FTIR confirmed that the PA was coated on CoCr, while the AFM showed that the PA coating on the CoCr surface was homogeneous. The successful deposition of l-AA on PA-coated CoCr was also confirmed by FTIR. The uniform distribution of l-AA crystals on PA-coated CoCr was shown by SEM, optical profilometer, and AFM. The drug release studies showed that l-AA (276 μg/cm(2)) was burst released from the PA platform by 1 h. For the PLGA platform, SEM showed that the l-AA incorporated polymer films were smoothly and uniformly coated on CoCr. FTIR showed that l-AA was incorporated into the bulk of the PLGA film. DSC showed that the l-AA was present in an amorphous form and formed an intermolecular bonding interaction with PLGA. The drug release studies showed that l-AA was sustained released from the PLGA coated CoCr for up to 24 h. The SEM, FTIR, and DSC characterizations of samples collected post drug release shed light on the mechanism of l-AA release from PLGA coated CoCr. Thus, this study demonstrated the delivery of l-AA from biomaterial surfaces for potential applications in stents and other implantable medical devices.

Omega 3 but not omega 6 fatty acids inhibit AP-1 activity and cell transformation in JB6 cells.

PubMed

Liu, G; Bibus, D M; Bode, A M; Ma, W Y; Holman, R T; Dong, Z

2001-06-19

Epidemiological and animal-based investigations have indicated that the development of skin cancer is in part associated with poor dietary practices. Lipid content and subsequently the derived fatty acid composition of the diet are believed to play a major role in the development of tumorigenesis. Omega 3 (omega3) fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), can effectively reduce the risk of skin cancer whereas omega 6 (omega6) fatty acids such as arachidonic acid (AA) reportedly promote risk. To investigate the effects of fatty acids on tumorigenesis, we performed experiments to examine the effects of the omega3 fatty acids EPA and DHA and of the omega6 fatty acid AA on phorbol 12-tetradecanoate 13-acetate (TPA)-induced or epidermal growth factor (EGF)-induced transcription activator protein 1 (AP-1) transactivation and on the subsequent cellular transformation in a mouse epidermal JB6 cell model. DHA treatment resulted in marked inhibition of TPA- and EGF-induced cell transformation by inhibiting AP-1 transactivation. EPA treatment also inhibited TPA-induced AP-1 transactivation and cell transformation but had no effect on EGF-induced transformation. AA treatment had no effect on either TPA- or EGF-induced AP-1 transactivation or transformation, but did abrogate the inhibitory effects of DHA on TPA- or EGF-induced AP-1 transactivation and cell transformation in a dose-dependent manner. The results of this study demonstrate that the inhibitory effects of omega3 fatty acids on tumorigenesis are more significant for DHA than for EPA and are related to an inhibition of AP-1. Similarly, because AA abrogates the beneficial effects of DHA, the dietary ratio of omega6 to omega3 fatty acids may be a significant factor in mediating tumor development.

An electrochemical sensor for simultaneous determination of ascorbic acid, dopamine, uric acid and tryptophan based on MWNTs bridged mesocellular graphene foam nanocomposite.

PubMed

Li, Huixiang; Wang, Yi; Ye, Daixin; Luo, Juan; Su, Biquan; Zhang, Song; Kong, Jilie

2014-09-01

A multi-walled carbon nanotubes (MWNTs) bridged mesocellular graphene foam (MGF) nanocomposite (MWNTs/MGF) modified glassy carbon electrode was fabricated and successfully used for simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (TRP). Comparing with pure MGF, MWNTs or MWNTs/GS (graphene sheets), MWNTs/MGF displayed higher catalytic activity and selectivity toward the oxidation of AA, DA, UA and TRP. Under the optimal conditions, MWCNs/MGF/GCE can simultaneously detect AA, DA, UA and TRP with high selectivity and sensitivity. The detection limits were 18.28 µmol L(-1), 0.06 µmol L(-1), 0.93 µmol L(-1) and 0.87 µmol L(-1), respectively. Moreover, the modified electrode exhibited excellent stability and reproducibility. Copyright © 2014. Published by Elsevier B.V.

GLANDULAR TRICHOME-SPECIFIC WRKY 1 promotes artemisinin biosynthesis in Artemisia annua.

PubMed

Chen, Minghui; Yan, Tingxiang; Shen, Qian; Lu, Xu; Pan, Qifang; Huang, Youran; Tang, Yueli; Fu, Xueqing; Liu, Meng; Jiang, Weimin; Lv, Zongyou; Shi, Pu; Ma, Ya-Nan; Hao, Xiaolong; Zhang, Lida; Li, Ling; Tang, Kexuan

2017-04-01

Artemisinin is a type of sesquiterpene lactone well known as an antimalarial drug, and is specifically produced in glandular trichomes of Artemisia annua. However, the regulatory network for the artemisinin biosynthetic pathway remains poorly understood. Exploration of trichome-specific transcription factors would facilitate the elucidation of regulatory mechanism of artemisinin biosynthesis. The WRKY transcription factor GLANDULAR TRICHOME-SPECIFIC WRKY 1 (AaGSW1) was cloned and analysed in A. annua. AaGSW1 exhibited similar expression patterns to the trichome-specific genes of the artemisinin biosynthetic pathway and AP2/ERF transcription factor AaORA. A β-glucuronidase (GUS) staining assay further demonstrated that AaGSW1 is a glandular trichome-specific transcription factor. AaGSW1 positively regulates CYP71AV1 and AaORA expression by directly binding to the W-box motifs in their promoters. Overexpression of AaGSW1 in A. annua significantly improves artemisinin and dihydroartemisinic acid contents; moreover, AaGSW1 can be directly regulated by AaMYC2 and AabZIP1, which are positive regulators of jasmonate (JA)- and abscisic acid (ABA)-mediated artemisinin biosynthetic pathways, respectively. These results demonstrate that AaGSW1 is a glandular trichome-specific WRKY transcription factor and a positive regulator in the artemisinin biosynthetic pathway. Moreover, we propose that two trifurcate feed-forward pathways involving AaGSW1, CYP71AV1 and AaMYC2/AabZIP1 function in the JA/ABA response in A. annua. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Molecular and functional characterization of single-box high-mobility group B (HMGB) chromosomal protein from Aedes aegypti.

PubMed

de Abreu da Silva, Isabel Caetano; Vicentino, Amanda Roberta Revoredo; Dos Santos, Renata Coutinho; da Fonseca, Rodrigo Nunes; de Mendonça Amarante, Anderson; Carneiro, Vitor Coutinho; de Amorim Pinto, Marcia; Aguilera, Estefania Anahi; Mohana-Borges, Ronaldo; Bisch, Paulo Mascarello; da Silva-Neto, Mario Alberto Cardoso; Fantappié, Marcelo Rosado

2018-05-30

High-mobility group B (HMGB) proteins have highly conserved, unique DNA-binding domains, HMG boxes, that can bind non-B-type DNA structures, such as bent, kinked and unwound structures, with high affinity. HMGB proteins also promote DNA bending, looping and unwinding. In this study, we determined the role of the Aedes aegypti single HMG-box domain protein AaHMGB; characterized its structure, spatiotemporal expression levels, subcellular localization, and nucleic acid binding activities; and compared these properties with those of its double-HMG-box counterpart protein, AaHMGB1. Via qRT-PCR, we showed that AaHMGB is expressed at much higher levels than AaHMGB1 throughout mosquito development. In situ hybridization results suggested a role for AaHMGB and AaHMGB1 during embryogenesis. Immunolocalization in the midgut revealed that AaHMGB is exclusively nuclear. Circular dichroism and fluorescence spectroscopy analyses showed that AaHMGB exhibits common features of α-helical structures and is more stably folded than AaHMGB1, likely due to the presence of one or two HMG boxes. Using several DNA substrates or single-stranded RNAs as probes, we observed significant differences between AaHMGB and AaHMGB1 in terms of their binding patterns, activity and/or specificity. Importantly, we showed that the phosphorylation of AaHMGB plays a critical role in its DNA-binding activity. Our study provides additional insight into the roles of single- versus double-HMG-box-containing proteins in nucleic acid interactions for better understanding of mosquito development, physiology and homeostasis. Copyright © 2017. Published by Elsevier B.V.

Proteomics analysis of altered proteins in kidney of mice with aristolochic acid nephropathy using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method.

PubMed

Lin, Chia-En; Chang, Wen-Shin; Lee, Jen-Ai; Chang, Ting-Ya; Huang, Yu-Shen; Hirasaki, Yoshiro; Chen, Hung-Shing; Imai, Kazuhiro; Chen, Shih-Ming

2018-03-01

Aristolochic acid (AA) causes interstitial renal fibrosis, called aristolochic acid nephropathy (AAN). There is no specific indicator for diagnosing AAN, so this study aimed to investigate the biomarkers for AAN using a proteomics method. The C3H/He female mice were given ad libitum AA-distilled water (0.5 mg/kg/day) and distilled water for 56 days in the AA and normal groups, respectively. The AA-induced proteins in the kidney were investigated using a proteomics study, including fluorogenic derivatization with 7-chloro-N-[2-(dimethylamino)ethyl]-2,1,3-benzoxadiazole-4-sulfonamide, followed by high-performance liquid chromatography analysis and liquid chromatography tandem mass spectrometry with a MASCOT database searching system. There were two altered proteins, thrombospondin type 1 (TSP1) and G protein-coupled receptor 87 (GPR87), in the kidney of AA-group mice on day 56. GPR87, a tumorigenesis-related protein, is reported for the first time in the current study. The renal interstitial fibrosis was certainly induced in the AA-group mice under histological examination. Based on the results of histological examination and the proteomics study, this model might be applied to AAN studies in the future. TSP1 might be a novel biomarker for AAN, and the further role of GPR87 leading to AA-induced tumorigenesis should be researched in future studies. Copyright © 2017 John Wiley & Sons, Ltd.

Use of Shark Dental Protein to Estimate Trophic Position via Amino Acid Compound-Specific Isotope Analysis

NASA Astrophysics Data System (ADS)

Hayes, M.; Herbert, G.; Ellis, G.

2017-12-01

The diets of apex predators such as sharks are expected to change in response to overfishing of their mesopredator prey, but pre-anthropogenic baselines necessary to test for such changes are lacking. Stable isotope analysis (SIA) of soft tissues is commonly used to study diets in animals based on the bioaccumulation of heavier isotopes of carbon and nitrogen with increasing trophic level. In specimens representing pre-anthropogenic baselines, however, a modified SIA approach is needed to deal with taphonomic challenges, such as loss of soft tissues or selective loss of less stable amino acids (AAs) in other sources of organic compounds (e.g., teeth or bone) which can alter bulk isotope values. These challenges can be overcome with a compound-specific isotope analysis of individual AAs (AA-CSIA), but this first requires a thorough understanding of trophic enrichment factors for individual AAs within biomineralized tissues. In this study, we compare dental and muscle proteins of individual sharks via AA-CSIA to determine how trophic position is recorded within teeth and whether that information differs from that obtained from soft tissues. If skeletal organics reliably record information about shark ecology, then archaeological and perhaps paleontological specimens can be used to investigate pre-anthropogenic ecosystems. Preliminary experiments show that the commonly used glutamic acid/phenylalanine AA pairing may not be useful for establishing trophic position from dental proteins, but that estimated trophic position determined from alternate AA pairs are comparable to those from muscle tissue within the same species.

Improved tandem mass spectrometry (MS/MS) derivatized method for the detection of tyrosinemia type I, amino acids and acylcarnitine disorders using a single extraction process.

PubMed

Dhillon, Kuldeep S; Bhandal, Ajit S; Aznar, Constantino P; Lorey, Fred W; Neogi, Partha

2011-05-12

Succinylacetone (SUAC), a specific marker for tyrosinemia type I (Tyr I) cannot be detected by the routine LC-MS/MS screening of amino acids (AA) and acylcarnitines (AC) in newborns. The current derivatized methods require double extraction of newborn dried blood spots (DBS); one for AA and AC and the second for SUAC from the blood spot left after the first extraction. We have developed a method in which AA, AC and SUAC are extracted in a single extraction resulting in significant reduction in labor and assay time. The 3.2 mm DBS were extracted by incubating at 45 °C for 45 min with 100 μl of acetonitrile (ACN)-water-formic acid mixture containing hydrazine and stable-isotope labeled internal standards of AA, AC and SUAC. The extract was derivatized with n-butanolic-HCl and analyzed by LC-MS/MS. The average inter-assay CVs for, AA, AC and SUAC were 10.1, 10.8 and 7.1% respectively. The extraction of analytes with ACN-water mixture showed no significant difference in their recovery compared to commonly used solvent MeOH. The concentration of hydrazine had considerable impact on SUAC extraction. We developed a new MS/MS derivatized method to detect AA/AC/SUAC in a single extraction process for screening Tyr I along with disorders of AA and AC. Published by Elsevier B.V.

Arachidonate-Regulated Ca2+ Influx in Human Airway Smooth Muscle

PubMed Central

Thompson, Michael A.; Prakash, Y. S.

2014-01-01

Plasma membrane Ca2+ influx, especially store-operated Ca2+ entry triggered by sarcoplasmic reticulum (SR) Ca2+ release, is a key component of intracellular calcium concentration ([Ca2+]i) regulation in airway smooth muscle (ASM). Agonist-induced Ca2+ oscillations in ASM that involve both influx and SR mechanisms have been previously demonstrated. In nonexcitable cells, [Ca2+]i oscillations involve Ca2+ influx via arachidonic acid (AA) –stimulated channels, which show similarities to store-operated Ca2+ entry, although their molecular identity remains undetermined. Little is known about AA-regulated Ca2+ channels or their regulation in ASM. In enzymatically dissociated human ASM cells loaded with the Ca2+ indicator, fura-2, AA (1–10 μM) triggered [Ca2+]i oscillations that were inhibited by removal of extracellular Ca2+. Other fatty acids, such as the diacylglycerol analog, 1-oleoyl-2-acetyl-SN-glycerol, oleic acid, and palmitic acid (10 μM each), failed to elicit similar [Ca2+]i responses. Preincubation with LaCl3 (1 μM or 1 mM) inhibited AA-induced oscillations. Inhibition of receptor-operated channels (SKF96,365 [10 μM]), lipoxygenase (zileuton [10 μM]), or cyclooxygenase (indomethacin [10 μM]) did not affect oscillation parameters. Inhibition of SR Ca2+ release (ryanodine [10 μM] or inositol 1,4,5-trisphosphate receptor inhibitor, xestospongin C [1 μM]) decreased [Ca2+]i oscillation frequency and amplitude. Small interfering RNA against caveolin-1, stromal interaction molecule 1, or Orai3 (20 nM each) reduced the frequency and amplitude of AA-induced [Ca2+]i oscillations. In ASM cells derived from individuals with asthma, AA increased oscillation amplitude, but not frequency. These results are highly suggestive of a novel AA-mediated Ca2+–regulatory mechanism in human ASM, reminiscent of agonist-induced oscillations. Given the role of AA in ASM intracellular signaling, especially with inflammation, AA-regulated Ca2+ channels could potentially contribute to increased [Ca2+]i in diseases such asthma. PMID:24471656

Cationic permethylated 6-monoamino-6-monodeoxy-β-cyclodextrin as chiral selector of dansylated amino acids in capillary electrophoresis.

PubMed

Németh, Krisztina; Domonkos, Celesztina; Sarnyai, Virág; Szemán, Julianna; Jicsinszky, László; Szente, Lajos; Visy, Júlia

2014-10-01

The resolution power of permethylated 6-monoamino-6-monodeoxy-βCD (PMMABCD) - a single isomer, cationic CD derivative - developed previously for chiral analyses in capillary electrophoresis was further studied here. Dansylated amino acids (Dns-AA) were chosen as amphoteric chiral model compounds. Changes in the resolutions of Dns-AAs by varying pH and selector concentrations were investigated and correlated with their structures and chemical properties (isoelectric point and lipophilicity). Maximal resolutions could be achieved at pH 6 or pH 4. The separations improved with increasing concentration of the selector. Baseline or substantially better resolution for 8 pairs of these Dns-AAs could be achieved. Low CD concentration was enough for the separation of the most apolar Dns-AAs. Chiral discrimination ability of PMMABCD was demonstrated by the separation of an artificial mixture of 8 Dns-AA pairs. Copyright © 2014 Elsevier B.V. All rights reserved.

Bacterial cellulose based hydrogel (BC-g-AA) and preliminary result of swelling behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hakam, Adil; Lazim, Azwan Mat; Abdul Rahman, I. Irman

2013-11-27

In this study, hydrogel based on Bacterial cellulose (BC) or local known as Nata de Coco, which grafted with monomer: Acrylic acid (AA) is synthesis by using gamma radiation technique. These hydrogel (BC-g-AA) has unique characteristic whereby responsive to pH buffer solution.

[Levels of serum ascorbate and its metabolites in hemodialysis patients].

PubMed

Hirano, Hiroko; Tone, Yoshinori; Otani, Haruhisa; Oya, Masaki; Kimura, Keigo; Saika, Yasushi; Fujii, Ryoichi; Mune, Masatoshi; Ichinose, Masakazu; Yukawa, Susumu

2004-07-01

The status of ascorbic acid (AA) in dialysis patients is the subject of debate. Some reports have found AA to be deficient in dialysis patients, while others have found that AA is not deficient. In an attempt to confirm AA serum concentrations in dialysis patients, we analyzed the concentrations of AA as well as its metabolites using the specific determination of AA with chemical derivatization and the HPLC method. We studied 131 patients under maintenance hemodialysis therapy (HD), 23 patients with chronic renal failure (CRF) and 48 healthy controls (C). Serum concentrations of AA and the AA metabolites dehydroascorbic acid (DHA) and 2, 3-diketogulonate (DKG) were measured by HPLC. Nine HD patients were taking AA supplements. Seventy-six (62.3%) of the 122 HD patients not taking AA supplements exhibited deficient levels of AA (< 20 microM), while 13 (56.5%) of the 23 CRF patients and 9 (18.8%) of the 48 C showed deficient levels of AA. Analysis of AA metabolites in the normal-range AA (20-80 microM) group revealed that the DHA/AA ratio in HD patients was significantly higher than in C (3.3 +/- 2.6% and 1.2 +/- 2.2%, respectively). The DKG/AA ratio in HD patients was higher than in CRF patients (3.6 +/- 5.2% vs. 0.9 +/- 1.9%), whereas DKG was not detected in C. When compared to serum levels before the start of dialysis, serum AA, DHA and DKG concentrations at the end of the dialysis session decreased by an average of 74.2, 84.0 and 78.8% respectively. In HD patients, serum levels of thiobarbituric reactive substances (TBARS) were significantly lower in the higher AA (> 80 microM) group than in the deficient and normal-range AA groups. In 12 AA-deficient patients, after 1 month of taking AA supplements (200 mg/day), serum AA levels rose to 79.9 microM, while serum TBARS level declined when compared with levels before supplementation. In conclusion, the frequency of AA deficiency in dialysis patients is extremely high. AA deficiency in HD patients may result in high TBARS levels, which reflect increased oxidative stress. Adequate AA supplementation should therefore be considered in such patients.

Amino acid composition of rumen bacteria and protozoa in cattle.

PubMed

Sok, M; Ouellet, D R; Firkins, J L; Pellerin, D; Lapierre, H

2017-07-01

Because microbial crude protein (MCP) constitutes more than 50% of the protein digested in cattle, its AA composition is needed to adequately estimate AA supply. Our objective was to update the AA contributions of the rumen microbial AA flowing to the duodenum using only studies from cattle, differentiating between fluid-associated bacteria (FAB), particle-associated bacteria (PAB), and protozoa, based on published literature (53, 16, and 18 treatment means were used for each type of microorganism, respectively). In addition, Cys and Met reported concentrations were retained only when an adequate protection of the sulfur groups was performed before the acid hydrolysis. The total AA (or true protein) fraction represented 82.4% of CP in bacteria. For 10 AA, including 4 essential AA, the AA composition differed between protozoa and bacteria. The most noticeable differences were a 45% lower Lys concentration and 40% higher Ala concentration in bacteria than in protozoa. Differences between FAB and PAB were less pronounced than differences between bacteria and protozoa. Assuming 33% FAB, 50% PAB, and 17% of protozoa in MCP duodenal flow, the updated concentrations of AA would decrease supply estimates of Met, Thr, and Val originating from MCP and increase those of Lys and Phe by 5 to 10% compared with those calculated using the FAB composition reported previously. Therefore, inclusion of the contribution of PAB and protozoa to the duodenal MCP flow is needed to adequately estimate AA supply from microbial origin when a factorial method is used to estimate duodenal AA flow. Furthermore, acknowledging the fact that hydrolysis of 1 kg of true microbial protein yields 1.16 kg of free AA substantially increases the estimates of AA supply from MCP. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Mutations in the conserved carboxy-terminal hydrophobic region of glycoprotein gB affect infectivity of herpes simplex virus.

PubMed

Wanas, E; Efler, S; Ghosh, K; Ghosh, H P

1999-12-01

Glycoprotein gB is the most highly conserved glycoprotein in the herpesvirus family and plays a critical role in virus entry and fusion. Glycoprotein gB of herpes simplex virus type 1 contains a hydrophobic stretch of 69 aa near the carboxy terminus that is essential for its biological activity. To determine the role(s) of specific amino acids in the carboxy-terminal hydrophobic region, a number of amino acids were mutagenized that are highly conserved in this region within the gB homologues of the family HERPESVIRIDAE: Three conserved residues in the membrane anchor domain, namely A786, A790 and A791, as well as amino acids G743, G746, G766, G770 and P774, that are non-variant in Herpesviridae, were mutagenized. The ability of the mutant proteins to rescue the infectivity of the gB-null virus, K082, in trans was measured by a complementation assay. All of the mutant proteins formed dimers and were incorporated in virion particles produced in the complementation assay. Mutants G746N, G766N, F770S and P774L showed negligible complementation of K082, whereas mutant G743R showed a reduced activity. Virion particles containing these four mutant glycoproteins also showed a markedly reduced rate of entry compared to the wild-type. The results suggest that non-variant residues in the carboxy-terminal hydrophobic region of the gB protein may be important in virus infectivity.

Determination of furan precursors and some thermal damage markers in baby foods: ascorbic acid, dehydroascorbic acid, hydroxymethylfurfural and furfural.

PubMed

Mesías-García, Marta; Guerra-Hernández, Eduardo; García-Villanova, Belén

2010-05-26

The presence of ascorbic acid (AA), vitamin C (AA + dehydroascorbic acid (DHAA)) and furfural as potential precursors of furan in commercial fruit and vegetable jarred baby food was studied. Hydroxymethylfurfural (HMF) was also determined and used, together with furfural levels, as markers of thermal damage. AA, calculated DHAA and vitamin C values ranged between 22.4 and 103, 2.9 and 13.8, and 32.1 and 113.2 mg/100 g, respectively, in fruit-based baby food. However, no trace of AA was found in the vegetable-based baby food samples tested, probably because these samples are not enriched in vitamin C and the content of this vitamin in fresh vegetables is destroyed during processing. Furfural values ranged from not detected to 236 microg/100 g, being higher in vegetable samples than in fruit samples possibly because of greater AA degradation favored by a higher pH in the vegetable samples. HMF values (range: not detected-959 microg/100 g), however, were higher in the fruit samples, probably due to greater carbohydrate content degradation and as a consequence of the Maillard reaction, favored by a lower pH in these samples. According to these results, HMF would be the optimum indicator of thermal treatment for fruits, and furfural for vegetables. The higher furfural content of vegetable baby food could be considered an index of greater AA degradation and, therefore, the furan content might be higher in this kind of sample than in fruit-based baby food.

Second-tier test for quantification of underivatized amino acids in dry blood spot for metabolic diseases in newborn screening.

PubMed

Wang, Chunyan; Zhu, Hongbin; Zhang, Wenyan; Song, Fengrui; Liu, Zhiqiang; Liu, Shuying

2013-02-01

The quantitative analysis of amino acids (AAs) in single dry blood spot (DBS) samples is an important issue for metabolic diseases as a second-tier test in newborn screening. An analytical method for quantifying underivatized AAs in DBS was developed by using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample preparation in this method is simple and ion-pairing agent is not used in the mobile phase that could avoid ion suppression, which happens in mass spectrometry and avoids damage to the column. Through chromatographic separation, some isomeric compounds could be identified and quantified, which cannot be solved through only appropriate multiple reactions monitoring transitions by MS/MS. The concentrations of the different AAs were determined using non-deuterated internal standard. All calibration curves showed excellent linearity within test ranges. For most of the amino acids the accuracy of extraction recovery was between 85.3 and 115 %, and the precision of relative standard deviation was <7.0 %. The 35 AAs could be identified in DBS specimens by the developed LC-MS/MS method in 17-19 min, and eventually 24 AAs in DBS were quantified. The results of the present study prove that this method as a second-tier test in newborn screening for metabolic diseases could be performed by the quantification of free AAs in DBS using the LC-MS/MS method. The assay has advantages of high sensitive, specific, and inexpensive merits because non-deuterated internal standard and acetic acid instead of ion-pairing agent in mobile phase are used in this protocol.

Amino and fatty acid dynamics of octopus (Octopus vulgaris) early life stages under ocean warming.

PubMed

Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui

2016-01-01

The oceans are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable early life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prostacyclin production in rabbit arteries in situ: inhibition by arachidonic acid-induced endothelial cell damage or by low-dose aspirin.

PubMed

Ingerman-Wojenski, C; Silver, M J; Smith, J B; Nissenbaum, M; Sedar, A W

1981-04-01

The central artery of the rabbit ear was perfused in situ and effluent fractions from the artery were assayed for 6-keto-prostaglandin F1 alpha (6-K-PGF1 alpha) and thromboxane B2 (TxB2), the stable metabolites of prostacyclin (PGI2) and TxA2, using specific radioimmunoassays. These metabolites of arachidonic acid (AA) were not detected in the effluent during infusion of Tyrode's solution but both metabolites were detected when small amounts of AA were infused into the artery. Examination of the arteries by scanning electron microscopy revealed that high concentrations of AA which caused a short burst of 6-K-PGF1 alpha and TxB2 production damaged the endothelial cells while lower concentrations which stimulated continuous production did not cause damage. When a non-damaging concentration of AA was infused into an artery that had previously received a damaging concentration, PG production was greatly reduced. Pretreatment of the rabbits with 4 mg/kg acetyl-salicylic acid (ASA) inhibited 6-K-PGF1 alpha production by the rabbit ear artery in response to AA and 70% inhibition was still evident 18 hours after ASA.

Evaluation of Toxicity and Biodegradability of Cholinium Amino Acids Ionic Liquids

PubMed Central

Hou, Xue-Dan; Liu, Qiu-Ping; Smith, Thomas J.; Li, Ning; Zong, Min-Hua

2013-01-01

Cholinium amino acid ionic liquids ([Ch][AA] ILs), which are wholly composed of renewable biomaterials, have recently been demonstrated to have very promising properties for applications in organic synthesis and biomass pretreatment. In this work, the toxicity of these ILs toward enzymes and bacteria was assessed, and the effect of the anion on these properties is discussed. The inhibitory potentials of this type of ILs to acetylcholinesterase were weaker approximately an order of magnitude than the traditional IL 1-butyl-3-methylimidazolium tetrafluoroborate. Additionally, the [Ch][AA] ILs displayed low toxicity toward the bacteria tested. Furthermore, the biodegradability of the [Ch][AA] ILs was evaluated via the closed bottle and CO2 headspace tests using wastewater microorganisms. All the ILs were classified as ‘readily biodegradable’ based on their high levels of mineralization (62-87%). The presence of extra carboxyl or amide groups on the amino acid side chain rendered the ILs significantly more susceptible to microbial breakdown. In addition, for most of the [Ch][AA] ILs, low toxicity correlated with good biodegradability. The low toxicity and high biodegradability of these novel [Ch][AA] make them promising candidates for use as environmentally friendly solvents in large-scale applications. PMID:23554985

Simultaneous determination of ascorbic acid and caffeine in commercial soft drinks using reversed-phase ultraperformance liquid chromatography.

PubMed

Turak, Fatma; Güzel, Remziye; Dinç, Erdal

2017-04-01

A new reversed-phase ultraperformance liquid chromatography method with a photodiode array detector was developed for the quantification of ascorbic acid (AA) and caffeine (CAF) in 11 different commercial drinks consisting of one energy drink and 10 ice tea drinks. Separation of the analyzed AA and CAF with an internal standard, caffeic acid, was performed on a Waters BEH C 18 column (100 mm × 2.1 mm, 1.7 μm i.d.), using a mobile phase consisting of acetonitrile and 0.2M H 3 PO 4 (11:89, v/v) with a flow rate of 0.25 mL/min and an injection volume of 1.0 μL. Calibration graphs for AA and CAF were computed from the peak area ratio of AA/internal standard and CAF/internal standard detected at 244.0 nm and 273.6 nm, respectively. The developed reversed-phase ultraperformance liquid chromatography method was validated by analyzing standard addition samples. The proposed reversed-phase ultraperformance liquid chromatography method gave us successful results for the quantitative analysis of commercial drinks containing AA and CAF substances. Copyright © 2016. Published by Elsevier B.V.

Changes in the amino acid profiles and free radical scavenging activities of Tenebrio molitor larvae following enzymatic hydrolysis.

PubMed

Tang, Yujiao; Debnath, Trishna; Choi, Eun-Ju; Kim, Young Wook; Ryu, Jung Pyo; Jang, Sejin; Chung, Sang Uk; Choi, Young-Jin; Kim, Eun-Kyung

2018-01-01

Tenebrio molitor (T. molitor) larvae provide food at low environmental cost and contribute positively to livelihoods. In this research, we compared the amino acids compositions and antioxidant activities of various extracts of T. molitor to enhance their quality as food. For the comparison, distilled water extracts, enzymatic hydrolysates, and condensed enzymatic hydrolysates of T. molitor larvae were prepared. Their amino acids (AAs) profiles and antioxidant activities, including ferric-reducing antioxidant power, oxygen radical absorption capacity, and DPPH, hydroxyl radical, and hydrogen peroxide radical scavenging properties assay were analyzed. DW extracts had the lowest AAs contents and antioxidant activity compared with enzymatic extracts. Condensed hydrolysates with a combination of alcalase and flavourzyme (C-A+F) exhibited the highest levels of total free AAs (11.1759 g/100 g). C-A+F produced higher total hydrolyzed AAs (32.5292 g/100 g) compared with the other groups. The C-A+F possessed the strongest antioxidant activity. Notably, the antioxidant activities of the hydrolysates and the total hydrolyzed AAs amount were correlated. Taken together, our findings showed that C-A+F was a promising technique for obtaining extracts of T. molitor larvae with antioxidant activity as potential nutritious functional food.

Time-dependent changes in the plasma amino acid concentration in diabetes mellitus.

PubMed

Mochida, Taiga; Tanaka, Takayuki; Shiraki, Yasuko; Tajiri, Hiroko; Matsumoto, Shirou; Shimbo, Kazutaka; Ando, Toshihiko; Nakamura, Kimitoshi; Okamoto, Masahiro; Endo, Fumio

2011-08-01

We investigated longitudinal change in the amino acid (AA) profile in type 1 diabetes mellitus (DM) using AKITA mice, which develop DM as a result of insulin deficiency. The plasma concentrations of valine, leucine, isoleucine, as well as the total branched chain amino acids, alanine, citrulline and proline, were significantly higher in the diabetic mice. We show that the degree and timing of the changes were different among the plasma amino acid concentrations (pAAs) during the development of type 1 DM. Copyright © 2011 Elsevier Inc. All rights reserved.

Safety assessment of azelaic acid and its derivatives entrapped in nanovesicles.

PubMed

Panyosak, A; Manosroi, J; Rojanasakul, Y; Manosroi, A

2009-06-01

The aim of this study was to determine the safety of azelaic acid (AA) and its derivatives in nanovesicles for pharmaceutical and cosmetic uses. The hydrophilic property of AA was modified by complexing AA with hydroxypropyl-beta-cyclodextrin (AACD). The lipophilic property of AA was improved to diethyl azelate (DA) by esterification with Fischer reaction. AA, AACD and DA were entrapped in liposomes and niosomes with the compositions of L-alpha-dipalmitoyl phosphatidylcholine/cholesterol = 7:3 and Tween 61/cholesterol = 1:1, respectively, by chloroform film method with sonication. The size of the vesicles ranged from 50 to 200 nm, indicating nanosize characteristics. The cytotoxicity of AA, AACD and DA entrapped nanovesicular formulations on mouse epidermal cell lines (JB6, normal cell lines) by the sulforhodamine B assay was modest when compared with cisplatin. Blank liposomes and niosomes gave no growth inhibitory effect. The irritation of AA, AACD and DA entrapped and not entrapped in nanovesicles on rabbit skin was examined according to the Environmental Protection Agency health effect test guidelines. The results showed no signs of erythema or edema within 72 h. AA and its derivatives were safe for topical use when entrapped in nanovesicles because of no toxicity to normal cell lines and no allergy on rabbit skin.

Digestion of feed amino acids in the rumen and intestine of steers measured using a mobile nylon bag technique.

PubMed

Taghizadeh, A; Danesh Mesgaran, M; Valizadeh, R; Shahroodi, F Eftekhar; Stanford, K

2005-05-01

The disappearance of dry matter (DM), crude protein (CP), and amino acids (AA) in steers after rumen incubation and intestinal passage of alfalfa hay, barley hay, corn silage, barley grain, corn grain, wheat bran, meat meal, fish meal, cottonseed meal, and soybean meal were measured in 3 steers using a mobile nylon bag technique. Ruminal degradation of individual AA differed between feedstuffs. For barley hay and corn silage, the ruminal disappearance of total AA was higher and lower than the other feedstuffs, respectively. The intestinal digestibility of total AA in alfalfa hay was lower than the digestion of CP. The intestinal digestibility of Arg and His was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, and wheat bran. In addition, the intestinal digestibility of Lys was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, corn silage, and wheat bran. The intestinal disappearance of CP in most cases was higher than that of DM. The results indicated that feedstuffs with lower ruminal disappearance of DM, CP, total AA, essential AA, and nonessential AA generally had a higher intestinal disappearance, resulting in a relatively constant total tract disappearance. These results could be used to improve the current system of diet formulation in ruminants.

Preparation of a solid-in-oil nanosuspension containing L-ascorbic acid as a novel long-term stable topical formulation.

PubMed

Piao, Hongyu; Kamiya, Noriho; Cui, Fude; Goto, Masahiro

2011-11-25

L-Ascorbic acid (AA, vitamin C) easily decomposes into inactive compounds in aqueous solutions and this has limited its topical use. This work reports the preparation of a solid-in-oil nanosuspension (SONS) containing AA and validation of its basic storage stability. Although AA itself is water-soluble, it can readily be nanosuspended in squalane via complex formation involving a combination of sucrose erucate (i.e. lipophilic surfactant) and sucrose monolaureate (i.e. hydrophilic surfactant) to yield SONS with a very low moisture content (<500 ppm). To extract encapsulated AA, a lipase-based enzymatic degradation technique was used to degrade a formulation phase making it easier for AA to distribute into an extraction solution. Our results demonstrate that almost all the encapsulated AA (95.3%) was readily extracted from the SONS upon addition of medium-chain triglyceride, which offers the possibility of degrading the formulation phase using lipase. Finally, its storage stability study was investigated at 25°C over 90 days under protection from light. An aqueous solution containing AA was used as a control. Compared with the control, the SONS markedly increased the stability of AA due to its low moisture content and, thus, the potential usefulness SONSs as a novel long-term stable topical formulation of AA has been proved. Copyright © 2011 Elsevier B.V. All rights reserved.

Diet quality influences isotopic discrimination among amino acids in an aquatic vertebrate

PubMed Central

Chikaraishi, Yoshito; Steffan, Shawn A; Takano, Yoshinori; Ohkouchi, Naohiko

2015-01-01

Stable nitrogen isotopic composition of amino acids (δ15NAA) has recently been employed as a powerful tool in ecological food web studies, particularly for estimating the trophic position (TP) of animal species in food webs. However, the validity of these estimates depends on the consistency of the trophic discrimination factor (TDF; - Δδ15NAA at each shift of trophic level) among a suite of amino acids within the tissues of consumer species. In this study, we determined the TDF values of amino acids in tadpoles (the Japanese toad, Bufo japonicus) reared exclusively on one of three diets that differed in nutritional quality. The diets were commercial fish-food pellets (plant and animal biomass), bloodworms (animal biomass), and boiled white rice (plant carbohydrate), representing a balanced, protein-rich, and protein-poor diet, respectively. The TDF values of two “source amino acids” (Src-AAs), methionine and phenylalanine, were close to zero (0.3–0.5‰) among the three diets, typifying the values reported in the literature (∼0.5‰ and ∼0.4‰, respectively). However, TDF values of “trophic amino acids” (Tr-AAs) including alanine, valine, leucine, isoleucine, and glutamic acid varied by diet: for example, the glutamic acid TDF was similar to the standard value (∼8.0‰) when tadpoles were fed either the commercial pellets (8.0‰) or bloodworms (7.9‰), but when they were fed boiled rice, the TDF was significantly reduced (0.6‰). These results suggest that a profound lack of dietary protein may alter the TDF values of glutamic acid (and other Tr-AAs and glycine) within consumer species, but not the two Src-AAs (i.e., methionine and phenylalanine). Knowledge of how a nutritionally poor diet can influence the TDF of Tr- and Src-AAs will allow amino acid isotopic analyses to better estimate TP among free-roaming animals. PMID:26045955

Novel rabies virus-neutralizing epitope recognized by human monoclonal antibody: fine mapping and escape mutant analysis.

PubMed

Marissen, Wilfred E; Kramer, R Arjen; Rice, Amy; Weldon, William C; Niezgoda, Michael; Faber, Milosz; Slootstra, Jerry W; Meloen, Rob H; Clijsters-van der Horst, Marieke; Visser, Therese J; Jongeneelen, Mandy; Thijsse, Sandra; Throsby, Mark; de Kruif, John; Rupprecht, Charles E; Dietzschold, Bernhard; Goudsmit, Jaap; Bakker, Alexander B H

2005-04-01

Anti-rabies virus immunoglobulin combined with rabies vaccine protects humans from lethal rabies infections. For cost and safety reasons, replacement of the human or equine polyclonal immunoglobulin is advocated, and the use of rabies virus-specific monoclonal antibodies (MAbs) is recommended. We produced two previously described potent rabies virus-neutralizing human MAbs, CR57 and CRJB, in human PER.C6 cells. The two MAbs competed for binding to rabies virus glycoprotein. Using CR57 and a set of 15-mer overlapping peptides covering the glycoprotein ectodomain, a neutralization domain was identified between amino acids (aa) 218 and 240. The minimal binding region was identified as KLCGVL (aa 226 to 231), with key residues K-CGV- identified by alanine replacement scanning. The critical binding region of this novel nonconformational rabies virus epitope is highly conserved within rabies viruses of genotype 1. Subsequently, we generated six rabies virus variants escaping neutralization by CR57 and six variants escaping CRJB. The CR57 escape mutants were only partially covered by CRJB, and all CRJB-resistant variants completely escaped neutralization by CR57. Without exception, the CR57-resistant variants showed a mutation at key residues within the defined minimal binding region, while the CRJB escape viruses showed a single mutation distant from the CR57 epitope (N182D) combined with mutations in the CR57 epitope. The competition between CR57 and CRJB, the in vitro escape profile, and the apparent overlap between the recognized epitopes argues against including both CR57 and CRJB in a MAb cocktail aimed at replacing classical immunoglobulin preparations.

In silico characterization of a novel pathogenic deletion mutation identified in XPA gene in a Pakistani family with severe xeroderma pigmentosum.

PubMed

Nasir, Muhammad; Ahmad, Nafees; Sieber, Christian M K; Latif, Amir; Malik, Salman Akbar; Hameed, Abdul

2013-09-24

Xeroderma Pigmentosum (XP) is a rare skin disorder characterized by skin hypersensitivity to sunlight and abnormal pigmentation. The aim of this study was to investigate the genetic cause of a severe XP phenotype in a consanguineous Pakistani family and in silico characterization of any identified disease-associated mutation. The XP complementation group was assigned by genotyping of family for known XP loci. Genotyping data mapped the family to complementation group A locus, involving XPA gene. Mutation analysis of the candidate XP gene by DNA sequencing revealed a novel deletion mutation (c.654del A) in exon 5 of XPA gene. The c.654del A, causes frameshift, which pre-maturely terminates protein and result into a truncated product of 222 amino acid (aa) residues instead of 273 (p.Lys218AsnfsX5). In silico tools were applied to study the likelihood of changes in structural motifs and thus interaction of mutated protein with binding partners. In silico analysis of mutant protein sequence, predicted to affect the aa residue which attains coiled coil structure. The coiled coil structure has an important role in key cellular interactions, especially with DNA damage-binding protein 2 (DDB2), which has important role in DDB-mediated nucleotide excision repair (NER) system. Our findings support the fact of genetic and clinical heterogeneity in XP. The study also predicts the critical role of DDB2 binding region of XPA protein in NER pathway and opens an avenue for further research to study the functional role of the mutated protein domain.

Modeling of the relationship between dipeptide structure and dipeptide stability, permeability, and ACE inhibitory activity.

PubMed

Foltz, Martin; van Buren, Leo; Klaffke, Werner; Duchateau, Guus S M J E

2009-09-01

Selected di- and tripeptides exhibit angiotensin-I converting enzyme (ACE) inhibitory activity in vitro. However, the efficacy in vivo is most likely limited for most peptides due to low bioavailability. The purpose of this study was to identify descriptors of intestinal stability, permeability, and ACE inhibitory activity of dipeptides. A total of 228 dipeptides were synthesized; intestinal stability was obtained by in vitro digestion, intestinal permeability using Caco-2 cells and ACE inhibitory activity by an in vitro assay. Databases were constructed to study the relationship between structure and activity, permeability, and stability. Quantitative structure-activity relationship (QSAR) modeling was performed based on computed models using partial least squares regression based on 400 molecular descriptors. QSAR modeling of dipeptide stability revealed high correlation coefficients (R > 0.65) for models based on Z and X scales. However, amino acid (AA) clustering showed the best results in describing stability of dipeptides. The N-terminal AA residues Asp, Gly, and Pro as well as the C-terminal residues Pro, Ser, Thr, and Asp stabilize dipeptides toward luminal enzymatic peptide hydrolysis. QSAR modeling did not reveal significant correlation models for intestinal permeability. 2D-fingerprint models were identified describing ACE inhibitory activity of dipeptides. The intestinal stability of 12 peptides was predicted. Peptides were synthesized and stability was confirmed in simulated digestion experiments. Based on the results, specific dipeptides can be designed to meet both stability and activity criteria. However, postabsorptive ACE inhibitory activities of dipeptides in vivo are most likely limited due to the very low intestinal permeability of dipeptides.

Low plasma eicosapentaenoic acid concentration as a possible risk factor for intracerebral hemorrhage.

PubMed

Ikeya, Yoshimori; Fukuyama, Naoto; Mori, Hidezo

2015-03-01

N-3 fatty acids, including eicosapentaenoic acid (EPA), prevent ischemic stroke. The preventive effect has been attributed to an antithrombic effect induced by elevated EPA and reduced arachidonic acid (AA) levels. However, the relationship between intracranial hemorrhage and N-3 fatty acids has not yet been elucidated. In this cross-sectional study, we compared common clinical and lifestyle parameters between 70 patients with intracranial hemorrhages and 66 control subjects. The parameters included blood chemistry data, smoking, alcohol intake, fish consumption, and the incidences of underlying diseases. The comparisons were performed using the Mann-Whitney U test followed by multiple logistic regression analysis. Nonparametric tests revealed that the 70 patients with intracerebral hemorrhages exhibited significantly higher diastolic blood pressures and alcohol intakes and lower body mass indices, high-density lipoprotein (HDL) cholesterol levels, EPA concentrations, EPA/AA ratios, and vegetable consumption compared with the 66 control subjects. A multiple logistic regression analysis revealed that higher diastolic blood pressure and alcohol intake and lower body mass index, HDL cholesterol, EPA/AA ratio, and vegetable consumption were relative risk factors for intracerebral hemorrhage. High HDL cholesterol was a common risk factor in both of the sex-segregated subgroups and the <65-year-old subgroup. However, neither EPA nor the EPA/AA ratio was a risk factor in these subgroups. Eicosapentaenoic acid was relative risk factor only in the ≥65-year-old subgroup. Rather than higher EPA levels, lower EPA concentrations and EPA/AA ratios were found to be risk factors for intracerebral hemorrhage in addition to previously known risk factors such as blood pressure, alcohol consumption, and lifestyle. Copyright © 2015 Elsevier Inc. All rights reserved.

Visual acuity and fatty acid status of term infants fed human milk and formulas with and without docosahexaenoate and arachidonate from egg yolk lecithin.

PubMed

Carlson, S E; Ford, A J; Werkman, S H; Peeples, J M; Koo, W W

1996-05-01

Preterm infants fed formulas with docosahexaenoic acid (DHA, 22:6n-3) during the interval equivalent to the last intrauterine trimester and beyond have higher circulating DHA and transiently higher visual acuity compared with infants fed formulas containing linolenic acid. In term infants several nonrandomized studies of infants receiving DHA from human milk suggest a relationship between DHA status and acuity, but the evidence for a cause-and-effect relationship is mixed. In the present study, term infants were randomly assigned to a standard term formula (n = 20) or the same formula with egg yolk lecithin to provide DHA (0.1%) and arachidonic acid (AA, 20:4n-6, 0.43%) (n = 19) at levels reported in milk of American women. A third group of infants was breast fed for > or = 3 mo (n = 19). Grating visual acuity (Teller Acuity Card procedure) and plasma and red blood cell (RBC) phosphatidylcholine (PC) and phosphatidylethanolamine (PE) DHA and AA were determined at corrected ages of 2, 4, 6, 9 (acuity only), and 12 mo past term = 40 wk postmenstrual age (PMA). At 2 mo breast-fed infants and infants fed the supplemented formula had higher grating acuity than term infants fed standard formula. As in preterm infants, the increase was transient. Plasma PC DHA and AA and RBC PE AA increased by 2 mo in supplemented infants, but RBC PE DHA in supplemented infants was not higher than in controls until 4 mo and beyond. Despite normal intrauterine accumulation of DHA and AA, infants fed formula with 2% linolenic acid and 0.1% DHA had better 2-mo visual acuity than infants fed formula with 2% linolenic acid.

Role of Arachidonic Acid in Promoting Hair Growth

PubMed Central

Munkhbayar, Semchin; Jang, Sunhyae; Cho, A-Ri; Choi, Soon-Jin; Shin, Chang Yup; Eun, Hee Chul; Kim, Kyu Han

2016-01-01

Background Arachidonic acid (AA) is an omega-6 polyunsaturated fatty acid present in all mammalian cell membranes, and involved in the regulation of many cellular processes, including cell survival, angiogenesis, and mitogenesis. The dermal papilla, composed of specialized fibroblasts located in the bulb of the hair follicle, contributes to the control of hair growth and the hair cycle. Objective This study investigated the effect of AA on hair growth by using in vivo and in vitro models. Methods The effect of AA on human dermal papilla cells (hDPCs) and hair shaft elongation was evaluated by MTT assay and hair follicle organ culture, respectively. The expression of various growth and survival factors in hDPCs were investigated by western blot or immunohistochemistry. The ability of AA to induce and prolong anagen phase in C57BL/6 mice was analyzed. Results AA was found to enhance the viability of hDPCs and promote the expression of several factors responsible for hair growth, including fibroblast growth factor-7 (FGF-7) and FGF-10. Western blotting identified the role of AA in the phosphorylation of various transcription factors (ERK, CREB, and AKT) and increased expression of Bcl-2 in hDPCs. In addition, AA significantly promoted hair shaft elongation, with increased proliferation of matrix keratinocytes, during ex vivo hair follicle culture. It was also found to promote hair growth by induction and prolongation of anagen phase in telogen-stage C57BL/6 mice. Conclusion This study concludes that AA plays a role in promoting hair growth by increasing the expression of growth factors in hDPCs and enhancing follicle proliferation and survival. PMID:26848219

Arachidonic acid metabolites follow the preferential course of cyclooxygenase pathway for the basal tone in the internal anal sphincter.

PubMed

de Godoy, Márcio A F; Rattan, Neeru; Rattan, Satish

2009-04-01

Present studies determined the roles of the cyclooxygenase (COX) versus the lipoxygenase (LO) pathways in the metabolic pathway of arachidonic acid (AA) in the internal anal sphincter (IAS) tone. Studies were performed in the rat IAS versus the nontonic rectal smooth muscle (RSM). Indomethacin, the dual COX inhibitor, but not nordihydroguaiaretic acid (NDGA), the LO inhibitor, produced a precipitous decrease in the IAS tone. However, when added in the background of indomethacin, NDGA caused significant reversal of the IAS tone. These inhibitors had no significant effect on the RSM. To follow the significance of COX versus LO pathways, we examined the effects of AA and its metabolites. In the IAS, AA caused an increase in the IAS tone (Emax=38.8+/-3.0% and pEC50=3.4+/-0.1). In the RSM, AA was significantly less efficacious and potent (Emax=11.3+/-3.5% and pEC50=2.2+/-0.3). The AA metabolites (via COXs) PGF2alpha and U-46619 (a stable analog of thromboxane A2) produced increases in the IAS tone and force in the RSM. Conversely, AA metabolites (via 5-LO) lipoxin A4, 5-HETE, and leukotriene C4 decreased the IAS tone. Finally, the contractile effects of AA in the IAS were selectively attenuated by the COX-1 but not the COX-2 inhibitor. Collectively, the specific effects of AA and the COX inhibitor, the Western blot and RT-PCR analyses showing specifically higher levels of COX-1, suggest a preferential role of the COX (specifically COX-1) pathway versus the LO in the regulation of the IAS tone.

Preparation and Properties of Ethylene Vinyl Acetate Copolymer/Silica Nanocomposites in Presence of EVA-g-Acrylic Acid.

PubMed

Tham, Do Quang; Tuan, Vu Manh; Thanh, Dinh Thi Mai; Chinh, Nguyen Thuy; Giang, Nguyen Vu; Trang, Nguyen Thi Thu; Hang, To Thi Xuan; Huong, Ho Thu; Dung, Nguyen Thi Kim; Hoang, Thai

2015-04-01

Here we report a facile approach to enhance the dispersibility of ethylene vinyl acetate copolymer (EVA)/silica nanocomposites (for the EVA/silica nanocomposites and interaction between silica nanoparticles (nanosilica) and EVA by adding EVA-g-acrylic acid (EVAgAA) as a compatibilizer, which was formed by grafting acrylic acid onto EVA chains with the aid of dicumyl peroxide). The above nanocomposites with and without EVAgAA were prepared by melt mixing in a Haake intermixer with different contents of silica and EVAgAA. Their structure and morphology were characterized by Fourier transform infra-red (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and the mechanical, rheological, dielectrical, and flammability properties of the nanocomposites were also investigated. The FT-IR spectra of the nanocomposites confirmed the formation of hydrogen bonds between the surface silanol groups of nanosilica and C=O groups of EVA and/or EVAgAA. The presence of EVAgAA remarkably increased the intensity of hydrogen bonding between nanosilica and EVA which not only enhanced the dispersion of nanosilica in EVA matrix but also increased the mechanical, viscosity and storage modulus of EVA/silica nanocomposites. In addition, the flammability of EVA/silica nanocomposites is also significantly reduced after the functionalization with EVAgAA. However, the mechanical properties of EVA/silica nanocomposites tended to level off when its content was above 1.5 wt.%. It has also been found that the dielectric constant value of the EVA/EVAgAA/silica nanocomposites is much lower than that of the EVA/silica nanocomposites, which is another evidence of the hydrogen bonding formation between EVAgAA and nanosilica.

Acanthoic acid protectsagainst ethanol-induced liver injury: Possible role of AMPK activation and IRAK4 inhibition.

PubMed

Yao, You-Li; Han, Xin; Song, Jian; Zhang, Jing; Li, Ya-Mei; Lian, Li-Hua; Wu, Yan-Ling; Nan, Ji-Xing

2017-11-05

The aim of this study was to investigate the effects of acanthoic acid (AA) on the regulation of inflammatory response, lipid accumulation, and fibrosis via AMPK- IRAK4 signaling against chronic alcohol consumption in mice. Ethanol-induced liver injury was induced in male mice by Lieber-DeCarli diet for 28d. And mice in AA groups were gavaged with AA (20 or 40mg/kg) for 28d. AA treatment significantly decreased serum AST and TG, hepatic TG levels, serum ethanol and LPS levels compared with chronic ethanol administration. AA ameliorated histological changes, lipid droplets, hepatic fibrosis, and inflammation induced by ethanol. AA significantly increased the expressions of p-LKB1, p-AMPK, and SIRT1 caused by chronic ethanol administration, and attenuated the increasing protein expressions of IRAK1 and IRAK4.siRNA against AMPKα1 blocked AMPKα1 and increased IRAK4 protein expressions, compared with control-siRNA-transfected group, while AA treatment significantly decreased IRAK4 expressions compared with AMPKα1-siRNA-transfected group. AMPK-siRNA also blocked the decreased effect of AA on inflammatory factors. AA decreased over-expression of IRAK4 and inflammation under ethanol plus LPS challenge. AA recruited LKB1-AMPK phosphorylation and activated SIRT1 to regulate alcoholic liver injury, especially, inhibited IRAK1/4 signaling pathway to regulate lipid metabolism, hepatic fibrosis and inflammation caused by alcohol consumption. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancement of myofibrillar proteolysis following infusion of amino acid mixture correlates positively with elevation of core body temperature in rats.

PubMed

Yamaoka, Ippei; Mikura, Mayumi; Nishimura, Masuhiro; Doi, Masako; Kawano, Yuichi; Nakayama, Mitsuo

2008-12-01

Administration of an amino acid (AA) mixture stimulates muscle protein synthesis and elevates core body temperature (T(b)), as characteristically found under anesthetic conditions. We tested the hypothesis that not only AA given, but also AA produced by degradation of endogenous muscular protein are provided for muscle protein synthesis, which is further reflected in T(b) modifications. Rats were intravenously administered an AA mixture or saline in combination with the anesthetic propofol or lipid emulsion. We measured plasma 3-methylhistidine (MeHis) concentrations as an index of myofibrillar protein degradation, rectal temperature and mRNA expression of atrogin-1, MuRF-1 and ubiquitin in gastrocnemius and soleus muscles of rats following 3 h infusion of test solutions. T(b) did not differ significantly between conscious groups, but was higher in the AA group than in the saline group among anesthetized rats. Plasma MeHis concentrations were higher in the AA group than in the saline group under both conditions. Plasma MeHis levels correlated positively with T(b) of rats under both conditions. AA administration decreased mRNA levels of atrogin-1 and ubiquitin in gastrocnemius muscle and all mRNA levels in soleus muscle. These results suggest that AA administration enhances myofibrillar protein degradation and that the change is a determinant of T(b) modification by AA administration. However, the mechanisms underlying AA administration-associated enhancement of myofibrillar proteolysis remains yet to be determined.

Effects of dexpanthenol on acetic acid-induced colitis in rats

PubMed Central

Cagin, Yasir Furkan; Parlakpinar, Hakan; Vardi, Nigar; Polat, Alaadin; Atayan, Yahya; Erdogan, Mehmet Ali; Tanbek, Kevser

2016-01-01

While the pathogenesis of acetic acid (AA)-induced colitis is unclear, reactive oxygen species are considered to have a significant effect. The aim of the present study was to elucidate the therapeutic potential of dexpanthenol (Dxp) on the amelioration of colitis in rats. Group I (n=8; control group) was intrarectally administered 1 ml saline solution (0.9%); group II [n=8; AA] was administered 4% AA into the colon via the rectum as a single dose for three consecutive days; group III (n=8; AA + Dxp) was administered AA at the same dosage as group II from day 4, and a single dose of Dxp was administered intraperitoneally; and group IV (n=8; Dxp) was administered Dxp similarly to Group III. Oxidative stress and colonic damage were assessed via biochemical and histologic examination methods. AA treatment led to an increase in oxidative parameters and a decrease in antioxidant systems. Histopathological examination showed that AA treatment caused tissue injury and increased caspase-3 activity in the distal colon and triggered apoptosis. Dxp treatment caused biochemical and histopathological improvements, indicating that Dxp may have an anti-oxidant effect in colitis; therefore, Dxp may be a potential therapeutic agent for the amelioration of IBD. PMID:27882101

Effects of dexpanthenol on acetic acid-induced colitis in rats.

PubMed

Cagin, Yasir Furkan; Parlakpinar, Hakan; Vardi, Nigar; Polat, Alaadin; Atayan, Yahya; Erdogan, Mehmet Ali; Tanbek, Kevser

2016-11-01

While the pathogenesis of acetic acid (AA)-induced colitis is unclear, reactive oxygen species are considered to have a significant effect. The aim of the present study was to elucidate the therapeutic potential of dexpanthenol (Dxp) on the amelioration of colitis in rats. Group I (n=8; control group) was intrarectally administered 1 ml saline solution (0.9%); group II [n=8; AA] was administered 4% AA into the colon via the rectum as a single dose for three consecutive days; group III (n=8; AA + Dxp) was administered AA at the same dosage as group II from day 4, and a single dose of Dxp was administered intraperitoneally; and group IV (n=8; Dxp) was administered Dxp similarly to Group III. Oxidative stress and colonic damage were assessed via biochemical and histologic examination methods. AA treatment led to an increase in oxidative parameters and a decrease in antioxidant systems. Histopathological examination showed that AA treatment caused tissue injury and increased caspase-3 activity in the distal colon and triggered apoptosis. Dxp treatment caused biochemical and histopathological improvements, indicating that Dxp may have an anti-oxidant effect in colitis; therefore, Dxp may be a potential therapeutic agent for the amelioration of IBD.

Analysis of amino acids and acyl carnitine profiles in low birth weight, preterm, and small for gestational age neonates.

PubMed

Liu, Qian; Wu, Jing; Shen, Wen; Wei, Ran; Jiang, Jianhui; Liang, Jinqun; Chen, Min; Zhong, Mei; Yin, Aihua

2017-11-01

To analyze the amino acids (AA) and acyl carnitine (AC) profiles in dry blood spot (DBS) specimens of low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA), and to compare the concentration difference of AA and AC with those without above. This is a retrospectively study. Eight thousand nine hundred and seventy-nine uncomplicated pregnant newborns were enrolled into the study. DBS were collected on the third day of life, and concentrations of 11 types of AA, free carnitine and 30 types of AC were detected by using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS). Shapiro-Wilk test and Kruskal-Wallis rank test were applied in statistical analysis. Concentrations of most AA and AC in infants born in SGA were significantly higher than those in non-SGA group, while lower in LBW and PTB groups than those in non-LBW and non-PTB groups (p < 0.05). The difference of concentration of AA and AC in the subgroups suggested there may be a dysutilization of AA and AC in SGA, but an inborn insufficient of AA and AC in LBW and PTB neonates.

Plasma ascorbic acid concentrations in prevalent patients with end-stage renal disease on hemodialysis.

PubMed

Sirover, William D; Liu, Yuguan; Logan, Amanda; Hunter, Krystal; Benz, Robert L; Prasad, Deepali; Avila, Jose; Venkatchalam, Thaliga; Weisberg, Lawrence S; Handelman, Garry J

2015-05-01

To determine the prevalence of vitamin C (ascorbic acid [AA]) deficiency in patients with end-stage renal disease, the effect of supplemental AA on plasma AA concentrations, and the extrinsic and intrinsic factors that affect plasma AA concentrations in this patient population. In study 1, we compared the effect of hemodialysis (HD) on plasma AA concentrations between patients with low and high pre-HD AA concentrations. In study 2, we analyzed kinetic and nonkinetic factors for their association with increased plasma AA concentrations in patients on maintenance HD. Study 1 was performed in a single outpatient HD clinic in Cherry Hill, New Jersey. Study 2 was performed in 4 outpatient HD clinics in Southern New Jersey. In study 1, we collected plasma samples from 8 adult patients on maintenance HD at various time points around their HD treatment and assayed them for AA concentration. In study 2, we enrolled 203 adult patients and measured pre-HD plasma AA concentrations. We ascertained supplemental AA use and assessed dietary AA intake. In study 1, plasma AA concentrations were compared during the intradialytic and interdialytic period. In study 2, pre-HD plasma AA concentrations were correlated with supplement use and demographic factors. Study 1 showed that over the course of a single HD treatment, the plasma AA concentration decreased by a mean (±standard deviation) of 60% (±6.6). In study 2, the median pre-HD plasma AA concentration was 15.7 μM (interquartile range, 8.7-66.8) in patients who did not take a supplement and 50.6 μM (interquartile range, 25.1-88.8) in patients who did take a supplement (P < .001). Supplement use, increasing age, and diabetes mellitus were associated with a pre-HD plasma AA concentration ≥30 μM. HD depletes plasma AA concentrations, and AA supplementation allows patients to achieve higher plasma AA concentrations. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Global Trophic Position Comparison of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses

PubMed Central

Choy, C. Anela; Davison, Peter C.; Drazen, Jeffrey C.; Flynn, Adrian; Gier, Elizabeth J.; Hoffman, Joel C.; McClain-Counts, Jennifer P.; Miller, Todd W.; Popp, Brian N.; Ross, Steve W.; Sutton, Tracey T.

2012-01-01

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry controlling δ15N values at the base of the food web. Trophic positions calculated from amino acid isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP ∼2.9) largely align with expectations from stomach content studies (TP ∼3.2), while AA-TPs for dragonfishes (family Stomiidae) (AA-TP ∼3.2) were lower than TPs derived from stomach content studies (TP∼4.1). We demonstrate that amino acid nitrogen isotope analysis can overcome shortcomings of bulk tissue isotope analysis across biogeochemically distinct systems to provide globally comparative information regarding marine food web structure. PMID:23209656

Global trophic position comparison of two dominant mesopelagic fish families (Myctophidae, Stomiidae) using amino acid nitrogen isotopic analyses

USGS Publications Warehouse

Choy, C. Anela; Davison, Peter C.; Drazen, Jeffrey C.; Flynn, Adrian; Gier, Elizabeth J.; Hoffman, Joel C.; McClain-Counts, Jennifer P.; Miller, Todd W.; Popp, Brian N.; Ross, Steve W.; Sutton, Tracey T.

2012-01-01

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry controlling δ15N values at the base of the food web. Trophic positions calculated from amino acid isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP ~2.9) largely align with expectations from stomach content studies (TP ~3.2), while AA-TPs for dragonfishes (family Stomiidae) (AA-TP ~3.2) were lower than TPs derived from stomach content studies (TP~4.1). We demonstrate that amino acid nitrogen isotope analysis can overcome shortcomings of bulk tissue isotope analysis across biogeochemically distinct systems to provide globally comparative information regarding marine food web structure.

Fatty acid composition of plasma and erythrocytes in term infants fed human milk and formulae with and without docosahexaenoic and arachidonic acids from egg yolk lecithin.

PubMed

Bondía-Martínez, E; López-Sabater, M C; Castellote-Bargalló, A I; Rodríguez-Palmero, M; González-Corbella, M J; Rivero-Urgell, M; Campoy-Folgoso, C; Bayés-García, R

1998-12-01

Human milk contains small but nutritionally significant amounts of long-chain polyunsaturated fatty acids (LCP), such as arachidonic (AA, 20:4n-6) and docosahexaenoic (DHA, 22:6n-3) acids, which are not present in most infant formulae. In the present study, the fatty acid composition of plasma and erythrocytes was determined at birth and again at 7 days, 1 and 3 months in 49 healthy full-term infants (37-42 week's gestation). One group of infants was fed exclusively with human milk (n=16) and the others were randomly assigned to a standard term formula (F) (n=15) or the same formula with egg yolk lecithin providing DHA (0.15%) and AA (0.30%) (LCP-F) (n=18). Plasma and erythrocyte LCP values of the three dietary groups did not differ at 7 days of age, but the contents of DHA and AA in plasma and erythrocytes at 1 and 3 months were significantly lower (P<0.05) in infants fed non supplemented formula than in infants fed breast milk and supplemented formula. There were no differences in plasma or erythrocyte AA or DHA concentrations between the group fed breast milk and the group fed supplemented formula during the period studied.

IMAGING BRAIN SIGNAL TRANSDUCTION AND METABOLISM VIA ARACHIDONIC AND DOCOSAHEXAENOIC ACID IN ANIMALS AND HUMANS

PubMed Central

Basselin, Mireille; Ramadan, Epolia; Rapoport, Stanley I.

2012-01-01

The polyunsaturated fatty acids (PUFAs), arachidonic acid (AA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), important second messengers in brain, are released from membrane phospholipid following receptor-mediated activation of specific phospholipase A2 (PLA2) enzymes. We developed an in vivo method in rodents using quantitative autoradiography to image PUFA incorporation into brain from plasma, and showed that their incorporation rates equal their rates of metabolic consumption by brain. Thus, quantitative imaging of unesterified plasma AA or DHA incorporation into brain can be used as a biomarker of brain PUFA metabolism and neurotransmission. We have employed our method to image and quantify effects of mood stabilizers on brain AA/DHA incorporation during neurotransmission by muscarinic M1,3,5, serotonergic 5-HT2A/2C, dopaminergic D2-like (D2, D3, D4) or glutamatergic N-methyl-D-aspartic acid (NMDA) receptors, and effects of inhibition of acetylcholinesterase, of selective serotonin and dopamine reuptake transporter inhibitors, of neuroinflammation (HIV-1 and lipopolysaccharide) and excitotoxicity, and in genetically modified rodents. The method has been extended for the use with positron emission tomography (PET), and can be employed to determine how human brain AA/DHA signaling and consumption are influenced by diet, aging, disease and genetics. PMID:22178644

Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin

PubMed Central

Brines, Michael; Patel, Nimesh S. A.; Villa, Pia; Brines, Courtenay; Mennini, Tiziana; De Paola, Massimiliano; Erbayraktar, Zubeyde; Erbayraktar, Serhat; Sepodes, Bruno; Thiemermann, Christoph; Ghezzi, Pietro; Yamin, Michael; Hand, Carla C.; Xie, Qiao-wen; Coleman, Thomas; Cerami, Anthony

2008-01-01

Erythropoietin (EPO), a member of the type 1 cytokine superfamily, plays a critical hormonal role regulating erythrocyte production as well as a paracrine/autocrine role in which locally produced EPO protects a wide variety of tissues from diverse injuries. Significantly, these functions are mediated by distinct receptors: hematopoiesis via the EPO receptor homodimer and tissue protection via a heterocomplex composed of the EPO receptor and CD131, the β common receptor. In the present work, we have delimited tissue-protective domains within EPO to short peptide sequences. We demonstrate that helix B (amino acid residues 58–82) of EPO, which faces the aqueous medium when EPO is bound to the receptor homodimer, is both neuroprotective in vitro and tissue protective in vivo in a variety of models, including ischemic stroke, diabetes-induced retinal edema, and peripheral nerve trauma. Remarkably, an 11-aa peptide composed of adjacent amino acids forming the aqueous face of helix B is also tissue protective, as confirmed by its therapeutic benefit in models of ischemic stroke and renal ischemia–reperfusion. Further, this peptide simulating the aqueous surface of helix B also exhibits EPO's trophic effects by accelerating wound healing and augmenting cognitive function in rodents. As anticipated, neither helix B nor the 11-aa peptide is erythropoietic in vitro or in vivo. Thus, the tissue-protective activities of EPO are mimicked by small, nonerythropoietic peptides that simulate a portion of EPO's three-dimensional structure. PMID:18676614

Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin.

PubMed

Brines, Michael; Patel, Nimesh S A; Villa, Pia; Brines, Courtenay; Mennini, Tiziana; De Paola, Massimiliano; Erbayraktar, Zubeyde; Erbayraktar, Serhat; Sepodes, Bruno; Thiemermann, Christoph; Ghezzi, Pietro; Yamin, Michael; Hand, Carla C; Xie, Qiao-wen; Coleman, Thomas; Cerami, Anthony

2008-08-05

Erythropoietin (EPO), a member of the type 1 cytokine superfamily, plays a critical hormonal role regulating erythrocyte production as well as a paracrine/autocrine role in which locally produced EPO protects a wide variety of tissues from diverse injuries. Significantly, these functions are mediated by distinct receptors: hematopoiesis via the EPO receptor homodimer and tissue protection via a heterocomplex composed of the EPO receptor and CD131, the beta common receptor. In the present work, we have delimited tissue-protective domains within EPO to short peptide sequences. We demonstrate that helix B (amino acid residues 58-82) of EPO, which faces the aqueous medium when EPO is bound to the receptor homodimer, is both neuroprotective in vitro and tissue protective in vivo in a variety of models, including ischemic stroke, diabetes-induced retinal edema, and peripheral nerve trauma. Remarkably, an 11-aa peptide composed of adjacent amino acids forming the aqueous face of helix B is also tissue protective, as confirmed by its therapeutic benefit in models of ischemic stroke and renal ischemia-reperfusion. Further, this peptide simulating the aqueous surface of helix B also exhibits EPO's trophic effects by accelerating wound healing and augmenting cognitive function in rodents. As anticipated, neither helix B nor the 11-aa peptide is erythropoietic in vitro or in vivo. Thus, the tissue-protective activities of EPO are mimicked by small, nonerythropoietic peptides that simulate a portion of EPO's three-dimensional structure.

Ameliorative effect of vitamin C against hepatotoxicity induced by emamectin benzoate in rats.

PubMed

Khaldoun Oularbi, H; Richeval, C; Lebaili, N; Zerrouki-Daoudi, N; Baha, M; Djennas, N; Allorge, D

2017-07-01

In the present study, we aimed to assess the potential protective effect of ascorbic acid (AA) against emamectin benzoate (EMB)-induced hepatotoxicity. For this purpose, biochemical, histopathological and analytical investigations were performed. Male Wistar rats were distributed into three groups, that is, a control group, an EMB group given 10 mg EMB/kg body weight (BW) by gavage and an EMB + AA group given 10 mg EMB/kg BW and vitamin C intraperitoneally (200 mg/kg). The duration of the treatment was 28 days and the duration of the study was 42 days. There was a statistically significant increase of all hepatic biomarkers, that is, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyltransferase activities, and glycemia, in EMB-treated group when compared with the control group. Light microscopic observations revealed variable signs of hepatotoxicity in the EMB group, which were represented by alteration of normal hepatic architecture, inflammatory cell infiltration, hepatocellular steatosis and foci of necrosis at 28 and 42 days post-treatment. However, co-treatment with vitamin C reduced EMB-related liver toxicity and diminished the abnormal biochemical and architectural damage. Emamectin B1a and B1b residues were detectable in all plasma samples of treated rats at 14, 21 and 28 days of treatment. The drug liver tissue concentration was significantly lower in EMB + AA group compared with EMB group at 28 and 42 days. In conclusion, the findings of the present study clearly indicate a significant protective action of vitamin C against EMB hepatotoxicity.

Effects of the Chemical Structures of Oligoarginines Conjugated to Biocompatible Polymers as a Mucosal Adjuvant on Antibody Induction in Nasal Cavities.

PubMed

Mohri, Kohta; Miyata, Kohei; Egawa, Tomomi; Tanishita, Sohei; Endo, Rikito; Yagi, Haruya; Ukawa, Masami; Ochiai, Kyohei; Hiwatari, Ken-Ichiro; Tsubaki, Kazufumi; Shigeno, Koichi; Tobita, Etsuo; Uto, Tomofumi; Baba, Masanori; Sakuma, Shinji

2018-01-01

We have been investigating the potential of oligoarginine-linked polymers as an adjuvant for mucosal vaccination that induces immunoglobulin G (IgG) in systemic circulation and immunoglobulin A (IgA) secreted on the mucosa. Our latest infection experiments demonstrated that mice immunized nasally with a mixture of inactivated influenza viruses and poly(N-vinylacetamide-co-acrylic acid) (PNVA-co-AA) modified with D-octaarginine were perfectly protected from homologous virus infection. On the contrary, virus infection was observed in mice immunized with the antigen alone. This difference was presumably due to insignificant induction of secreted IgA on the nasal mucosa in the latter mice. Since it was unclear whether the current induction level was sufficient for heterologous virus infection, we evaluated the effects of the chemical structures of oligoarginines conjugated to PNVA-co-AA on induction of intranasal IgA. The number and optical activity of the arginine residues and the degree of modification with oligoarginines in the polymer backbone were listed as a factor that would influence IgA induction. Mouse experiments revealed that maximization of the modification resulted in an increase in adjuvant activities of oligoarginine-linked polymers most effectively. Glycine segments inserted between oligoarginines and the polymer backbone were a prerequisite for the maximization. The highest IgA level was observed when antigens were coadministered with diglycine-D-octaarginine-linked PNVA-co-AA.

Identification of critical residues in Hepatitis E virus macro domain involved in its interaction with viral methyltransferase and ORF3 proteins

PubMed Central

Anang, Saumya; Subramani, Chandru; Nair, Vidya P.; Kaul, Sheetal; Kaushik, Nidhi; Sharma, Chandresh; Tiwari, Ashutosh; Ranjith-Kumar, CT; Surjit, Milan

2016-01-01

Hepatitis E virus (HEV) is a major cause of hepatitis in normal and organ transplant individuals. HEV open reading frame-1 encodes a polypeptide comprising of the viral nonstructural proteins as well as domains of unknown function such as the macro domain (X-domain), V, DUF3729 and Y. The macro domain proteins are ubiquitously present from prokaryotes to human and in many positive-strand RNA viruses, playing important roles in multiple cellular processes. Towards understanding the function of the HEV macro domain, we characterized its interaction partners among other HEV encoded proteins. Here, we report that the HEV X-domain directly interacts with the viral methyltransferase and the ORF3 proteins. ORF3 association with the X-domain was mediated through two independent motifs, located within its N-terminal 35aa (amino acids) and C-terminal 63-123aa. Methyltransferase interaction domain was mapped to N-terminal 30-90aa. The X-domain interacted with both ORF3 and methyltransferase through its C-terminal region, involving 66th,67th isoleucine and 101st,102nd leucine, conserved across HEV genotypes. Furthermore, ORF3 and methyltransferase competed with each other for associating with the X-domain. These findings provide molecular understanding of the interaction between the HEV macro domain, methyltransferase and ORF3, suggesting an important role of the macro domain in the life cycle of HEV. PMID:27113483

Broad Range Amino Acid Specificity of RNA-dependent Lipid Remodeling by Multiple Peptide Resistance Factors*

PubMed Central

Roy, Hervé; Ibba, Michael

2009-01-01

Aminoacylphosphatidylglycerol synthases (aaPGSs) are multiple peptide resistance factors that transfer amino acids from aminoacyl-tRNAs to phosphatidylglycerol (PG) in the cytoplasmic membrane. Aminoacylation of PG is used by bacteria to decrease the net negative charge of the cell envelope, diminishing affinity for charged molecules and allowing for adaptation to environmental changes. Lys-PGS, which transfers lysine to PG, is essential for the virulence of certain pathogens, providing resistance to both host cationic antimicrobial peptides and therapeutic antibiotics. Ala-PGS was also recently described, but little is known about the possible activities of other members of the highly diverse aaPGS family of proteins. Systematic deletion of the predicted membrane-inserted domains of several aaPGSs revealed that the carboxyl-terminal hydrophilic domain alone is sufficient for aminoacylphosphatidylglycerol transferase catalytic activity. In contrast to previously characterized aaPGSs, the Enterococcus faecium enzyme used an expanded repertoire of amino acids to modify PG with Ala, Arg, or Lys. Reexamination of previously characterized aaPGSs also revealed broader than anticipated substrate specificity, for example Bacillus subtilis Lys-PGS was shown to also catalyze Ala-PG synthesis. The relaxed substrate specificities of these aaPGSs allows for more elaborate remodeling of membrane lipids than previously thought, potentially providing bacteria that harbor these enzymes resistance to a broad spectrum of antibiotics and environmental stresses. PMID:19734140

Pharmacokinetics of aniracetam and its metabolites in rat brain.

PubMed

Ogiso, T; Uchiyama, K; Suzuki, H; Yoshimoro, M; Tanino, T; Iwakai, M; Uno, S

2000-04-01

The pharmacokinetics of aniracetam (AP) and its main metabolites, 4-p-anisamidobutyric acid (ABA), 2-pyrrolidinone (PD) and p-anisic acid (AA), in 3 brain regions (cerebral cortex, hippocampus and thalamus) was investigated after single intravenous (i.v.) and oral administrations of AP to rats. AP, AA and PD were rapidly distributed into the 3 brain regions after i.v. administration of AP, but the amounts of AP were low. The concentrations of AP and AA in brain regions rapidly declined, whereas PD levels were higher and more sustained than those of AP and AA. ABA levels in the regions were below the detection limit. There were no significant differences in the distribution of these compounds in the 3 brain regions. The AUCbrain/AUCplasma ratio of PD was 53--55%, in contrast to the low ratio of AP (2.4--3.2%) and AA (3.9--4.2%). On oral administration of AP, the AUCbrain/AUCplasma ratio of PD was also higher than that of AA. When the transport of PD was tested using the in situ brain perfusion technique, it was clarified that PD was not transported across the blood-brain barrier (BBB) by a neutral amino acid carrier system. The high brain levels of PD and the low levels of AP suggest that the clinical efficacy of dosed AP may partly result from PD penetrating into the brain.

Biogeochemistry of Dimethylsulfide, Dimethylsulfoniopropionate, and Acrylic Acid in the Changjiang Estuary and the East China Sea

NASA Astrophysics Data System (ADS)

Wu, Xi; Li, Pei-Feng; Liu, Chun-Ying; Zhang, Hong-Hai; Yang, Gui-Peng; Zhang, Sheng-Hui; Zhu, Mao-Xu

2017-12-01

The distributions of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), and acrylic acid (AA) were investigated in the Changjiang Estuary during winter (dry season) and summer (wet season) 2014 and in the East China Sea (ECS) during summer 2015. The rates of dissolved DMSP (DMSPd) degradation with DMS and AA production, DMS degradation, and AA degradation in the ECS were also studied. Significant seasonal variations in DMS(P) and AA concentrations were observed in the Changjiang Estuary with higher values during the wet season than during the dry season. The maximum ratio of AA/chlorophyll a (Chl a) occurred at the mouth of the Changjiang Estuary due to the combined effects of production from DMSP and terrestrial inputs from the Changjiang Estuary. The distributions of DMS(P) and AA in the ECS were dramatically influenced by the Kuroshio Current and the upwelling caused by the Taiwan Warm Current. The ratios of DMS(P)/Chl a and AA/Chl a exhibited similar patterns in the surface seawater of the ECS, which indicated that phytoplankton species and biomass might play important roles in controlling the distributions of DMS(P) and AA. In vertical profiles, high values of AA emerged in the upper water column and bottom seawater of the Changjiang Estuary. Meanwhile, the maxima of DMS(P) and AA generally appeared in the surface or euphotic layer, whereas their minima arose in the bottom seawater of the ECS. The degradation rates of DMSPd, DMS, and AA in the inshore waters were higher than those in the open sea.

Bicarbonate and amino acids are co-germinants for spores of Clostridium perfringens type A isolates carrying plasmid-borne enterotoxin gene.

PubMed

Alnoman, Maryam; Udompijitkul, Pathima; Banawas, Saeed; Sarker, Mahfuzur R

2018-02-01

Clostridium perfringens type A isolates carrying a chromosomal enterotoxin (cpe) gene (C-cpe) are generally linked to food poisoning, while isolates carrying cpe on a plasmid (P-cpe) are associated with non-food-borne gastrointestinal diseases. Both C-cpe and P-cpe isolates can form metabolically dormant spores, which through germination process return to actively growing cells to cause diseases. In our previous study, we showed that only 3 out of 20 amino acids (aa) in phosphate buffer (pH 7.0) triggered germination of spores of P-cpe isolates (P-cpe spores). We now found that 14 out of 20 individual aa tested induced germination of P-cpe spores in the presence of bicarbonate buffer (pH 7.0). However, no significant spore germination was observed with bicarbonate (pH 7.0) alone, indicating that aa and bicarbonate are co-germinants for P-cpe spores. P-cpe strain F4969 gerKC spores did not germinate, and gerAA spores germinated extremely poorly as compared to wild-type and gerKA spores with aa-bicarbonate (pH 7.0) co-germinants. The germination defects in gerKC and gerAA spores were partially restored by complementing gerKC or gerAA spores with wild-type gerKC or gerAA, respectively. Collectively, this study identified aa-bicarbonate as a novel nutrient germinant for P-cpe spores and provided evidence that GerKC and GerAA play major roles in aa-bicarbonate induced germination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic cooperation of ascorbic acid and glutathione in normal and vitamin C-deficient ODS rats.

PubMed

Wang, Y; Kashiba, M; Kasahara, E; Tsuchiya, M; Sato, E F; Utsumi, K; Inoue, M

2001-01-01

Although the coordination of various antioxidants is important for the protection of organisms from oxidative stress, dynamic aspects of the interaction of endogenous antioxidants in vivo remain to be elucidated. We studied the metabolic coordination of two naturally occurring water-soluble antioxidants, ascorbic acid (AA) and reduced glutathione (GSH), in liver, kidney and plasma of control and scurvy-prone osteogenic disorder Shionogi (ODS) rats that hereditarily lack the ability to synthesize AA. When supplemented with AA, its levels in liver and kidney of ODS rats increased to similar levels of those in control rats. Hepato-renal levels of glutathione were similar with the two animal groups except for the slight increase in its hepatic levels in AA-supplemented ODS rats. Administration of L-buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, rapidly decreased the hepato-renal levels of glutathione in a biphasic manner, a rapid phase followed by a slower phase. Kinetic analysis revealed that glutathione turnover was enhanced significantly in liver mitochondria and renal cytosol of ODS rats. Administration of BSO significantly increased AA levels in the liver and kidney of control rats but decreased them in AA-supplemented ODS rats. Kinetic analysis revealed that AA is synthesized by control rat liver by some BSO-enhanced mechanism and the de novo synthesized AA is transferred to the kidney. Such a coordination of the metabolism of GSH and AA in liver and kidney is suppressed in AA-deficient ODS rats. These and other results suggest that the metabolism of AA and GSH forms a compensatory network by which oxidative stress can be decreased.

A Novel Di-Leucine Motif at the N-Terminus of Human Organic Solute Transporter Beta Is Essential for Protein Association and Membrane Localization.

PubMed

Xu, Shuhua; Soroka, Carol J; Sun, An-Qiang; Backos, Donald S; Mennone, Albert; Suchy, Frederick J; Boyer, James L

2016-01-01

The heteromeric membrane protein Organic Solute Transporter alpha/beta is the major bile acid efflux transporter in the intestine. Physical association of its alpha and beta subunits is essential for their polarized basolateral membrane localization and function in the transport of bile acids and other organic solutes. We identified a highly conserved acidic dileucine motif (-EL20L21EE) at the extracellular amino-tail of organic solute transporter beta from multiple species. To characterize the role of this protein interacting domain in the association of the human beta and alpha subunits and in membrane localization of the transporter, Leu20 and Leu21 on the amino-tail of human organic solute transporter beta were replaced with alanines by site-directed mutagenesis. Co-immunoprecipitation study in HEK293 cells demonstrated that substitution of the leucine residues with alanines prevented the interaction of the human beta mutant with the alpha subunit. Membrane biotinylation demonstrated that the LL/AA mutant eliminated membrane expression of both subunits. Computational-based modelling of human organic solute transporter beta suggested that the LL/AA mutation substantially alters both the structure and lipophilicity of the surface, thereby not only affecting the interaction with the alpha subunit but also possibly impacting the capacity of the beta subunit to traffick through the cell and interact with the membrane. In summary, our findings indicate that the dileucine motif in the extracellular N-terminal region of human organic solute transporter beta subunit plays a critical role in the association with the alpha subunit and in its polarized plasma membrane localization.

Association of polyunsaturated fatty acids in breast milk with fatty acid desaturase gene polymorphisms among Chinese lactating mothers.

PubMed

Ding, Zhen; Liu, Guo-Liang; Li, Xiang; Chen, Xue-Yan; Wu, Yi-Xia; Cui, Can-Can; Zhang, Xi; Yang, Guang; Xie, Lin

2016-06-01

The fatty acid desaturase (FADS) controls polyunsaturated fatty acid (PUFA) synthesis in human tissues and breast milk. Evaluate the influence of 10 single nucleotide polymorphisms (SNPs) and various haplotypes in the FADS gene cluster (FADS1, FADS2, FADS3) on PUFA concentration in the breast milk of 209 healthy Chinese women. PUFA concentrations were measured in breast milk using gas chromatography and genotyping was performed using the Sequenom Mass Array system. A SNP (rs1535) and 2-locus haplotypes (rs3834458-rs1535, rs1535-rs174575) in the FADS2 gene were associated with concentrations of γ-linoleic acid (GLA) and arachidonic acid (AA) in breast milk. Likewise, in the FADS1 gene, a 2-locus constructed haplotype (rs174547-rs174553) also affected GLA and AA concentration (P<0.05 for all). Minor allele carriers of the SNP and haplotypes described above had lower concentrations of GLA and AA. In the FADS2 gene, the 3-locus haplotype rs3834458-rs1535-rs174575, significantly affected concentrations of GLA but not AA. Pairwise comparison showed that individuals major homozygous for the SNP rs1000778 in the FADS3 gene had lower concentrations of ALA and linoleic acid (LA) in their breast milk. Polymorphisms in the FADS gene cluster influence PUFA concentrations in the breast milk of Chinese Han lactating women. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics and anti-proliferative activity of azelaic acid and its derivatives entrapped in bilayer vesicles in cancer cell lines.

PubMed

Manosroi, Aranya; Panyosak, Atchara; Rojanasakul, Yon; Manosroi, Jiradej

2007-06-01

The hydrophilicity and lipophilicity of azelaic acid (AA) were modified to diethyl azelate (DA) which was synthesized by Fisher esterification reaction and identified by IR, MS and (1)H NMR and to azelaic acid-beta-cyclodextrin complex (AACD) which was prepared by inclusion complexation and identified by IR, DSC and XRD respectively. AA, DA and AACD were entrapped in liposomes and niosomes comprising of L-alpha-dipalmitoyl phosphatidylcholine (DPPC)/cholesterol at 7:3 molar ratio and Tween61/cholesterol at 1:1 molar ratio, respectively, using a thin-film hydration method with sonication. The size and morphology of these bilayer vesicles were determined by optical and transmission electron microscopy. The particle size was found to be in the range of 90-190 nm. The entrapment efficiency of AA, DA and AACD in all vesicular formulations was more than 80%, as analyzed by HPLC for AA and AACD, and GC for DA. Anti-proliferative activity of AA and its derivatives (DA and AACD) both entrapped and not entrapped in bilayer vesicles, using MTT assay in three cancer cell lines (HeLa, KB and B(16)F(10)) comparing with vincristine, were investigated. AACD showed the highest potency comparing to AA in HeLa, KB and B(16)F(10) of 1.48, 1.6 and 1.5 times, respectively. AA entrapped in liposomes was about 90 times more potent than the free AA, and about 1.5 times less potent than vincristine. When entrapped in bilayer vesicles, DA and AACD were more effective than AA in killing cancer cells. AACD entrapped in liposomes gave the highest anti-proliferation activity in HeLa cell lines with the IC(50) of 2.3 and 327 times more potent than vincristine and AA, respectively. DA in liposomes demonstrated the IC(50) of 0.03 times less potent than vincristine in KB cell lines, while in B(16)F(10) AACD in niosomes showed the IC(50) of 0.05 times less potent than vincristine. This study has suggested that the modification of AA by derivatization and complexation as well as the entrapment in bilayer vesicles can enhance its therapeutic efficacy.

The controlled preparation of polypyrrole nanostructures via tuning the concentration of acrylic acid.

PubMed

Wang, Yujie; Zhong, Wenbin; Ning, Xutao; Li, Yuntao; Chen, Xiaohua; Wang, Yongxin; Yang, Wantai

2013-03-01

Two types of nanostructures, nanowires and nanoribbons were prepared with polypyrrole (PPy) by controlling the concentration of acrylic acid (AA) in systems containing cationic surfactant, cetyltrimethylammonium bromide (CTAB) at about 12 degrees C. The effect of reaction conditions involving the concentration of AA, CTAB, pyrrole as well as the reaction temperature was systematically studied on the final structures of prepared PPy. The results revealed that the polymerization of AA, resulting in PAA, played a key role in the evolution of PPy nanostructures. A possible mechanism was briefly discussed on the formation of these two nanostructures, nanowires and nanoribbons.

Amino acid and carbohydrate tradeoffs by honey bee nectar foragers and their implications for plant-pollinator interactions.

PubMed

Hendriksma, Harmen P; Oxman, Karmi L; Shafir, Sharoni

2014-10-01

Honey bees are important pollinators, requiring floral pollen and nectar for nutrition. Nectar is rich in sugars, but contains additional nutrients, including amino acids (AAs). We tested the preferences of free-flying foragers between 20 AAs at 0.1% w/w in sucrose solutions in an artificial meadow. We found consistent preferences amongst AAs, with essential AAs preferred over nonessential AAs. The preference of foragers correlated negatively with AA induced deviations in pH values, as compared to the control. Next, we quantified tradeoffs between attractive and deterrent AAs at the expense of carbohydrates in nectar. Bees were attracted by phenylalanine, willing to give up 84units sucrose for 1unit AA. They were deterred by glycine, and adding 100 or more units of sucrose could resolve to offset 1unit AA. In addition, we tested physiological effects of AA nutrition on forager homing performance. In a no-choice context, caged bees showed indifference to 0.1% proline, leucine, glycine or phenylalanine in sucrose solutions. Furthermore, flight tests gave no indication that AA nutrition affected flight capacity directly. In contrast, low carbohydrate nutrition reduced the performance of bees, with important methodological implications for homing studies that evaluate the effect of substances that may affect imbibition of sugar solution. In conclusion, low AA concentrations in nectar relative to pollen suggest a limited role in bee nutrition. Most of the 20 AAs evoked a neutral to a mild deterrent response in bees, thus it seems unlikely that bees respond to AAs in nectar as a cue to assess nutritional quality. Nonetheless, free choice behavior of foraging bees is influenced, for instance by phenylalanine and glycine. Thus, AAs in nectar may affect plant-pollinator interactions and thereby exhibit a selective pressure on the flora in the honey bee habitat. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis of organic/inorganic hybrid gel with acid activated clay after γ-ray radiation.

PubMed

Kim, Donghyun; Lee, Hoik; Sohn, Daewon

2014-08-01

A hybrid gel was prepared from acid activated clay (AA clay) and acrylic acid by gamma ray irradiation. Irradiated inorganic particles which have peroxide groups act as initiator because it generates oxide radicals by increasing temperature. Inorganic nanoparticles which are rigid part in hybrid gel also contribute to increase the mechanical property as a crosslinker. We prepared two hybrid gels to compare the effect of acid activated treatment of clay; one is synthesized with raw clay particles and another is synthesized with AA clay particles. The composition and structure of AA clay particles and raw clay particles were confirmed by X-ray diffraction (XRD), X-ray fluorescence instrument and surface area analyzer. And chemical and physical property of hybrid gel with different ratios of acrylic acid and clay particle was tested by Raman spectroscope and universal testing machine (UTM). The synthesized hydrogel with 76% gel contents can elongated approximately 1000% of its original size.

Early changes in tissue amino acid metabolism and nutrient routing in rats fed a high-fat diet: evidence from natural isotope abundances of nitrogen and carbon in tissue proteins.

PubMed

Mantha, Olivier L; Polakof, Sergio; Huneau, Jean-François; Mariotti, François; Poupin, Nathalie; Zalko, Daniel; Fouillet, Helene

2018-05-01

Little is known about how diet-induced obesity and insulin resistance affect protein and amino acid (AA) metabolism in tissues. The natural relative abundances of the heavy stable isotopes of C (δ 13C) and N (δ 15N) in tissue proteins offer novel and promising biomarkers of AA metabolism. They, respectively, reflect the use of dietary macronutrients for tissue AA synthesis and the relative metabolic use of tissue AA for oxidation v. protein synthesis. In this study, δ 13C and δ 15N were measured in the proteins of various tissues in young adult rats exposed perinatally and/or fed after weaning with a normal- or a high-fat (HF) diet, the aim being to characterise HF-induced tissue-specific changes in AA metabolism. HF feeding was shown to increase the routing of dietary fat to all tissue proteins via non-indispensable AA synthesis, but did not affect AA allocation between catabolic and anabolic processes in most tissues. However, the proportion of AA directed towards oxidation rather than protein synthesis was increased in the small intestine and decreased in the tibialis anterior muscle and adipose tissue. In adipose tissue, the AA reallocation was observed in the case of perinatal or post-weaning exposure to HF, whereas in the small intestine and tibialis anterior muscle the AA reallocation was only observed after HF exposure that covered both the perinatal and post-weaning periods. In conclusion, HF exposure induced an early reorganisation of AA metabolism involving tissue-specific effects, and in particular a decrease in the relative allocation of AA to oxidation in several peripheral tissues.

Mutational analysis of immunoglobulin E-binding epitopes of beta-casein and beta-lactoglobulin showed a heterogeneous pattern of critical amino acids between individual patients and pooled sera.

PubMed

Cocco, R R; Järvinen, K-M; Han, N; Beyer, K; Sampson, H A

2007-06-01

For immunotherapeutic approaches, 'critical' amino acids (AAs) within allergenic epitopes are replaced with alternate AAs to eliminate IgE antibody binding. To determine the critical AAs for IgE binding in beta-casein and beta-lactoglobulin (BLG). Peptides of 10-14 AAs in length were synthesized on a derivatized cellulose membrane with single AA substitutions (alanine or glycine) at each position. Membranes were incubated with a pool of sera from 15 cow's milk-allergic patients and individual sera from six of the 15 patients. In cases where no decrease in binding occurred with a single AA substitution, peptides with two AA substitutions were generated and labelled. Using pooled patient sera, single AA substitutions led to complete elimination of binding to six of 11 peptides for beta-casein and to all six peptides for BLG. Substituting two AAs led to an elimination of binding to four of the remaining five beta-casein epitopes. However, in three of the 11 modified beta-casein peptides and five of the six BLG peptides, no decrease in IgE binding occurred in at least one individual patient. For these patients, critical AAs other than those defined by the patient serum pool were identified, indicating a heterogeneous pattern of IgE recognition. These results indicate that AAs critical for IgE binding are more heterogeneous than initially defined by pooled milk-allergic patient sera. For future immunotherapeutic interventions with mutated peptides, critical AAs should also be identified with individual patient sera to account for heterogeneity of IgE binding between patients.

[Comparison of long-chain polyunsaturated fatty acids in plasma and erythrocyte phospholipids for biological monitoring].

PubMed

Kawabata, Terue; Nakai, Kunihiko; Hagiwara, Chie; Kurokawa, Naoyuki; Murata, Katsuyuki; Yaginuma, Kozue; Satoh, Hiroshi

2011-01-01

Previous data have indicated that the erythrocyte membrane may be the preferred sample type for assessing long-chain polyunsaturated fatty acid (LCPUFA) contents in cardiac and cerebral membranes. In this epidemiological study, we examined whether plasma phospholipids can be used for accurate biological monitoring of the LCPUFA state or whether analysis of erythrocyte membrane phospholipids is indispensable. (1) The analysis of LCPUFA contents in erythrocyte membrane phospholipids was conducted at baseline and after 1 and 3 days at 4°C, and 21 days at -40°C, after blood drawing, and the changes in LCPUFA content were examined. (2) The LCPUFA compositions of plasma and erythrocyte phospholipids in 133 young women (18-30 years old) were examined and the relationships between the sample type and the levels of LCPUFAs were determined. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and DHA/arachidonic acid (AA) and (EPA+DHA)/AA ratios in erythrocyte membrane phospholipids after 21 days of blood drawing significantly decreased compared with the corresponding baseline data. Regarding AA, EPA and DHA, a significant positive correlation was shown between levels of erythrocyte membrane phospholipids and plasma phospholipids (AA, r=0.364; EPA, r=0.709; DHA, r=0.653). The predictive value of plasma phospholipids for determining the highest concentration quartile in erythrocyte phospholipids was better in EPA (70%) than in DHA (55%) and AA (42%). The measurement of LCPUFA content in erythrocyte membrane phospholipids is necessary for accurate biological monitoring. We also found that LCPUFA in erythrocyte membrane phospholipids is stable in cold storage (4°C) for 3 days after blood drawing.

Reduced amino acids in the bovine uterine lumen of cloned versus in vitro fertilized pregnancies prior to implantation.

PubMed

Groebner, Anna E; Zakhartchenko, Valeri; Bauersachs, Stefan; Rubio-Aliaga, Isabel; Daniel, Hannelore; Büttner, Mathias; Reichenbach, Horst D; Meyer, Heinrich H D; Wolf, Eckhard; Ulbrich, Susanne E

2011-10-01

Fetal overgrowth and placental abnormalities frequently occur in pregnancies following somatic cell nuclear transfer (SCNT). An optimal intrauterine supply of amino acids (AA) is of specific importance for the development of the bovine preimplantation embryo, and a defective regulation of AA supply might contribute to pregnancy failures. Thus, we analyzed 41 AA and derivatives by liquid chromatography-tandem mass spectrometry in uterine flushings of day 18 pregnant heifers carrying in vitro fertilized (IVF) or SCNT embryos, which were cultured under identical conditions until transfer to recipients. The concentrations of several AA were reduced in samples from SCNT pregnancies: L-leucine (1.8-fold), L-valine (1.6-fold), L-isoleucine (1.9-fold), L-phenylalanine (1.5-fold), L-glutamic acid (3.9-fold), L-aspartic acid (4.0-fold), L-proline (2.6-fold), L-alanine (2.0-fold), L-arginine (2.5-fold), and L-lysine (1.9-fold). The endometrial transcript abundance for the AA transporter solute carrier family 7 (amino acid transporter, L-type), member 8 (SLC7A8) was also 2.4-fold lower in SCNT pregnancies. O-phosphoethanolamine (PetN) was 11-fold (p=0.0001) reduced in the uterine fluid of animals carrying an SCNT conceptus, pointing toward changes of the phospholipid metabolism. We provide evidence for disturbed embryo-maternal interactions in the preimplantation period after transfer of SCNT embryos, which may contribute to developmental abnormalities. These are unlikely related to the major embryonic pregnancy recognition signal interferon-tau, because similar activities were detected in uterine flushings of the SCNT and IVF groups.

40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

Code of Federal Regulations, 2013 CFR

2013-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to...

40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

Code of Federal Regulations, 2012 CFR

2012-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to...

40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

Code of Federal Regulations, 2011 CFR

2011-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to...

A novel voltammetric sensor for ascorbic acid based on molecularly imprinted poly(o-phenylenediamine-co-o-aminophenol).

PubMed

Kong, Yong; Shan, Xueling; Ma, Jianfeng; Chen, Meilan; Chen, Zhidong

2014-01-27

A molecularly imprinted copolymer, poly(o-phenylenediamine-co-o-aminophenol) (PoPDoAP), was prepared as a new ascorbic acid (AA) sensor. The copolymer was synthesized by incorporation of AA as template molecules during the electrochemical copolymerization of o-phenylenediamine and o-aminophenol, and complementary sites were formed after the copolymer was electrochemically reduced in ammonium aqueous solution. The molecularly imprinted copolymer sensor exhibited a high sensitivity and selectivity toward AA. Differential pulse voltammograms (DPVs) showed a linear concentration range of AA from 0.1 to 10 mM, and the detection limit was calculated to be 36.4 μM. Compared to conventional polyaniline-based AA sensors, the analytical performance of the imprinted copolymer sensor was improved due to the broadened usable pH range of PoPDoAP (from pH 1.0 to pH 8.0). The sensor also exhibited a good reproducibility and stability. And it has been successfully applied in the determination of AA in real samples, including vitamin C tablet and orange juices, with satisfactory results. Copyright © 2013 Elsevier B.V. All rights reserved.

Increase of essential amino acids in the bovine uterine lumen during preimplantation development.

PubMed

Groebner, Anna E; Rubio-Aliaga, Isabel; Schulke, Katy; Reichenbach, Horst D; Daniel, Hannelore; Wolf, Eckhard; Meyer, Heinrich H D; Ulbrich, Susanne E

2011-05-01

Amino acids (AAs) are crucial for the developing conceptus prior to implantation. To provide insights into the requirements of the bovine embryo, we determined the AA composition of the uterine fluid. At days 12, 15, and 18 post-estrus, the uteri of synchronized pregnant and non-pregnant Simmental heifers were flushed for the analysis of 41 AAs and their derivatives by liquid chromatography-tandem mass spectrometry. The ipsilateral endometrium was sampled for quantitative PCR. In addition to a pregnancy-dependent increase of the essential AAs (P<0.01), we detected elevated concentrations for most non-essential proteinogenic AAs. Histidine (His) and the expression of the His/peptide transporter solute carrier 15A3 (SLC15A3) were significantly increased at day 18 of pregnancy in vivo. In addition, SLC15A3 was predominantly stimulated by trophoblast-derived interferon-τ in stroma cells of an in vitro co-culture model of endometrial cells. Our results show an increased concentration of AAs most likely to optimally provide the elongating pre-attachment conceptus with nutrients.

Arachidonic acid with taurine enhances pulmonary absorption of macromolecules without any serious histopathological damages.

PubMed

Miyake, Masateru; Minami, Takanori; Yamazaki, Hiroyuki; Emoto, Chie; Mukai, Tadashi; Toguchi, Hajime

2017-05-01

Therapeutic peptides and protein are being used in several indications; however, their poor permeability still remains to be solved. This study focused on the pulmonary route of macromolecules. First, the effects of arachidonic acid (AA) as an absorption enhancer on drug serum concentration, after intratracheal administration, were investigated in rats. Second, the safety of AA was assessed in rats in an acute toxicity study for 7days. AA enhanced the exposure of both interferon-α (IFN-α) and fluorescein isothiocyanate 4000 (FD-4). In addition, the histopathological analysis indicated that AA caused alveolitis and bronchitis in rats. In combination with Taurine (Tau), these lung injuries were prevented through the histopathological analysis. The combined use of Tau with AA did not show any changes in the pharmacokinetics of FD-4. From these results, we suggest the combined use of AA with Tau as a novel formulation on the pulmonary route of macromolecule drugs. This formulation could improve the bioavailability of macromolecule drugs without any serious local damage to the lungs. Copyright © 2017 Elsevier B.V. All rights reserved.

Amino acids and peptides. XXXII: A bifunctional poly(ethylene glycol) hybrid of fibronectin-related peptides.

PubMed

Maeda, M; Izuno, Y; Kawasaki, K; Kaneda, Y; Mu, Y; Tsutsumi, Y; Lem, K W; Mayumi, T

1997-12-18

An amino acid type poly(ethylene glycol) (aaPPEG) was prepared and its application to a drug carrier was examined. The peptides, Arg-Gly-Asp (RGD) and Glu-Ile-Leu-Asp-Val (EILDV) which were reported as active fragments of Fibronectin (a cell adhesion protein), were conjugated with aaPEG (molecular weight, 10,000). The hybrid, RGD-aaPEG-EILDV, was prepared by a combination of the solid-phase method and the solution method. Antiadhesive activity of the peptides was not lost by its hybrid formation with the large aaPEG molecule. A mixture of RGD (0.43 mmol) and EILDV (0.43 mmol) did not demonstrate an antiadhesive effect, but the hybrid containing 0.43 mmol of each peptide did exhibit this effect.

Long-chain polyunsaturated fatty acid sources and evaluation of their nutritional and functional properties

PubMed Central

Abedi, Elahe; Sahari, Mohammad Ali

2014-01-01

Recent studies have clearly shown the importance of polyunsaturated fatty acids (as essential fatty acids) and their nutritional value for human health. In this review, various sources, nutritional properties, and metabolism routes of long-chain polyunsaturated fatty acids (LC-PUFA) are introduced. Since the conversion efficiency of linoleic acid (LA) to arachidonic acid (AA) and also α-linolenic acid (ALA) to docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA) is low in humans, looking for the numerous sources of AA, EPA and EPA fatty acids. The sources include aquatic (fish, crustaceans, and mollusks), animal sources (meat, egg, and milk), plant sources including 20 plants, most of which were weeds having a good amount of LC-PUFA, fruits, herbs, and seeds; cyanobacteria; and microorganisms (bacteria, fungi, microalgae, and diatoms). PMID:25473503

Net Flux of Amino Acids Across the Portal-drained Viscera and Liver of the Ewe During Abomasal Infusion of Protein and Glucose

USDA-ARS?s Scientific Manuscript database

Decreasing the fraction of amino acids metabolized by the mucosal cells may increase the fraction of AA being released into the blood. A potential mechanism to reduce AA catabolism by mucosal cells is to provide an alternative source of energy. We hypothesized that increasing glucose flow to the s...

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools.

PubMed

Taha, Ameer Y; Cheon, Yewon; Faurot, Keturah F; Macintosh, Beth; Majchrzak-Hong, Sharon F; Mann, J Douglas; Hibbeln, Joseph R; Ringel, Amit; Ramsden, Christopher E

2014-05-01

Dietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations. To evaluate the extent to which 12 weeks of dietary n-6 PUFA lowering, with or without increased dietary n-3 PUFAs, alters unesterified and esterified plasma n-6 and n-3 PUFA concentrations in subjects with chronic headache. Secondary analysis of a randomized trial. Subjects with chronic headache were randomized for 12 weeks to (1) average n-3, low n-6 (L6) diet; or (2) high n-3, low n-6 LA (H3-L6) diet. Esterified and unesterified plasma fatty acids were quantified at baseline (0 weeks) and after 12 weeks on a diet. Compared to baseline, the L6 diet reduced esterified plasma LA and increased esterified n-3 PUFA concentrations (nmol/ml), but did not significantly change plasma arachidonic acid (AA, 20:4n-6) concentration. In addition, unesterified EPA concentration was increased significantly among unesterified fatty acids. The H3-L6 diet decreased esterified LA and AA concentrations, and produced more marked increases in esterified and unesterified n-3 PUFA concentrations. Dietary n-6 PUFA lowering for 12 weeks significantly reduces LA and increases n-3 PUFA concentrations in plasma, without altering plasma AA concentration. A concurrent increase in dietary n-3 PUFAs for 12 weeks further increases n-3 PUFA plasma concentrations and reduces AA. Published by Elsevier Ltd.

Synthesis of bioadditives of fuels from biodiesel-derived glycerol by esterification with acetic acid on solid catalysts.

PubMed

Bedogni, Gabriel A; Acevedo, Mauro D; Aguzín, Federico; Okulik, Nora B; Padró, Cristina L

2017-07-07

In this paper, glycerol esterification with acetic acid (AA) was studied on several solid acid catalysts: Al 2 O 3 , Al-MCM-41, HPA/SiO 2 , HBEA, Amberlyst 15 and Amberlyst 36 with the aim of determining the reaction conditions and the nature of the surface acid sites required to produce selectively triacetylglycerol (triacetin). The acidity of the catalysts (nature, density and strength of acid sites) was characterized by temperature-programmed desorption of NH 3 and FTIR of adsorbed pyridine. Al 2 O 3 (Lewis acidity) did not show any activity in the reaction. In contrast, highest activity and selectivity to the triacetylated product (triacetin) were obtained on catalysts with Brønsted acidity: Amberlyst 15 and Amberlyst 36. The effect of temperature and molar ratio of AA to glycerol was studied, and the results showed that both parameters have a significant impact on the production of the desired product. Glycerol conversion rate and selectivity to triacetin increased when temperature or AA to glycerol molar ratio were increased, reaching a triacetin yield on Amberlyst 36 of 44% at 393 K and AA to glycerol molar ratio of 6. Deactivation and reusability of Amberlyst 36 were evaluated by performing consecutive catalytic tests. The presence of some irreversible deactivation due to sulfur loss was observed. In addition, the feasibility of using crude glycerol from biodiesel production as reactant was also investigated. Conversion of crude pretreated glycerol yielded values of triacetin and diacetin similar to those obtained with the commercial pure glycerol although at a lower rate.

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools

PubMed Central

Taha, Ameer Y.; Cheon, Yewon; Faurot, Keturah F.; MacIntosh, Beth; Majchrzak-Hong, Sharon F.; Mann, J. Douglas; Hibbeln, Joseph R.; Ringel, Amit; Ramsden, Christopher E.

2014-01-01

Background Dietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations. Objective To evaluate the extent to which 12 weeks of dietary n-6 PUFA lowering, with or without increased dietary n-3 PUFAs, change unesterified and esterified plasma n-6 and n-3 PUFA concentrations in subjects with chronic headache. Design Secondary analysis of a randomized trial. Subjects with chronic headache were randomized for 12 weeks to: (1) average n-3, low n-6 (L6) diet; or (2) high n-3, low n-6 LA (H3-L6) diet. Esterified and unesterified plasma fatty acids were quantified at baseline (0 weeks) and after 12 weeks on a diet. Results Compared to baseline, the L6 diet reduced esterified plasma LA and increased esterified n-3 PUFA concentrations (nmol/ml), but did not significantly change plasma arachidonic acid (AA, 20:4n-6) concentration. In addition, unesterified EPA concentration was increased significantly among unesterified fatty acids. The H3-L6 diet decreased esterified LA and AA concentrations, and produced more marked increases in esterified and unesterified n-3 PUFA concentrations. Conclusion Dietary n-6 PUFA lowering for 12 weeks significantly reduces LA and increases n-3 PUFA concentrations in plasma, without altering plasma AA concentration. A concurrent increase in dietary n-3 PUFA for 12 weeks further increases n-3 PUFA plasma concentrations, but also reduces AA. PMID:24675168

The simultaneous electrochemical detection of ascorbic acid, dopamine, and uric acid using graphene/size-selected Pt nanocomposites.

PubMed

Sun, Chia-Liang; Lee, Hsin-Hsien; Yang, Jen-Ming; Wu, Ching-Chou

2011-04-15

In this study, a graphene/Pt-modified glassy carbon (GC) electrode was created to simultaneously characterize ascorbic acid (AA), dopamine (DA), and uric acid (UA) levels via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). During the preparation of the nanocomposite, size-selected Pt nanoparticles with a mean diameter of 1.7 nm were self-assembled onto the graphene surface. In the simultaneous detection of the three aforementioned analytes using CV, the electrochemical potential differences among the three detected peaks were 185 mV (AA to DA), 144 mV (DA to UA), and 329 mV (AA and UA), respectively. In comparison to the CV results of bare GC and graphene-modified GC electrodes, the large electrochemical potential difference that is achieved via the use of the graphene/Pt nanocomposites is essential to the distinguishing of these three analytes. An optimized adsorption of size-selected Pt colloidal nanoparticles onto the graphene surface results in a graphene/Pt nanocomposite that can provide a good platform for the routine analysis of AA, DA, and UA. Copyright © 2011 Elsevier B.V. All rights reserved.

Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements.

PubMed

Gao, Wei; Chen, Aodong; Zhang, Bowen; Kong, Ping; Liu, Chenli; Zhao, Jie

2015-04-01

This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID) of dry matter, crude protein (CP), and amino acids (AA) of cottonseed meal (CSM), sunflower seed meal (SFSM) and distillers dried grains with solubles (DDGS) by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA) varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP) content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01). The SID of individual RUP-AA was different within specific RUP origin (p<0.01). Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

Standardized Ileal Amino Acid Digestibility of Corn, Corn Distillers' Dried Grains with Solubles, Wheat Middlings, and Bakery By-Products in Broilers and Laying Hens.

PubMed

Adedokun, S A; Jaynes, P; Payne, R L; Applegate, T J

2015-10-01

Standardized ileal amino acid digestibility (SIAAD) of 5 samples of corn distillers dried grain with solubles (DDGS), 5 samples of bakery by-products (BBP), 3 samples of corn, and 1 sample of wheat middlings (WM) were evaluated in broilers and laying hens. Diets containing each of the 14 feed ingredients were evaluated in 21 day-old broiler chickens. The DDGS and BBP containing diets were fed to 30-week-old laying hens, while corn and wheat middling were evaluated in 50-week-old laying hens. All the diets were semi-purified with each feed ingredient being the only source of amino acid (AA). To obtain SIAAD values, apparent ileal AA digestibility was corrected for basal ileal endogenous AA losses using values generated from broilers and laying hens fed a nitrogen-free diet. Ileal crude protein digestibility for the 5 DDGS samples was higher (P < 0.05) in broilers than in laying hens. Broilers had higher SIAAD for DDGS 2, 3, 4, and 5 while there was no difference for DDGS 1 except for 4 AA where broilers had higher (P < 0.05) SIAAD values. Standardized ileal AA digestibility values for broilers were higher (P < 0.05) for BBP 1 and 4. Ileal CP digestibility for corn 1 was higher (P < 0.05) for broilers compared to laying hens, and SIAAD values for the 16 AA (9 indispensable and 7 dispensable) evaluated in this study were higher (P < 0.05) in broilers. Broilers had higher (P < 0.05) SIAAD values for 4 (histidine, leucine, phenylalanine, and valine) and 6 (histidine, leucine, methionine, phenylalanine, threonine, and valine) indispensable and 3 (cysteine, glutamic acid, and proline) and 4 (cysteine, glutamic acid, proline, and serine) dispensable AA for corn 2 and corn 3, respectively. No difference in SIAAD between broilers and laying hens was observed for WM. Results from this study confirm that high variability in digestibility exists between different samples of DDGS. Differences in SIAAD between broilers and laying hens were observed in some samples of DDGS and BBP. © 2015 Poultry Science Association Inc.

Detection of AA76, a Common Form of Amyloid A Protein, as a Way of Diagnosing AA Amyloidosis.

PubMed

Sato, Junji; Okuda, Yasuaki; Kuroda, Takeshi; Yamada, Toshiyuki

2016-01-01

Reactive amyloid deposits consist of amyloid A (AA) proteins, the degradation products of serum amyloid A (SAA). Since the most common species of AA is the amino terminal portion produced by cleavage between residues 76 and 77 of SAA (AA76), the presence of AA76 in tissues could be a consequence of AA amyloid deposition. This study assessed the diagnostic significance of the detection of AA76 for AA amyloidosis using two different approaches. Biopsy specimens (n=130 from 54 subjects) from gastroduodenal mucosa or abdominal fat (n=9 from 9 subjects) of patients who had already been diagnosed with or were suspected of having AA amyloidosis were used. Fixed mucosal sections were subjected to immunohistochemistry using a newly developed antibody recognizing the carboxyl terminal end of AA76 (anti-AA76). The non-fixed materials from gastroduodenal mucosa or abdominal fat were subjected to immunoblotting for detection of the size of AA76. Among the gastroduodenal specimens (n=115) from already diagnosed patients, the positive rates of Congo red staining, immunohistochemistry using anti-AA76, and immunoblotting were 68.4%, 73.0%, and 92.2%, respectively. The anti-AA76 did not stain the supposed SAA in the blood or leakage, which was stained by anti-SAA antibody. AA76 was not detected either by immunohistochemistry or by immunoblot in the materials from patients in whom AA amyloidosis had been ruled out. In the abdominal fat, the immunoblot detected AA76 in 8 materials from 8 already diagnosed patients and did not in 1 patient whose gastroduodenal mucosa was negative. In conclusion, the detection of AA76 may alter the ability to diagnose AA amyloidosis. In immunohistochemistry for fixed specimens, the new anti-AA76 antibody can improve the specificity. Immunoblot for non-fixed materials, which can considerably improve the sensitivity, should be beneficial for small materials like abdominal fat. © 2016 by the Association of Clinical Scientists, Inc.

Targeting fatty acid amide hydrolase and transient receptor potential vanilloid-1 simultaneously to modulate colonic motility and visceral sensation in the mouse: A pharmacological intervention with N-arachidonoyl-serotonin (AA-5-HT).

PubMed

Bashashati, M; Fichna, J; Piscitelli, F; Capasso, R; Izzo, A A; Sibaev, A; Timmermans, J-P; Cenac, N; Vergnolle, N; Di Marzo, V; Storr, M

2017-12-01

Endocannabinoid anandamide (AEA) inhibits intestinal motility and visceral pain, but it may also be proalgesic through transient receptor potential vanilloid-1 (TRPV1). AEA is degraded by fatty acid amide hydrolase (FAAH). This study explored whether dual inhibition of FAAH and TRPV1 reduces diarrhea and abdominal pain. Immunostaining was performed on myenteric plexus of the mouse colon. The effects of the dual FAAH/TRPV1 inhibitor AA-5-HT on electrically induced contractility, excitatory junction potential (EJP) and fast (f) and slow (s) inhibitory junction potentials (IJP) in the mouse colon, colonic propulsion and visceromotor response (VMR) to rectal distension were studied. The colonic levels of endocannabinoids and fatty acid amides were measured. CB1-positive neurons exhibited TRPV1; only some TRPV1 positive neurons did not express CB1. CB1 and FAAH did not colocalize. AA-5-HT (100 nM-10 μM) decreased colonic contractility by ~60%; this effect was abolished by TRPV1 antagonist 5'-IRTX, but not by CB1 antagonist, SR141716. AA-5-HT (1 μM-10 μM) inhibited EJP by ~30% and IJPs by ~50%. The effects of AA-5-HT on junction potentials were reversed by SR141716 and 5`-IRTX. AA-5-HT (20 mg/kg; i.p.) inhibited colonic propulsion by ~30%; SR141716 but not 5`-IRTX reversed this effect. AA-5-HT decreased VMR by ~50%-60%; these effects were not blocked by SR141716 or 5`-IRTX. AA-5-HT increased AEA in the colon. The effects of AA-5-HT on visceral sensation and colonic motility are differentially mediated by CB1, TRPV1 and non-CB1/TRPV1 mechanisms, possibly reflecting the distinct neuromodulatory roles of endocannabinoid and endovanilloid FAAH substrates in the mouse intestine. © 2017 John Wiley & Sons Ltd.

Fatty acid profile of maternal and fetal erythrocytes and placental expression of fatty acid transport proteins in normal and intrauterine growth restriction pregnancies.

PubMed

Assumpção, Renata P; Mucci, Daniela B; Fonseca, Fernanda C P; Marcondes, Henrique; Sardinha, Fátima L C; Citelli, Marta; Tavares do Carmo, Maria G

2017-10-01

Long-chain polyunsaturated fatty acids (LC-PUFA), mainly docosahexaenoic (DHA) and arachidonic acids (AA), are critical for adequate fetal growth and development. We investigated mRNA expression of proteins involved in hydrolysis, uptake and/or transport of fatty acids in placenta of fifteen full term normal pregnancies and eleven pregnancies complicated by intrauterine growth restriction (IUGR) with normal umbilical blood flows. The mRNA expression of LPL, FATPs (-1, -2 and -4) and FABPs (-1 and -3) was increased in IUGR placentas, however, tissue profile of LC-PUFA was not different between groups. Erythrocytes from both mothers and fetuses of the IUGR group showed lower concentrations of AA and DHA and inferior DHA/ALA ratio compared to normal pregnancies (P < 0.05). We hypothesize that reduced circulating levels of AA and DHA could up-regulate mRNA expression of placental fatty acids transporters, as a compensatory mechanism, however this failed to sustain normal LC-PUFA supply to the fetus in IUGR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Degradation kinetics of chlorogenic acid at various pH values and effects of ascorbic acid and epigallocatechin gallate on its stability under alkaline conditions.

PubMed

Narita, Yusaku; Inouye, Kuniyo

2013-01-30

5-Caffeoylquinic acid (5-CQA) is generally referred to as chlorogenic acid and exhibits various biological activities such as antioxidant activity and porcine pancreas α-amylase inhibitory activities. 5-CQA may be useful as an antioxidant for food and to prevent diabetes and obesity. The degradation of 5-CQA and caffeic acid (CA) in an aqueous solution at 37 °C and pH 5.0-9.0 was studied. The degradation of 5-CQA and CA, demonstrating time and pH dependence (i.e., the rate constant, k, was higher at higher pH), was satisfactorily described by the Weibull equation. The stability of 5-CQA at pH 7.4 and 9.0 was improved by adding (-)-epigallocatechin gallate (EGCG) and ascorbic acid (AA). Moreover, the degradation of 5-CQA in the presence of EGCG or AA could be described by the Weibull equation. The k value in the presence of EGCG or AA was dependent on their concentration.

Surface Finish and Residual Stresses Induced by Orthogonal Dry Machining of AA7075-T651

PubMed Central

Jomaa, Walid; Songmene, Victor; Bocher, Philippe

2014-01-01

The surface finish was extensively studied in usual machining processes (turning, milling, and drilling). For these processes, the surface finish is strongly influenced by the cutting feed and the tool nose radius. However, a basic understanding of tool/surface finish interaction and residual stress generation has been lacking. This paper aims to investigate the surface finish and residual stresses under the orthogonal cutting since it can provide this information by avoiding the effect of the tool nose radius. The orthogonal machining of AA7075-T651 alloy through a series of cutting experiments was performed under dry conditions. Surface finish was studied using height and amplitude distribution roughness parameters. SEM and EDS were used to analyze surface damage and built-up edge (BUE) formation. An analysis of the surface topography showed that the surface roughness was sensitive to changes in cutting parameters. It was found that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles play a determinant role in controlling the surface finish during dry orthogonal machining of the AA7075-T651 alloy. Hoop stress was predominantly compressive on the surface and tended to be tensile with increased cutting speed. The reverse occurred for the surface axial stress. The smaller the cutting feed, the greater is the effect of cutting speed on both axial and hoop stresses. By controlling the cutting speed and feed, it is possible to generate a benchmark residual stress state and good surface finish using dry machining. PMID:28788534

Hydrogels Synthesized by Electron Beam Irradiation for Heavy Metal Adsorption

PubMed Central

Manaila, Elena; Craciun, Gabriela; Ighigeanu, Daniel; Cimpeanu, Catalina; Barna, Catalina; Fugaru, Viorel

2017-01-01

Poly(acrylamide co-acrylic acid) hydrogels were prepared by free-radical copolymerization of acrylamide and acrylic acid in aqueous solutions using electron beam irradiation in the dose range of 2.5 kGy to 6 kGy in atmospheric conditions and at room temperature. The influence of the absorbed dose, the amount of cross-linker (trimethylolpropane trimethacrylate) and initiator (potassium persulfate) on the swelling properties and the diffusion coefficient and network parameters of hydrogels were investigated. The structure and morphology of hydrogels were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The use of the obtained hydrogels by the removal of Cu2+ and Cr6+ from aqueous solutions was investigated at room temperature. During the adsorption of metal ions on hydrogels, the residual metal ion concentration in the solution was measured by an atomic absorption spectrophotometer (AAS). It has been established that the use of a relatively small amount of trimethylolpropane trimethacrylate for hydrogel preparation has led to the increasing of swelling up to 8500%. PMID:28772904

Hydrogels Synthesized by Electron Beam Irradiation for Heavy Metal Adsorption.

PubMed

Manaila, Elena; Craciun, Gabriela; Ighigeanu, Daniel; Cimpeanu, Catalina; Barna, Catalina; Fugaru, Viorel

2017-05-18

Poly(acrylamide co-acrylic acid) hydrogels were prepared by free-radical copolymerization of acrylamide and acrylic acid in aqueous solutions using electron beam irradiation in the dose range of 2.5 kGy to 6 kGy in atmospheric conditions and at room temperature. The influence of the absorbed dose, the amount of cross-linker (trimethylolpropane trimethacrylate) and initiator (potassium persulfate) on the swelling properties and the diffusion coefficient and network parameters of hydrogels were investigated. The structure and morphology of hydrogels were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The use of the obtained hydrogels by the removal of Cu 2+ and Cr 6+ from aqueous solutions was investigated at room temperature. During the adsorption of metal ions on hydrogels, the residual metal ion concentration in the solution was measured by an atomic absorption spectrophotometer (AAS). It has been established that the use of a relatively small amount of trimethylolpropane trimethacrylate for hydrogel preparation has led to the increasing of swelling up to 8500%.

The molecular relationship between antigenic domains and epitopes on hCG.

PubMed

Berger, Peter; Lapthorn, Adrian J

2016-08-01

Antigenic domains are defined to contain a limited number of neighboring epitopes recognized by antibodies (Abs) but their molecular relationship remains rather elusive. We thoroughly analyzed the antigenic surface of the important pregnancy and tumor marker human chorionic gonadotropin (hCG), a cystine knot (ck) growth factor, and set antigenic domains and epitopes in molecular relationships to each other. Antigenic domains on hCG, its free hCGα and hCGβ subunits are dependent on appropriate inherent molecular features such as molecular accessibility and protrusion indices that determine bulging structures accessible to Abs. The banana-shaped intact hCG comprises ∼7500Å(2) of antigenic surface with minimally five antigenic domains that encompass a continuum of overlapping non-linear composite epitopes, not taking into account the C-terminal peptide extension of hCGβ (hCGβCTP). Epitopes within an antigenic domain are defined by specific Abs, that bury nearly 1000Å(2) of surface accessible area on the antigen and recognize a few up to 15 amino acid (aa) residues, whereby between 2 and 5 of these provide the essential binding energy. Variability in Ab binding modes to the contact aa residues are responsible for the variation in affinity and intra- and inter-species specificity, e.g. cross-reactions with luteinizing hormone (LH). Each genetically distinct fragment antigen binding (Fab) defines its own epitope. Consequently, recognition of the same epitope by different Abs is only possible in cases of genetically identical sequences of its binding sites. Due to combinatorial V(D)J gene segment variability of heavy and light chains, Abs defining numerous epitopes within an antigenic domain can be generated by different individuals and species. Far more than hundred Abs against the immuno-dominant antigenic domains of either subunit at both ends of the hCG-molecule, the tips of peptide loops one and three (Ł1+3) protruding from the central ck, encompassing hCGβŁ1+3 (aa 20-25+64+68-81) and hCGαŁ1 (aa 13-22; Pro16, Phe17, Phe18) plus hCGαŁ3 (Met71, Phe74), respectively, have been identified in the two "ISOBM Tissue Differentiation-7 Workshops on hCG and Related Molecules" and in other studies. These Abs recognize distinct but overlapping epitopes with slightly different specificity profiles and affinities. Heterodimeric-specific epitopes involve neighboring αŁ1 plus βŁ2 (hCGβ44/45 and 47/48). Diagnostically important Abs recognize the middle of the molecule, the ck (aa Arg10, Arg60 and possibly Gln89) and the linear hCGβCTP "tail" (aa 135-145; Asp139, Pro144, Gln145), respectively. Identification of antigenic domains and of specific epitopes is essential for harmonization of Abs in methods that are used for reliable and robust hCG measurements for the management of pregnancy, pregnancy-related disease and tumors. Copyright © 2016. Published by Elsevier Ltd.

Parenteral Lipid Dose Restriction With Soy Oil, Not Fish Oil, Preserves Retinal Function in Neonatal Piglets.

PubMed

Lansing, Marihan; Sauvé, Yves; Dimopoulos, Ioannis; Field, Catherine J; Suh, Miyoung; Wizzard, Pamela; Goruk, Susan; Lim, David; Muto, Mitsuru; Wales, Paul; Turner, Justine

2018-03-13

A dietary supply of docosahexaenoic acid (DHA) and arachidonic acid (AA) is critical for neonatal retinal development. Both are absent/minimal in parenteral nutrition (PN) using soy-oil emulsions ([SO] Intralipid®) traditionally used for neonatal intestinal failure. In contrast, fish-oil emulsions ([FO] Omegaven®) are enriched in DHA/AA. The aim of this study was to compare retinal function and fatty acid content in neonatal piglets fed PN with SO or FO. Two-5-day-old piglets were randomly allocated to SO (n = 4) or FO (n = 4), provided at equivalent doses (5g/kg/d). After 14 days of PN, retinal function was assessed by electroretinography and retinas were harvested for fatty acid content analysis. Sow-fed piglets served as a reference (REF). Light flash-elicited stoppage of cone and rod dark-currents (a-waves) and the ensuing postsynaptic activation of cone and rod ON bipolar cells (b-waves) were comparable between SO and REF. Responses recorded from FO were subnormal (P <0.001) when compared with both SO and REF. Retinal DHA content was similar in both groups (FO, 14.59% vs SO, 12.22%; P = 0.32); while AA was lower in FO (FO, 6.01% vs SO, 8.21%; P = .001). Paradoxically, FO containing more DHA and AA did not preserve retinal function when compared with the same low dose of SO. This may be due to the reduced AA enrichment in the retina with FO treatment. Further investigation into the ideal amounts of DHA and AA for optimal neonatal retinal function is required. © 2018 American Society for Parenteral and Enteral Nutrition.

Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

NASA Astrophysics Data System (ADS)

Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

2016-09-01

Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

Serum n-6 and n-9 Fatty Acids Correlate With Serum IGF-1 and Growth Up to 4 Months of Age in Healthy Infants.

PubMed

Kjellberg, Emma; Roswall, Josefine; Bergman, Stefan; Strandvik, Birgitta; Dahlgren, Jovanna

2018-01-01

The aim of this study was to study the relationship between insulin-like growth factor-1 (IGF-1), serum phospholipid fatty acids, and growth in healthy full-term newborns during infancy. Prospective observational study of a population-based Swedish cohort comprising 126 healthy, term infants investigating cord blood and serum at 2 days and 4 months of age for IGF-1 and phospholipid fatty acid profile and breast milk for fatty acids at 2 days and 4 months, compared with anthropometric measurements (standard deviation scores). At all time-points arachidonic acid (AA) was negatively associated with IGF-1. IGF-1 had positive associations with linoleic acid (LA) at 2 days and 4 months and mead acid (MA) showed positive associations in cord blood. Multiple regression analyses adjusted for maternal factors (body mass index, weight gain, smoking, education), sex, birth weight and feeding modality confirmed a negative association for the ratio AA/LA to IGF-1. MA in cord blood correlated to birth size. Changes in the ratios of n-6/n-3 and AA/docosahexaenoic acid from day 2 to 4 months together with infants' weight and feeding modality determined 55% of the variability of delta-IGF-1. Breast-fed infants at 4 months had lower IGF-1 correlating with lower LA and higher AA concentrations, which in girls correlated with lower weight gain from birth to 4 months of age. Our data showed interaction of n-6 fatty acids with IGF-1 during the first 4 months of life, and an association between MA and birth size when adjusted for confounding factors. Further follow-up may indicate whether these correlations are associated with later body composition.

High-throughput quantification of the levels and labeling abundance of free amino acids by liquid chromatography tandem mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cocuron, Jean-Christophe; Tsogtbaatar, Enkhtuul; Alonso, Ana P.

Accurate assessment of mass isotopomer distributions (MIDs) of intracellular metabolites, such as free amino acids (AAs), is crucial for quantifying in vivo fluxes. To date, the majority of studies that measured AA MIDs have relied on the analysis of proteinogenic rather than free AAs by: i) GC–MS, which involved cumbersome process of derivatization, or ii) NMR, which requires large quantities of biological sample. In this work, the development and validation of a high-throughput LC–MS/MS method allowing the quantification of the levels and labeling of free AAs is described. Sensitivity in the order of the femtomol was achieved using multiple reactionmore » monitoring mode (MRM). The MIDs of all free AAs were assessed without the need of derivatization, and were validated (except for Trp) on a mixture of unlabeled AA standards. Finally, this method was applied to the determination of the 13C-labeling abundance in free AAs extracted from maize embryos cultured with 13C-glutamine or 13C-glucose. Although Cys was below the limit of detection in these biological samples, the MIDs of a total of 18 free AAs were successfully determined. Due to the increased application of tandem mass spectrometry for 13C-Metabolic Flux Analysis, this novel method will enable the assessment of more complete and accurate labeling information of intracellular AAs, and therefore a better definition of the fluxes.« less

High-throughput quantification of the levels and labeling abundance of free amino acids by liquid chromatography tandem mass spectrometry

DOE PAGES

Cocuron, Jean-Christophe; Tsogtbaatar, Enkhtuul; Alonso, Ana P.

2017-02-16

Accurate assessment of mass isotopomer distributions (MIDs) of intracellular metabolites, such as free amino acids (AAs), is crucial for quantifying in vivo fluxes. To date, the majority of studies that measured AA MIDs have relied on the analysis of proteinogenic rather than free AAs by: i) GC–MS, which involved cumbersome process of derivatization, or ii) NMR, which requires large quantities of biological sample. In this work, the development and validation of a high-throughput LC–MS/MS method allowing the quantification of the levels and labeling of free AAs is described. Sensitivity in the order of the femtomol was achieved using multiple reactionmore » monitoring mode (MRM). The MIDs of all free AAs were assessed without the need of derivatization, and were validated (except for Trp) on a mixture of unlabeled AA standards. Finally, this method was applied to the determination of the 13C-labeling abundance in free AAs extracted from maize embryos cultured with 13C-glutamine or 13C-glucose. Although Cys was below the limit of detection in these biological samples, the MIDs of a total of 18 free AAs were successfully determined. Due to the increased application of tandem mass spectrometry for 13C-Metabolic Flux Analysis, this novel method will enable the assessment of more complete and accurate labeling information of intracellular AAs, and therefore a better definition of the fluxes.« less

Aristolochic Acid in the Etiology of Renal Cell Carcinoma

PubMed Central

Hoang, Margaret L.; Chen, Chung-Hsin; Chen, Pau-Chung; Roberts, Nicholas J.; Dickman, Kathleen G.; Yun, Byeong Hwa; Turesky, Robert J.; Pu, Yeong-Shiau; Vogelstein, Bert; Papadopoulos, Nickolas; Grollman, Arthur P.; Kinzler, Kenneth W.; Rosenquist, Thomas A.

2017-01-01

Background Aristolochia species used in the practice of traditional herbal medicine contains aristolochic acid (AA), an established human carcinogen contributing to urothelial carcinomas of the upper urinary tract. AA binds covalently to genomic DNA, forming aristolactam (AL)–DNA adducts. Here we investigated whether AA is also an etiologic factor in clear cell renal cell carcinoma (ccRCC). Methods We conducted a population-based case–control study to investigate the linkage between Aristolochia prescription history, cumulative AA consumption, and ccRCC incidence in Taiwan (5,709 cases and 22,836 matched controls). The presence and level of mutagenic dA-AL-I adducts were determined in the kidney DNA of 51 Taiwanese ccRCC patients. The whole-exome sequences of ccRCC tumors from 10 Taiwanese ccRCC patients with prior exposure to AA were determined. Results Cumulative ingestion of more than 250 mg of AA increased risk of ccRCC (OR, 1.25), and we detected dA-AL-I adducts in 76% of Taiwanese ccRCC patients. Furthermore, the distinctive AA mutational signature was evident in six of 10 sequenced ccRCC exomes from Taiwanese patients. Conclusions This study strongly suggests that AA contributes to the etiology of certain RCCs. Impact The current study offers compelling evidence implicating AA in a significant fraction of the RCC arising in Taiwan and illustrates the power of integrating epidemiologic, molecular, and genetic data in the investigation of cancer etiology. PMID:27555084

The polyomavirus BK agnoprotein co-localizes with lipid droplets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unterstab, Gunhild; Gosert, Rainer; Leuenberger, David

Agnoprotein encoded by human polyomavirus BK (BKV) is a late cytoplasmic protein of 66 amino acids (aa) of unknown function. Immunofluorescence microscopy revealed a fine granular and a vesicular distribution in donut-like structures. Using BKV(Dunlop)-infected or agnoprotein-transfected cells, we investigated agnoprotein co-localization with subcellular structures. We found that agnoprotein co-localizes with lipid droplets (LD) in primary human renal tubular epithelial cells as well as in other cells supporting BKV replication in vitro (UTA, Vero cells). Using agnoprotein-enhanced green fluorescent protein (EGFP) fusion constructs, we demonstrate that agnoprotein aa 20-42 are required for targeting LD, whereas aa 1-20 or aa 42-66more » were not. Agnoprotein aa 22-40 are predicted to form an amphipathic helix, and mutations A25D and F39E, disrupting its hydrophobic domain, prevented LD targeting. However, changing the phosphorylation site serine-11 to alanine or aspartic acid did not alter LD co-localization. Our findings provide new clues to unravel agnoprotein function.« less

Electrochemical determination of dopamine and ascorbic acid at a novel gold nanoparticles distributed poly(4-aminothiophenol) modified electrode.

PubMed

Gopalan, Anantha Iyengar; Lee, Kwang-Pill; Manesh, Kalayil Manian; Santhosh, Padmanabhan; Kim, Jun Heon; Kang, Jae Soo

2007-03-15

A modified electrode is fabricated by embedding gold nanoparticles into a layer of electroactive polymer, poly(4-aminothiophenol) (PAT) on the surface of glassy carbon (GC) electrode. Cyclic voltammetry (CV) is performed to deposit PAT and concomitantly deposit Au nanoparticles. Field emission transmission electron microscopic image of the modified electrode, PAT-Au(nano)-ME, indicates the presence of uniformly distributed Au nanoparticles having the sizes of 8-10nm. Electrochemical behavior of the PAT-Au(nano)-ME towards detection of ascorbic acid (AA) and dopamine (DA) is studied using CV. Electrocatalytic determination of DA in the presence of fixed concentration of AA and vice versa, are studied using differential pulse voltammetry (DPV). PAT-Au(nano)-ME exhibits two well defined anodic peaks at the potential of 75 and 400mV for the oxidation of AA and DA, respectively with a potential difference of 325mV. Further, the simultaneous determination of AA and DA is studied by varying the concentration of AA and DA. PAT-Au(nano)-ME exhibits selectivity and sensitivity for the simultaneous determination of AA and DA without fouling by the oxidation products of AA or DA. PAT and Au nanoparticles provide synergic influence on the accurate electrochemical determination of AA or DA from a mixture having any one of the component (AA or DA) in excess. The practical analytical utilities of the PAT-Au(nano)-ME are demonstrated by the determination of DA and AA in dopamine hydrochloride injection and human blood serum samples.

Erythrocyte polyunsaturated fatty acid composition is associated with depression and FADS genotype in Caucasians.

PubMed

Cribb, Lachlan; Murphy, Jenifer; Froud, Amy; Oliver, Georgina; Bousman, Chad A; Ng, Chee H; Sarris, Jerome

2017-05-29

Polyunsaturated fatty acids (PUFAs) play an important role in the pathophysiology of major depressive disorder (MDD), related, in part, to their role in inflammatory systems. The enzymes δ-5 and δ-6 desaturase are the rate-limiting steps in the metabolism of PUFAs and are encoded in the genes fatty acid desaturase (FADS) 1 and 2, respectively. Single nucleotide polymorphisms (SNPs) and haplotypes within the FADS gene cluster have been shown to influence PUFA composition. The objective of this study was to determine whether key omega-3 (n-3) and omega-6 (n-6) fatty acids may be associated with depression, and to explore the role of FADS genotype in PUFA variation. Four erythrocyte long chain (LC) fatty acids (linoleic acid [LA], α-linolenic acid [ALA], arachidonic acid [AA] and Eicosapentaenoic acid [EPA]), as well as six SNPs (rs174537, rs174547, rs174570, rs174575, rs498793 and rs3834458) within the FADS gene cluster were measured in a sample of 207 participants (154 with MDD versus 53 non-depressed controls). The precursor LC-PUFAs LA and ALA appeared to be negatively associated with depression (P < 0.001 and P < 0.01, respectively), while AA:LA (surrogate measure of desaturase activity) was positively associated with depression (P < 0.01). No significant differences were noted in erythrocyte EPA, AA or AA:EPA between groups. Minor alleles of each SNP (excluding rs498793) were associated with variation in desaturase activity and LA. Both rs174537 and rs174547 were associated with ALA. No genotype was associated with EPA or AA. Minor alleles of rs174537 and rs174547 were significantly associated with lower odds of MDD (although significance was lost after correction for multiple comparisons). Precursor LC-PUFAs, LA and ALA, appear to be associated with MDD and potentially modulated by genetic variation in the FADS gene cluster. These results provide support for the consideration of PUFA composition, diet and FADS genetic variation in the pathophysiology of MDD.

Evaluating the efficacy of amino acids as CO2 capturing agents: a first principles investigation.

PubMed

Hussain, M Althaf; Soujanya, Yarasi; Sastry, G Narahari

2011-10-01

Comprehension of the basic concepts for the design of systems for CO2 adsorption is imperative for increasing interest in technology for CO2 capture from the effluents. The efficacy of 20 naturally occurring amino acids (AAs) is demonstrated as the most potent CO2 capturing agents in the process of chemical absorption and physisorption through a systematic computational study using highly parametrized M05-2X/6-311+G(d,p) method. The ability of AAs to bind CO2 both in the noncovalent and covalent fashion and presence of multiple adsorption sites with varying magnitude of binding strengths in all 20 AAs makes them as most promising materials in the process of physisorption. The binding energies (BEs) estimating the strength of noncovalent interaction of AAs and CO2 are calculated and results are interpreted in terms of the nature and strength of the various types of cooperative interactions which are present. The study underlines the possibility to engineer the porous solid materials with extended networks by judiciously employing AA chains as linkers which can substantially augment their efficacy. Results show that a significant increase in the CO2···AA affinity is achieved in the case of AAs with polar neutral side chains. Furthermore, the study proposes AAs as effective alternatives to alkanolamines in chemical dissolution of CO2.

Stereological studies of the effects of sodium benzoate or ascorbic acid on rats` cerebellum.

PubMed

Noorafshan, Ali; Erfanizadeh, Mahboobeh; Karbalay-Doust, Saied

2014-12-01

To evaluate the cerebellar structure in sodium benzoate (NaB) or ascorbic acid (AA) treated rats. This experimental study was conducted between May and September 2013 in the Laboratory Animal Center of Shiraz University of Medical Sciences, Shiraz, Iran. The rats received distilled either water, NaB (200mg/kg/day), AA (100mg/kg/day), or NaB+AA. The hemispheres were removed after 28 days and underwent quantitative study. The total volume of the cerebellar hemisphere, its cortex, intracerebellar nuclei; the total number of the Purkinje, Bergman, granule, neurons, and glial cells of the molecular layer; and neurons and glial cells of the intracerebellar nuclei reduced by 21-52% in the NaB-treated rats compared with the distilled water group (p=0.004). The total number of the Purkinje, Bergman, Golgi, and granule cells was 29-45% higher in the AA-treated rats compared with the distilled water group (p=0.05). However, these measures reduced by 17-50% in the NaB+AA-treated rats compared with the distilled water group (p=0.004). The NaB+AA group did not induce any significant structural changes in comparison with the NaB group (p>0.05). The NaB exposure with or without AA treatment could alter the cerebellum. Yet, AA could prevent the loss of some cells in the cerebellum. 

Safety and tolerance of ester-C compared with regular ascorbic acid.

PubMed

Gruenwald, Joerg; Graubaum, Hans-Joachim; Busch, Regina; Bentley, Christine

2006-01-01

The goal of this randomized, double-blind crossover clinical trial in 50 healthy volunteers sensitive to acidic foods was to evaluate whether Ester-C calcium ascorbate causes fewer epigastric adverse effects than are produced by regular ascorbic acid (AA). Volunteers were randomly separated into 2 groups of 25. The study comprised an observation period of 9 days (phase 1 medication for 3 consecutive days, washout phase for 3 consecutive days, phase 2 medication for 3 consecutive days). Participants took 1000 mg vitamin C as Ester-C during phase 1 of the study followed by 1000 mg of vitamin C as AA during phase 2, or vice versa. During the course of the study, 3 examinations for the evaluation of epigastric adverse effects were performed (on days 0, 3, and 9). Participants used a diary to record epigastric adverse effects on a daily basis. In total, 28 (56%) of 50 participants reported 88 epigastric adverse effects of mild to moderate intensity. Of these 88 adverse effects, 33 (37.5%) occurred after intake of Ester-C and 55 (62.5%) were noted after intake of AA. The tolerability of Ester-C was rated "very good" by 72% of participants, whereas AA was rated "very good" by only 54%. This difference is statistically significant (P<.05). Investigators concluded that Ester-C compared with AA caused significantly fewer epigastric adverse effects in participants sensitive to acidic foods and that Ester-C is much better tolerated.

Reaction Mechanisms and Structural and Physicochemical Properties of Caffeic Acid Grafted Chitosan Synthesized in Ascorbic Acid and Hydroxyl Peroxide Redox System.

PubMed

Liu, Jun; Pu, Huimin; Chen, Chong; Liu, Yunpeng; Bai, Ruyu; Kan, Juan; Jin, Changhai

2018-01-10

The ascorbic acid (AA) and hydroxyl peroxide (H 2 O 2 ) redox pair induced free radical grafting reaction is a promising approach to conjugate phenolic groups with chitosan (CS). In order to reveal the exact mechanisms of the AA/H 2 O 2 redox pair induced grafting reaction, free radicals generated in the AA/H 2 O 2 redox system were compared with hydroxyl radical ( • OH) produced in the Fe 2+ /H 2 O 2 redox system. Moreover, the structural and physicochemical properties of caffeic acid grafted CS (CA-g-CS) synthesized in these two redox systems were compared. Results showed that only ascorbate radical (Asc •- ) was produced in the AA/H 2 O 2 system. The reaction between Asc •- and CS produced novel carbon-centered radicals, whereas no new free radicals were detected when • OH reacted with CS. Thin layer chromatography, UV-vis, Fourier transform infrared, and nuclear magnetic resonance spectroscopic analyses all confirmed that CA was successfully grafted onto CS through Asc •- . However, CA could be hardly grafted onto CS via • OH. CA-g-CS synthesized through Asc •- exhibited lower thermal stability and crystallinity than the reaction product obtained through • OH. For the first time, our results demonstrated that the synthesis of CA-g-CS in the AA/H 2 O 2 redox system was mediated by Asc •- rather than • OH.

Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid.

PubMed

Yang, Guangming; Li, Ling; Jiang, Jinhe; Yang, Yunhui

2012-08-01

Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02×10(-7)-5.23×10(-4) mol L(-1) and 1.43×10(-7)-4.64×10(-4) mol L(-1), the detection limits were 1.12×10(-8) mol L(-1) and 2.24×10(-8) mol L(-1), respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. Copyright © 2012 Elsevier B.V. All rights reserved.

Ascorbic acid as a free radical scavenger in porcine and bovine aqueous humour.

PubMed

Erb, Carl; Nau-Staudt, Kerstin; Flammer, Josef; Nau, Werner

2004-01-01

To study the antioxidant activity, UV absorption, concentration and stability of ascorbic acid (AA) in porcine and bovine aqueous humour (AH). Porcine and bovine AH was taken within 5 min after death and frozen at -70 degrees C. The characteristic UV absorption band of AA and the concentration of AA in AH was determined by UV spectrophotometry. The antioxidant activity of AA to serve as a free radical scavenger in AH has been determined by using a novel fluorescent probe for antioxidants, the azoalkane 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO). The fluorescence lifetime and intensity of this probe reflect the concentration of dissolved antioxidants. The time-resolved fluorescence of DBO (laser excitation at 351 nm) in AH and in a neutral phosphate-buffered saline (PBS) solution containing only the natural amount of AA as an additive were measured. The characteristic UV absorption band of AA has its maximum at 266 nm in AH. The concentration of AA in porcine and bovine AH was found to be 0.547 +/- 0.044 and 1.09 +/- 0.16 mM, respectively, by spectrophotometry. The fluorescence lifetime of the probe DBO was reduced from 320 +/- 5 ns in pure aerated PBS to 205 +/- 5 ns in porcine AH and 165 +/- 3 ns in bovine AH. A detailed kinetic analysis of the lifetime shortening suggests that AA contributes approximately 75 and 85% to the antioxidant activity of porcine and bovine AH, respectively. Our experiments suggest that AA is the major contributor to the antioxidant activity of porcine and bovine AH. The role of AA to serve as an antioxidant in AH is discussed. In addition, UV spectrophotometry is established as an alternative method to determine the concentration of AA in AH. Copyright 2004 S. Karger AG, Basel

The abundance and activation of mTORC1 regulators in skeletal muscle of neonatal pigs are modulated by insulin, amino acids, and age

USDA-ARS?s Scientific Manuscript database

Previously we demonstrated that the insulin (INS) and amino acid (AA) -induced activation of the mammalian target of rapamycin complex 1 (mTORC1) is developmentally regulated in neonatal pigs. This study aimed to determine the effects of the post-prandial rise in INS and AA on the activation and abu...

Identification and Analysis of Novel Amino-Acid Sequence Repeats in Bacillus anthracis str. Ames Proteome Using Computational Tools

PubMed Central

Hemalatha, G. R.; Rao, D. Satyanarayana; Guruprasad, L.

2007-01-01

We have identified four repeats and ten domains that are novel in proteins encoded by the Bacillus anthracis str. Ames proteome using automated in silico methods. A “repeat” corresponds to a region comprising less than 55-amino-acid residues that occur more than once in the protein sequence and sometimes present in tandem. A “domain” corresponds to a conserved region with greater than 55-amino-acid residues and may be present as single or multiple copies in the protein sequence. These correspond to (1) 57-amino-acid-residue PxV domain, (2) 122-amino-acid-residue FxF domain, (3) 111-amino-acid-residue YEFF domain, (4) 109-amino-acid-residue IMxxH domain, (5) 103-amino-acid-residue VxxT domain, (6) 84-amino-acid-residue ExW domain, (7) 104-amino-acid-residue NTGFIG domain, (8) 36-amino-acid-residue NxGK repeat, (9) 95-amino-acid-residue VYV domain, (10) 75-amino-acid-residue KEWE domain, (11) 59-amino-acid-residue AFL domain, (12) 53-amino-acid-residue RIDVK repeat, (13) (a) 41-amino-acid-residue AGQF repeat and (b) 42-amino-acid-residue GSAL repeat. A repeat or domain type is characterized by specific conserved sequence motifs. We discuss the presence of these repeats and domains in proteins from other genomes and their probable secondary structure. PMID:17538688

Comparison of PrestoBlue® and plating method to evaluate antimicrobial activity of ascorbic acid, boric acid and curcumin in an in vitro gastrointestinal model.

PubMed

Hernandez-Patlan, D; Solis-Cruz, B; Méndez-Albores, A; Latorre, J D; Hernandez-Velasco, X; Tellez, G; López-Arellano, R

2018-02-01

To compare the conventional plating method vs a fluorometric method using PrestoBlue ® as a dye by determining the antimicrobial activity of two organic acids and curcumin (CUR) against Salmonella Enteritidis in an avian in vitro digestion model that simulates the crop, proventriculus and intestine. A concentration of 10 8  CFU per ml of S. Enteritidis was exposed to groups with different rates of ascorbic acid (AA), boric acid (BA) and CUR. Significant differences were observed when the means of the treatments were compared with the controls in the compartments that simulate the crop and intestine (P < 0·05). Ascorbic acid alone and high rates of AA in the mixtures were the most efficient treatments in the crop compartment. However, in the intestinal compartment BA alone and at different rates in the mixture BA-CUR (1 : 1) were the best treatments to decrease the concentration of S. Enteritidis. The results of this study suggest that there could be an antagonistic bactericidal effect between AA and CUR and AA and BA as well as a synergistic bactericidal effect between BA and CUR. These findings may contribute to the development of a formulation with microencapsulated compounds to liberate them in different compartments to combat S. Enteritidis infections in broiler chickens. © 2017 The Society for Applied Microbiology.

Ileal endogenous losses in pigs feeding a protein-free diet or diets with different contents of casein or crystalline amino acids.

PubMed

Brestenský, Matej; Nitrayová, Soňa; Patráš, Peter

2017-06-01

The common usage of protein-free diets to estimate unspecific AA losses has been criticised as unphysiological and incorrect. Therefore, in this study different diets were tested for the determination of endogenous losses (EL) of amino acids (AA) and nitrogen (N) assuming a complete absorption in the small intestine. Seven cannulated gilts received a protein-free diet (Diet PF) or diets with 3%, 6% or 10% crude protein (CP) from crystalline AA (Diets CA) or casein (Diets CAS) according to a 7 × 7 Latin square design. After 6 d adaptation to the diet, ileal digesta was collected for 24 h and thereafter analysed for AA, N and the digestibility markers Cr 2 O 3 and acid insoluble ash (AIA). Generally, among all AA, the highest amounts of EL were found for Pro, Glu and Gly, and the smallest for Met. Different levels of CP in Diets CA and CAS had no effect on EL. Significant differences between treatments were observed only for the EL of Glu, Ile, Ser (higher in Diets CA and PF), Pro and Tyr (higher in Diet PF) (p < 0.05). There were no differences in determined EL using Cr 2 O 3 or AIA as digestibility markers.

Targeted antitumoral dehydrocrotonin nanoparticles with L-ascorbic acid 6-stearate.

PubMed

Frungillo, Lucas; Martins, Dorival; Teixeira, Sérgio; Anazetti, Maristela Conti; Melo, Patrícia da Silva; Durán, Nelson

2009-12-01

Tumoral cells are known to have a higher ascorbic acid uptake than normal cells. Therefore, the aim of this study was to obtain polymeric nanoparticles containing the antitumoral compound trans-dehydrocrotonin (DHC) functionalized with L-ascorbic acid 6-stearate (AAS) to specifically target this system tumoral cells. Nanoparticle suspensions (NP-AAS-DHC) were prepared by the nanoprecipitation method. The systems were characterized for AAS presence by thin-layer chromatography and for drug loading (81-88%) by UV-Vis spectroscopy. To further characterize these systems, in vitro release kinetics, size distribution (100-140 nm) and Zeta potential by photon-correlation spectroscopic method were used. In vitro toxicity against HL60 cells was evaluated by tetrazolium reduction and Trypan blue exclusion assays. Cell death by apoptosis was quantified and characterized by flow cytometry and caspase activity. Zeta potential analyses showed that the system has a negatively charged outer surface and also indicate that AAS is incorporated on the external surface of the nanoparticles. In vitro release kinetics assay showed that DHC loaded in nanoparticles had sustained release behavior. In vitro toxicity assays showed that NP-AAS-DHC suspension was more effective as an antitumoral than free DHC or NP-DHC and increased apoptosis induction by receptor-mediated pathway. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

Protective effect of asiatic acid in an experimental cerulein-induced model of acute pancreatitis in mice

PubMed Central

Xiao, Wenqin; Jiang, Weiliang; Li, Kai; Hu, Yangyang; Li, Sisi; Zhou, Li; Wan, Rong

2017-01-01

Asiatic acid (AA), a triterpenoid derived from the medicinal plant Centella asiatica, is considered to have anti-inflammatory, anti-fibrotic and anti-tumor effects, but its effects in acute pancreatitis (AP) are unknown. Our purpose of this study was to investigate the effects of AA in a mouse model of cerulein-induced pancreatitis. We evaluated AA in an experimental model of AP induced in mice by six hourly intraperitoneal injections of cerulein 50 µg/kg. Mice were pretreated with vehicle or AA 50 mg/kg 2 h before the first cerulein injection. The severity of AP was evaluated histologically and by biochemistry, myeloperoxidase activity, proinflammatory cytokine production, and nuclear factor (NF)-κB activity. Administration of AA significantly reduced the severity of AP, and was associated with reduction of serum amylase and lipase levels, decreased pancreatic histological damage, and decreased myeloperoxidase activity. The serum levels and mRNA expression of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and NF-κB activity were reduced. AA also significantly improved the in vitro viability of pancreatic acinar cells induced by cholecystokinin (CCK) and suppressed NF-κB activity. AA protected against experimental AP, possibly by reducing production of proinflammatory cytokines via suppression NF-κB activation. PMID:28861174

Cannabis, tobacco, and caffeine use modify the blood pressure reactivity protection of ascorbic acid.

PubMed

Brody, Stuart; Preut, Ragnar

2002-07-01

Cannabis, caffeine, and tobacco use are associated with increased mesolimbic dopamine activity. Ascorbic acid (AA) modulates some dopaminergic agent effects, and was recently found to decrease systolic blood pressure (SBP) stress reactivity. To examine how AA SBP stress reactivity protection varies by use of these substances, data from an AA trial (Cetebe, 3000 mg/day for 14 days; N=108) were compared by substance use level regarding SBP reactivity to the anticipation and actual experience phases of a standardized psychological stressor (10 min of public speaking and arithmetic). Self-reported never users of cannabis, persons not currently smoking tobacco, and persons consuming three or more caffeine beverages daily all exhibited AA SBP stress reactivity protection to the actual stressor, but not during the anticipation phase. Conversely, self-reported ever cannabis users, current tobacco smokers, and persons consuming less than three caffeine beverages daily exhibited the AA SBP protection during the anticipation phase, but only the lower caffeine consumption group exhibited AA protection during both phases. Covariates (neuroticism, extraversion, and depression scores, age, sex, body mass index) were all nonsignificant. Results are discussed in terms of dopaminergic effects of these substances, modulation of catecholaminergic and endothelial activity, and AA support of coping styles.

Degradation of vitamin C by low-energy electrons

NASA Astrophysics Data System (ADS)

Abdoul-Carime, Hassan; Illenberger, Eugen

2004-06-01

We report on the degradation of gas phase vitamin C (ascorbic acid, AA) induced by low-energy electrons. In the energy range of (0-12) eV, different negatively charged fragments, attributed to the dehydro-ascorbic acid anion ((AA-H) -), OH -, O - and H -, are observed. The yield functions indicate that these ions are formed via dissociative electron attachment, DEA. While the formation of (AA-H) - is exclusively observed at sub-excitation energies (<1.5 eV), the other fragments arise from resonance features at higher energies. Possible implications of these observations for radiation damage and food treatment by high energy radiation are considered.

Roles of d-Amino Acids on the Bioactivity of Host Defense Peptides

PubMed Central

Li, Hao; Anuwongcharoen, Nuttapat; Malik, Aijaz Ahmad; Prachayasittikul, Virapong; Wikberg, Jarl E. S.; Nantasenamat, Chanin

2016-01-01

Host defense peptides (HDPs) are positively-charged and amphipathic components of the innate immune system that have demonstrated great potential to become the next generation of broad spectrum therapeutic agents effective against a vast array of pathogens and tumor. As such, many approaches have been taken to improve the therapeutic efficacy of HDPs. Amongst these methods, the incorporation of d-amino acids (d-AA) is an approach that has demonstrated consistent success in improving HDPs. Although, virtually all HDP review articles briefly mentioned about the role of d-AA, however it is rather surprising that no systematic review specifically dedicated to this topic exists. Given the impact that d-AA incorporation has on HDPs, this review aims to fill that void with a systematic discussion of the impact of d-AA on HDPs. PMID:27376281

Stabilization of Proteins and Noncovalent Protein Complexes during Electrospray Ionization by Amino Acid Additives.

PubMed

Zhang, Hua; Lu, Haiyan; Chingin, Konstantin; Chen, Huanwen

2015-07-21

Ionization of proteins and noncovalent protein complexes with minimal disturbance to their native structure presents a great challenge for biological mass spectrometry (MS). In living organisms, the native structure of intracellular proteins is commonly stabilized by solute amino acids (AAs) accumulated in cells at very high concentrations. Inspired by nature, we hypothesized that AAs could also pose a stabilizing effect on the native structure of proteins and noncovalent protein complexes during ionization. To test this hypothesis, here we explored MS response for various protein complexes upon the addition of free AAs at mM concentrations into the electrospray ionization (ESI) solution. Thermal activation of ESI droplets in the MS inlet capillary was employed as a model destabilizing factor during ionization. Our results indicate that certain AAs, in particular proline (Pro), pose considerable positive effect on the stability of noncovalent protein complexes in ESI-MS without affecting the signal intensity of protein ions and original protein-ligand equilibrium, even when added at the 20 mM concentration. The data suggest that the degree of protein stabilization is primarily determined by the osmolytic and ampholytic characteristics of AA solutes. The highest stability and visibility of noncovalent protein complexes in ESI-MS are achieved using AA additives with neutral isoelectric point, moderate proton affinity, and unfavorable interaction with the native protein state. Overall, our results indicate that the simple addition of free amino acids into the working solution can notably improve the stability and accuracy of protein analysis by native ESI-MS.

Three-dimensional graphene-like carbon frameworks as a new electrode material for electrochemical determination of small biomolecules.

PubMed

Deng, Wenfang; Yuan, Xiaoyan; Tan, Yueming; Ma, Ming; Xie, Qingji

2016-11-15

Three-dimensional (3D) graphene-like carbon frameworks (3DGLCFs) were facilely prepared via copyrolysis of polyaniline and nickel nitrate powder, followed by acid etching. The as-prepared 3DGLCFs possess graphene-like network structure, high specific surface area, and high content nitrogen dopant. Because these features enable large electrochemically active surface area, rapid electron transfer, and fast transport of analytes to electrode surface, the 3DGLCFs modified glassy carbon electrode (GCE) shows current response much higher than commercial graphene (CG) modified GCE towards the oxidation of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The anodic peak separations at 3DGLCFs/GCE are 0.23V between AA and DA, 0.13V between DA and UA, and 0.36V between AA and UA. For the simultaneous electrochemical determination of AA, DA and UA using differential pulse voltammetry, the 3DGLCFs/GCE shows linear response ranges of 1.25×10(-5)-4×10(-4)M for AA, 5×10(-8)-1.0×10(-5)M for DA, and 5×10(-8)-1.5×10(-5)M for UA, with low detection limits of 2×10(-6)M for AA, 1×10(-8)M for DA, and 1×10(-8)M for UA. The 3DGLCFs/GCE was also applied for the measurement of human serum, exhibiting satisfactory recoveries. Copyright © 2016 Elsevier B.V. All rights reserved.