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Sample records for acid total protein

  1. Total protein

    MedlinePlus

    The total protein test measures the total amount of two classes of proteins found in the fluid portion of your ... nutritional problems, kidney disease or liver disease . If total protein is abnormal, you will need to have more ...

  2. Total protein

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003483.htm Total protein To use the sharing features on this page, please enable JavaScript. The total protein test measures the total amount of two classes ...

  3. Bioprocess monitoring: minimizing sample matrix effects for total protein quantification with bicinchoninic acid assay.

    PubMed

    Reichelt, Wieland N; Waldschitz, Daniel; Herwig, Christoph; Neutsch, Lukas

    2016-09-01

    Determining total protein content is a routine operation in many laboratories. Despite substantial work on assay optimization interferences, the widely used bicinchoninic acid (BCA) assay remains widely recognized for its robustness. Especially in the field of bioprocess engineering the inaccuracy caused by interfering substances remains hardly predictable and not well understood. Since the introduction of the assay, sample pre-treatment by trichloroacetic acid (TCA) precipitation has been indicated as necessary and sufficient to minimize interferences. However, the sample matrix in cultivation media is not only highly complex but also dynamically changing over process time in terms of qualitative and quantitative composition. A significant misestimation of the total protein concentration of bioprocess samples is often observed when following standard work-up schemes such as TCA precipitation, indicating that this step alone is not an adequate means to avoid measurement bias. Here, we propose a modification of the BCA assay, which is less influenced by sample complexity. The dynamically changing sample matrix composition of bioprocessing samples impairs the conventional approach of compensating for interfering substances via a static offset. Hence, we evaluated the use of a correction factor based on an internal spike measurement for the respective samples. Using protein spikes, the accuracy of the BCA protein quantification could be improved fivefold, taking the BCA protein quantification to a level of accuracy comparable to other, more expensive methods. This will allow reducing expensive iterations in bioprocess development to due inaccurate total protein analytics. PMID:27314233

  4. Total protein quantitation using the bicinchoninic acid assay and gradient elution moving boundary electrophoresis.

    PubMed

    Kralj, Jason G; Munson, Matthew S; Ross, David

    2014-07-01

    We investigated the ability of gradient elution moving boundary electrophoresis (GEMBE) with capacitively coupled contactless conductivity detection (C(4) D) to assay total protein concentration using the bicinchoninic acid (BCA) reaction. We chose this format because GEMBE-C(4) D behaves as a concentration dependent detection system, unlike optical methods that also rely on pathlength (due to Beer's law). This system tolerates proteins well compared with other capillary electrophoretic methods, allowing the capillary to be reused without coatings or additional hydroxide wash steps. The typical reaction protocol was modified by reducing the pH slightly from 11.25 to 9.4, which enabled elimination of tartrate from the reagents. We estimated that copper (I) could be detected at approximately 3.0 μmol/L, which agrees with similar GEMBE and CZE systems utilizing C(4) D. Under conditions similar to the BCA "micro method" assay, we determined the LOD for three common proteins (insulin, BSA, and bovine gamma globulin) and found that they agree well with the existing spectroscopic detection methods. Further, we investigated how long reaction times impact the LOD and found that the conversion was proportional to log(time). This indicated that little sensitivity is gained by extending the reaction past 1 h. Hence, GEMBE provides an alternative platform for total protein assays while maintaining the excellent sensitivity of the optical-based methods. PMID:24648165

  5. Isotopomer distributions in amino acids from a highly expressed protein as a proxy for those from total protein

    SciTech Connect

    Shaikh, Afshan; Shaikh, Afshan S.; Tang, Yinjie; Mukhopadhyay, Aindrila; Keasling, Jay D.

    2008-06-27

    {sup 13}C-based metabolic flux analysis provides valuable information about bacterial physiology. Though many biological processes rely on the synergistic functions of microbial communities, study of individual organisms in a mixed culture using existing flux analysis methods is difficult. Isotopomer-based flux analysis typically relies on hydrolyzed amino acids from a homogeneous biomass. Thus metabolic flux analysis of a given organism in a mixed culture requires its separation from the mixed culture. Swift and efficient cell separation is difficult and a major hurdle for isotopomer-based flux analysis of mixed cultures. Here we demonstrate the use of a single highly-expressed protein to analyze the isotopomer distribution of amino acids from one organism. Using the model organism E. coli expressing a plasmid-borne, his-tagged Green Fluorescent Protein (GFP), we show that induction of GFP does not affect E. coli growth kinetics or the isotopomer distribution in nine key metabolites. Further, the isotopomer labeling patterns of amino acids derived from purified GFP and total cell protein are indistinguishable, indicating that amino acids from a purified protein can be used to infer metabolic fluxes of targeted organisms in a mixed culture. This study provides the foundation to extend isotopomer-based flux analysis to study metabolism of individual strains in microbial communities.

  6. CSF total protein

    MedlinePlus

    CSF total protein is a test to determine the amount of protein in your spinal fluid, also called cerebrospinal fluid (CSF). ... The normal protein range varies from lab to lab, but is typically about 15 to 60 mg/dL. Note: mg/dL = ...

  7. Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae).

    PubMed

    Chia, Mathias Ahii; Lombardi, Ana Teresa; da Graça Gama Melão, Maria; Parrish, Christopher C

    2015-03-01

    Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10(-7) and 2.0×10(-8)molL(-1) Cd) under varying nitrogen (2.9×10(-6), 1.1×10(-5) and 1.1×10(-3)molL(-1)N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production. PMID:25625522

  8. Unexpected depletion of plasma arachidonate and total protein in cats fed a low arachidonic acid diet due to peroxidation.

    PubMed

    Chamberlin, Amy; Mitsuhashi, Yuka; Bigley, Karen; Bauer, John E

    2011-10-01

    An opportunity to investigate a low-arachidonic acid (AA) feline diet possibly related to elevated peroxide value (PV) during storage on plasma phospholipid (PL) and reproductive tissue fatty acid (FA) profiles presented itself in the present study. Cats (nine animals per group) had been fed one of three dry extruded, complete and balanced diets for 300 d before spaying. The diets contained adequate AA (0.3 g/kg), similar concentration of antioxidants and were stored at ambient temperature, but differed in FA composition. The diets were designated as follows: diet A (high linoleic acid), diet B (high γ-linolenic acid) and diet C (adequate linoleic acid). Diet samples that were obtained the week before spaying revealed an elevated PV of diet A v. diets B and C (135 v. 5.80 and 2.12 meq/kg fat, respectively). Records revealed decreased food consumption of diet A cats beginning at 240 d but without weight loss; thus an opportunity presented to investigate diet PV effects. Total plasma protein and PL-AA concentrations in group A were significantly decreased at 140 and 300 d. Uterine and ovarian tissues collected at surgery revealed modest decrements of AA. Diet A was below minimum standards at 0.015 % (minimum 0.02 %), probably due to oxidation. The time at which diet A became unacceptable may have occurred between 60 and 140 d because plasma PL-AA was within our normal colony range (approximately 4-7 % relative) after 56 d of feeding. High-linoleic acid-containing diets may be more likely to be oxidised requiring additional antioxidants. The findings suggest that reduced plasma protein in combination with plasma AA concentrations may serve as biomarkers of diet peroxidation in cats before feed refusal, weight loss or tissue depletion. PMID:22005409

  9. [Effects of colchicine on the content of ribonucleic acids and total proteins of cultured nerve cells. Preliminary study].

    PubMed

    Noel-Courtey, B

    1975-03-01

    Nervous cells from chick embryo lumbo-sacral spinal cord have been cultivated in vitro and treated with colchicine. The effects of this alkaloid on the RNA and the total protein contents of nervous cells have been studied by quantitative cytochemical methods. The RNA content has been measured by cytophotometry after DNase digestion and gallocyanine-chromalun staining; the cellular protein content has been measured after Naphtol Yellow S staining. In colchicine treated cultures, the main part of the nervous cell population consists of spheroidal and piriform neuroblasts; some cells are neurocytes with short processes. During the 48 first hours in vitro, the RNA content is approximatively identical in treated cells as in controls. The cellular total protein content is much lower in the treated cells than in the controls. PMID:1222295

  10. Proteins and Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...

  11. Master Amino acid Pattern as sole and total substitute for dietary proteins during a weight-loss diet to achieve the body's nitrogen balance equilibrium.

    PubMed

    Lucà-Moretti, M; Grandi, A; Lucà, E; Muratori, G; Nofroni, M G; Mucci, M P; Gambetta, P; Stimolo, R; Drago, P; Giudice, G; Tamburlin, N; Karbalai, M; Valente, C; Moras, G

    2003-01-01

    Results of this multicentric study have shown that by giving Master Amino acid Pattern (MAP) as a sole and total substitute of dietary proteins to 500 overweight participants undergoing the American Nutrition Clinics/Overweight Management Program (ANC/OMP), the participants' body nitrogen balance could be maintained in equilibrium with essentially no calories (MAP 1 g=0.04 kcal), thereby preserving the body's structural and functional proteins, eliminating excessive water retention from the interstitial compartment, and preventing the sudden weight increase after study conclusion commonly known as the yo-yo effect. Study results have shown that the use of MAP, in conjunction with the ANC/OMP regimen, has proven to be safe and effective by preventing those adverse effects associated with a negative nitrogen balance, such as oversized or flabby tissue, stretch marks, the sagging of breast tissue, increased hair loss, faded hair color, and fragile or brittle nails. Also prevented were those anomalies commonly associated with weight-loss diets, such as hunger, weakness, headache caused by ketosis, constipation, and decreased libido. The use of MAP in conjunction with the ANC/OMP also allowed for mean weight loss of 2.5 kg (5.5 lb) per week, achieved through reduction of excessive fat tissue and elimination of excessive water retention from the interstitial compartment. PMID:14964347

  12. Total synthesis of (+)-zaragozic acid C.

    PubMed

    Armstrong, A; Barsanti, P A; Jones, L H; Ahmed, G

    2000-10-20

    A total synthesis of (+)-zaragozic acid C is described. Key features of the synthesis are the use of a double Sharpless asymmetric dihydroxylation reaction of diene 6 to control stereochemistry at four contiguous stereocenters from C3 to C6; the introduction of the C1-side chain by reaction between the anion derived from the dithiane monosulfoxide 27 and the core aldehyde 12; a high yielding, acid-mediated simultaneous acetonide deprotection-dithiane removal-ketalization procedure leading exclusively to the 2, 8-dioxabicyclo[3.2.1]octane core 34; and a novel triple oxidation procedure allowing installation of the tricarboxylic acid. PMID:11031024

  13. Enantioselective Total Synthesis of Secalonic Acid E.

    PubMed

    Ganapathy, Dhandapani; Reiner, Johannes R; Löffler, Lorenz E; Ma, Ling; Gnanaprakasam, Boopathy; Niepötter, Benedikt; Koehne, Ingo; Tietze, Lutz F

    2015-11-16

    The first enantioselective synthesis of a secalonic acid containing a dimeric tetrahydroxanthenone skeleton is described, using a Wacker-type cyclization of a methoxyphenolic compound to form a chiral chroman with a quaternary carbon stereogenic center with >99% ee. Further steps are a Sharpless dihydroxylation and a Dieckmann condensation to give a tetrahydroxanthenone. A late-stage one-pot palladium-catalyzed Suzuki-dimerization reaction leads to the 2,2'-biphenol linkage to complete the enantioselective total synthesis of secalonic acid E in 18 steps with 8% overall yield. PMID:26447631

  14. Comparison of Urinary Total Proteins by Four Different Methods.

    PubMed

    Yalamati, Padma; Karra, Madhu Latha; Bhongir, Aparna V

    2016-10-01

    The total proteins in human urine have been compared by sulfosalicylic acid, sulfosalicylic acid with sodium sulphate and trichloroacetic acid methods with pyrogallol red molybdate method as there are no studies found quantifying imprecision and bias components. Fresh urine of 36 patients was analyzed by four methods. Imprecision and inaccuracy were determined by repeated analysis and method comparison studies using correlation plots, Bland and Altman, and Passing and Bablok regression analyses respectively. The coefficient of variation was 5.07 % for pyrogallol red molybdate; 6.84 % for sulfosalicylic acid; 3.97 % for sulfosalicylic acid with sodium sulphate and 5.93 % for trichloroacetic acid methods. Bland and Altman analysis showed a bias of 5.8, 1.7 and -5.4 for pyrogallol red molybdate versus sulfosalicylic acid, sulfosalicylic acid with sodium sulphate and trichloroacetic acid methods respectively. Passing and Bablok regression revealed a constant bias for pyrogallol red molybdate versus all turbidimetric methods but a proportional bias only with trichloroacetic acid method. Sulfosalicylic acid with sodium sulphate method is preferred to sulfosalicylic acid and trichloroacetic acid methods. PMID:27605745

  15. Total Cellular RNA Modulates Protein Activity.

    PubMed

    Majumder, Subhabrata; DeMott, Christopher M; Reverdatto, Sergey; Burz, David S; Shekhtman, Alexander

    2016-08-16

    RNA constitutes up to 20% of a cell's dry weight, corresponding to ∼20 mg/mL. This high concentration of RNA facilitates low-affinity protein-RNA quinary interactions, which may play an important role in facilitating and regulating biological processes. In the yeast Pichia pastoris, the level of ubiquitin-RNA colocalization increases when cells are grown in the presence of dextrose and methanol instead of methanol as the sole carbon source. Total RNA isolated from cells grown in methanol increases β-galactosidase activity relative to that seen with RNA isolated from cells grown in the presence of dextrose and methanol. Because the total cellular RNA content changes with growth medium, protein-RNA quinary interactions can alter in-cell protein biochemistry and may play an important role in cell adaptation, critical to many physiological and pathological states. PMID:27456029

  16. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  17. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  18. Microspectrophotometric quantitation of nucleic acid and protein in irradiated epidermis.

    PubMed

    Conti, C J; Giménez, I B; Cabrini, R L

    1976-03-01

    Nucleic acid and proteins of newborn rat tail subjected to local X-irradiation were microspectrophotometrically studied. Feulgen, gallocyanine chrom-alum and naphthol yellow S methods were performed for demonstration of DNA, total nucleic acid and proteins respectively. The amount of proteins and total nucleic acid increases concomitantly with reactional acanthosis. However, the proteins and nucleic acid decrease as from day 3 post-irradiation. A tentative interpretation of the results would point to a giantization of the epidermic cells not only caused by aqueous imbition but also by an actual increase of the cellular protoplasm. PMID:1258094

  19. Formulation of plant based Rainbow trout feeds on an Ideal Protein Basis can reduce total dietary protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fish meal has been a primary protein source in trout feeds and any changes that can reduce fish meal levels and total costs are beneficial. Replacing fish meal with plant protein is a first step, but amino acid content of plant based diets can be limiting. Amino acids are needed for many metabolic...

  20. Total Protein and Albumin/Globulin Ratio Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Total Protein and Albumin/Globulin (A/G) Ratio Share this ... Globulin Ratio; A/G Ratio Formal name: Total Protein; Albumin to Globulin Ratio Related tests: Albumin ; Liver ...

  1. Total synthesis and complete stereostructure of gambieric acid A.

    PubMed

    Fuwa, Haruhiko; Ishigai, Kazuya; Hashizume, Keisuke; Sasaki, Makoto

    2012-07-25

    Total synthesis of gambieric acid A, a potent antifungal polycyclic ether metabolite, has been accomplished for the first time, which firmly established the complete stereostructure of this natural product. PMID:22779404

  2. Concise total synthesis of (±)-actinophyllic acid

    PubMed Central

    Granger, Brett A.; Jewett, Ivan T.; Butler, Jeffrey D.; Martin, Stephen F.

    2014-01-01

    A concise total synthesis of the complex indole alkaloid (±)-actinophyllic acid was accomplished by a sequence of reactions requiring only 10 steps from readily-available, known starting materials. The approach featured a Lewis acid-catalyzed cascade of reactions involving stabilized carbocations that delivered the tetracyclic core of the natural product in a single chemical operation. Optimal conversion of this key intermediate into (±)-actinophyllic acid required judicious selection of a protecting group strategy. PMID:24882888

  3. Protein and Amino Acid Requirements during Pregnancy.

    PubMed

    Elango, Rajavel; Ball, Ronald O

    2016-07-01

    Protein forms an essential component of a healthy diet in humans to support both growth and maintenance. During pregnancy, an exceptional stage of life defined by rapid growth and development, adequate dietary protein is crucial to ensure a healthy outcome. Protein deposition in maternal and fetal tissues increases throughout pregnancy, with most occurring during the third trimester. Dietary protein intake recommendations are based on factorial estimates because the traditional method of determining protein requirements, nitrogen balance, is invasive and undesirable during pregnancy. The current Estimated Average Requirement and RDA recommendations of 0.88 and 1.1 g · kg(-1) · d(-1), respectively, are for all stages of pregnancy. The single recommendation does not take into account the changing needs during different stages of pregnancy. Recently, with the use of the minimally invasive indicator amino acid oxidation method, we defined the requirements to be, on average, 1.2 and 1.52 g · kg(-1) · d(-1) during early (∼16 wk) and late (∼36 wk) stages of pregnancy, respectively. Although the requirements are substantially higher than current recommendations, our values are ∼14-18% of total energy and fit within the Acceptable Macronutrient Distribution Range. Using swine as an animal model we showed that the requirements for several indispensable amino acids increase dramatically during late gestation compared with early gestation. Additional studies should be conducted during pregnancy to confirm the newly determined protein requirements and to determine the indispensable amino acid requirements during pregnancy in humans. PMID:27422521

  4. Human Protein and Amino Acid Requirements.

    PubMed

    Hoffer, L John

    2016-05-01

    Human protein and amino acid nutrition encompasses a wide, complex, frequently misunderstood, and often contentious area of clinical research and practice. This tutorial explains the basic biochemical and physiologic principles that underlie our current understanding of protein and amino acid nutrition. The following topics are discussed: (1) the identity, measurement, and essentiality of nutritional proteins; (2) the definition and determination of minimum requirements; (3) nutrition adaptation; (4) obligatory nitrogen excretion and the minimum protein requirement; (5) minimum versus optimum protein intakes; (6) metabolic responses to surfeit and deficient protein intakes; (7) body composition and protein requirements; (8) labile protein; (9) N balance; (10) the principles of protein and amino acid turnover, including an analysis of the controversial indicator amino acid oxidation technique; (11) general guidelines for evaluating protein turnover articles; (12) amino acid turnover versus clearance; (13) the protein content of hydrated amino acid solutions; (14) protein requirements in special situations, including protein-catabolic critical illness; (15) amino acid supplements and additives, including monosodium glutamate and glutamine; and (16) a perspective on the future of protein and amino acid nutrition research. In addition to providing practical information, this tutorial aims to demonstrate the importance of rigorous physiologic reasoning, stimulate intellectual curiosity, and encourage fresh ideas in this dynamic area of human nutrition. In general, references are provided only for topics that are not well covered in modern textbooks. PMID:26796095

  5. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Total protein test system. 862.1635 Section 862.1635 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1635 Total protein test system....

  6. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Total protein test system. 862.1635 Section 862.1635 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1635 Total protein test system....

  7. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Total protein test system. 862.1635 Section 862.1635 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1635 Total protein test system....

  8. Total sulfate vs. sulfuric acid monomer concenterations in nucleation studies

    NASA Astrophysics Data System (ADS)

    Neitola, K.; Brus, D.; Makkonen, U.; Sipilä, M.; Mauldin, R. L., III; Sarnela, N.; Jokinen, T.; Lihavainen, H.; Kulmala, M.

    2015-03-01

    Sulfuric acid is known to be a key component for atmospheric nucleation. Precise determination of sulfuric-acid concentration is a crucial factor for prediction of nucleation rates and subsequent growth. In our study, we have noticed a substantial discrepancy between sulfuric-acid monomer concentrations and total-sulfate concentrations measured from the same source of sulfuric-acid vapor. The discrepancy of about 1-2 orders of magnitude was found with similar particle-formation rates. To investigate this discrepancy, and its effect on nucleation, a method of thermally controlled saturator filled with pure sulfuric acid (97% wt.) for production of sulfuric-acid vapor is applied and rigorously tested. The saturator provided an independent vapor-production method, compared to our previous method of the furnace (Brus et al., 2010, 2011), to find out if the discrepancy is caused by the production method itself. The saturator was used in a H2SO4-H2O nucleation experiment, using a laminar flow tube to check reproducibility of the nucleation results with the saturator method, compared to the furnace. Two independent methods of mass spectrometry and online ion chromatography were used for detecting sulfuric-acid or sulfate concentrations. Measured sulfuric-acid or total-sulfate concentrations are compared to theoretical predictions calculated using vapor pressure and a mixing law. The calculated prediction of sulfuric-acid concentrations agrees very well with the measured values when total sulfate is considered. Sulfuric-acid monomer concentration was found to be about 2 orders of magnitude lower than theoretical predictions, but with a temperature dependency similar to the predictions and the results obtained with the ion-chromatograph method. Formation rates are reproducible when compared to our previous results with both sulfuric-acid or total-sulfate detection and sulfuric-acid production methods separately, removing any doubts that the vapor-production method would

  9. First total synthesis of prasinic acid and its anticancer activity.

    PubMed

    Chakor, Narayan; Patil, Ganesh; Writer, Diana; Periyasamy, Giridharan; Sharma, Rajiv; Roychowdhury, Abhijit; Mishra, Prabhu Dutt

    2012-11-01

    The first total synthesis of prasinic acid is being reported along with its biological evaluation. The ten step synthesis involved readily available and cheap starting materials and can easily be transposed to large scale manufacturing. The crucial steps of the synthesis included the formation of two different aromatic units (7 and 9) and their coupling reaction. The synthetic prasinic acid exhibited moderate antitumor activity (IC(50) 4.3-9.1 μM) in different lines of cancer cells. PMID:23031589

  10. Strategies for the Total Synthesis of Clavicipitic Acid.

    PubMed

    Ito, Mamoru; Tahara, Yu-Ki; Shibata, Takanori

    2016-04-11

    Clavicipitic acid is an ergot alkaloid, which was isolated from Claviceps strain and Claviceps fusiformis. Its unique tricyclic azepinoindole skeleton has attracted synthetic chemists, and various strategies have been developed for its total synthesis. These strategies can be generally categorized into two types based on the synthetic intermediates, namely, 4-substituted gramine derivatives and 4-substituted tryptophan derivatives. This Minireview summarizes the reported total syntheses from the point of these two key intermediates. PMID:26822254

  11. Protein biosynthesis with conformationally restricted amino acids

    SciTech Connect

    Mendel, D. Lawrence Berkeley Lab., CA ); Ellman, J.; Schultz, P.G. )

    1993-05-19

    The incorporation of conformationally constrained amino acids into peptides is a powerful approach for generating structurally defined peptides as conformational probes and bioactive agents. The ability to site-specifically introduce constrained amino acids into large polypeptide chains would provide a similar opportunity to probe the flexibility, conformation, folding and stability of proteins. To this end, we have examined the competence of the Escherichia coli protein biosynthetic machinery to incorporate a number of these unnatural amino acids into the 164 residue protein T4 lysozyme (T4L). Results clearly demonstrate that the protein biosynthetic machinery can accommodate a wide variety of conformationally constrained amino acids. The expansion of structural motifs that can be biosynthetically incorporated into proteins to include a large number of conformationally constrained amino acids significantly increases the power of mutagenesis methods as probes of protein structure and function and provides additional insights into the steric requirements of the translational machinery. 13 refs., 2 figs.

  12. Total Syntheses of Secalonic Acids A and D**

    PubMed Central

    Qin, Tian

    2014-01-01

    Total syntheses of the dimeric tetrahydroxanthone natural products secalonic acids A and D are described. Key steps involve kinetic resolution of the tetrahydroxanthone core structure using homobenzotetramisole (HBTM) catalysis and late-stage copper (I)-mediated homodimerization of complex aryl stannane monomers. PMID:24519991

  13. Distinguishing Proteins From Arbitrary Amino Acid Sequences

    PubMed Central

    Yau, Stephen S.-T.; Mao, Wei-Guang; Benson, Max; He, Rong Lucy

    2015-01-01

    What kinds of amino acid sequences could possibly be protein sequences? From all existing databases that we can find, known proteins are only a small fraction of all possible combinations of amino acids. Beginning with Sanger's first detailed determination of a protein sequence in 1952, previous studies have focused on describing the structure of existing protein sequences in order to construct the protein universe. No one, however, has developed a criteria for determining whether an arbitrary amino acid sequence can be a protein. Here we show that when the collection of arbitrary amino acid sequences is viewed in an appropriate geometric context, the protein sequences cluster together. This leads to a new computational test, described here, that has proved to be remarkably accurate at determining whether an arbitrary amino acid sequence can be a protein. Even more, if the results of this test indicate that the sequence can be a protein, and it is indeed a protein sequence, then its identity as a protein sequence is uniquely defined. We anticipate our computational test will be useful for those who are attempting to complete the job of discovering all proteins, or constructing the protein universe. PMID:25609314

  14. Indirect electrochemical detection for total bile acids in human serum.

    PubMed

    Zhang, Xiaoqing; Zhu, Mingsong; Xu, Biao; Cui, Yue; Tian, Gang; Shi, Zhenghu; Ding, Min

    2016-11-15

    Bile acids level in serum is a useful index for screening and diagnosis of hepatobiliary diseases. As bile acids concentration is closely related to the degree of hepatobiliary diseases, detecting it is a vital factor to understand the stage of the diseases. The prevalent determination for bile acids is the enzymatic cycling method which has low sensitivity while reagent-consuming. It is desirable to develop a new method with lower cost and higher sensitivity. An indirect electrochemical detection (IED) for bile acids in human serum was established using the screen printed carbon electrode (SPCE). Since bile acids do not show electrochemical signals, they were converted to 3-ketosteroids by 3-α-hydroxysteroid dehydrogenase (3α-HSD) in the presence of nicotinamide adenine dinucleotide (NAD(+)), which was reduced to NADH. NADH could then be oxidized on the surface of SPCE, generating a signal that was used to calculate the total bile acids (TBA) concentration. A good linear calibration for TBA was obtained at the concentration range from 5.00μM to 400μM in human serum. Both the precisions and recoveries were sufficient to be used in a clinical setting. The TBA concentrations in 35 human serum samples by our IED method didn't show significant difference with the result by enzymatic cycling method, using the paired t-test. Moreover, our IED method is reagent-saving, sensitive and cost-effective. PMID:27236139

  15. Modular Total Synthesis of Protein Kinase C Activator (-)-Indolactam V.

    PubMed

    Haynes-Smith, Jeremy; Diaz, Italia; Billingsley, Kelvin L

    2016-05-01

    A concise, eight-step total synthesis of (-)-indolactam V, a nanomolar agonist of protein kinase C, is reported. The synthesis relies upon an efficient copper-catalyzed amino acid arylation to establish the indole C4-nitrogen bond. This cross-coupling method is applicable to a range of hydrophobic amino acids, providing a platform for further diversification of indolactam alkaloid scaffolds and studies on their potent biological activity. PMID:27074538

  16. Phenol-Sulfuric Acid Method for Total Carbohydrates

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    The phenol-sulfuric acid method is a simple and rapid colorimetric method to determine total carbohydrates in a sample. The method detects virtually all classes of carbohydrates, including mono-, di-, oligo-, and polysaccharides. Although the method detects almost all carbohydrates, the absorptivity of the different carbohydrates varies. Thus, unless a sample is known to contain only one carbohydrate, the results must be expressed arbitrarily in terms of one carbohydrate.

  17. Total Synthesis of (−)-Nodulisporic Acid D

    PubMed Central

    Zou, Yike; Melvin, Jason E.; Gonzales, Stephen S.; Spafford, Matthew J.; Smith, Amos B.

    2015-01-01

    A convergent total synthesis of the architecturally complex indole diterpenoid (−)-nodulisporic acid D has been achieved. Key synthetic transformations include vicinal difunctionalization of an advanced α,β-unsaturated aldehyde to form the E,F-transfused 5,6-ring system of the eastern hemisphere and a cascade cross-coupling/indolization protocol leading to the CDE multisubstituted indole core. PMID:26029849

  18. Practical Total Syntheses of Acromelic Acids A and B.

    PubMed

    Inai, Makoto; Ouchi, Hitoshi; Asahina, Aya; Asakawa, Tomohiro; Hamashima, Yoshitaka; Kan, Toshiyuki

    2016-07-01

    Practical total syntheses of acromelic acids A (1) and B (2), which were scarce natural products isolated from toxic mushroom by Shirahama and Matsumoto, were accomplished in 13 (36% total yield) and 17 steps (6.9% total yield), respectively, from 2,6-dichloropyridine (8). Beginning with regioselective transformation of symmetric 8 by either ortho-lithiation or bromination, nitroalkenes 15 and 16 were provided. Stereoselective construction of the vicinal stereocenters at the C-3, 4 positions of 1 and 2 was performed by a Ni-catalyzed asymmetric conjugate addition of α-ketoesters to the nitroalkenes. Construction of the pyrrolidine ring was accomplished in a single operation via a sequence consisting of reduction of the nitro group, intramolecular condensation with the ketone, and reduction of the resulting ketimine. PMID:26911556

  19. Total synthesis of the squalene synthase inhibitor zaragozic acid C.

    PubMed

    Nakamura, Seiichi

    2005-01-01

    Zaragozic acids and squalestatins were documented by Merck, Glaxo, and Tokyo Noko University/Mitsubishi Kasei Corporation as part of a program aimed at identifying novel inhibitors of squalene synthase, as well as farnesyl transferase. These natural products have attracted considerable attention from numerous synthetic chemists because of their therapeutic potential and novel architecture. This review highlights our total syntheses of zaragozic acid C by two convergent strategies. The key steps in our first-generation synthesis involve 1) simultaneous creation of the C4 and C5 quaternary stereocenters through the Sn(OTf)2-promoted aldol coupling reaction between the alpha-keto ester and silyl ketene thioacetal derived from L- and D-tartaric acids, respectively; and 2) construction of the bicyclic core structure via acid-catalyzed internal ketalization under kinetically controlled conditions. The second-generation strategy relies on a tandem carbonyl ylide formation/1,3-dipolar cycloaddition approach and features elongation of the C1 alkyl side chain through an olefin cross-metathesis as well as high convergency and flexibility. PMID:15635219

  20. Quantification Assays for Total and Polyglutamine-Expanded Huntingtin Proteins

    PubMed Central

    Boogaard, Ivette; Smith, Melanie; Pulli, Kristiina; Szynol, Agnieszka; Albertus, Faywell; Lamers, Marieke B. A. C.; Dijkstra, Sipke; Kordt, Daniel; Reindl, Wolfgang; Herrmann, Frank; McAllister, George; Fischer, David F.; Munoz-Sanjuan, Ignacio

    2014-01-01

    The expansion of a CAG trinucleotide repeat in the huntingtin gene, which produces huntingtin protein with an expanded polyglutamine tract, is the cause of Huntington's disease (HD). Recent studies have reported that RNAi suppression of polyglutamine-expanded huntingtin (mutant HTT) in HD animal models can ameliorate disease phenotypes. A key requirement for such preclinical studies, as well as eventual clinical trials, aimed to reduce mutant HTT exposure is a robust method to measure HTT protein levels in select tissues. We have developed several sensitive and selective assays that measure either total human HTT or polyglutamine-expanded human HTT proteins on the electrochemiluminescence Meso Scale Discovery detection platform with an increased dynamic range over other methods. In addition, we have developed an assay to detect endogenous mouse and rat HTT proteins in pre-clinical models of HD to monitor effects on the wild type protein of both allele selective and non-selective interventions. We demonstrate the application of these assays to measure HTT protein in several HD in vitro cellular and in vivo animal model systems as well as in HD patient biosamples. Furthermore, we used purified recombinant HTT proteins as standards to quantitate the absolute amount of HTT protein in such biosamples. PMID:24816435

  1. SEED PROTEIN QUANTITIES OF FIELD-GROWN SOYBEANS EXPOSED TO SIMULATED ACIDIC RAIN

    EPA Science Inventory

    Analysis of seeds harvested from field-grown soybeans demonstrated that simulated acidic rainfalls from two experimental protocols can significantly decrease total protein contents of soybeans. Statistically significant differences in protein content per seed mass were obtained i...

  2. Non-protein amino acids and neurodegeneration: the enemy within.

    PubMed

    Rodgers, Kenneth J

    2014-03-01

    Animals, in common with plants and microorganisms, synthesise proteins from a pool of 20 protein amino acids (plus selenocysteine and pyrolysine) (Hendrickson et al., 2004). This represents a small proportion (~2%) of the total number of amino acids known to exist in nature (Bell, 2003). Many 'non-protein' amino acids are synthesised by plants, and in some cases constitute part of their chemical armoury against pathogens, predators or other species competing for the same resources (Fowden et al., 1967). Microorganisms can also use selectively toxic amino acids to gain advantage over competing organisms (Nunn et al., 2010). Since non-protein amino acids (and imino acids) are present in legumes, fruits, seeds and nuts, they are ubiquitous in the diets of human populations around the world. Toxicity to humans is unlikely to have been the selective force for their evolution, but they have the clear potential to adversely affect human health. In this review we explore the links between exposure to non-protein amino acids and neurodegenerative disorders in humans. Environmental factors play a major role in these complex disorders which are predominantly sporadic (Coppede et al., 2006). The discovery of new genes associated with neurodegenerative diseases, many of which code for aggregation-prone proteins, continues at a spectacular pace but little progress is being made in identifying the environmental factors that impact on these disorders. We make the case that insidious entry of non-protein amino acids into the human food chain and their incorporation into protein might be contributing significantly to neurodegenerative damage. PMID:24374297

  3. A Soluble, Folded Protein without Charged Amino Acid Residues.

    PubMed

    Højgaard, Casper; Kofoed, Christian; Espersen, Roall; Johansson, Kristoffer Enøe; Villa, Mara; Willemoës, Martin; Lindorff-Larsen, Kresten; Teilum, Kaare; Winther, Jakob R

    2016-07-19

    Charges are considered an integral part of protein structure and function, enhancing solubility and providing specificity in molecular interactions. We wished to investigate whether charged amino acids are indeed required for protein biogenesis and whether a protein completely free of titratable side chains can maintain solubility, stability, and function. As a model, we used a cellulose-binding domain from Cellulomonas fimi, which, among proteins of more than 100 amino acids, presently is the least charged in the Protein Data Bank, with a total of only four titratable residues. We find that the protein shows a surprising resilience toward extremes of pH, demonstrating stability and function (cellulose binding) in the pH range from 2 to 11. To ask whether the four charged residues present were required for these properties of this protein, we altered them to nontitratable ones. Remarkably, this chargeless protein is produced reasonably well in Escherichia coli, retains its stable three-dimensional structure, and is still capable of strong cellulose binding. To further deprive this protein of charges, we removed the N-terminal charge by acetylation and studied the protein at pH 2, where the C-terminus is effectively protonated. Under these conditions, the protein retains its function and proved to be both soluble and have a reversible folding-unfolding transition. To the best of our knowledge, this is the first time a soluble, functional protein with no titratable side chains has been produced. PMID:27307139

  4. Probing protein stability with unnatural amino acids

    SciTech Connect

    Mendel, D.; Ellman, J.A.; Zhiyuh Chang; Veenstra, D.L.; Kollman, P.A.; Schultz, P.G. )

    1992-06-26

    Unnatural amino acid mutagenesis, in combination with molecular modeling and simulation techniques, was used to probe the effect of side chain structure on protein stability. Specific replacements at position 133 in T4 lysozyme included (1) leucine (wt), norvaline, ethylglycine, and alanine to measure the cost of stepwise removal of methyl groups from the hydrophobic core, (2) norvaline and O-methyl serine to evaluate the effects of side chain solvation, and (3) leucine, S,S-2-amino-4-methylhexanoic acid, and S-2-amino-3-cyclopentylpropanoic acid to measure the influence of packing density and side chain conformational entropy on protein stability. All of these factors (hydrophobicity, packing, conformational entropy, and cavity formation) significantly influence protein stability and must be considered when analyzing any structural change to proteins.

  5. A flow injection sampling resonance light scattering system for total protein determination in human serum

    NASA Astrophysics Data System (ADS)

    Dong, Lijun; Li, Ying; Zhang, Yaheng; Chen, Xingguo; Hu, Zhide

    2007-04-01

    A novel flow injection method with resonance light scattering detection was developed for the determination of total protein concentrations. This method is based on the enhancement of RLS signals from Methyl Blue (MB) by protein. The enhanced RLS intensities at 333 nm, in a pH 4.1 acidic aqueous solution, were proportional to the protein concentration over the range 2.0-37.3 and 1.0-36.0 μg ml -1 for human serum albumin (HSA) and bovine serum albumin (BSA), respectively. The corresponding limits of detection (3 σ) of 45 ng ml -1 for HSA and 80 ng ml -1 for BSA were attained. The method was successfully applied to the quantification of total proteins in human serum samples, the maximum relative error is less than 1% and the recovery is between 98% and 102%. The sample throughput was 60 h -1.

  6. Intestinal mucosa in diabetes: synthesis of total proteins and sucrase-isomaltase

    SciTech Connect

    Olsen, W.A.; Perchellet, E.; Malinowski, R.L.

    1986-06-01

    The effects of insulin deficiency on nitrogen metabolism in muscle and liver have been extensively studied with recent in vivo demonstration of impaired protein synthesis in rats with streptozotocin-induced diabetes. Despite the significant contribution of small intestinal mucosa to overall protein metabolism, the effect of insulin deficiency on intestinal protein synthesis have not been completely defined. The authors studied the effects of streptozotocin-induced diabetes on total protein synthesis by small intestinal mucosa and on synthesis of a single enzyme protein of the enterocyte brush-border membrane sucrase-isomaltase. They used the flood-dose technique to minimize the difficulties of measuring specific radioactivity of precursor phenylalanine and determined incorporation into mucosal proteins and sucrase-isomaltase 20 min after injection of the labeled amino acid. Diabetes did not alter mucosal mass as determined by weight and content of protein and DNA during the 5 days after injection of streptozotocin. Increased rates of sucrase-isomaltase synthesis developed beginning on day 3, and those of total protein developed on day 5. Thus intestinal mucosal protein synthesis is not an insulin-sensitive process.

  7. Detection of non-protein amino acids in the presence of protein amino acids. II.

    NASA Technical Reports Server (NTRS)

    Shapshak, P.; Okaji, M.

    1972-01-01

    Studies conducted with the JEOL 5AH amino acid analyzer are described. This instrument makes possible the programming of the chromatographic process. Data are presented showing the separations of seventeen non-protein amino acids in the presence of eighteen protein amino acids. It is pointed out that distinct separations could be obtained in the case of a number of chemically similar compounds, such as ornithine and lysine, N-amidino alanine and arginine, and iminodiacetic acid and S-carboxymethyl cysteine and aspartic acid.

  8. Protein and amino Acid supplementation in athletes.

    PubMed

    Armsey, Thomas D; Grime, Todd E

    2002-08-01

    Amino acid supplementation is practiced by numerous individuals with the hope of increasing muscle mass and function by increasing available proteins. Theoretically, this makes a great deal of sense; the scientific facts, however, fail to conclusively prove that ingesting more than the recommended dietary allowance of protein has any effect on otherwise healthy adults. Athletes may be the exception to this rule. This review examines the most current literature pertaining to amino acid supplementation, and reports on the potential benefits and risks of this common practice. PMID:12831703

  9. Proteins, Peptides and Amino Acids: Role in Infant Nutrition.

    PubMed

    Nutten, Sophie

    2016-01-01

    Proteins are polymers composed of 30 or more amino acids; some of them are essential dietary components, since they are not synthetized by human metabolic processes. They are crucial for healthy growth and development and influence major functions of the body. The infant's first year is a critical time of rapid growth and development, which must be supported by a high rate of protein synthesis. Breast milk, as a single specific food source in the first months of life, is providing the total protein and essential amino acids required. Infant formulas have been designed for infants who cannot be breastfed. They should be similar to breast milk in their composition and their functional outcomes, insuring appropriate growth, optimal development, maturation of the immune system, easy digestion and healthy metabolic programming. By modifying their protein components, specific infant formulas have also been developed for specific needs. For example, partially hydrolyzed (prevention of atopic dermatitis) and extensively hydrolyzed or amino-acid-based infant formulas (reduction in allergy symptoms) have been designed for the management of cow's milk protein allergy. In conclusion, proteins provided via breast milk or infant formula are essential components of the infant's diet; therefore, the specific quality, quantity and conformation of proteins are of utmost importance for healthy growth and development. PMID:27336588

  10. Nucleic acids, proteins, and chirality

    NASA Technical Reports Server (NTRS)

    Usher, D. A.; Profy, A. T.; Walstrum, S. A.; Needels, M. C.; Bulack, S. C.; Lo, K. M.

    1984-01-01

    The present investigation is concerned with experimental results related, in one case, to the chirality of nucleotides, and, in another case, to the possibility of a link between the chirality of nucleic acids, and that of peptides. It has been found that aminoacylation of the 'internal' hydroxyl group of a dinucleoside monophosphate can occur stereoselectively. However, this reaction has not yet been made a part of a working peptide synthesis scheme. The formation and cleavage of oligonucleotides is considered. In the event of the formation of a helical complex between the oligonucleotide and the polymer, 1-prime,5-prime-bonds in the oligomer are found to become more resistant towards cleavage. The conditions required for peptide bond formation are examined, taking into account the known structures of RNA and possible mechanisms for prebiotic peptide bond formation. The possibility is considered that the 2-prime,5-prime-internucleotide linkage could have played an important part in the early days of biological peptide synthesis.

  11. Total protein or high-abundance protein: Which offers the best loading control for Western blotting?

    PubMed

    Thacker, Jonathan S; Yeung, Derrick H; Staines, W Richard; Mielke, John G

    2016-03-01

    Western blotting routinely involves a control for variability in the amount of protein across immunoblot lanes. Normalizing a target signal to one found for an abundantly expressed protein is widely regarded as a reliable loading control; however, this approach is being increasingly questioned. As a result, we compared blotting for two high-abundance proteins (actin and glyceraldehyde 3-phosphate dehydrogenase [GAPDH]) and two total protein membrane staining methods (Ponceau and Coomassie Brilliant Blue) to determine the best control for loading variability. We found that Ponceau staining optimally balanced accuracy and precision, and we suggest that this approach be considered as an alternative to normalizing with a high-abundance protein. PMID:26706797

  12. The cysteine, total sulfur amino acid, tyrosine, phenylalanine + tyrosine, and non-essential amino acid maintenance requirements of broiler breeders.

    PubMed

    Ekmay, R D; Mei, S J; Sakomura, N K; Coon, C N

    2016-06-01

    Two hundred and fifty Cobb-Vantress broiler breeders were used to determine the maintenance requirement and efficiency of utilization of dietary Cys, Tyr, and non-essential amino acids (AA) in a 21-day experiment. The breeders were fed crystalline amino acid diets containing graded levels of Cys or Tyr representing 0, 10, 20, 30, and 40% of their suggested requirement level with all other amino acids maintained at 40% of their suggested requirement level. To determine the non-essential AA maintenance requirement, graded levels of non-essential AA were provided by glutamic acid to represent 12, 19, 26, 33, and 40% of the ideal level of glutamic acid with all other amino acids maintained at their maintenance requirement level. The total sulfur amino acid (TSAA) and Phe + Tyr requirements were calculated by combining Cys and Tyr results, respectively, with previously determined Met and Phe, respectively. The slope of Cys, Tyr, and non-essential AA accretion regression line indicated that 29% Cys, 24% TSAA, 21% Tyr, 20% Phe + Tyr, and 9% non-essential AA of crystalline amino acids were retained. The Cys requirement for zero protein accretion was calculated to be 30.48 mg/d or 17.006 mg/ kgBW(0.75)/d or 75.426 mg/kgCP/d. The TSAA requirement for zero accretion was calculated to be 132.25 mg/b/d, 71.48 mg/kgBW(0.75)/d, and 307.55 mg/kgCP/d. The Tyr requirement for zero protein accretion was calculated to be 65.907 mg/d or 37.233 mg/ kgBW(0.75)/d or 175.566 mg/kgCP/d. The Phe + Tyr requirement for zero protein accretion was calculated to be 352.18 mg/b/d, 190.37 mg/kgBW(0.75)/d, and 749.33 mg/kgCP/d. The non-essential AA requirement for zero protein accretion was calculated to be 3715.194 mg/d or 2003.155 mg/kgBW(0.75)/d or 9452.954 mg/kgCP/d. PMID:26994191

  13. Amino acid profiles and digestible indispensable amino acid scores of proteins from the prioritized key foods in Bangladesh.

    PubMed

    Shaheen, Nazma; Islam, Saiful; Munmun, Sarah; Mohiduzzaman, Md; Longvah, Thingnganing

    2016-12-15

    Concentrations of standard amino acids were determined in the composite samples (representing 30 agro-ecological zones of Bangladesh) of six prioritized key dietary protein sources: Oryza sativa (rice), Triticum aestivum (wheat flour), Lens culinaris (lentils), Pangusius pangusius (pangas), Labeo rohita (rohu) and Oreochromis mossambicus (tilapia). Digestible indispensable amino acid scores (DIAAS) was calculated using published data on amino acids' digestibility to evaluate the protein quality of these foods. Indispensable amino acid (IAA) contents (mg IAA/g protein), found to be highest in pangas (430) and lowest in wheat (336), of all these analyzed foods exceeded the FAO recommended daily allowance (277mg IAA/g protein) and contributed on average 40% to total amino acid contents. Untruncated DIAAS values ranged from 51% (lysine) in wheat to 106% (histidine) in pangas and distinguished pangas, rohu, and tilapia containing 'excellent quality' protein (DIAAS>100%) with potential to complement lower quality protein of cereals, fruits, and vegetables. PMID:27451158

  14. Dihydrolipoic acid reduces cytochrome b561 proteins.

    PubMed

    Bérczi, Alajos; Zimányi, László; Asard, Han

    2013-03-01

    Cytochrome b561 (Cyt-b561) proteins constitute a family of trans-membrane proteins that are present in a wide variety of organisms. Two of their characteristic properties are the reducibility by ascorbate (ASC) and the presence of two distinct b-type hemes localized on two opposite sides of the membrane. Here we show that the tonoplast-localized and the putative tumor suppressor Cyt-b561 proteins can be reduced by other reductants than ASC and dithionite. A detailed spectral analysis of the ASC-dependent and dihydrolipoic acid (DHLA)-dependent reduction of these two Cyt-b561 proteins is also presented. Our results are discussed in relation to the known antioxidant capability of DHLA as well as its role in the regeneration of other antioxidant compounds of cells. These results allow us to speculate on new biological functions for the trans-membrane Cyt-b561 proteins. PMID:22526465

  15. Nucleic acid-protein interactions: Wedding for love or circumstances?

    PubMed

    Lavelle, Christophe; Buckle, Malcolm

    2009-08-01

    The sixth Figeac meeting on nucleic acid-protein interactions was held in Figeac, France, from September 26th to October 1st, 2008. It was organized by the working group "nucleic acid-protein interactions and gene expression" from the French Society for Biochemistry and Molecular Biology. This report briefly summarizes the presentations by 40 speakers during the four plenary sessions, which were organised as follows: (1) nucleic acids: targets and tools, (2) RNA superstar, (3) nuclear structure and dynamics, and (4) new concepts - new approaches. A total of 22 plenary lectures, 18 oral communications and 40 posters were presented over the 5 days, providing a highly stimulating environment for scientific exchange between the approximately 80 participants (biochemists, physicists, bio-informaticians and molecular and cellular biologists). PMID:19422875

  16. Continuous versus intermittent exercise effects on urinary excretion of albumin and total protein.

    PubMed

    Montelpare, W J; Klentrou, P; Thoden, J

    2002-09-01

    Several studies have reported post-exercise increases of urinary concentrations of plasma proteins. However, under normal conditions, through mechanisms of size and electrical charge selection, the kidney restricts the clearance of molecules as large as albumin. Post-exercise increases in albuminuria occur following the physiological stress of intense exercise, most likely as a result of the exercise induced blood acidity changes which lead to a change in the arrangement of the albumin molecule, and subsequently the filtration characteristics of the glomerular capillary wall. The purpose of the present study was therefore to determine the extent to which different types of exercise could induce a transient condition of post-exercise increases in the urinary output of total protein and albumin. All 14 males, who agreed to participate in the study, performed a continuous and an intermittent cycling protocol on a stationary bicycle ergometer. The results showed that: a) intermittent exercise had a greater influence than continuous exercise on the total output of urine albumin, and of urine total protein; b) concentrations of blood pH and blood lactate, were associated with changes in the clearance of urine albumin and urine total protein. Post-exercise proteinuria response seems to be transient and therefore renal trauma is not suspected at the early stages of observation. Furthermore, these results indicate that the kidney undergoes distinct physiological adjustments during exercise, and that these adjustments are relative to the intensity of the exercise stress. PMID:12413038

  17. The Exchangeability of Amino Acids in Proteins

    PubMed Central

    Yampolsky, Lev Y.; Stoltzfus, Arlin

    2005-01-01

    The comparative analysis of protein sequences depends crucially on measures of amino acid similarity or distance. Many such measures exist, yet it is not known how well these measures reflect the operational exchangeability of amino acids in proteins, since most are derived by methods that confound a variety of effects, including effects of mutation. In pursuit of a pure measure of exchangeability, we present (1) a compilation of data on the effects of 9671 amino acid exchanges engineered and assayed in a set of 12 proteins; (2) a statistical procedure to combine results from diverse assays of exchange effects; (3) a matrix of “experimental exchangeability” values EXij derived from applying this procedure to the compiled data; and (4) a set of three tests designed to evaluate the power of an exchangeability measure to (i) predict the effects of amino acid exchanges in the laboratory, (ii) account for the disease-causing potential of missense mutations in the human population, and (iii) model the probability of fixation of missense mutations in evolution. EX not only captures useful information on exchangeability while remaining free of other effects, but also outperforms all measures tested except for the best-performing alignment scoring matrix, which is comparable in performance. PMID:15944362

  18. Changes in total nitrogen and amino acid composition of New Zealand Undaria pinnatifida with growth, location and plant parts.

    PubMed

    Zhou, April Yongdong; Robertson, John; Hamid, Nazimah; Ma, Qianli; Lu, Jun

    2015-11-01

    Undaria pinnatifida is known as unwanted organism in New Zealand. However, Wakame is a traditional food made of U. pinnatifida, which is now cultured extensively in East Asia. Therefore, it is important to examine this introduced alga as a potential source of dietary protein for human consumption in New Zealand. This study determined total nitrogen content and amino acid profile of New Zealand U. pinnatifida harvested from the Marlborough Sounds on a monthly basis from June to November 2011. Total average nitrogen content and crude protein content was 21.02 mg/g dry weight and 13.1% of dry weight, respectively. The three most abundant amino acids that contributed to flavour (glutamic acid, aspartic acid and alanine) were present and the most abundant essential amino acids were arginine, leucine, lysine and valine. The results showed that the amino acid content in blades from the exposed farm was significantly higher (P < 0.05) than the others. Sporophyll maturation of U. pinnatifida in New Zealand influenced protein content and amino acid composition. Sporophyll, considered as a waste product by many, was found to be a potentially good source of protein. PMID:25976828

  19. Cholesterol-lowering effect of rice bran protein containing bile acid-binding proteins.

    PubMed

    Wang, Jilite; Shimada, Masaya; Kato, Yukina; Kusada, Mio; Nagaoka, Satoshi

    2015-01-01

    Dietary plant protein is well known to reduce serum cholesterol levels. Rice bran is a by-product of rice milling and is a good source of protein. The present study examined whether feeding rats a high-cholesterol diet containing 10% rice bran protein (RBP) for 10 d affected cholesterol metabolism. Rats fed dietary RBP had lower serum total cholesterol levels and increased excretion of fecal steroids, such as cholesterol and bile acids, than those fed dietary casein. In vitro assays showed that RBP strongly bound to taurocholate, and inhibited the micellar solubility of cholesterol, compared with casein. Moreover, the bile acid-binding proteins of the RBP were eluted by a chromatographic column conjugated with cholic acid, and one of them was identified as hypothetical protein OsJ_13801 (NCBI accession No. EAZ29742) using MALDI-TOF mass spectrometry analysis. These results suggest that the hypocholesterolemic action of the RBP may be caused by the bile acid-binding proteins. PMID:25374002

  20. A nine-country study of the protein content and amino acid composition of mature human milk

    PubMed Central

    Feng, Ping; Gao, Ming; Burgher, Anita; Zhou, Tian Hui; Pramuk, Kathryn

    2016-01-01

    Background Numerous studies have evaluated protein and amino acid levels in human milk. However, research in this area has been limited by small sample sizes and study populations with little ethnic or racial diversity. Objective Evaluate the protein and amino acid composition of mature (≥30 days) human milk samples collected from a large, multinational study using highly standardized methods for sample collection, storage, and analysis. Design Using a single, centralized laboratory, human milk samples from 220 women (30–188 days postpartum) from nine countries were analyzed for amino acid composition using Waters AccQ-Tag high-performance liquid chromatography and total nitrogen content using the LECO FP-528 nitrogen analyzer. Total protein was calculated as total nitrogen×6.25. True protein, which includes protein, free amino acids, and peptides, was calculated from the total amino acids. Results Mean total protein from individual countries (standard deviation [SD]) ranged from 1,133 (125.5) to 1,366 (341.4) mg/dL; the mean across all countries (SD) was 1,192 (200.9) mg/dL. Total protein, true protein, and amino acid composition were not significantly different across countries except Chile, which had higher total and true protein. Amino acid profiles (percent of total amino acids) did not differ across countries. Total and true protein concentrations and 16 of 18 amino acid concentrations declined with the stage of lactation. Conclusions Total protein, true protein, and individual amino acid concentrations in human milk steadily decline from 30 to 151 days of lactation, and are significantly higher in the second month of lactation compared with the following 4 months. There is a high level of consistency in the protein content and amino acid composition of human milk across geographic locations. The size and diversity of the study population and highly standardized procedures for the collection, storage, and analysis of human milk support the validity and

  1. Interference of N-hydroxysuccinimide with bicinchoninic acid protein assay.

    PubMed

    Vashist, Sandeep Kumar; Dixit, Chandra Kumar

    2011-07-29

    We report here substantial interference from N-hydroxysuccinimide (NHS) in the bicinchoninic acid (BCA) protein assay. NHS is one of the most commonly used crosslinking agents in bioanalytical sciences, which can lead to serious potential errors in the BCA protein assay based protein estimation if it is present in the protein analyte solution. It was identified to be a reducing substance, which interferes with the BCA protein assay by reducing Cu(2+) in the BCA working reagent. The absorbance peak and absorbance signal of NHS were very similar to those of bovine serum albumin (BSA), thereby indicating a similar BCA reaction mechanism for NHS and protein. However, the combined absorbance of NHS and BSA was not additive. The time-response measurements of the BCA protein assay showed consistent single-phase kinetics for NHS and gradually decreasing kinetics for BSA. The error in protein estimation due to the presence of NHS was counteracted effectively by plotting additional BCA standard curve for BSA with a fixed concentration of NHS. The difference between the absorbance values of BSA and BSA with a fixed NHS concentration provided the absorbance contributed by NHS, which was then subtracted from the total absorbance of analyte sample to determine the actual absorbance of protein in the analyte sample. PMID:21762678

  2. Total synthesis of legionaminic acid as basis for serological studies.

    PubMed

    Matthies, Stefan; Stallforth, Pierre; Seeberger, Peter H

    2015-03-01

    Legionaminic acid is a nine-carbon diamino monosaccharide that is found coating the surface of various bacterial human pathogens. Its unique structure makes it a valuable biological probe, but access via isolation is difficult and no practical synthesis has been reported. We describe a stereoselective synthesis that yields a legionaminic acid building block as well as linker-equipped conjugation-ready legionaminic acid starting from cheap d-threonine. To set the desired amino and hydroxyl group pattern of the target, we designed a concise sequence of stereoselective reactions. The key transformations rely on chelation-controlled organometallic additions and a Petasis multicomponent reaction. The legionaminic acid was synthesized in a form that enables attachment to surfaces. Glycan microarray containing legionaminic acid revealed that human antibodies bind the synthetic glycoside. The synthetic bacterial monosaccharide is a valuable probe to detect an immune response to bacterial pathogens such as Legionella pneumophila, the causative agent of Legionnaire's disease. PMID:25668389

  3. Tranexamic Acid Administration in Total Knee Arthroplasty Without Tourniquet

    PubMed Central

    Bohler, Iain R M; Howse, Louise; Baird, Andrew; Giles, Nigel

    2016-01-01

    Objective: There are multiple documented advantages of undertaking total knee arthroplasty (TKA) without tourniquet, however, increased rates of blood loss and transfusion are often cited as contraindications to this approach. The aim of this study was to examine the effect of intra-operative TA administration on blood loss and transfusion rates in TKA without pneumatic tourniquet, using Rivaroxaban as thrombo-embolic prophylaxis. Method: 120 patients split into two continuous data sets, (A+B), underwent TKA without application of above knee tourniquet, receiving a post-operative dose of oral Rivaroxaban within 8 hours. Group B patients received an intra-operative dose of 1 gram of Tranexamic Acid intravenously before the first cut, whilst those in group A did not. Haemoglobin and Haematocrit levels were recorded peri-operatively. A revised Gross formula was used to calculate blood loss. Four patients were excluded from the study for incomplete data. Result: 58 patients (M34F24) in Group A, average age 6, had a mean Haemoglobin drop of 33gram/litre, Haematocrit drop of 0.097litre/litre (9.7%), with an average calculated blood loss of 1393 ml. 58 (M34, F24) patients in group B, average age 67, had a Haemoglobin drop of 25.2gram/litre, Haematocrit drop of 0.076litre/litre (7.6%) with an average calculated blood loss of1079 ml. Thus Group A patients were seen to sustain significantly more blood loss without TA administration, with a 29.1% larger calculated blood loss, a 25.5% larger drop in Haemoglobin and a 27.6% larger fall in Haematocrit. Transfusion rate was 5.2%(3 patients) per group. Conclusion: TA was shown to be effective in reducing blood loss in TKA without tourniquet using Rivaroxaban. Transfusion rates of 5.2% across both groups is close to 1/10th of the transfusion rate reported for major studies of TKA using Rivaroxaban with tourniquet application, and 1/8th of the transfusion rate in studies of TKA with administration of TA and use of tourniquet.

  4. Why do total-body decay curves of iodine-labeled proteins begin with a delay

    SciTech Connect

    Regoeczi, E.

    1987-09-01

    The initial delay that occurs in total-body radiation curves reaching their single-exponential slopes was analyzed from 106 experiments involving several mammalian species (guinea pig, mouse, rabbit, and rat) and plasma proteins (alpha 1-acid glycoprotein, antithrombin III, fibrinogen, immunoglobulin G, and transferrin) in 14 different combinations. The time interval (Td) between injection and the intercept of the slope with the full-dose value was adopted as a measure of curve nonideality. The overall mean Td was 6.6 h, but individual values showed a significant correlation to protein half-lives, whereby proteins of unequal metabolic properties exhibited different mean Td values. Targeting protein to the liver abolished delay. Choice of the isotope (/sup 125/I or /sup 131/I) and size of the labeled protein had no influence on the magnitude of delay. Whole-body radiation curves of animals that received (/sup 125/I)iodotyrosines, Na/sup 131/I, or /sup 131/I-polyvinylpyrrolidone exhibited no initial delays. These results do not support the earlier notion that delay is caused by a redistribution of the labeled protein in the body to radiometrically more favorable sites. However, they are compatible with the assumption that delayed passage of a protein dose through the extracellular matrix and/or retarded transfer of proteolytic products from extravascular catabolic sites to plasma may be responsible for the phenomenon.

  5. The natural non-protein amino acid N-β-methylamino-L-alanine (BMAA) is incorporated into protein during synthesis.

    PubMed

    Glover, W Broc; Mash, Deborah C; Murch, Susan J

    2014-11-01

    N-β-methylamino-L-alanine (BMAA) is an amino acid produced by cyanobacteria and accumulated through trophic levels in the environment and natural food webs. Human exposure to BMAA has been linked to progressive neurodegenerative diseases, potentially due to incorporation of BMAA into protein. The insertion of BMAA and other non-protein amino acids into proteins may trigger protein misfunction, misfolding and/or aggregation. However, the specific mechanism by which BMAA is associated with proteins remained unidentified. Such studies are challenging because of the complexity of biological systems and samples. A cell-free in vitro protein synthesis system offers an excellent approach for investigation of changing amino acid composition in protein. In this study, we report that BMAA incorporates into protein as an error in synthesis when a template DNA sequence is used. Bicinchoninic acid assay of total protein synthesis determined that BMAA effectively substituted for alanine and serine in protein product. LC-MS/MS confirmed that BMAA was selectively inserted into proteins in place of other amino acids, but isomers N-(2-aminoethyl)glycine (AEG) and 2,4-diaminobutyric acid (DAB) did not share this characteristic. Incorporation of BMAA into proteins was significantly higher when genomic DNA from post-mortem brain was the template. About half of BMAA in the synthetic proteins was released with denaturation with sodium dodecylsulfonate and dithiothreitol, but the remaining BMAA could only be released by acid hydrolysis. Together these data demonstrate that BMAA is incorporated into the amino acid backbone of proteins during synthesis and also associated with proteins through non-covalent bonding. PMID:25096519

  6. Acid mine drainage: An economic total resource recovery solution

    SciTech Connect

    Clarke, R.L.; Clarke, S.R.; Brackenbury, D.R.

    1995-12-31

    A common feature of abandoned hard rock mines and subterranean coal mines is the creation of toxic and acidic solution often containing iron, copper, zinc, lead, cadmium, manganese and alkaline earth and alkali metals. A process is described which sequentially removes heavy metals using electrochemical ion exchange and rotating cylinder electrodes. Studies summarized indicate recovery of copper, zinc, iron, and aluminum oxide; selective stripping of arsenic, cadmium, chromium, and lead; and recovery of water acceptable for drinking after removal of heavy metals.

  7. Effect of Growth on Fatty Acid Composition of Total Intramuscular Lipid and Phospholipids in Ira Rabbits

    PubMed Central

    Lu, Jingzhi; Li, Hongjun

    2015-01-01

    The changes in fatty acid composition of total intramuscular lipid and phospholipids were investigated in the longissimus dorsi, left-hind leg muscle, and abdominal muscle of male Ira rabbits. Changes were monitored at 35, 45, 60, 75, and 90 d. Analysis using gas chromatography identified 21 types of fatty acids. Results showed that the intramuscular lipid increased and the intramuscular phospholipids (total intramuscular lipid %) decreased in all muscles with increasing age (p<0.05). An abundant amount of unsaturated fatty acids, especially polyunsaturated fatty acids, was distributed in male Ira rabbits at different ages and muscles. Palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), and arachidonic acid (C20:4) were the major fatty acids, which account to the dynamic changes of the n-6/n-3 value in Ira rabbit meat. PMID:26761795

  8. Fast and selective determination of total protein in milk powder via titration of moving reaction boundary electrophoresis.

    PubMed

    Guo, Cheng-ye; Wang, Hou-yu; Liu, Xiao-ping; Fan, Liu-yin; Zhang, Lei; Cao, Cheng-xi

    2013-05-01

    In this paper, moving reaction boundary titration (MRBT) was developed for rapid and accurate quantification of total protein in infant milk powder, from the concept of moving reaction boundary (MRB) electrophoresis. In the method, the MRB was formed by the hydroxide ions and the acidic residues of milk proteins immobilized via cross-linked polyacrylamide gel (PAG), an acid-base indicator was used to denote the boundary motion. As a proof of concept, we chose five brands of infant milk powders to study the feasibility of MRBT method. The calibration curve of MRB velocity versus logarithmic total protein content of infant milk powder sample was established based on the visual signal of MRB motion as a function of logarithmic milk protein content. Weak influence of nonprotein nitrogen (NPN) reagents (e.g., melamine and urea) on MRBT method was observed, due to the fact that MRB was formed with hydroxide ions and the acidic residues of captured milk proteins, rather than the alkaline residues or the NPN reagents added. The total protein contents in infant milk powder samples detected via the MRBT method were in good agreement with those achieved by the classic Kjeldahl method. In addition, the developed method had much faster measuring speed compared with the Kjeldahl method. PMID:23483553

  9. Fluorinated amino acids: compatibility with native protein structures and effects on protein-protein interactions.

    PubMed

    Salwiczek, Mario; Nyakatura, Elisabeth K; Gerling, Ulla I M; Ye, Shijie; Koksch, Beate

    2012-03-21

    Fluorinated analogues of the canonical α-L-amino acids have gained widespread attention as building blocks that may endow peptides and proteins with advantageous biophysical, chemical and biological properties. This critical review covers the literature dealing with investigations of peptides and proteins containing fluorinated analogues of the canonical amino acids published over the course of the past decade including the late nineties. It focuses on side-chain fluorinated amino acids, the carbon backbone of which is identical to their natural analogues. Each class of amino acids--aliphatic, aromatic, charged and polar as well as proline--is presented in a separate section. General effects of fluorine on essential properties such as hydrophobicity, acidity/basicity and conformation of the specific side chains and the impact of these altered properties on stability, folding kinetics and activity of peptides and proteins are discussed (245 references). PMID:22130572

  10. Multiexcitation Fluorogenic Labeling of Surface, Intracellular, and Total Protein Pools in Living Cells.

    PubMed

    Naganbabu, Matharishwan; Perkins, Lydia A; Wang, Yi; Kurish, Jeffery; Schmidt, Brigitte F; Bruchez, Marcel P

    2016-06-15

    Malachite green (MG) is a fluorogenic dye that shows fluorescence enhancement upon binding to its engineered cognate protein, a fluorogen activating protein (FAP). Energy transfer donors such as cyanine and rhodamine dyes have been conjugated with MG to modify the spectral properties of the fluorescent complexes, where the donor dyes transfer energy through Förster resonance energy transfer to the MG complex resulting in binding-conditional fluorescence emission in the far-red region. In this article, we use a violet-excitable dye as a donor to sensitize the far-red emission of the MG-FAP complex. Two blue emitting fluorescent coumarin dyes were coupled to MG and evaluated for energy transfer to the MG-FAP complex via its secondary excitation band. 6,8-Difluoro-7-hydroxycoumarin-3-carboxylic acid (Pacific blue, PB) showed the most efficient energy transfer and maximum brightness in the far-red region upon violet (405 nm) excitation. These blue-red (BluR) tandem dyes are spectrally varied from other tandem dyes and are able to produce fluorescence images of the MG-FAP complex with a large Stokes shift (>250 nm). These dyes are cell-permeable and are used to label intracellular proteins. Used together with a cell-impermeable hexa-Cy3-MG (HCM) dye that labels extracellular proteins, we are able to visualize extracellular, intracellular, and total pools of cellular protein using one fluorogenic tag that combines with distinct dyes to effect different spectral characteristics. PMID:27159569

  11. Truly Absorbed Microbial Protein Synthesis, Rumen Bypass Protein, Endogenous Protein, and Total Metabolizable Protein from Starchy and Protein-Rich Raw Materials: Model Comparison and Predictions.

    PubMed

    Parand, Ehsan; Vakili, Alireza; Mesgaran, Mohsen Danesh; van Duinkerken, Gert; Yu, Peiqiang

    2015-07-29

    This study was carried out to measure truly absorbed microbial protein synthesis, rumen bypass protein, and endogenous protein loss, as well as total metabolizable protein, from starchy and protein-rich raw feed materials with model comparisons. Predictions by the DVE2010 system as a more mechanistic model were compared with those of two other models, DVE1994 and NRC-2001, that are frequently used in common international feeding practice. DVE1994 predictions for intestinally digestible rumen undegradable protein (ARUP) for starchy concentrates were higher (27 vs 18 g/kg DM, p < 0.05, SEM = 1.2) than predictions by the NRC-2001, whereas there was no difference in predictions for ARUP from protein concentrates among the three models. DVE2010 and NRC-2001 had highest estimations of intestinally digestible microbial protein for starchy (92 g/kg DM in DVE2010 vs 46 g/kg DM in NRC-2001 and 67 g/kg DM in DVE1994, p < 0.05 SEM = 4) and protein concentrates (69 g/kg DM in NRC-2001 vs 31 g/kg DM in DVE1994 and 49 g/kg DM in DVE2010, p < 0.05 SEM = 4), respectively. Potential protein supplies predicted by tested models from starchy and protein concentrates are widely different, and comparable direct measurements are needed to evaluate the actual ability of different models to predict the potential protein supply to dairy cows from different feedstuffs. PMID:26118653

  12. Nucleic acids encoding human trithorax protein

    DOEpatents

    Evans, Glen A.; Djabali, Malek; Selleri, Licia; Parry, Pauline

    2001-01-01

    In accordance with the present invention, there is provided an isolated peptide having the characteristics of human trithorax protein (as well as DNA encoding same, antisense DNA derived therefrom and antagonists therefor). The invention peptide is characterized by having a DNA binding domain comprising multiple zinc fingers and at least 40% amino acid identity with respect to the DNA binding domain of Drosophila trithorax protein and at least 70% conserved sequence with respect to the DNA binding domain of Drosophila trithorax protein, and wherein said peptide is encoded by a gene located at chromosome 11 of the human genome at q23. Also provided are methods for the treatment of subject(s) suffering from immunodeficiency, developmental abnormality, inherited disease, or cancer by administering to said subject a therapeutically effective amount of one of the above-described agents (i.e., peptide, antagonist therefor, DNA encoding said peptide or antisense DNA derived therefrom). Also provided is a method for the diagnosis, in a subject, of immunodeficiency, developmental abnormality, inherited disease, or cancer associated with disruption of chromosome 11 at q23.

  13. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2011-12-06

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  14. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2011-03-22

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  15. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2008-10-07

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  16. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2012-02-14

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  17. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2009-04-28

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  18. [Comparative analysis of total cell protein electrophoregram of pathogenic Burkholderia].

    PubMed

    Budchenko, A A; Iliukhin, V I; Viktorov, D V

    2005-01-01

    Whole-cell proteins of 22 strain of Burkhoderia pseudomallei, including 13 B. mallei, 5 B. cepacia strains and 14 strains of opportunistically pathogenic Pseudomonas defined by 1D SDC-PAAG electrophoresis. Electrophoregrams contained 35 to 45 protein fractions sized 19 to 130 kDa, which were highly reproductive. On the basis of computer-aided comparative analysis of protein patterns the interspecies and intraspecies grouping of studied microorganisms was made. The cluster analysis of the similarity matrix of protein spectra made it possible to allocate two groups of strains at the level of similarity of 78%. Group I was formed by Burkholderia species that previously belonged to the II RNA-DNA homology group of Pseudomonas: B. pseudomallei, B. mallei, B. cepacia. All Pseudomonas species were added to the 2nd Group: P. aeruginosa, P. stutzeri, P. testosterone, P. fluorescens, P. putida, P. mendocina. Four phenons were isolated among the strains of B. pseudomallei and 2 phenons--among the strains of B. mallei at the threshold similarity level (89%). The authors conclude that the comparative analysis of electrophoregrams of whole-cell proteins can be useful in the identification and typing of pathogenic Burkholderia. PMID:15954473

  19. Relatedness of acyl carrier proteins shown by amino acid compositions.

    PubMed

    Walker, T A; Ernst-Fonberg, M L

    1982-01-01

    1. Relatedness among the following carrier proteins was assessed on the basis of amino acid compositions: eight acyl carrier proteins (ACP's) associated with fatty acid synthesis, ACP's associated with citrate lyase and citramalate lyase, a biotin carboxyl carrier protein and cytochrome 552. Two independent indices of amino acid composition were used. 2. The fatty acid synthesis-associated ACP's of many organisms and the lyase-associated ACP's show a high degree of relatedness among one another. 3. The ACP's show no relatedness to biotin carboxyl carrier protein or cytochrome 552. PMID:7128903

  20. 7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... corresponding total soluble solids. 51.1178 Section 51.1178 Agriculture Regulations of the Department of... corresponding total soluble solids. For determining the grade of juice, the maximum permissible anhydrous citric acid content in relation to corresponding total soluble solids in the fruit is set forth in...

  1. 7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... corresponding total soluble solids. 51.1178 Section 51.1178 Agriculture Regulations of the Department of... corresponding total soluble solids. For determining the grade of juice, the maximum permissible anhydrous citric acid content in relation to corresponding total soluble solids in the fruit is set forth in...

  2. Strained cycloalkynes as new protein sulfenic acid traps.

    PubMed

    Poole, Thomas H; Reisz, Julie A; Zhao, Weiling; Poole, Leslie B; Furdui, Cristina M; King, S Bruce

    2014-04-30

    Protein sulfenic acids are formed by the reaction of biologically relevant reactive oxygen species with protein thiols. Sulfenic acid formation modulates the function of enzymes and transcription factors either directly or through the subsequent formation of protein disulfide bonds. Identifying the site, timing, and conditions of protein sulfenic acid formation remains crucial to understanding cellular redox regulation. Current methods for trapping and analyzing sulfenic acids involve the use of dimedone and other nucleophilic 1,3-dicarbonyl probes that form covalent adducts with cysteine-derived protein sulfenic acids. As a mechanistic alternative, the present study describes highly strained bicyclo[6.1.0]nonyne (BCN) derivatives as concerted traps of sulfenic acids. These strained cycloalkynes react efficiently with sulfenic acids in proteins and small molecules yielding stable alkenyl sulfoxide products at rates more than 100× greater than 1,3-dicarbonyl reagents enabling kinetic competition with physiological sulfur chemistry. Similar to the 1,3-dicarbonyl reagents, the BCN compounds distinguish the sulfenic acid oxoform from the thiol, disulfide, sulfinic acid, and S-nitrosated forms of cysteine while displaying an acceptable cell toxicity profile. The enhanced rates demonstrated by these strained alkynes identify them as new bioorthogonal probes that should facilitate the discovery of previously unknown sulfenic acid sites and their parent proteins. PMID:24724926

  3. Effects of postruminal protein on fatty acid digestibility in dairy cows.

    PubMed

    Goodling, L E; Grummer, R R

    1998-06-01

    Eight ruminally cannulated Holstein cows (four multiparous and four primiparous) were used in a replicated 4 x 4 Latin square with an extra period to determine the effects of postruminal protein on fatty acid digestibility. Samples were collected during the last 4 d of each 14-d period. Total mixed rations were composed of 41% alfalfa haylage, 42% corn silage, 12% concentrate based on corn, and 5% tallow. Cows were fed at 90% of ad libitum intake. Treatments were abomasal infusion of guar gum or guar gum plus urea, corn gluten meal, or blood meal in 12 L of water. The basal ration contained 12% crude protein (CP), and infusion of N sources increased CP to approximately 14%. Dry matter intake was similar for cows on all treatments. Milk, 3.5% fat-corrected milk, milk protein, and milk fat yields increased for cows receiving postruminal CP. Postruminal CP did not affect milk fat and protein percentages. Dry matter, organic matter, and CP digestibilities were greater in cows receiving postruminal CP. Total fatty acid and total C18 fatty acid digestibilities were not affected by treatment. Total C16 fatty acid and C18:0 fatty acid digestibilities were greater for cows receiving nonprotein N than for those receiving true protein. PMID:9684169

  4. Echinococcus granulosus fatty acid binding proteins subcellular localization.

    PubMed

    Alvite, Gabriela; Esteves, Adriana

    2016-05-01

    Two fatty acid binding proteins, EgFABP1 and EgFABP2, were isolated from the parasitic platyhelminth Echinococcus granulosus. These proteins bind fatty acids and have particular relevance in flatworms since de novo fatty acids synthesis is absent. Therefore platyhelminthes depend on the capture and intracellular distribution of host's lipids and fatty acid binding proteins could participate in lipid distribution. To elucidate EgFABP's roles, we investigated their intracellular distribution in the larval stage by a proteomic approach. Our results demonstrated the presence of EgFABP1 isoforms in cytosolic, nuclear, mitochondrial and microsomal fractions, suggesting that these molecules could be involved in several cellular processes. PMID:26873273

  5. Enteral obeticholic acid promotes intestinal growth in total parenteral nutrition fed neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intestinal atrophy is an adverse outcome associated with prolonged total parenteral nutrition (PN) partly due to disruption of normal enterohepatic circulation of bile acids. Previously we showed that enteral treatment with chenodeoxycholic acid (CDCA), a dual agonist for the nuclear receptor, farne...

  6. ANALYSIS SYSTEM FOR TOTAL SULFURIC ACID IN AMBIENT AIR. DEVELOPMENT AND PRELIMINARY EVALUATION

    EPA Science Inventory

    A total sulfuric acid analysis (TSAA) system was developed and shown to provide quantitative determinations of sulfuric acid in air at concentrations as low as 0.26 micrograms/cu m. Quantitation at lower concentrations appears to be possible. The general approach in the design an...

  7. Effect of Tranexamic Acid on Blood Loss and Blood Transfusion Reduction after Total Knee Arthroplasty

    PubMed Central

    Seol, Young-Jun; Seon, Jong-Keun; Lee, Seung-Hun; Jin, Cheng; Prakash, Jatin; Park, Yong-Jin

    2016-01-01

    Purpose Total knee arthroplasty (TKA) accompanies the risk of bleeding and need for transfusion. There are several methods to reduce postoperative blood loss and blood transfusion. One such method is using tranexamic acid during TKA. The purpose of this study was to confirm whether tranexamic acid reduces postoperative blood loss and blood transfusion after TKA. Materials and Methods A total of 100 TKA patients were included in the study. The tranexamic acid group consisted of 50 patients who received an intravenous injection of tranexamic acid. The control included 50 patients who received a placebo injection. The amounts of drainage, postoperative hemoglobin, and transfusion were compared between the groups. Results The mean amount of drainage was lower in the tranexamic acid group (580.6±355.0 mL) than the control group (886.0±375.5 mL). There was a reduction in the transfusion rate in the tranexamic acid group (48%) compared with the control group (64%). The hemoglobin level was higher in the tranexamic acid group than in the control group at 24 hours postoperatively. The mean units of transfusion were smaller in the tranexamic acid group (0.76 units) than in the control group (1.28 units). Conclusions Our data suggest that intravenous injection of tranexamic acid decreases the total blood loss and transfusion after TKA. PMID:27595071

  8. Photoaffinity labeling of retinoic acid-binding proteins.

    PubMed Central

    Bernstein, P S; Choi, S Y; Ho, Y C; Rando, R R

    1995-01-01

    Retinoid-binding proteins are essential mediators of vitamin A function in vertebrate organisms. They solubilize and stabilize retinoids, and they direct the intercellular and intracellular trafficking, transport, and metabolic function of vitamin A compounds in vision and in growth and development. Although many soluble retinoid-binding proteins and receptors have been purified and extensively characterized, relatively few membrane-associated enzymes and other proteins that interact with retinoids have been isolated and studied, due primarily to their inherent instabilities during purification. In an effort to identify and purify previously uncharacterized retinoid-binding proteins, it is shown that radioactively labeled all-trans-retinoic acid can be used as a photoaffinity labeling reagent to specifically tag two known retinoic acid-binding proteins, cellular retinoic acid-binding protein and albumin, in complex mixtures of cytosolic proteins. Additionally, a number of other soluble and membrane-associated proteins that bind all-trans-[11,12-3H]retinoic acid with high specificity are labeled utilizing the same photoaffinity techniques. Most of these labeled proteins have molecular weights that do not correspond to any known retinoid-binding proteins. Thus, photoaffinity labeling with all-trans-retinoic acid and related photoactivatable retinoids is a method that should prove extremely useful in the identification and purification of novel soluble and membrane-associated retinoid-binding proteins from ocular and nonocular tissues. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7846032

  9. [The behavior of serum total protein and protein fractions during the use of various hormonal contraceptives].

    PubMed

    Klinger, G; Scheler, R; Tarnick, M; Krause, G; Hesse, A; Carol, W

    1977-01-01

    Total protein fractions in the serum were measured in 213 women who used various contraceptive preparations (53 used Gravistat, 56 Non-Ovlon, 37 Ovosiston, 67 Deposiston). Blood samples were taken before the 1st, 3rd, 6th, 12th, and 24th cycles of use and 4 weeks after discontinuing preparation use. Serum protein concentrations decreased through the first 18 cycles of contraceptive use, after which a continual increase was observed. Serum albumin concentrations deceased during the first 3 cycles of use, after which increases were observed, which in the case of Non-Ovlon and Gravistat exceeded original values. Serum alpha 1 and alpha 2 globulin concentrations showed relative increases during the first 3 cycles, after which a decrease was observed. Serum beta globulin increased in the first 3 cycles of use; a decrease was observed between the 12th and 18 cycles, followed by another increase. Serum gamma globulin levels increased during the first 6 cycles, followed by a marked decrease, which extended partially into the post-treatment period. The changes are comparable to those observed during an undisturbed pregnancy. Deposiston caused the most marked changes in the parameters; this is attributed to the estrogenic nature of the preparation. PMID:73442

  10. 7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... corresponding total soluble solids. 51.1178 Section 51.1178 Agriculture Regulations of the Department of... solids. For determining the grade of juice, the maximum permissible anhydrous citric acid content in relation to corresponding total soluble solids in the fruit is set forth in the following Table II...

  11. 7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... corresponding total soluble solids. 51.1178 Section 51.1178 Agriculture Regulations of the Department of... solids. For determining the grade of juice, the maximum permissible anhydrous citric acid content in relation to corresponding total soluble solids in the fruit is set forth in the following Table II...

  12. 7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... corresponding total soluble solids. 51.1178 Section 51.1178 Agriculture Regulations of the Department of... solids. For determining the grade of juice, the maximum permissible anhydrous citric acid content in relation to corresponding total soluble solids in the fruit is set forth in the following Table II...

  13. Indole diterpene synthetic studies. Total synthesis of (+)-nodulisporic acid F and construction of the heptacyclic cores of (+)-nodulisporic acids A and B and (-)-nodulisporic acid D.

    PubMed

    Smith, Amos B; Davulcu, Akin H; Cho, Young Shin; Ohmoto, Kazuyuki; Kürti, László; Ishiyama, Haruaki

    2007-06-22

    A first-generation strategy for construction of (+)-nodulisporic acids A (1) and B (2) is described. The strategy entails union of the eastern and western hemisphere subtargets via the indole synthesis protocol developed in our laboratory. Subsequent elaboration of rings E and F, however, revealed the considerable acid instability of the C(24) hydroxyl, thereby preventing further advancement. Nonetheless, preparation of the heptacyclic core of (+)-nodulisporic acids A and B, the total synthesis of (+)-nodulisporic acid F, the simplest member of the nodulisporic acid family, and elaboration of the heptacyclic core of (-)-nodulisporic acid D were achieved. PMID:17511507

  14. Amino acid metabolism and protein synthesis in malarial parasites*

    PubMed Central

    Sherman, I. W.

    1977-01-01

    Malaria-infected red cells and free parasites have limited capabilities for the biosynthesis of amino acids. Therefore, the principal amino acid sources for parasite protein synthesis are the plasma free amino acids and host cell haemoglobin. Infected cells and plasmodia incorporate exogenously supplied amino acids into protein. However, the hypothesis that amino acid utilization (from an external source) is related to availability of that amino acid in haemoglobin is without universal support: it is true for isoleucine and for Plasmodium knowlesi and P. falciparum, but not for methionine, cysteine, and other amino acids, and it does not apply to P. lophurae. More by default than by direct evidence, haemoglobin is believed to be the main amino acid reservoir available to the intraerythrocytic plasmodium. Haemoglobin, ingested via the cytostome, is held in food vacuoles where auto-oxidation takes place. As a consequence, haem is released and accumulates in the vacuole as particulate haemozoin (= malaria pigment). Current evidence favours the view that haemozoin is mainly haematin. Acid and alkaline proteases (identified in crude extracts from mammalian and avian malarias) are presumably secreted directly into the food vacuole. They then digest the denatured globin and the resulting amino acids are incorporated into parasite protein. Cell-free protein synthesizing systems have been developed using P. knowlesi and P. lophurae ribosomes. In the main these systems are typically eukaryotic. Studies of amino acid metabolism are exceedingly limited. Arginine, lysine, methionine, and proline are incorporated into protein, whereas glutamic acid is metabolized via an NADP-specific glutamic dehydrogenase. Glutamate oxidation generates NADPH and auxiliary energy (in the form of α-ketoglutarate). The role of red cell glutathione in the economy of the parasite remains obscure. Important goals for future research should be: quantitative assessment of the relative importance of

  15. Phosphate acceptor amino acid residues in structural proteins of rhabdoviruses.

    PubMed

    Sokol, F; Tan, K B; McFalls, M L; Madore, P

    1974-07-01

    Partial acid hydrolysates of the [(32)P]phosphate- or [(3)H]serine-labeled proteins of purified vesicular stomatitis, rabies, Lagos bat, Mokola, or spring viremia of carp virions and of purified intracellular nucleocapsids of these viruses have been analyzed by paper electrophoresis for the presence of phosphorylated amino acids. Both phosphoserine and phosphothreonine, with the former predominant, were present in virion and nucleocapsid preparations that contained phosphoproteins. An exception was the fish rhabdovirus, which contained only phosphoserine. When vesicular stomatitis or rabies virus proteins were phosphorylated in a cell-free system by the virion-associated protein kinase and analyzed for the presence of phosphorylated amino acid residues, phosphoserine was again found to be more abundant than phosphothreonine. After in vitro protein phosphorylation, another phospho-compound, possibly a third phosphoamino acid, was detected in the partial acid hydrolysates of these viruses. PMID:4365328

  16. Protein and amino acid metabolism and requirements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the major structural and functional components of all cells of the body. Enzymes, membrane carriers, blood transport molecules, intracellular matrix, and even hair and fingernails are proteins, as are many hormones. Proteins also constitute a major portion of all membranes, and the cons...

  17. Interaction of milk whey protein with common phenolic acids

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Yu, Dandan; Sun, Jing; Guo, Huiyuan; Ding, Qingbo; Liu, Ruihai; Ren, Fazheng

    2014-01-01

    Phenolics-rich foods such as fruit juices and coffee are often consumed with milk. In this study, the interactions of α-lactalbumin and β-lactoglobulin with the phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, and coumalic acid) were examined. Fluorescence, CD, and FTIR spectroscopies were used to analyze the binding modes, binding constants, and the effects of complexation on the conformation of whey protein. The results showed that binding constants of each whey protein-phenolic acid interaction ranged from 4 × 105 to 7 × 106 M-n and the number of binding sites n ranged from 1.28 ± 0.13 to 1.54 ± 0.34. Because of these interactions, the conformation of whey protein was altered, with a significant reduction in the amount of α-helix and an increase in the amounts of β-sheet and turn structures.

  18. Determination of free and total phenolic acids in plant-derived foods by HPLC with diode-array detection.

    PubMed

    Mattila, Pirjo; Kumpulainen, Jorma

    2002-06-19

    A high-performance liquid chromatographic (HPLC) method with diode-array detection (DAD) was used to identify and quantify free and total phenolic acids (m-hydroxybenzoic acid, p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, syringic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid, chlorogenic acid, and ellagic acid) in plant foods. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were liberated using first alkaline and then acid hydrolysis followed by extraction with diethyl ether/ethyl acetate (1:1). All fractions were quantified separately by HPLC. After HPLC quantification, results of alkali and acid hydrolysates were calculated to represent total phenolic acids. Ellagic acid was quantified separately after long (20 h) acid hydrolysis. The methods developed were effective for the determination of phenolic acids in plant foods. DAD response was linear for all phenolic acids within the ranges evaluated, with correlation coefficients exceeding 0.999. Coefficients of variation for 4-8 sample replicates were consistently below 10%. Recovery tests of phenolic acids were performed for every hydrolysis condition using several samples. Recoveries were generally good (mean >90%) with the exceptions of gallic acid and, in some cases, caffeic acid samples. PMID:12059140

  19. Measuring protein-protein and protein-nucleic Acid interactions by biolayer interferometry.

    PubMed

    Sultana, Azmiri; Lee, Jeffrey E

    2015-01-01

    Biolayer interferometry (BLI) is a simple, optical dip-and-read system useful for measuring interactions between proteins, peptides, nucleic acids, small molecules, and/or lipids in real time. In BLI, a biomolecular bait is immobilized on a matrix at the tip of a fiber-optic sensor. The binding between the immobilized ligand and another molecule in an analyte solution produces a change in optical thickness at the tip and results in a wavelength shift proportional to binding. BLI provides direct binding affinities and rates of association and dissociation. This unit describes an efficient approach using streptavidin-based BLI to analyze DNA-protein and protein-protein interactions. A quantitative set of equilibrium binding affinities (K(d)) and rates of association and dissociation (k(a)/k(d)) can be measured in minutes using nanomole quantities of sample. PMID:25640894

  20. Lactate dehydrogenase X, malate dehydrogenase and total protein in rat spermatozoa during epididymal transit.

    PubMed

    Vermouth, N T; Carriazo, C S; Ponce, R H; Blanco, A

    1986-01-01

    Lactate dehydrogenase isozyme X (LDH X), malate dehydrogenase (MDH) and total soluble protein have been determined in lysates of spermatozoa isolated from caput, corpus and cauda of rat epididymis. Transit of spermatozoa through epididymis is accompanied by a reduction of LDH X, MDH and total protein per cell in sexually rested animals. The profiles of reduction along epididymal segments are different for the three variables studied. Mating with receptive females during the 5 days prior to determinations increases significantly the levels of MDH in spermatozoa from all sections of epididymis and produces increase of total soluble protein in the cells contained in cauda. PMID:3956158

  1. Acute Administration of Branched-Chain Amino Acids Increases the Pro-BDNF/Total-BDNF Ratio in the Rat Brain.

    PubMed

    Scaini, Giselli; Morais, Meline O S; Furlanetto, Camila B; Kist, Luiza W; Pereira, Talita C B; Schuck, Patrícia F; Ferreira, Gustavo C; Pasquali, Matheus A B; Gelain, Daniel P; Moreira, José Cláudio F; Bogo, Maurício R; Streck, Emilio L

    2015-05-01

    Maple syrup urine disease (MSUD) is caused by an inborn error in metabolism resulting from a deficiency in the branched-chain α-keto acid dehydrogenase complex activity. This blockage leads to accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine and valine, as well as their corresponding α-keto acids and α-hydroxy acids. High levels of BCAAs are associated with neurological dysfunction and the role of pro- and mature brain-derived neurotrophic factor (BDNF) in the neurological dysfunction of MSUD is still unclear. Thus, in the present study we investigated the effect of an acute BCAA pool administration on BDNF levels and on the pro-BDNF cleavage-related proteins S100A10 and tissue plasminogen activator (tPA) in rat brains. Our results demonstrated that acute Hyper-BCAA (H-BCAA) exposure during the early postnatal period increases pro-BDNF and total-BDNF levels in the hippocampus and striatum. Moreover, tPA levels were significantly decreased, without modifications in the tPA transcript levels in the hippocampus and striatum. On the other hand, the S100A10 mRNA and S100A10 protein levels were not changed in the hippocampus and striatum. In the 30-day-old rats, we observed increased pro-BDNF, total-BDNF and tPA levels only in the striatum, whereas the tPA and S100A10 mRNA expression and the immunocontent of S100A10 were not altered. In conclusion, we demonstrated that acute H-BCAA administration increases the pro-BDNF/total-BDNF ratio and decreases the tPA levels in animals, suggesting that the BCAA effect may depend, at least in part, on changes in BDNF post-translational processing. PMID:25681161

  2. Speed associated with plasma pH, oxygen content, total protein and urea in an 80 km race.

    PubMed

    Hoffman, R M; Hess, T M; Williams, C A; Kronfeld, D S; Griewe-Crandell, K M; Waldron, J E; Graham-Thiers, P M; Gay, L S; Splan, R K; Saker, K E; Harris, P A

    2002-09-01

    To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine kinase, aspartate amino transferase, lipid hydroperoxides, total protein, albumin and creatinine, and erythrocyte glutathione and glutathione peroxidase. Data from 34 finishers were analysed statistically. Reference ranges for resting and running horses were wide and overlapping and, therefore, limiting with respect to evaluation of individual horses. Speed correlations were most repeatable, with variables reflecting blood oxygen transport (enabling exercise), acidity and electrolytes (limiting exercise) and total protein (enabling then, perhaps, limiting). Stepwise regressions also included plasma urea concentration (limiting). The association of speed with less plasma acidity and urea suggests the potential for fat adaptation and protein restriction in endurance horses, as found previously in Arabians performing repeated sprints. Conditioning horses fed fat-fortified and protein-restricted diets may not only improve performance but also avoid grain-associated disorders. PMID:12405657

  3. Amino acid composition and crude protein values of some Cyanobacteria from Çanakkale (Turkey).

    PubMed

    Akgül, Rıza; Kızılkaya, Bayram; Akgül, Füsun; Erduğan, Hüseyin

    2015-09-01

    Cyanobacteria (blue-green algae) form an important component of integrated nutrient managements in agriculture and are exploited in commercial biotechnological ventures. In this study, Rivularia bullata (Poir) Berkeley ex Bornet & Flahault, Nostocs pongiaeforme C. Agardh ex Bornet & Flahault were researched for their amino acid composition and crude protein values. R. bullata was collected from coastal zones of the Gulf of Saros and N. spongiaeforme from the Ayazma Stream. The levels of amino acids were measured in algae samples using EZ: fast kits (EZ: fast GC/FID Protein Hydrolysate Amino Acid Kit) by gas chromatography. The crude proteins of samples were determined by the Kjeldahl method and were calculated using a nitrogen conversion factor of 6.25. Thirty-two amino acids were investigated, for N. spongiaeforme eight free essential amino acids (EAA), eight free non-essential amino acids (NEAA) and eleven other amino acids (OAA); for R. bullata eight EAA, eight NEAA and eight OAA were detected. Aspartic acid is the major constituent for both species. The total protein percents were determined for N. spongiaeforme as % 19.83 and for R. bullata as % 6.15. When considering the increasing world population and reducing natural products; Cyanobacteria will benew feed sources for all living. PMID:26408895

  4. Heat capacities of amino acids, peptides and proteins.

    PubMed

    Makhatadze, G I

    1998-04-20

    The heat capacity is one of the fundamental parameters describing thermodynamic properties of a system. It has wide applications in a number of areas such as polymer chemistry, protein folding and DNA stability. To aid the scientific community in the analysis of such data, I have compiled a database on the experimentally measured heat capacities of amino acids, polyamino acids, peptides, and proteins in solid state and in aqueous solutions. PMID:9648205

  5. First total syntheses of (Z)-15-methyl-10-hexadecenoic acid and the (Z)-13-methyl-8-tetradecenoic acid

    PubMed Central

    Carballeira, Néstor M.; Montano, Nashbly; Padilla, Luis F.

    2006-01-01

    The first total syntheses for the (Z)-15-methyl-10-hexadecenoic acid and the (Z)-13-methyl-8-tetradecenoic acid were accomplished in seven steps and in 31–32% overall yields. The (trimethylsilyl)acetylene was the key reagent in both syntheses. It is proposed that the best synthetic strategy towards monounsaturated iso methyl-branched fatty acids with double bonds close to the ω end of the acyl chain is first acetylide coupling of (trimethylsilyl)acetylene to a long-chain bifunctional bromoalkane followed by a second acetylide coupling to a short-chain iso bromoalkane, since higher yields are thus obtained. Spectral data is also presented for the first time for these two unusual fatty acids with potential as biomarkers and as topoisomerase I inhibitors. PMID:17125759

  6. Phthalic acid chemical probes synthesized for protein-protein interaction analysis.

    PubMed

    Liang, Shih-Shin; Liao, Wei-Ting; Kuo, Chao-Jen; Chou, Chi-Hsien; Wu, Chin-Jen; Wang, Hui-Min

    2013-01-01

    Plasticizers are additives that are used to increase the flexibility of plastic during manufacturing. However, in injection molding processes, plasticizers cannot be generated with monomers because they can peel off from the plastics into the surrounding environment, water, or food, or become attached to skin. Among the various plasticizers that are used, 1,2-benzenedicarboxylic acid (phthalic acid) is a typical precursor to generate phthalates. In addition, phthalic acid is a metabolite of diethylhexyl phthalate (DEHP). According to Gene_Ontology gene/protein database, phthalates can cause genital diseases, cardiotoxicity, hepatotoxicity, nephrotoxicity, etc. In this study, a silanized linker (3-aminopropyl triethoxyslane, APTES) was deposited on silicon dioxides (SiO2) particles and phthalate chemical probes were manufactured from phthalic acid and APTES-SiO2. These probes could be used for detecting proteins that targeted phthalic acid and for protein-protein interactions. The phthalic acid chemical probes we produced were incubated with epithelioid cell lysates of normal rat kidney (NRK-52E cells) to detect the interactions between phthalic acid and NRK-52E extracted proteins. These chemical probes interacted with a number of chaperones such as protein disulfide-isomerase A6, heat shock proteins, and Serpin H1. Ingenuity Pathways Analysis (IPA) software showed that these chemical probes were a practical technique for protein-protein interaction analysis. PMID:23797655

  7. Fluorimetric determination of total ascorbic acid by a stopped-flow mixing technique.

    PubMed

    Pérez-Ruiz, T; Martínez-Lozano, C; Tomás, V; Fenoll, J; Fenol, J

    2001-08-01

    A simple, rapid and automatic fluorimetric method for the determination of total ascorbic acid is described. The method makes use of the stopped-flow mixing technique in order to achieve the rapid oxidation of ascorbic acid by dissolved oxygen to dehydroascorbic acid, which then reacts with o-phenylenediamine to form a fluorescent quinoxaline. The initial rate and fluorescence signal of this system are directly proportional to the ascorbic acid concentration. The calibration graph was linear over the range 0.1-30 microg ml(-1) (kinetic method) and 0.25-34 microg ml(-1) (equilibrium method). The precision (% RSD) was close to 0.5%. The method has been used for the determination of ascorbic acid in pharmaceutical formulations, fruit juices, soft drinks and blood serum. PMID:11534621

  8. HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO

    EPA Science Inventory

    HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO. MR Blanton and ES Hunter. Reproductive Toxicology Division, NHEERL, ORD, US EPA, RTP, NC, USA.
    Sponsor: JM Rogers.
    Haloacetic Acids (HAAs) formed during the disinfection process are present in drin...

  9. Conformational Entropy of Intrinsically Disordered Proteins from Amino Acid Triads

    PubMed Central

    Baruah, Anupaul; Rani, Pooja; Biswas, Parbati

    2015-01-01

    This work quantitatively characterizes intrinsic disorder in proteins in terms of sequence composition and backbone conformational entropy. Analysis of the normalized relative composition of the amino acid triads highlights a distinct boundary between globular and disordered proteins. The conformational entropy is calculated from the dihedral angles of the middle amino acid in the amino acid triad for the conformational ensemble of the globular, partially and completely disordered proteins relative to the non-redundant database. Both Monte Carlo (MC) and Molecular Dynamics (MD) simulations are used to characterize the conformational ensemble of the representative proteins of each group. The results show that the globular proteins span approximately half of the allowed conformational states in the Ramachandran space, while the amino acid triads in disordered proteins sample the entire range of the allowed dihedral angle space following Flory’s isolated-pair hypothesis. Therefore, only the sequence information in terms of the relative amino acid triad composition may be sufficient to predict protein disorder and the backbone conformational entropy, even in the absence of well-defined structure. The predicted entropies are found to agree with those calculated using mutual information expansion and the histogram method. PMID:26138206

  10. Effects of gamma irradiation on chickpea seeds vis-a-vis total seed storage proteins, antioxidant activity and protein profiling.

    PubMed

    Bhagyawant, S S; Gupta, N; Shrivastava, N

    2015-01-01

    The present work describes radiation—induced effects on seed composition vis—à—vis total seed proteins, antioxidant levels and protein profiling employing two dimensional gel electrophoresis (2D—GE) in kabuli and desi chickpea varities. Seeds were exposed to the radiation doses of 1,2,3,4 and 5 kGy. The total protein concentrations decreased and antioxidant levels were increased with increasing dose compared to control seed samples. Radiation induced effects were dose dependent to these seed parameters while it showed tolerance to 1 kGy dose. Increase in the dose was complimented with increase in antioxidant levels, like 5 kGy enhanced % scavenging activities in all the seed extracts. Precisely, the investigations reflected that the dose range from 2 to 5 kGy was effective for total seed storage proteins, as depicted quantitatively and qualitative 2D—GE means enhance antioxidant activities in vitro. PMID:26516115

  11. Contents of total fat, fatty acids, starch, sugars and dietary fibre in Swedish market basket diets.

    PubMed

    Becker, W; Eriksson, A; Haglund, M; Wretling, S

    2015-05-14

    The typical dietary supply of total fat, fatty acids, starch, sugars, polyols and dietary fibre in Sweden was assessed from analyses of market baskets (MB) purchased in 2005 and 2010. MB were based on food balance sheets, with each basket comprising about 130 foods, which represented more than 90% of annual dietary supply. Foods were divided into ten to twelve categories. In 2010, total fat contributed 34% of energy (E%), SFA 14.3 E%, MUFA 12.8 E%, PUFA 4.6 E%, n-6 fatty acids 3.6 E%, n-3 fatty acids 1.0 E% and trans-fatty acids (TFA) 0.5 E%. Glycaemic carbohydrates contributed 47 E%, monosaccharides 9 E%, sucrose 11 E%, disaccharides 15 E% and total sugars 24 E%. Added sugars contributed about 15 E%. Dietary fibre content was about 1.7 g/MJ in the 2010 MB. Compared with the 2005 MB, the dietary supply of TFA and dietary fibre was lower, otherwise differences were small. The present MB survey shows that the content of SFA and added sugars was higher than the current Nordic Nutrition Recommendations, while the content of PUFA and especially dietary fibre was lower. TFA levels decreased and dietary supply was well below the recommendations of the WHO. These results emphasise a focus on quality and food sources of fat and carbohydrates, limiting foods rich in SFA and added sugars and replacing them with foods rich in dietary fibre and cis-unsaturated fatty acids. PMID:25989998

  12. Total synthsis of (+)-ambuic acid: α-bromination with 1,2-dibromotetrachloroethane.

    PubMed

    Jung, Sun Hee; Hwang, Geum-Sook; Lee, Sung Il; Ryu, Do Hyun

    2012-03-01

    Total synthesis of (+)-ambuic acid has been accomplished from the readily available stereocontrolled Diels-Alder adduct of cyclopentadiene and iodo-1,4-benzoquinone monoketal through an efficient series of steps. A new method for the highly commendable synthesis of α-brominated Diels-Alder adduct is described. PMID:22280015

  13. 21 CFR 862.1020 - Acid phosphatase (total or prostatic) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Acid phosphatase (total or prostatic) test system. 862.1020 Section 862.1020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  14. 21 CFR 862.1020 - Acid phosphatase (total or prostatic) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Acid phosphatase (total or prostatic) test system. 862.1020 Section 862.1020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  15. 21 CFR 862.1020 - Acid phosphatase (total or prostatic) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Acid phosphatase (total or prostatic) test system. 862.1020 Section 862.1020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  16. 21 CFR 862.1020 - Acid phosphatase (total or prostatic) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Acid phosphatase (total or prostatic) test system. 862.1020 Section 862.1020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  17. 21 CFR 862.1020 - Acid phosphatase (total or prostatic) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Acid phosphatase (total or prostatic) test system. 862.1020 Section 862.1020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  18. Rapid Online Non-Enzymatic Protein Digestion Combining Microwave Heating Acid Hydrolysis and Electrochemical Oxidation

    PubMed Central

    Basile, Franco; Hauser, Nicolas

    2010-01-01

    We report an online non-enzymatic method for site-specific digestion of proteins to yield peptides that are well suited for collision induced dissociation (CID) tandem mass spectrometry (MS/MS). The method combines online microwave heating acid hydrolysis at aspartic acid and online electrochemical oxidation at tryptophan and tyrosine. The combined microwave/electrochemical (microwave/echem) digestion is reproducible and produces peptides with an average sequence length of 10 amino acids. This peptide length is similar to the average peptide length of 9 amino acids obtained by digestion of proteins with the enzyme trypsin. As a result, the peptides produced by this novel non-enzymatic digestion method, when analyzed by ESI-MS, produce protonated molecules with mostly +1 and +2 charge states. The combination of these two non-enzymatic methods overcomes shortcomings with each individual method in that: i) peptides generated by the microwave-hydrolysis method have an average amino acid length of 16 amino acids, and ii) the inability of the electrochemical-cleavage method to reproducibly digest proteins with molecular masses above 4 kDa. Preliminary results are presented on the application and utility of this rapid online digestion (total of 6 min digestion time) on a series of standard peptides and proteins as well as an E. coli protein extract. PMID:21138252

  19. Production of hydrophobic amino acids from biobased resources: wheat gluten and rubber seed proteins.

    PubMed

    Widyarani; Sari, Yessie W; Ratnaningsih, Enny; Sanders, Johan P M; Bruins, Marieke E

    2016-09-01

    Protein hydrolysis enables production of peptides and free amino acids that are suitable for usage in food and feed or can be used as precursors for bulk chemicals. Several essential amino acids for food and feed have hydrophobic side chains; this property may also be exploited for subsequent separation. Here, we present methods for selective production of hydrophobic amino acids from proteins. Selectivity can be achieved by selection of starting material, selection of hydrolysis conditions, and separation of achieved hydrolysate. Several protease combinations were applied for hydrolysis of rubber seed protein concentrate, wheat gluten, and bovine serum albumin (BSA). High degree of hydrolysis (>50 %) could be achieved. Hydrophobic selectivity was influenced by the combination of proteases and by the extent of hydrolysis. Combination of Pronase and Peptidase R showed the highest selectivity towards hydrophobic amino acids, roughly doubling the content of hydrophobic amino acids in the products compared to the original substrates. Hydrophobic selectivity of 0.6 mol-hydrophobic/mol-total free amino acids was observed after 6 h hydrolysis of wheat gluten and 24 h hydrolysis of rubber seed proteins and BSA. The results of experiments with rubber seed proteins and wheat gluten suggest that this process can be applied to agro-industrial residues. PMID:27118013

  20. Manipulating Fatty Acid Biosynthesis in Microalgae for Biofuel through Protein-Protein Interactions

    PubMed Central

    Blatti, Jillian L.; Beld, Joris; Behnke, Craig A.; Mendez, Michael; Mayfield, Stephen P.; Burkart, Michael D.

    2012-01-01

    Microalgae are a promising feedstock for renewable fuels, and algal metabolic engineering can lead to crop improvement, thus accelerating the development of commercially viable biodiesel production from algae biomass. We demonstrate that protein-protein interactions between the fatty acid acyl carrier protein (ACP) and thioesterase (TE) govern fatty acid hydrolysis within the algal chloroplast. Using green microalga Chlamydomonas reinhardtii (Cr) as a model, a structural simulation of docking CrACP to CrTE identifies a protein-protein recognition surface between the two domains. A virtual screen reveals plant TEs with similar in silico binding to CrACP. Employing an activity-based crosslinking probe designed to selectively trap transient protein-protein interactions between the TE and ACP, we demonstrate in vitro that CrTE must functionally interact with CrACP to release fatty acids, while TEs of vascular plants show no mechanistic crosslinking to CrACP. This is recapitulated in vivo, where overproduction of the endogenous CrTE increased levels of short-chain fatty acids and engineering plant TEs into the C. reinhardtii chloroplast did not alter the fatty acid profile. These findings highlight the critical role of protein-protein interactions in manipulating fatty acid biosynthesis for algae biofuel engineering as illuminated by activity-based probes. PMID:23028438

  1. Predicting protein disorder by analyzing amino acid sequence

    PubMed Central

    Yang, Jack Y; Yang, Mary Qu

    2008-01-01

    Background Many protein regions and some entire proteins have no definite tertiary structure, presenting instead as dynamic, disorder ensembles under different physiochemical circumstances. These proteins and regions are known as Intrinsically Unstructured Proteins (IUP). IUP have been associated with a wide range of protein functions, along with roles in diseases characterized by protein misfolding and aggregation. Results Identifying IUP is important task in structural and functional genomics. We exact useful features from sequences and develop machine learning algorithms for the above task. We compare our IUP predictor with PONDRs (mainly neural-network-based predictors), disEMBL (also based on neural networks) and Globplot (based on disorder propensity). Conclusion We find that augmenting features derived from physiochemical properties of amino acids (such as hydrophobicity, complexity etc.) and using ensemble method proved beneficial. The IUP predictor is a viable alternative software tool for identifying IUP protein regions and proteins. PMID:18831799

  2. Total and free valproic acid: plasma level/dose ratio in monotherapy.

    PubMed

    Abadín, J A; Durán, J A; Sánchez, A; Serrano, J S

    1991-04-01

    Free plasma level/dose ratio of valproic acid (L/D-F) can be more effective than total plasma level/dose ratio (L/D-T) in adjusting dosage regimens. The influence of age, dose, and plasma concentration have been studied on L/D-T and L/D-F ratios. L/D-T and L/D-F ratios from 67 outpatients under long-term monotherapy were obtained. Analytical data was carried out by fluorescent polarized immunoassay. L/D-T and L/D-F ratios do not vary according to age. L/D-T and L/D-F ratios decreased while the dosage increased; both ratios increased with an increase in total plasma level of valproic acid. Significant differences were found between L/D-T and L/D-F ratios. Dose and interindividual variations are the factors which most influence L/D ratios of valproic acid. PMID:2051846

  3. Stable carbon isotopic compositions of organic acids in total suspended particles and dusts from Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

    2010-10-01

    Stable carbon isotopic compositions of individual organic acids were determined in total suspended particles and dusts from Guangzhou. The δ 13C values of high molecular weight n-alkanoic acids (C 20-C 28) varied from -34.1‰ to -32.4‰ and tended to be heavier in summer and lighter in winter. These δ 13C values indicate that high molecular weight n-alkanoic acids were derived mainly from emission by C 3 plants. Reduced biological synthesis of high molecular weight n-alkanoic acids in winter may be the reason for the light carbon isotopic composition. The δ 13C values of low molecular weight n-alkanoic acids (C 10-C 18) changed from -31.7‰ to -30.3‰ and exhibited a reverse seasonal trend, i.e., heavier in winter and lighter in summer. Slightly heavier δ 13C values of low molecular weight n-alkanoic acids than those of high molecular weight n-alkanoic acids suggested that they may be emitted from blended sources, e.g., anthropogenic sources and vegetation waxes. Lighter δ 13C values in summer may be attributed to relatively low anthropogenic sources and high botanic sources in summer. Dicarboxylic acids and aromatic acids have been proposed as secondary products from photochemical degradation. The average δ 13C values of dicarboxylic acids and aromatic acids were heavier, and ranged from -25.2‰ to -22.9‰ and from -30.0‰ to -27.6‰, respectively. Both dicarboxylic acids and aromatic acids displayed the same temporal variations in the δ 13C values, i.e., negative δ 13C in the summer samples and positive in the winter samples, which may be controlled by photochemical reactions; they are generally severe in winter in Guangzhou under the monsoon weather system. The heaviest δ 13C values were observed in dicarboxylic acids, indicating that dicarboxylic acids were formed by fast and more complete oxidation reactions. These results indicate that the stable carbon isotopic composition of organic acids may provide important information about sources and

  4. IR-UV photochemistry of protein-nucleic acid systems

    SciTech Connect

    Kozub, J.; Edwards, G.

    1995-12-31

    UV light has often been used to induce the formation of covalent bonds between DNA (or RNA) and tightly-bound protein molecules. However, the internal photoreactions of nucleic acids and proteins limit the yield and complicate the analysis of intermolecular crosslinks. In an ongoing search for improved reaction specificity or new photoreactions in these systems, we have employed UV photons from a Nd:YAG-pumped dye laser and mid-IR photons from the Vanderbilt FEL. Having crosslinked several protein-nucleic acid systems with nanosecond UV laser pulses, we are currently studying the effect of various IR wavelengths on a model system (gene 32 protein and poly[dT]). We have found that irradiation with sufficiently intense FEL macropulses creates an altered form of gene 32 protein which was not observed with UV-only irradiation. The electrophoretic nobility of the product is consistent with the formation of a specific protein-protein crosslink. No evidence of the non-specific protein damage typically induced by UV light is found. The yield of the new photoproduct is apparently enhanced by exposure to FEL macropulses which are synchronized with UV laser pulses. With ideal exposure parameters, the two-color reaction effectively competes with UV-only reactions. Experiments designed to determine the reaction mechanism and to demonstrate FEL-induced reactions in other protein-nucleic acid systems are currently underway.

  5. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    NASA Astrophysics Data System (ADS)

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts.

  6. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    PubMed Central

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts. PMID:10639127

  7. Protein and Essential Amino Acids to Protect Musculoskeletal Health during Spaceflight: Evidence of a Paradox?

    PubMed

    Hackney, Kyle J; English, Kirk L

    2014-01-01

    Long-duration spaceflight results in muscle atrophy and a loss of bone mineral density. In skeletal muscle tissue, acute exercise and protein (e.g., essential amino acids) stimulate anabolic pathways (e.g., muscle protein synthesis) both independently and synergistically to maintain neutral or positive net muscle protein balance. Protein intake in space is recommended to be 12%-15% of total energy intake (≤1.4 g∙kg-1∙day-1) and spaceflight is associated with reduced energy intake (~20%), which enhances muscle catabolism. Increasing protein intake to 1.5-2.0 g∙kg-1∙day-1 may be beneficial for skeletal muscle tissue and could be accomplished with essential amino acid supplementation. However, increased consumption of sulfur-containing amino acids is associated with increased bone resorption, which creates a dilemma for musculoskeletal countermeasures, whereby optimizing skeletal muscle parameters via essential amino acid supplementation may worsen bone outcomes. To protect both muscle and bone health, future unloading studies should evaluate increased protein intake via non-sulfur containing essential amino acids or leucine in combination with exercise countermeasures and the concomitant influence of reduced energy intake. PMID:25370374

  8. Protein and Essential Amino Acids to Protect Musculoskeletal Health during Spaceflight: Evidence of a Paradox?

    PubMed Central

    Hackney, Kyle J.; English, Kirk L.

    2014-01-01

    Long-duration spaceflight results in muscle atrophy and a loss of bone mineral density. In skeletal muscle tissue, acute exercise and protein (e.g., essential amino acids) stimulate anabolic pathways (e.g., muscle protein synthesis) both independently and synergistically to maintain neutral or positive net muscle protein balance. Protein intake in space is recommended to be 12%–15% of total energy intake (≤1.4 g∙kg−1∙day−1) and spaceflight is associated with reduced energy intake (~20%), which enhances muscle catabolism. Increasing protein intake to 1.5–2.0 g∙kg−1∙day−1 may be beneficial for skeletal muscle tissue and could be accomplished with essential amino acid supplementation. However, increased consumption of sulfur-containing amino acids is associated with increased bone resorption, which creates a dilemma for musculoskeletal countermeasures, whereby optimizing skeletal muscle parameters via essential amino acid supplementation may worsen bone outcomes. To protect both muscle and bone health, future unloading studies should evaluate increased protein intake via non-sulfur containing essential amino acids or leucine in combination with exercise countermeasures and the concomitant influence of reduced energy intake. PMID:25370374

  9. Influence of various nitrogen applications on protein and amino acid profiles of amaranth and quinoa.

    PubMed

    Thanapornpoonpong, Sa-nguansak; Vearasilp, Suchada; Pawelzik, Elke; Gorinstein, Shela

    2008-12-10

    The effect of nitrogen application levels (0.16 and 0.24 g N kg(-1) soil) on seed proteins and their amino acid compositions of amaranth (Amaranthus spp.) and quinoa (Chenopodium quinoa Willd) was studied. Total proteins of amaranth and quinoa had high contents of lysine (6.3-8.2 g 100 g(-1) protein) but low contents of methionine (1.2-1.8 g 100 g(-1) protein). Seed proteins were fractionated on the basis of different solubility in water, saline, and buffer as albumin-1 (Albu-1), albumin-2 (Albu-2), globulin (Glob), and glutelin (Glu) and were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Albu-1 was high in lysine (5.4-8.6 g 100 g(-1) protein), while Albu-2, which is a part of storage proteins, had a high leucine content (7.2-8.9 g 100 g(-1) protein) as an effect of different nitrogen application levels. Glu fractions were well-balanced in their essential amino acids with the exception of methionine. In conclusion, nitrogen application can be used for the nutritional improvement in human diet by increasing and maintaining protein and essential amino acid contents. PMID:19006392

  10. Dietary protein and plasma total homocysteine, cysteine concentrations in coronary angiographic subjects

    PubMed Central

    2013-01-01

    Background Dietary patterns are associated with plasma total homocysteine (tHcy) concentrations in healthy populations, but the associations between dietary protein and tHcy, total cysteine (tCys) in high risk populations are unclear. We therefore examined the association between dietary protein and tHcy and tCys concentrations in coronary angiographic subjects. Methods We conducted a cross-sectional study of 1015 Chinese patients who underwent coronary angiography (40–85 y old). With the use of food-frequency questionnaires, we divided the total protein intakes into high animal-protein and high plant-protein diets. Circulating concentrations of tHcy and tCys were simultaneously measured by high-performance liquid chromatography with fluorescence detection. Results We found that high animal-protein diet was positively associated with hyperhomocysteinemia after adjustment for potential confounders, with the subjects in the highest quartile of intake having the greatest increase in risk (OR: 4.14, 95% CI: 2.67-6.43), whereas high plant-protein diet was inversely related to hyperhomocysteinemia, with a higher intake being protective. Compared with the first quartile of intake, the adjusted OR was 0.59 (95% CI: 0.38-0.91) for the fourth quartile. The total protein intake was positively associated with the risk of hypercysteinemia and the participants in highest quartile had significant OR of 1.69 (95% CI: 1.02-2.87) compared with those in lowest quartile. In multivariate linear regression analyses, high animal-protein and total-protein intakes were positively associated with plasma tHcy and tCys concentrations. The plant-protein intake was a negative determinant of plasma tHcy concentrations. Conclusions High animal-protein diet was positively associated with high tHcy concentrations, whereas high plant-protein diet was inversely associated with tHcy concentrations. Furthermore the total protein intake was strongly related to tCys concentrations. PMID:24195518

  11. Changes in total plasma content of electrolytes and proteins with maximal exercise.

    NASA Technical Reports Server (NTRS)

    Van Beaumont, W.; Strand, J. C.; Petrofsky, J. S.; Hipskind, S. G.; Greenleaf, J. E.

    1973-01-01

    To determine to what extent the increases in concentration of plasma proteins and electrolytes with short maximal work were a result of hemoconcentration, the changes in plasma volume and total content of the plasma constituents were simultaneously evaluated. The results obtained from six human subjects indicated that in comparison to preexercise values there was a net decrease in total content of plasma protein, sodium, and chloride in the first 2 min of the postexercise period, due primarily to a significant loss (13-15%) of plasma fluid. The total plasma potassium content was increased immediately after exercise but was significantly below the preexercise plasma content after 2 min of recovery.

  12. Direct Sensing of Total Acidity by Chronopotentiometric Flash Titrations at Polymer Membrane Ion-Selective Electrodes

    PubMed Central

    Gemene, Kebede L.; Bakker, Eric

    2008-01-01

    Polymer membrane ion-selective electrodes containing lipophilic ionophores are traditionally interrogated by zero current potentiometry, which, ideally, gives information on the sample activity of ionic species. It is shown here that a discrete cathodic current pulse across an H+-selective polymeric membrane doped with the ionophore ETH 5294 may be used for the chronopotentiometric detection of pH in well buffered samples. However, a reduction in the buffer capacity leads to large deviations from the expected Nernstian response slope. This is explained by the local depletion of hydrogen ions at the sample-membrane interface as a result of the galvanostatically imposed ion flux in direction of the membrane. This depletion is found to be a function of the total acidity of the sample and can be directly monitored chronopotentiometrically in a flash titration experiment. The subsequent application of a baseline potential pulse reverses the extraction process of the current pulse, allowing one to interrogate the sample with minimal perturbation. In one protocol, total acidity is found to be proportional to the magnitude of applied current at the flash titration endpoint. More conveniently, the square root of the flash titration endpoint time observed at a fixed applied current is a linear function of the total acid concentration. This suggests that it is possible to perform rapid localized pH titrations at ion-selective electrodes without the need for volumetric titrimetry. The technique is explored here for acetic acid, MES and citric acid with promising results. Polymeric membrane electrodes on the basis of poly(vinyl chloride) plasticized with o-nitrophenyloctylether in a 1:2 mass ratio may be used for the detection of acids of up to ca. 1 mM concentration, with flash titration times on the order of a few seconds. Possible limitations of the technique are discussed, including variations of the acid diffusion coefficients and influence of electrical migration. PMID

  13. Blood Loss and Transfusion After Topical Tranexamic Acid Administration in Primary Total Knee Arthroplasty.

    PubMed

    Wang, Hao; Shen, Bin; Zeng, Yi

    2015-11-01

    There has been much debate and controversy about the safety and efficacy of the topical use of tranexamic acid in primary total knee arthroplasty (TKA). The purpose of this study was to perform a meta-analysis to evaluate whether there is less blood loss and lower rates of transfusion after topical tranexamic acid administration in primary TKA. A systematic review of the electronic databases PubMed, CENTRAL, Web of Science, and Embase was undertaken. All randomized, controlled trials and prospective cohort studies evaluating the effectiveness of topical tranexamic acid during primary TKA were included. The focus of the analysis was on the outcomes of blood loss results, transfusion rate, and thromboembolic complications. Subgroup analysis was performed when possible. Of 387 studies identified, 16 comprising 1421 patients (1481 knees) were eligible for data extraction and meta-analysis. This study indicated that when compared with the control group, topical application of tranexamic acid significantly reduced total drain output (mean difference, -227.20; 95% confidence interval, -347.11 to -107.30; P<.00001), total blood loss (mean difference, -311.28; 95% confidence interval, -404.94 to -217.62; P<.00001), maximum postoperative hemoglobin decrease (mean difference, -0.73; 95% confidence interval, -0.96 to -0.50; P<.00001), and blood transfusion requirements (risk ratios, 0.33; 95% confidence interval, 0.24 to 0.43; P=.14). The authors found a statistically significant reduction in blood loss and transfusion rates when using topical tranexamic acid in primary TKA. Furthermore, the currently available evidence does not support an increased risk of deep venous thrombosis or pulmonary embolism due to tranexamic acid administration. Topical tranexamic acid was effective for reducing postoperative blood loss and transfusion requirements without increasing the prevalence of thromboembolic complications. PMID:26558665

  14. [Amino acid composition of rice grain proteins].

    PubMed

    Peruanskiĭ, Iu V; Savich, I M

    1976-01-01

    The composition of the major reserve proteins of rice grain--globulins, prolamines and glutelins--was examined in four rice varieties (Dubovsky 129, Kuban 3, Alakul, Ushtobinsky). Globulins proved to be most heterogeneous whereas glutelins appeared to be least heterogeneous. In regards to the ratio of components globulins showed high variability and glutelins displayed high stability. PMID:1005365

  15. Real-time Measurements of Amino Acid and Protein Hydroperoxides Using Coumarin Boronic Acid*

    PubMed Central

    Michalski, Radoslaw; Zielonka, Jacek; Gapys, Ewa; Marcinek, Andrzej; Joseph, Joy; Kalyanaraman, Balaraman

    2014-01-01

    Hydroperoxides of amino acid and amino acid residues (tyrosine, cysteine, tryptophan, and histidine) in proteins are formed during oxidative modification induced by reactive oxygen species. Amino acid hydroperoxides are unstable intermediates that can further propagate oxidative damage in proteins. The existing assays (oxidation of ferrous cation and iodometric assays) cannot be used in real-time measurements. In this study, we show that the profluorescent coumarin boronic acid (CBA) probe reacts with amino acid and protein hydroperoxides to form the corresponding fluorescent product, 7-hydroxycoumarin. 7-Hydroxycoumarin formation was catalase-independent. Based on this observation, we have developed a fluorometric, real-time assay that is adapted to a multiwell plate format. This is the first report showing real-time monitoring of amino acid and protein hydroperoxides using the CBA-based assay. This approach was used to detect protein hydroperoxides in cell lysates obtained from macrophages exposed to visible light and photosensitizer (rose bengal). We also measured the rate constants for the reaction between amino acid hydroperoxides (tyrosyl, tryptophan, and histidine hydroperoxides) and CBA, and these values (7–23 m−1 s−1) were significantly higher than that measured for H2O2 (1.5 m−1 s−1). Using the CBA-based competition kinetics approach, the rate constants for amino acid hydroperoxides with ebselen, a glutathione peroxidase mimic, were also determined, and the values were within the range of 1.1–1.5 × 103 m−1 s−1. Both ebselen and boronates may be used as small molecule scavengers of amino acid and protein hydroperoxides. Here we also show formation of tryptophan hydroperoxide from tryptophan exposed to co-generated fluxes of nitric oxide and superoxide. This observation reveals a new mechanism for amino acid and protein hydroperoxide formation in biological systems. PMID:24928516

  16. Nucleic acid compositions and the encoding proteins

    DOEpatents

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  17. Survey of duckweed diversity in Lake Chao and total fatty acid, triacylglycerol, profiles of representative strains.

    PubMed

    Tang, J; Li, Y; Ma, J; Cheng, J J

    2015-09-01

    Lemnaceae (duckweeds) are widely distributed aquatic flowering plants. Their high growth rate, starch content and suitability for bioremediation make them potential feedstock for biofuels. However, few natural duckweed resources have been investigated in China, and there is no information about total fatty acid (TFA) and triacylglycerol (TAG) composition of duckweeds from China. Here, the genetic diversity of a natural duckweed population collected from Lake Chao, China, was investigated using multilocus sequence typing (MLST). The 54 strains were categorised into four species in four genera, representing 12 distinct sequence types. Strains representing Lemna aequinoctialis and Spirodela polyrhiza were predominant. Interestingly, a surprisingly high degree of genetic diversification within L. aequinoctialis was observed. The four duckweed species revealed a uniform fatty acid composition, with three fatty acids, palmitic acid, linoleic acid and linolenic acid, accounting for more than 80% of the TFA. The TFA in biomass varied among species, ranging from 1.05% (of dry weight, DW) for L. punctata and S. polyrhiza to 1.62% for Wolffia globosa. The four duckweed species contained similar TAG contents, 0.02% mg · DW(-1). The fatty acid profiles of TAG were different from those of TFA, and also varied among the four species. The survey investigated the genetic diversity of duckweeds from Lake Chao, and provides an initial insight into TFA and TAG of four duckweed species, indicating that intraspecific and interspecific variations exist in the content and composition of both TFA and TAG in comparison with other studies. PMID:25950142

  18. FLU, an amino acid substitution model for influenza proteins

    PubMed Central

    2010-01-01

    Background The amino acid substitution model is the core component of many protein analysis systems such as sequence similarity search, sequence alignment, and phylogenetic inference. Although several general amino acid substitution models have been estimated from large and diverse protein databases, they remain inappropriate for analyzing specific species, e.g., viruses. Emerging epidemics of influenza viruses raise the need for comprehensive studies of these dangerous viruses. We propose an influenza-specific amino acid substitution model to enhance the understanding of the evolution of influenza viruses. Results A maximum likelihood approach was applied to estimate an amino acid substitution model (FLU) from ~113, 000 influenza protein sequences, consisting of ~20 million residues. FLU outperforms 14 widely used models in constructing maximum likelihood phylogenetic trees for the majority of influenza protein alignments. On average, FLU gains ~42 log likelihood points with an alignment of 300 sites. Moreover, topologies of trees constructed using FLU and other models are frequently different. FLU does indeed have an impact on likelihood improvement as well as tree topologies. It was implemented in PhyML and can be downloaded from ftp://ftp.sanger.ac.uk/pub/1000genomes/lsq/FLU or included in PhyML 3.0 server at http://www.atgc-montpellier.fr/phyml/. Conclusions FLU should be useful for any influenza protein analysis system which requires an accurate description of amino acid substitutions. PMID:20384985

  19. Acid Cleavable Surface enhanced Raman Tagging for Protein Detection

    PubMed Central

    Zhang, Dongmao; Vangala, Karthikeshwar; Li, Shaoyong; Yanney, Michael; Xia, Hao; Zou, Sige; Sygula, Andrzej

    2010-01-01

    Dye conjugation is a common strategy improving the surface enhanced Raman detection sensitivity of biomolecules. Reported is a proof-of-concept study of a novel surface enhanced Raman spectroscopic tagging strategy termed as acid-cleavable SERS tag (ACST) method. Using Rhodamine B as the starting material, we prepared the first ACST prototype that consisted of, from the distal end, a SERS tag moiety (STM), an acid-cleavable linker, and a protein reactive moiety. Complete acid cleavage of the ACST tags was achieved at a very mild condition that is 1.5% trifluoroacetic acid (TFA) aqueous solution at room temperature. SERS detection of this ACST tagged protein was demonstrated using bovine serum albumin (BSA) as the model protein. While the SERS spectrum of intact ACST-BSA was entirely dominated by the fluorescent signal of STM, quality SERS spectra can be readily obtained with the acid cleaved ACST-BSA conjugates. Separation of the acid cleaved STM from protein further enhances the SERS sensitivity. Current SERS detection sensitivity, achieved with the acid cleaved ACST-BSA conjugate is ~5 nM in terms of the BSA concentration and ~1.5 nM in ACST content. The linear dynamic range of the cleaved ACST-BSA conjugate spans four orders of magnitudes from ~10 nM to ~100 μM in protein concentrations. Further improvement in the SERS sensitivity can be achieved with resonance Raman acquisition. This cleavable tagging strategy may also be used for elimination of protein interference in fluorescence based biomolecule detection. PMID:21109888

  20. Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity.

    PubMed

    Dhavan, Atul A; Kaduskar, Rahul D; Musso, Loana; Scaglioni, Leonardo; Martino, Piera Anna; Dallavalle, Sabrina

    2016-01-01

    The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments. PMID:27559415

  1. Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

    PubMed Central

    Dhavan, Atul A; Kaduskar, Rahul D; Musso, Loana; Scaglioni, Leonardo; Martino, Piera Anna

    2016-01-01

    Summary The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments. PMID:27559415

  2. Total Protein Extraction and 2-D Gel Electrophoresis Methods for Burkholderia Species

    PubMed Central

    Velapatiño, Billie; Zlosnik, James E. A.; Hird, Trevor J.; Speert, David P.

    2013-01-01

    The investigation of the intracellular protein levels of bacterial species is of importance to understanding the pathogenic mechanisms of diseases caused by these organisms. Here we describe a procedure for protein extraction from Burkholderia species based on mechanical lysis using glass beads in the presence of ethylenediamine tetraacetic acid and phenylmethylsulfonyl fluoride in phosphate buffered saline. This method can be used for different Burkholderia species, for different growth conditions, and it is likely suitable for the use in proteomic studies of other bacteria. Following protein extraction, a two-dimensional (2-D) gel electrophoresis proteomic technique is described to study global changes in the proteomes of these organisms. This method consists of the separation of proteins according to their isoelectric point by isoelectric focusing in the first dimension, followed by separation on the basis of molecular weight by acrylamide gel electrophoresis in the second dimension. Visualization of separated proteins is carried out by silver staining. PMID:24192802

  3. New quantitative total protein S-assay system for diagnosing protein S type II deficiency: clinical application of the screening system for protein S type II deficiency.

    PubMed

    Tsuda, Tomohide; Jin, Xiuri; Tsuda, Hiroko; Ieko, Masahiro; Morishita, Eriko; Adachi, Tomoko; Hamasaki, Naotaka

    2012-01-01

    Venous thromboembolism (VTE) incidence is rising rapidly in Japan with lifestyle westernization and aging. Deficiency of protein S, an important blood coagulation regulator, is a risk factor for VTE. Protein S deficiency prevalence in Asians is approximately 10 times that in Caucasians and that of protein S type II deficiency, associated with the protein S Tokushima mutation (K155E), is quite high in Japan. However, currently available methods for measuring protein S are not precise enough for detection of this deficiency. We developed a novel assay system for precise simultaneous determinations of total protein S activity and total protein S antigen level, using a general-purpose automated analyzer, allowing protein S-specific activity (ratio of total protein S activity to total protein S antigen level) to be calculated. Mean specific activity was 0.99 for samples from healthy individuals but 0.69 or less (mean-3SD) in protein S type II-deficient and warfarin-treated samples, but was 1.0 in an estrogen-treated sample with significantly decreased protein S antigen. Protein S gene analyses in healthy individuals with specific activity 0.69 or less revealed the K155E mutation in all three. These results show our new assay system to be an effective screening tool for protein S type II deficiency. This system can also be used in an automated analyzer, facilitating numerous sample measurements, and is, thus, applicable to regular medical checkups and diagnosing VTE. Such applications would potentially contribute to early detection of protein S type II deficiency, and, thereby, to thrombosis prevention. PMID:22157257

  4. Fatty acid induced remodeling within the human liver fatty acid-binding protein.

    PubMed

    Sharma, Ashwani; Sharma, Amit

    2011-09-01

    We crystallized human liver fatty acid-binding protein (LFABP) in apo, holo, and intermediate states of palmitic acid engagement. Structural snapshots of fatty acid recognition, entry, and docking within LFABP support a heads-in mechanism for ligand entry. Apo-LFABP undergoes structural remodeling, where the first palmitate ingress creates the atomic environment for placement of the second palmitate. These new mechanistic insights will facilitate development of pharmacological agents against LFABP. PMID:21757748

  5. Study of the effect of total serum protein and albumin concentrations on canine fructosamine concentration.

    PubMed Central

    Loste, A; Marca, M C

    1999-01-01

    The relationship among serum fructosamine concentration and total serum protein and albumin concentrations were evaluated in healthy and sick dogs (diabetics and dogs with insulinoma were not included). Fructosamine was determined using a commercial colorimetric nitroblue tetrazolium method applied to the Technicon RA-500 (Bayer). Serum fructosamine concentration was not correlated to total protein in normoproteinemic (r = 0.03) and hyperproteinemic dogs (r = 0.29), but there was a high correlation (r = 0.73) in hypoproteinemic dogs. Similar comparison between serum fructosamine and albumin concentrations showed middle correlation (r = 0.49) in normoalbuminemic dogs and high degree of correlation (r = 0.67) in hypoalbuminemic dogs. These results showed the importance of recognizing serum glucose concentration as well as total serum protein and albumin concentrations in the assay of canine serum fructosamine concentration. PMID:10369572

  6. Simultaneous serum desalting and total protein determination by macroporous reversed-phase chromatography.

    PubMed

    Boichenko, Alexander; Govorukhina, Natalia; van der Zee, Ate G J; Bischoff, Rainer

    2013-04-01

    Macroporous reversed-phase (mRP) chromatography was successfully used to develop an accurate and precise method for total protein in serum. The limits of detection (0.83 μg, LOD) and quantification (2.51 μg, LOQ) for the mRP method are comparable with those of the widely used micro BCA protein assay. The mRP method can be used to determine the total protein concentration across a wide dynamic range by detecting chromatographic peaks at 215 nm and 280 nm. The method has the added advantage of desalting and denaturing proteins, leading to more complete digestion by trypsin and to better LC-MS-MS identification in shotgun proteomics experiments. PMID:23388688

  7. Culture media optimization of Porphyridium purpureum: production potential of biomass, total lipids, arachidonic and eicosapentaenoic acid.

    PubMed

    Kavitha, Mysore Doddaiah; Kathiresan, Shanmugam; Bhattacharya, Sila; Sarada, Ravi

    2016-05-01

    Porphyridium purpureum a red marine microalga is known for phycobiliproteins (PB), polyunsaturated fatty acids and sulphated exopolysaccharides. In the present study, effects of media constituents for the production of different polyunsaturated fatty acids from P. purpureum were considered using a response surface methodology (RSM). A second order polynomial was used to predict the response functions in terms of the independent variables such as the concentrations of sodium chloride, magnesium sulphate, sodium nitrate and potassium dihydrogen phosphate. The response functions were production of biomass yield, total lipid and polyunsaturated fatty acids like arachidonic acid (AA 20:4) and eicosapentaenoic acid (EPA 20:5). Results corroborated that maximum Biomass (0.95 gL(-1)) yield was at the concentrations of sodium chloride (14.89 gL(-1)), magnesium sulfate (3.93 gL(-1)) and sodium nitrate (0.96 gL(-1)) and potassium dihydrogen phosphate (0.09 gL(-1)). Optimum total lipid (17.9 % w/w) and EPA (34.6 % w/w) content was at the concentrations of sodium chloride (29.98 gL(-1)), magnesium sulfate (9.34 gL(-1)) and sodium nitrate (1.86 gL(-1)). Variation in concentration of potassium dihydrogen phosphate for both lipid (0.01gL(-1)) and EPA content (0.20 gL(-1)) was observed. The optimum conditions for biomass, total lipid, AA and EPA varied indicating their batch mode of growth and interaction effect of the salt. PMID:27407193

  8. Production of total reducing sugar (TRS) from acid hydrolysed potato peels by sonication and its optimization.

    PubMed

    Bhattacharyya, Saurav; Chakraborty, Sudip; Datta, Siddhartha; Drioli, Enrico; Bhattacharjee, Chiranjib

    2013-01-01

    Potato peel is a waste biomass which can be a source of raw material for biofuel production. This biomass contains a sufficient amount of total reducing sugar (TRS), which can be extracted and further treated with microbial pathways to produce bioethanol. The extraction of TRS from potato peels by hydrolysis in dilute sulphuric acid was investigated at different acid concentrations (0.50%, 0.75% and 1% w/v) and sonication was carried out to improve the extent of sugar extraction after hydrolysis. Response surface methodology based on central composite design was used to verify the experimental data and later applied for the optimization of the main important reaction variables including amplitude (60%, 80% and 100%), cycle (0.6, 0.8 and 1.0) and treatment time (5, 10 and 15 min) for the responses of TRS extraction by acid hydrolysis and later compared with the experimental data. PMID:24191439

  9. Antioxidant activity, ascorbic acid and total phenol of exotic fruits occurring in Brazil.

    PubMed

    de Assis, Sandra Aparecida; Vellosa, José Carlos Rebuglio; Brunetti, Iguatemy Lourenço; Khalil, Najeh Maissar; Leite, Kátia Maria da Silva Cerqueira; Martins, Antonio Baldo Geraldo; Oliveira, Olga Maria Mascarenhas de Faria

    2009-08-01

    The antioxidant activity, ascorbic acid and phenolic content were studied in 10 exotic fruits from Brazil: abiu, acerola, wax jambu, cashew, mamey sapote, carambola or star fruit, Surinam cherry, longan, sapodilla and jaboticaba. The ascorbic acid was determined by 2,6-dichloroindophenol titrimetic methods and total phenols were measured colorimetrically using the Folin-Ciocalteu reagent. The antioxidant activity was investigated with three different methods: hypochlorous acid scavenging activity, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging method. The highest content of vitamin C (1,525.00 mg/100 g pulp) occurred in acerola. The total phenol content was higher in abiu, acerola, Surinam cherry and sapodilla. In relation to antioxidant activity, acerola has showed the great values in all three different methods tested. It was found that the fruits have a significant antioxidant effect when tested by each method, respectively, and these antioxidant capacities are promising. The sample concentration also influenced its antioxidant power. PMID:18785051

  10. Analysis of soybean root proteins affected by gibberellic acid treatment under flooding stress.

    PubMed

    Oh, Myeong Won; Nanjo, Yohei; Komatsu, Setsuko

    2014-01-01

    Flooding is a serious abiotic stress for soybean because it restricts growth and reduces grain yields. To investigate the effect of gibberellic acid (GA) on soybean under flooding stress, root proteins were analyzed using a gel-free proteomic technique. Proteins were extracted from the roots of 4-days-old soybean seedlings exposed to flooding stress in the presence and absence of exogenous GA3 for 2 days. A total of 307, 324, and 250 proteins were identified from untreated, and flooding-treated soybean seedlings without or with GA3, respectively. Secondary metabolism- and cell-related proteins, and proteins involved in protein degradation/synthesis were decreased by flooding stress; however, the levels of these proteins were restored by GA3 supplementation under flooding. Fermentation- and cell wall-related proteins were not affected by GA3 supplementation. Furthermore, putative GA-responsive proteins, which were identified by the presence of a GA-responsive element in the promoter region, were less abundant by flooding stress; however, these proteins were more abundant by GA3 supplementation under flooding. Taken together, these results suggest that GA3 affects the abundance of proteins involved in secondary metabolism, cell cycle, and protein degradation/synthesis in soybeans under flooding stress. PMID:24702262

  11. A macromolecular delivery vehicle for protein-based vaccines: Acid-degradable protein-loaded microgels

    PubMed Central

    Murthy, Niren; Xu, Mingcheng; Schuck, Stephany; Kunisawa, Jun; Shastri, Nilabh; Fréchet, Jean M. J.

    2003-01-01

    The development of protein-based vaccines remains a major challenge in the fields of immunology and drug delivery. Although numerous protein antigens have been identified that can generate immunity to infectious pathogens, the development of vaccines based on protein antigens has had limited success because of delivery issues. In this article, an acid-sensitive microgel material is synthesized for the development of protein-based vaccines. The chemical design of these microgels is such that they degrade under the mildly acidic conditions found in the phagosomes of antigen-presenting cells (APCs). The rapid cleavage of the microgels leads to phagosomal disruption through a colloid osmotic mechanism, releasing protein antigens into the APC cytoplasm for class I antigen presentation. Ovalbumin was encapsulated in microgel particles, 200–500 nm in diameter, prepared by inverse emulsion polymerization with a synthesized acid-degradable crosslinker. Ovalbumin is released from the acid-degradable microgels in a pH-dependent manner; for example, microgels containing ovalbumin release 80% of their encapsulated proteins after 5 h at pH 5.0, but release only 10% at pH 7.4. APCs that phagocytosed the acid-degradable microgels containing ovalbumin were capable of activating ovalbumin-specific cytoxic T lymphocytes. The acid-degradable microgels developed in this article should therefore find applications as delivery vehicles for vaccines targeted against viruses and tumors, where the activation of cytoxic T lymphocytes is required for the development of immunity. PMID:12704236

  12. Nucleic Acid Programmable Protein Array: A Just-In-Time Multiplexed Protein Expression and Purification Platform

    PubMed Central

    Qiu, Ji; LaBaer, Joshua

    2012-01-01

    Systematic study of proteins requires the availability of thousands of proteins in functional format. However, traditional recombinant protein expression and purification methods have many drawbacks for such study at the proteome level. We have developed an innovative in situ protein expression and capture system, namely NAPPA (nucleic acid programmable protein array), where C-terminal tagged proteins are expressed using an in vitro expression system and efficiently captured/purified by antitag antibodies coprinted at each spot. The NAPPA technology presented in this chapter enable researchers to produce and display fresh proteins just in time in a multiplexed high-throughput fashion and utilize them for various downstream biochemical researches of interest. This platform could revolutionize the field of functional proteomics with it ability to produce thousands of spatially separated proteins in high density with narrow dynamic rand of protein concentrations, reproducibly and functionally. PMID:21943897

  13. Amino acid repeats and the structure and evolution of proteins.

    PubMed

    Albà, M M; Tompa, P; Veitia, R A

    2007-01-01

    Many proteins have repeats or runs of single amino acids. The pathogenicity of some repeat expansions has fueled proteomic, genomic and structural explorations of homopolymeric runs not only in human but in a wide variety of other organisms. Other types of amino acid repetitive structures exhibit more complex patterns than homopeptides. Irrespective of their precise organization, repetitive sequences are defined as low complexity or simple sequences, as one or a few residues are particularly abundant. Prokaryotes show a relatively low frequency of simple sequences compared to eukaryotes. In the latter the percentage of proteins containing homopolymeric runs varies greatly from one group to another. For instance, within vertebrates, amino acid repeat frequency is much higher in mammals than in amphibians, birds or fishes. For some repeats, this is correlated with the GC-richness of the regions containing the corresponding genes. Homopeptides tend to occur in disordered regions of transcription factors or developmental proteins. They can trigger the formation of protein aggregates, particularly in 'disease' proteins. Simple sequences seem to evolve more rapidly than the rest of the protein/gene and may have a functional impact. Therefore, they are good candidates to promote rapid evolutionary changes. All these diverse facets of homopolymeric runs are explored in this review. PMID:18753788

  14. Single-Cell Protein Production by the Acid-Tolerant Fungus Scytalidium acidophilum from Acid Hydrolysates of Waste Paper †

    PubMed Central

    Ivarson, K. C.; Morita, H.

    1982-01-01

    The bioconversion of waste paper to single-cell protein at pH <1 by Scytalidium acidophilum is described. Waste paper pretreated with 72% H2SO4 at 4°C was diluted with water to a pH of <0.1 and hydrolyzed. This yielded an adequate sugar-containing substrate for the growth of the fungus. A total of 97% of the sugars (glucose, galactose, mannose, xylose, arabinose) in the hydrolysates were converted to cell biomass. Microbial contamination was not observed. Based on the sugars consumed, S. acidophilum produced higher yields in shake cultures than many other Fungi Imperfecti. In aerated cultures, productivity increased, and yields of 43 to 46% containing 44 to 47% crude protein were obtained. This compares favorably with Candida utilis, a yeast used commercially to produce single-cell protein. The chemical constituents and the essential amino acids of the fungal cells were similar to those of other fungi. The nucleic acid content was characteristic of microbes containing low levels of nucleic acid. The advantages of using S. acidophilum for single-cell protein production are discussed. PMID:16345970

  15. Single-cell protein production by the acid-tolerant fungus Scytalidium acidophilum from acid hydrolysates of waste paper

    SciTech Connect

    Ivarson, K.C.; Morita, H.

    1982-03-01

    The bioconversion of waste paper to single-cell protein at pH less than 1 by Scytalidium acidophilum is described. Waste paper pretreated with 72% H/sub 2/SO/sub 4/ at 4 degrees C was diluted with water to a pH of less than 0.1 and hydrolyzed. This yielded an adequate sugar-containing substrate for the growth of the fungus. A total of 97% of the sugars (glucose, galactose, mannose, xylose, arabinose) in the hydrolysates were converted to cell biomass. Microbial contamination was not observed. Based on the sugars consumed, S. acidophilum produced higher yields in shake cultures than many other Fungi Imperfecti. In aerated cultures, productivity increased, and yields of 43 to 46% containing 44 to 47% crude protein were obtained. This compares favorably with Candida utilis, a yeast used commercially to produce single-cell protein. The chemical constituents and the essential amino acids of the fungal cells were similar to those of other fungi. The nucleic acid content was characteristic of microbes containing low levels of nucleic acid. The advantages of using S. acidophilum for single-cell protein production are discussed. (Refs. 30).

  16. (-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats.

    PubMed

    Han, Ningning; Li, Longlong; Peng, Mengling; Ma, Haitian

    2016-08-01

    (-)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress body weight gain and fat accumulation in animals and humans. While, the underlying mechanism of (-)-HCA has not fully understood. Thus, this study was aimed to investigate the effects of long-term supplement with (-)-HCA on body weight gain and variances of amino acid content in rats. Results showed that (-)-HCA treatment reduced body weight gain and increased feed conversion ratio in rats. The content of hepatic glycogen, muscle glycogen, and serum T4 , T3 , insulin, and Leptin were increased in (-)-HCA treatment groups. Protein content in liver and muscle were significantly increased in (-)-HCA treatment groups. Amino acid profile analysis indicated that most of amino acid contents in serum and liver, especially aromatic amino acid and branched amino acid, were higher in (-)-HCA treatment groups. However, most of the amino acid contents in muscle, especially aromatic amino acid and branched amino acid, were reduced in (-)-HCA treatment groups. These results indicated that (-)-HCA treatment could reduce body weight gain through promoting energy expenditure via regulation of thyroid hormone levels. In addition, (-)-HCA treatment could promote protein synthesis by altering the metabolic directions of amino acids. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27145492

  17. Suppression of muscle protein turnover and amino acid degradation by dietary protein deficiency

    NASA Technical Reports Server (NTRS)

    Tawa, N. E. Jr; Goldberg, A. L.

    1992-01-01

    To define the adaptations that conserve amino acids and muscle protein when dietary protein intake is inadequate, rats (60-70 g final wt) were fed a normal or protein-deficient (PD) diet (18 or 1% lactalbumin), and their muscles were studied in vitro. After 7 days on the PD diet, both protein degradation and synthesis fell 30-40% in skeletal muscles and atria. This fall in proteolysis did not result from reduced amino acid supply to the muscle and preceded any clear decrease in plasma amino acids. Oxidation of branched-chain amino acids, glutamine and alanine synthesis, and uptake of alpha-aminoisobutyrate also fell by 30-50% in muscles and adipose tissue of PD rats. After 1 day on the PD diet, muscle protein synthesis and amino acid uptake decreased by 25-40%, and after 3 days proteolysis and leucine oxidation fell 30-45%. Upon refeeding with the normal diet, protein synthesis also rose more rapidly (+30% by 1 day) than proteolysis, which increased significantly after 3 days (+60%). These different time courses suggest distinct endocrine signals for these responses. The high rate of protein synthesis and low rate of proteolysis during the first 3 days of refeeding a normal diet to PD rats contributes to the rapid weight gain ("catch-up growth") of such animals.

  18. Evidence that the ZNT3 protein controls the total amount of elemental zinc in synaptic vesicles

    USGS Publications Warehouse

    Linkous, D.H.; Flinn, J.M.; Koh, J.Y.; Lanzirotti, A.; Bertsch, P.M.; Jones, B.F.; Giblin, L.J.; Frederickson, C.J.

    2008-01-01

    The ZNT3 protein decorates the presynaptic vesicles of central neurons harboring vesicular zinc, and deletion of this protein removes staining for zinc. However, it has been unclear whether only histochemically reactive zinc is lacking or if, indeed, total elemental zinc is missing from neurons lacking the Slc30a3 gene, which encodes the ZNT3 protein. The limitations of conventional histochemical procedures have contributed to this enigma. However, a novel technique, microprobe synchrotron X-ray fluorescence, reveals that the normal 2- to 3-fold elevation of zinc concentration normally present in the hippocampal mossy fibers is absent in Slc30a3 knockout (ZNT3) mice. Thus, the ZNT3 protein evidently controls not only the "stainability" but also the actual mass of zinc in mossy-fiber synaptic vesicles. This work thus confirms the metal-transporting role of the ZNT3 protein in the brain. ?? The Histochemical Society, Inc.

  19. Evidence That the ZNT3 Protein Controls the Total Amount of Elemental Zinc in Synaptic Vesicles

    SciTech Connect

    Linkous,D.; Flinn, J.; Koh, J.; Lanzirotti, A.; Bertsch, P.; Jones, B.; Giblin, L.; Fredrickson, C.

    2008-01-01

    The ZNT3 protein decorates the presynaptic vesicles of central neurons harboring vesicular zinc, and deletion of this protein removes staining for zinc. However, it has been unclear whether only histochemically reactive zinc is lacking or if, indeed, total elemental zinc is missing from neurons lacking the Slc30a3 gene, which encodes the ZNT3 protein. The limitations of conventional histochemical procedures have contributed to this enigma. However, a novel technique, microprobe synchrotron X-ray fluorescence, reveals that the normal 2- to 3-fold elevation of zinc concentration normally present in the hippocampal mossy fibers is absent in Slc30a3 knockout (ZNT3) mice. Thus, the ZNT3 protein evidently controls not only the 'stainability' but also the actual mass of zinc in mossy-fiber synaptic vesicles. This work thus confirms the metal-transporting role of the ZNT3 protein in the brain.

  20. Age-related changes in total protein and collagen metabolism in rat liver.

    PubMed

    Mays, P K; McAnulty, R; Laurent, G J

    1991-12-01

    Liver collagen levels are determined by a balance between synthesis and degradation, processes known to have rapid rates in growing animals. We report age-related changes in liver collagen synthesis and degradation rates, as well as protein synthesis rates, in rats at five ages from 1 to 24 mo. Fractional collagen synthesis rates were determined after injection of [14C]proline with a flooding dose of unlabeled proline and its incorporation as hydroxy-[14C]proline into proteins. Fractional protein synthesis rates were based on the uptake of [14C]proline into proteins. Fractional collagen degradation rates were calculated from the difference between collagen fractional synthesis and deposition rates. Fractional rates of collagen synthesis were similar between 1 mo (23.0% +/- 4.6%/day) and 24 mo (19.6% +/- 3.4%/day) of age. Collagen deposition into the extracellular matrix was extremely low at every age studied; therefore degradation pathways accounted for the bulk of the collagen synthesized. The mean fractional synthesis rate for the total protein pool was unaltered between 1 mo (105.0% +/- 7.2%/day) and 15 mo (89.9% +/- 6.0%/day) of age, after which it increased to 234.9% +/- 33.0%/day (p less than 0.05) by 24 mo of age. These results indicate that liver collagen and total protein synthesis rates were maintained at relatively high levels during development and maturity but that protein synthesis rates were highest in senescent animals. PMID:1959872

  1. Structural Assessment of the Effects of Amino Acid Substitutions on Protein Stability and Protein-Protein Interaction

    PubMed Central

    Teng, Shaolei; Wang, Liangjiang; Srivastava, Anand K.; Schwartz, Charles E.; Alexov, Emil

    2012-01-01

    A structure-based approach is described for predicting the effects of amino acid substitutions on protein function. Structures were predicted using a homology modelling method. Folding and binding energy differences between wild-type and mutant structures were computed to quantitatively assess the effects of amino acid substitutions on protein stability and protein–protein interaction, respectively. We demonstrated that pathogenic mutations at the interaction interface could affect binding energy and destabilise protein complex, whereas mutations at the non-interface might reduce folding energy and destabilise monomer structure. The results suggest that the structure-based analysis can provide useful information for understanding the molecular mechanisms of diseases. PMID:21297231

  2. Estimation of Levels of Salivary Mucin, Amylase and Total Protein in Gingivitis and Chronic Periodontitis Patients

    PubMed Central

    Bhandary, Rahul; Thomas, Biju; Kumari, Suchetha

    2014-01-01

    Background: Periodontal diseases are a group of inflammatory conditions resulting from interaction between a pathogenic bacterial biofilm and susceptible host’s inflammatory response eventually leading to the destruction of periodontal structures and subsequent tooth loss. Hence, investigation of salivary proteins in individuals with periodontal diseases may be useful to enhance the knowledge of their roles in these diseases. Materials and Methods: This case-control study was conducted at A.B. Shetty Memorial Institute of Dental Sciences, Mangalore. The study comprised of 90 patients of age between 25-60 years who were clinically examined and divided into three groups of 30 each: namely clinically healthy, gingivitis and chronic periodontitis. These were classified according to the values of gingival index score, clinical attachment loss and probing pocket depth. Unstimulated saliva was collected and salivary mucin, amylase and total protein levels were determined. Statistical analysis: Results obtained were tabulated and statistically analyzed using ANOVA test and Karl pearson’s correlation test. Results: The results of the study showed an increased concentration of salivary mucin, amylase and total protein in gingivitis patients and increased levels of amylase and total protein in saliva of chronic periodontitis patients compared to healthy individuals which were statistically significant. A decrease in mucin concentration was observed in the periodontitis group compared to gingivitis group. A positive correlation was present between salivary mucin, amylase and total protein levels in the three groups. Conclusion: Salivary mucin, amylase and total protein may serve as an important biochemical parameter of inflammation of the periodontium. Also, it can be hypothesized that various enzyme inhibitors might be useful as a part of host modulation therapy in the treatment of periodontal diseases. PMID:25478449

  3. Characterization and amino acid sequence of a fatty acid-binding protein from human heart.

    PubMed

    Offner, G D; Brecher, P; Sawlivich, W B; Costello, C E; Troxler, R F

    1988-05-15

    The complete amino acid sequence of a fatty acid-binding protein from human heart was determined by automated Edman degradation of CNBr, BNPS-skatole [3'-bromo-3-methyl-2-(2-nitrobenzenesulphenyl)indolenine], hydroxylamine, Staphylococcus aureus V8 proteinase, tryptic and chymotryptic peptides, and by digestion of the protein with carboxypeptidase A. The sequence of the blocked N-terminal tryptic peptide from citraconylated protein was determined by collisionally induced decomposition mass spectrometry. The protein contains 132 amino acid residues, is enriched with respect to threonine and lysine, lacks cysteine, has an acetylated valine residue at the N-terminus, and has an Mr of 14768 and an isoelectric point of 5.25. This protein contains two short internal repeated sequences from residues 48-54 and from residues 114-119 located within regions of predicted beta-structure and decreasing hydrophobicity. These short repeats are contained within two longer repeated regions from residues 48-60 and residues 114-125, which display 62% sequence similarity. These regions could accommodate the charged and uncharged moieties of long-chain fatty acids and may represent fatty acid-binding domains consistent with the finding that human heart fatty acid-binding protein binds 2 mol of oleate or palmitate/mol of protein. Detailed evidence for the amino acid sequences of the peptides has been deposited as Supplementary Publication SUP 50143 (23 pages) at the British Library Lending Division, Boston Spa, Yorkshire LS23 7BQ, U.K., from whom copies may be obtained as indicated in Biochem. J. (1988) 249, 5. PMID:3421901

  4. Standard test method for total base number of petroleum products by potentiometric perchloric acid titration

    SciTech Connect

    Not Available

    1980-01-01

    This method covers the determination of basic constituents in petroleum products by titration with perchloric acid. For many materials the results obtained by this method will be similar to those obtained by Method D 664-IP 177. With certain compounds such as strongly overbased oil additives and nitrogenous polymeric compounds, higher results may be obtained. Summary of method: the sample is dissolved in an essentially anhydrous mixture of chlorobenzene and glacial acetic acid and titrated with a solution of perchloric acid in glacial acetic acid with a potentiometric titrimeter. A glass indicating electrode and a calomel reference electrode are used, the latter being connected with the sample solution by means of a salt bridge. The meter readings are plotted against the respective volumes of titrating solution, and the end point is taken at the inflection in the resulting curve. Occasionally certain used oils give no inflection in the standard titration, in which case a back titration modification with sodium acetate titrant is employed. Total base number is the quantity of perchloric acid expressed in terms of the equivalent number of milligrams of potassium hydroxide that is required to neutralize all basic constituents present in 1 g of sample.

  5. Dissolved total hydrolyzable enantiomeric amino acids in precipitation: Implications on bacterial contributions to atmospheric organic matter

    NASA Astrophysics Data System (ADS)

    Yan, Ge; Kim, Guebuem; Kim, Jeonghyun; Jeong, Yu-Sik; Kim, Young Il

    2015-03-01

    We analyzed dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved enantiomeric amino acids in precipitation samples collected at two sites in Korea over a one-year period. The average concentrations of DOC, DON, and total hydrolyzable amino acids at Seoul (an inland urban area) were lower than those at Uljin (a coastal rural area). The different bulk compositions of dissolved organic matter (DOM) at these two sites (reflected by qualitative indicators) were mainly attributed to differences in contributing sources. The D-enantiomers of four individual amino acids (aspartic acid, glutamic acid, serine, and alanine) were ubiquitously present, with average enantiomeric (D/L) ratios of 0.34, 0.26, 0.21, and 0.61 for Seoul, and 0.18, 0.11, 0.09, and 0.31 for Uljin, respectively. The much higher D/L ratios observed at Seoul than at Uljin might result from more advanced diagenetic stages as well as higher contributions from bacteria inhabiting terrestrial environments. The C- and N-normalized yields of D-alanine in DOM of our samples were found to be comparable to literature values reported for aquatic systems, where a significant portion of DOM was suggested to be of bacterial origin. Our study suggests that bacteria and their remnants might constitute an important fraction of OM in the atmosphere, contributing significantly to the quality of atmospheric OM and its post-depositional bioavailability in the surface ecosystems.

  6. INCAP studies of energy, amino acids, and protein.

    PubMed

    Viteri, Fernando E

    2010-03-01

    This Special Issue summarizes the results of several studies aimed at providing information on a series of questions related to the adequate protein and energy intakes that allow adequate growth and function in children and work performance and productivity in adults. The effect of different sources of protein on nitrogen balance and the requirements of essential amino acids in young children were also explored in fully recovered, previously malnourished children housed in the Metabolic Ward of the Biomedical Division of INCAP. The following are the main results of these investigations: Animal experiments and studies in children recovering from protein-energy malnutrition (PEM) strongly suggest that even when requirements of all nutrients are satisfied, inactivity reduces the rate of linear growth and physical activity improves it as well as lean body mass repletion. The effects of different energy intakes on nitrogen balance demonstrated how energy intake modifies the need to ingest different amounts of protein to satisfy protein requirements. Insensible nitrogen losses in preschool children and their relation to protein intake was demonstrated. The quality of even "good protein sources" modifies the amount needed to satisfy nitrogen requirements, and corn and bean-based diets can satisfy protein needs for health and even growth of young children. Essential amino acid requirements of 2-year-old children was assessed by diverse measurements of nitrogen metabolism and amino acid levels in blood, and were found lower than those recommended by FAO-WHO. In rural adult populations the relationship between energy and protein intake, productivity and body composition, and the impact of environmental hygiene on nitrogen balance was demonstrated and measured. PMID:20461903

  7. Changes in unbound and total valproic acid concentrations after replacement of carbamazepine with oxcarbazepine.

    PubMed

    Battino, D; Croci, D; Granata, T; Bernardi, G; Monza, G

    1992-10-01

    Total and free valproic acid (VPA) concentrations were measured in patients switched from a combined VPA and carbamazepine (CBZ) to a combined VPA and oxcarbazepine (OXC) therapy, both administered in individualized daily doses. Four young epileptic patients (13-17 years old) were studied for a 12-week period, total and free VPA concentrations being analyzed just before and 4 h after the morning dose, at the end of VPA and CBZ therapy, and 2 and 10 weeks after CBZ was replaced by OXC. The expected increase in the level/dose (L/D) ratio of total VPA observed at the end of the study was preceded by a clear-cut increase in the L/D ratio of free VPA, which led to VPA-related side effects and required the retitration of VPA daily doses. PMID:1448844

  8. Thiol-based Redox Proteins in Brassica napus Guard Cell Abscisic Acid and Methyl Jasmonate Signaling

    PubMed Central

    Zhu, Mengmeng; Zhu, Ning; Song, Wen-yuan; Harmon, Alice C.; Assmann, Sarah M.; Chen, Sixue

    2014-01-01

    SUMMARY Reversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing that are important in different physiological processes. Little is known, however, about redox sensitive proteins in guard cells and how they function in stomatal signaling. In this study, Brassica napus guard cell proteins altered by redox in response to abscisic acid (ABA) or methyl jasmonate (MeJA) were identified by complementary proteomics approaches, saturation differential in-gel electrophoresis (DIGE) and isotope-coded affinity tag (ICAT). In total, 65 and 118 potential redox responsive proteins were identified in ABA and MeJA treated guard cells, respectively. All the proteins contain at least one cysteine, and over half of them are predicted to form intra-molecular disulfide bonds. Most of the proteins fall into the functional groups of energy, stress and defense, and metabolism. Based on the peptide sequences identified by mass spectrometry, 30 proteins were common to ABA and MeJA treated samples. A total of 44 cysteines was mapped in all the identified proteins, and their levels of redox sensitivity were quantified. Two of the proteins, a SNRK2 kinase and an isopropylmalate dehydrogenase were confirmed to be redox regulated and involved in stomatal movement. This study creates an inventory of potential redox switches, and highlights a protein redox regulatory mechanism in guard cell ABA and MeJA signal transduction. PMID:24580573

  9. Studies on fatty acid-binding proteins. The diurnal variation shown by rat liver fatty acid-binding protein.

    PubMed Central

    Wilkinson, T C; Wilton, D C

    1987-01-01

    The concentration of fatty acid-binding protein in rat liver was examined by SDS/polyacrylamide-gel electrophoresis, by Western blotting and by quantifying the fluorescence enhancement achieved on the binding of the fluorescent probe 11-(dansylamino)undecanoic acid. A 2-3-fold increase in the concentration of this protein produced by treatment of rats with the peroxisome proliferator tiadenol was readily detected; however, only a small variation in the concentration of the protein due to a diurnal rhythm was observed. This result contradicts the 7-10-fold variation previously reported for this protein [Hargis, Olson, Clarke & Dempsey (1986) J. Biol. Chem. 261, 1988-1991]. Images Fig. 1. Fig. 3. PMID:3593284

  10. Total Protein of Whole Saliva as a Biomarker of Anaerobic Threshold

    ERIC Educational Resources Information Center

    Bortolini, Miguel Junior Sordi; De Agostini, Guilherme Gularte; Reis, Ismair Teodoro; Lamounier, Romeu Paulo Martins Silva; Blumberg, Jeffrey B.; Espindola, Foued Salmen

    2009-01-01

    Saliva provides a convenient and noninvasive matrix for assessing specific physiological parameters, including some biomarkers of exercise. We investigated whether the total protein concentration of whole saliva (TPWS) would reflect the anaerobic threshold during an incremental exercise test. After a warm-up period, 13 nonsmoking men performed a…

  11. Development of a new method for determination of total haem protein in fish muscle.

    PubMed

    Chaijan, Manat; Undeland, Ingrid

    2015-04-15

    Using classic haem protein quantification methods, the extraction step in buffer or acid acetone often becomes limiting if muscle is oxidised and/or stored; haem-proteins then tend to bind to muscle components like myofibrils and/or biomembranes. The objective of this study was to develop a new haem protein determination method for fish muscle overcoming such extractability problems. The principle was to homogenise and heat samples in an SDS-containing phosphate buffer to dissolve major muscle components and convert ferrous/ferric haem proteins to hemichromes with a unique absorption peak at 535 nm. Hb-recovery tests with the new and classic methods showed that the new method and Hornsey's method performed significantly better on fresh Hb-enriched cod mince than Brown's and Drabkin's methods; recovery was ⩾98%. However, in highly oxidised samples and in cod protein isolates made with acid pH-shift processing, the new method performed better than Hornsey's method (63% and 87% vs. 50% and 68% recovery). Further, the new method performed well in fish muscle with ⩽30% lipid, <5% NaCl and pH 5.5-7.0; it was also unaffected by freezing/frozen storage. PMID:25466135

  12. Protein and amino acid metabolism in the human newborn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Birth and adaptation to extrauterine life involve major shifts in the protein and energy metabolism of the human newborn. These include a shift from a state of continuous supply of nutrients including amino acids from the mother to cyclic periodic oral intake, a change in the redox state of organs, ...

  13. Rumen Degradability and Small Intestinal Digestibility of the Amino Acids in Four Protein Supplements

    PubMed Central

    Wang, Y.; Jin, L.; Wen, Q. N.; Kopparapu, N. K.; Liu, J.; Liu, X. L.; Zhang, Y. G.

    2016-01-01

    The supplementation of livestock feed with animal protein is a present cause for public concern, and plant protein shortages have become increasingly prominent in China. This conflict may be resolved by fully utilizing currently available sources of plant protein. We estimated the rumen degradability and the small intestinal digestibility of the amino acids (AA) in rapeseed meal (RSM), soybean meal (SBM), sunflower seed meal (SFM) and sesame meal (SSM) using the mobile nylon bag method to determine the absorbable AA content of these protein supplements as a guide towards dietary formulations for the dairy industry. Overall, this study aimed to utilize protein supplements effectively to guide dietary formulations to increase milk yield and save plant protein resources. To this end, we studied four cows with a permanent rumen fistula and duodenal T-shape fistula in a 4×4 Latin square experimental design. The results showed that the total small intestine absorbable amino acids and small intestine absorbable essential amino acids were higher in the SBM (26.34% and 13.11% dry matter [DM], respectively) than in the SFM (13.97% and 6.89% DM, respectively). The small intestine absorbable Lys contents of the SFM, SSM, RSM and SBM were 0.86%, 0.88%, 1.43%, and 2.12% (DM basis), respectively, and the absorbable Met contents of these meals were 0.28%, 1.03%, 0.52%, and 0.47% (DM basis), respectively. Among the examined food sources, the milk protein score of the SBM (0.181) was highest followed by those of the RSM (0.136), SSM (0.108) and SFM (0.106). The absorbable amino acid contents of the protein supplements accurately reflected protein availability, which is an important indicator of the balance of feed formulation. Therefore, a database detailing the absorbable AA should be established. PMID:26732449

  14. Rumen Degradability and Small Intestinal Digestibility of the Amino Acids in Four Protein Supplements.

    PubMed

    Wang, Y; Jin, L; Wen, Q N; Kopparapu, N K; Liu, J; Liu, X L; Zhang, Y G

    2016-02-01

    The supplementation of livestock feed with animal protein is a present cause for public concern, and plant protein shortages have become increasingly prominent in China. This conflict may be resolved by fully utilizing currently available sources of plant protein. We estimated the rumen degradability and the small intestinal digestibility of the amino acids (AA) in rapeseed meal (RSM), soybean meal (SBM), sunflower seed meal (SFM) and sesame meal (SSM) using the mobile nylon bag method to determine the absorbable AA content of these protein supplements as a guide towards dietary formulations for the dairy industry. Overall, this study aimed to utilize protein supplements effectively to guide dietary formulations to increase milk yield and save plant protein resources. To this end, we studied four cows with a permanent rumen fistula and duodenal T-shape fistula in a 4×4 Latin square experimental design. The results showed that the total small intestine absorbable amino acids and small intestine absorbable essential amino acids were higher in the SBM (26.34% and 13.11% dry matter [DM], respectively) than in the SFM (13.97% and 6.89% DM, respectively). The small intestine absorbable Lys contents of the SFM, SSM, RSM and SBM were 0.86%, 0.88%, 1.43%, and 2.12% (DM basis), respectively, and the absorbable Met contents of these meals were 0.28%, 1.03%, 0.52%, and 0.47% (DM basis), respectively. Among the examined food sources, the milk protein score of the SBM (0.181) was highest followed by those of the RSM (0.136), SSM (0.108) and SFM (0.106). The absorbable amino acid contents of the protein supplements accurately reflected protein availability, which is an important indicator of the balance of feed formulation. Therefore, a database detailing the absorbable AA should be established. PMID:26732449

  15. Hydrodynamic size-based separation and characterization of protein aggregates from total cell lysates

    PubMed Central

    Tanase, Maya; Zolla, Valerio; Clement, Cristina C; Borghi, Francesco; Urbanska, Aleksandra M; Rodriguez-Navarro, Jose Antonio; Roda, Barbara; Zattoni, Andrea; Reschiglian, Pierluigi; Cuervo, Ana Maria; Santambrogio, Laura

    2016-01-01

    Herein we describe a protocol that uses hollow-fiber flow field-flow fractionation (FFF) coupled with multiangle light scattering (MALS) for hydrodynamic size-based separation and characterization of complex protein aggregates. The fractionation method, which requires 1.5 h to run, was successfully modified from the analysis of protein aggregates, as found in simple protein mixtures, to complex aggregates, as found in total cell lysates. In contrast to other related methods (filter assay, analytical ultracentrifugation, gel electrophoresis and size-exclusion chromatography), hollow-fiber flow FFF coupled with MALS allows a flow-based fractionation of highly purified protein aggregates and simultaneous measurement of their molecular weight, r.m.s. radius and molecular conformation (e.g., round, rod-shaped, compact or relaxed). The polyethersulfone hollow fibers used, which have a 0.8-mm inner diameter, allow separation of as little as 20 μg of total cell lysates. In addition, the ability to run the samples in different denaturing and nondenaturing buffer allows defining true aggregates from artifacts, which can form during sample preparation. The protocol was set up using Paraquat-induced carbonylation, a model that induces protein aggregation in cultured cells. This technique will advance the biochemical, proteomic and biophysical characterization of molecular-weight aggregates associated with protein mutations, as found in many CNS degenerative diseases, or chronic oxidative stress, as found in aging, and chronic metabolic and inflammatory conditions. PMID:25521790

  16. Evaluation of Plasma Fibrinogen Degradation Products and Total Serum Protein Concentration in Oral Submucous Fibrosis

    PubMed Central

    B.N.V.S., Satish; B., Maharudrappa; K.M., Prashant; Hugar, Deepa; Allad, Umesh; Prabhu, Prasanth S.

    2014-01-01

    Background: Oral submucous fibrosis (OSMF) is a potentially malignant disorder with a multifactorial etiology. Malnutrition is a major problem for the inhabitants of most countries where OSMF is prevalent. Recently, a new direction in the etiopathogenesis was provided by the identification of fibrinogen degradation products (FDP) in the plasma of OSMF patients. Aims and Objectives: To assess the role of FDP in the etiology of OSMF and to correlate with the nutritional status by evaluating the total serum protein level. The study also determines to evaluate the correlation between the levels of plasma FDP with respect to the staging and grading of OSMF. Correlation between the levels of Total Serum Protein (TSP) with respect to the staging and grading of OSMF was also evaluated. Materials and Methods: The study included 30 cases clinically and histopathologically diagnosed as oral submucous fibrosis. The FDP levels were assessed using both qualitative and semi quantitative method as supplied by ‘Tulip Diagnostics (P) Ltd. Total Serum Protein (TSP) estimation was done by Biuret method using Liquixx Protein kit by Erba, Manheim. Results: The study indicates that in qualitative assessment of FDP only 14 subjects showed the presence of FDP levels>200ng/ml. In semiquantitative assessment there is no significant association between varying clinical stages and histopathological grades and FDP levels. Total serum Protein level showed a marginal increase in all subjects. The study revealed a positive correlation between FDP and TSP in all OSMF subjects. Conclusion: A larger sample size which would be a better representation of the population and the use of different methods which have higher sensitivities and specificities to evaluate FDP level and detailed fractional analysis of protein along with immunoglobulin profiling would facilitate in attaining more conclusive results. PMID:24995245

  17. Acidic and total primary sulfates: development of emission factors for major stationary combustion sources

    SciTech Connect

    Goklany, I.M.; Hoffnagle, G.F.; Brackbill, E.A.

    1984-01-01

    ''Best estimates'' of emission factors for major sources of acidic and total primary sulfates are developed for use in the compilation of emission inventories for the eastern U.S. These may, in turn, be used for modeling of acidic or sulfate deposition. The factors are based upon a critical evaluation of the generic measurement methods used to quantify total and acidic primary sulfate emissions, and an exhaustive review and critique of individual papers and studies available in the open literature which present measurement data on primary sulfate emissions. It develops a qualitative rating scheme which specifies the level of confidence that should be attached to the emission factor determinations. The paper concludes that much of the existing data on primary sulfates from stationary combustion sources are, probably, significantly biased upward and, therefore, inappropriate for the derivation of emission factors. Therefore, existing estimates of primary sulfate emissions for these source categories are, probably, substanitally inflated. It also concludes that, for most source categories, very little confidence can be attached to the best estimates because of the paucity of data obtained from measurement techniques which are likely to be free of systematic bias. 68 references.

  18. A new microwave acid digestion bomb method for the determination of total fluorine.

    PubMed

    Grobler, S R; Louw, A J

    1998-01-01

    A new microwave acid digestion method for total fluorine analysis was compared to the reliable reverse-extraction technique. The commercially available Parr bombs which are compatible with microwave heating were modified for this purpose. The Mann-Whitney statistical test did not show any significant differences (p > 0.05) in the determinations of total fluorine in various samples between the two above-mentioned methods. The microwave method also gave high fluorine recoveries (> 97%) when fluoride was added to different samples. The great advantage of the microwave acid digestion bomb method is that the digestion under pressure is so aggressive that only a few minutes is needed for complete digestion (also of covalently bonded fluorine), which reduces the time for fluorine analysis dramatically, while no loss of fluorine or contamination from extraneous sources could take place during the ashing procedure. The digestion solution was made up of 300 microliter of concentrated nitric acid plus 537 microliter of water. After digestion 675 microliter of approximately 8.5 M sodium hydroxide plus 643 microliter of citrate/TISAB buffer was added resulting in an alkaline solution (pH approximately 12) which was finally adjusted to a pH of approximately 5.3 for fluoride determination. PMID:9701663

  19. Pyridoxic acid excretion during low vitamin B-6 intake, total fasting, and bed rest

    NASA Technical Reports Server (NTRS)

    Coburn, S. P.; Thampy, K. G.; Lane, H. W.; Conn, P. S.; Ziegler, P. J.; Costill, D. L.; Mahuren, J. D.; Fink, W. J.; Pearson, D. R.; Schaltenbrand, W. E.

    1995-01-01

    Vitamin B-6 metabolism in 10 volunteers during 21 d of total fasting was compared with results from 10 men consuming a diet low only in vitamin B-6 (1.76 mumol/d) and with men consuming a normal diet during bed rest. At the end of the fast mean plasma concentrations of vitamin B-6 metabolites and urinary excretion of 4-pyridoxic acid tended to be higher in the fasting subjects than in the low-vitamin B-6 group. The fasting subjects lost approximately 10% of their total vitamin B-6 pool and approximately 13% of their body weight. The low-vitamin B-6 group lost only approximately 4% of their vitamin B-6 pool. Compared with baseline, urinary excretion of pyridoxic acid was significantly increased during 17 wk of bed rest. There was no increase in pyridoxic acid excretion during a second 15-d bed rest study. These data suggest the possibility of complex interactions between diet and muscle metabolism that may influence indexes that are frequently used to assess vitamin B-6 status.

  20. Measurements of long-range interactions between protein-functionalized surfaces by total internal reflection microscopy.

    PubMed

    Wang, Zhaohui; Gong, Xiangjun; Ngai, To

    2015-03-17

    Understanding the interaction between protein-functionalized surfaces is an important subject in a variety of protein-related processes, ranging from coatings for biomedical implants to targeted drug carriers and biosensors. In this work, utilizing a total internal reflection microscope (TIRM), we have directly measured the interactions between micron-sized particles decorated with three types of common proteins concanavalin A (ConA), bovine serum albumin (BSA), lysozyme (LYZ), and glass surface coated with soy proteins (SP). Our results show that the protein adsorption greatly affects the charge property of the surfaces, and the interactions between those protein-functionalized surfaces depend on solution pH values. At pH 7.5-10.0, all these three protein-functionalized particles are highly negatively charged, and they move freely above the negatively charged SP-functionalized surface. The net interaction between protein-functionalized surfaces captured by TIRM was found as a long-range, nonspecific double-layer repulsion. When pH was decreased to 5.0, both protein-functionalized surfaces became neutral and double-layer repulsion was greatly reduced, resulting in adhesion of all three protein-functionalized particles to the SP-functionalized surface due to the hydrophobic attraction. The situation is very different at pH = 4.0: BSA-decorated particles, which are highly charged, can move freely above the SP-functionalized surfaces, while ConA- and LYZ-decorated particles can only move restrictively in a limited range. Our results quantify these nonspecific kT-scale interactions between protein-functionalized surfaces, which will enable the design of surfaces for use in biomedical applications and study of biomolecular interactions. PMID:25719226

  1. Effects of total gastrectomy on plasma silicon and amino acid concentrations in men.

    PubMed

    Tatara, Marcin R; Krupski, Witold; Szpetnar, Maria; Dąbrowski, Andrzej; Bury, Paweł; Szabelska, Anna; Charuta, Anna; Boguszewska-Czubara, Anna; Maciejewski, Ryszard; Wallner, Grzegorz

    2015-12-01

    The aim of the study was to determine one-year effects of total gastrectomy on plasma silicon and free amino acid concentrations in patients and evaluate changes of volumetric bone mineral density (vBMD) in lumbar spine. Eight patients were enrolled to the control (CTR) group. Six patients subjected to total gastrectomy (GX group) were included to the experimental group. vBMD in trabecular and cortical bone was measured in lumbar vertebrae at baseline (before surgery) and one year later using quantitative computed tomography. Plasma concentrations of silicon and free amino acids were determined at baseline and one year later using photometric method and ion-exchange chromatography. Body weights within CTR and GX groups were not different after one-year follow-up when compared to the baseline values (P > 0.05). An average annual decrease of vBMD in the trabecular bone in the gastrectomized patients reached 15.0% in lumbar spine and was significantly different in comparison to the percentage changes observed in CTR group (P = 0.02). One-year percentage change of vBMD in the cortical bone in L1 and L2 has shown significantly decreased values by 10.5 and 9.1% in the GX group when compared to the percentage change observed in the controls (P < 0.05). Plasma concentration of adipic acid was significantly higher by 101.6% one year after total gastrectomy procedure in the patients when compared to the baseline value (P = 0.01). Plasma concentration of silicon was significantly lowered by 26.7% one year after the total gastrectomy when compared to the baseline value (P = 0.009). Total gastrectomy in patients has induced severe osteoporotic changes in lumbar spine within one-year period. The observed osteoporotic changes were associated with decreased plasma concentration of silicon indicating importance of exocrine and endocrine functions of stomach for silicon homeostasis maintenance. Gastrectomy-induced bone loss was not related to decreased amino acid

  2. Total dietary fat and omega-3 fatty acids have modest effects on urinary sex hormones in postmenopausal women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total fat and omega-3 fatty acids in the diet may affect breast cancer risk by altering estrogen metabolism. The purpose of this study was to elucidate the effects of differing total fat and omega-3 fatty acid content of diets on a panel of urinary estrogens and metabolites. A controlled, cross-ove...

  3. Acid extraction and purification of recombinant spider silk proteins.

    PubMed

    Mello, Charlene M; Soares, Jason W; Arcidiacono, Steven; Butler, Michelle M

    2004-01-01

    A procedure has been developed for the isolation of recombinant spider silk proteins based upon their unique stability and solubilization characteristics. Three recombinant silk proteins, (SpI)7, NcDS, and [(SpI)4/(SpII)1]4, were purified by extraction with organic acids followed by affinity or ion exchange chromatography resulting in 90-95% pure silk solutions. The protein yield of NcDS (15 mg/L culture) and (SpI)7 (35 mg/L) increased 4- and 5-fold, respectively, from previously reported values presumably due to a more complete solubilization of the expressed recombinant protein. [(SpI)4/(SpII)1]4, a hybrid protein based on the repeat sequences of spidroin I and spidroin II, had a yield of 12.4 mg/L. This method is an effective, reproducible technique that has broad applicability for a variety of silk proteins as well as other acid stable biopolymers. PMID:15360297

  4. A reliable non-separation fluorescence quenching assay for total glycated serum protein: a simple alternative to nitroblue tetrazolium reduction.

    PubMed

    Blincko, S; Colbert, D; John, W G; Edwards, R

    2000-05-01

    A simple non-separation assay for the measurement of total glycated serum protein is described. It was found that the fluorescence intensity of a solution of a fluorescein-boronic acid derivative was quenched in proportion to the amount of serum added. This led to the development of an assay in which 10 microL of serum is added to 4 mL of a solution of the fluorescein-boronic acid derivative and the fluorescence intensity is measured after 15 min. The results, as measured by drop in fluorescence intensity, calibrated by a single standard, were compared with the results for nitroblue tetrazolium (NBT) reduction of fructosamine and showed good correlation (r=0.936, n=114). The intra-assay precision (seven samples each measured 10 times) was less than 2.1% (concentration range 190-660 micromol/L); inter-assay precision for seven samples in 10 assays was less than 2.5% (over the same concentration range). Dilution of serum that had a high concentration of total glycated protein showed the assay to be linear. Serum samples (with low, medium and high total glycated protein concentrations) showed less than 2.1% difference from base results with added glucose (up to 60 mmol/L), less than 9.7% difference with added bilirubin (up to 250 micromol/L) and less than 6.9% with added triglycerides (up to 50 mmol/L). Addition of haemoglobin (up to 0.9 g/dL) with high glycation (11.7% HbA1c) to plasma (298 micromol/L total glycated protein) showed less than 10% difference from the base result. Assays performed over a range of temperatures (12-34 degrees C) showed no significant differences in the results. The assay gives similar results to the currently used NTB method but with significantly less susceptibility to interferences. As such the method should be a useful aid in the management of diabetes. PMID:10817254

  5. RubisCO is not a major fraction of total protein in marine phytoplankton

    NASA Astrophysics Data System (ADS)

    Losh, J.; Young, J. N.; Morel, F. M.

    2012-12-01

    Ribulose 1,5 bisphosphate carboxylase oxygnenase (Rubisco) concentrations were quantified as a proportion of total protein in diatoms to determine whether Rubisco is as abundant in phytoplankton as previously thought. This enzyme has been assumed to be a major fraction of total protein in phytoplankton, as has been demonstrated in plants, potentially constituting a large sink for cellular nitrogen (N). Marine diatoms were grown in batch cultures, and in N-limited continuous cultures at various carbon dioxide (CO2) levels. Quantitative western blots were performed using commercially available global antibodies and protein standards. Field incubations with natural populations of organisms from the coast of California were conducted under both N-limited and N-replete incubations with varying CO2. In all experiments, Rubisco represented less than 5% of total protein. Within exponentially growing batch cultures, concentrations ranged from 2-4%, while in N-limited laboratory and field cultures, concentrations were less than 1%. In some experiments under N-limiting conditions, Rubisco concentrations decreased with decreasing growth rates or with increasing CO2. These results were used as a basis of a theoretical calculation of maximum Rubisco activity and suggest that phytoplankton contain the minimum amount of Rubisco necessary to operate. Unlike plants, Rubisco is not a major sink of cellular N in phytoplankton. This has implications for phytoplankton's response to increasing CO2 under N-limitation.

  6. Rubisco is a small fraction of total protein in marine phytoplankton.

    PubMed

    Losh, Jenna L; Young, Jodi N; Morel, François M M

    2013-04-01

    Ribulose 1,5 bisphosphate carboxylase oxygenase (Rubisco) concentrations were quantified as a proportion of total protein in eight species of microalgae. This enzyme has been assumed to be a major fraction of total protein in phytoplankton, as has been demonstrated in plants, potentially constituting a large sink for cellular nitrogen. Representative microalgae were grown in batch and continuous cultures under nutrient-replete, nitrogen (N)-limited, or phosphorus (P)-limited conditions with varying CO(2). Quantitative Western blots were performed using commercially available global antibodies and protein standards. Field incubations with natural populations of organisms from the coast of California were conducted under both nutrient-replete and N-limited conditions with varying CO(2). In all experiments, Rubisco represented < 6% of total protein. In nutrient-replete exponentially growing batch cultures, concentrations ranged from 2% to 6%, while in nutrient-limited laboratory and field cultures, concentrations were < 2.5%. Rubisco generally decreased with increasing CO(2) and with decreasing growth rates. Based on a calculation of maximum Rubisco activity, these results suggest that phytoplankton contain the minimum concentration of enzyme necessary to support observed growth rates. Unlike in plants, Rubisco does not account for a major fraction of cellular N in phytoplankton. PMID:23343368

  7. A conserved patch of hydrophobic amino acids modulates Myb activity by mediating protein-protein interactions.

    PubMed

    Dukare, Sandeep; Klempnauer, Karl-Heinz

    2016-07-01

    The transcription factor c-Myb plays a key role in the control of proliferation and differentiation in hematopoietic progenitor cells and has been implicated in the development of leukemia and certain non-hematopoietic tumors. c-Myb activity is highly dependent on the interaction with the coactivator p300 which is mediated by the transactivation domain of c-Myb and the KIX domain of p300. We have previously observed that conservative valine-to-isoleucine amino acid substitutions in a conserved stretch of hydrophobic amino acids have a profound effect on Myb activity. Here, we have explored the function of the hydrophobic region as a mediator of protein-protein interactions. We show that the hydrophobic region facilitates Myb self-interaction and binding of the histone acetyl transferase Tip60, a previously identified Myb interacting protein. We show that these interactions are affected by the valine-to-isoleucine amino acid substitutions and suppress Myb activity by interfering with the interaction of Myb and the KIX domain of p300. Taken together, our work identifies the hydrophobic region in the Myb transactivation domain as a binding site for homo- and heteromeric protein interactions and leads to a picture of the c-Myb transactivation domain as a composite protein binding region that facilitates interdependent protein-protein interactions of Myb with regulatory proteins. PMID:27080133

  8. Buffer interference with protein dynamics: a case study on human liver fatty acid binding protein.

    PubMed

    Long, Dong; Yang, Daiwen

    2009-02-18

    Selection of suitable buffer types is often a crucial step for generating appropriate protein samples for NMR and x-ray crystallographic studies. Although the possible interaction between MES buffer (2-(N-morpholino)ethanesulfonic acid) and proteins has been discussed previously, the interaction is usually thought to have no significant effects on the structures of proteins. In this study, we demonstrate the direct, albeit weak, interaction between MES and human liver fatty acid binding protein (hLFABP). Rather than affecting the structure of hLFABP, we found that the dynamics of hLFABP, which were previously proposed to be relevant to its functions, were significantly affected by the binding of hLFABP with MES. Buffer interference with protein dynamics was also demonstrated with Bis-Tris buffer, which is quite different from MES and fatty acids in terms of their molecular structures and properties. This result, to our knowledge, is the first published report on buffer interference with protein dynamics on a microsecond to millisecond timescale and could represent a generic problem in the studies of functionally relevant protein dynamics. Although being a fortuity, our finding of buffer-induced changes in protein dynamics offers a clue to how hLFABP accommodates its ligands. PMID:19217864

  9. Development of radiation sterilized dip slides for enumerating lactic acid bacteria and total count in foodstuffs

    NASA Astrophysics Data System (ADS)

    Eisenberg, E.; Padova, R.; Kirsch, E.; Weissman, Sh.; Hirshfeld, T.; Shenfeld, A.

    APT agar (APT) used for enumeration of lactic acid bacteria and Plate Count agar (PCA) applied for total count were sterilized by gamma radiation using radiation dose of 10-15 kGy. Radiosterilized PCA and APT modified by adding catalase prior to irradiation, or APT with increased content of yeast extract performed, as well as, the heat sterilized commercial media. Growth performance was evaluated on several strains of microorganisms, as well as, by enumeration of bacteria in food products. Radiosterilization of culture media in final packaging, can be applied to produce dip slide kits containing PCA or APT.

  10. Expression of liver fatty acid binding protein in hepatocellular carcinoma.

    PubMed

    Cho, Soo-Jin; Ferrell, Linda D; Gill, Ryan M

    2016-04-01

    Loss of expression of liver fatty acid binding protein (LFABP) by immunohistochemistry has been shown to be characteristic of a subset of hepatocellular adenomas (HCAs) in which HNF1A is inactivated. Transformation to hepatocellular carcinoma is thought to be a very rare phenomenon in the HNF1A-inactivated variant of HCA. However, we recently observed 2 cases at our institution, 1 definite hepatocellular carcinoma and 1 possible hepatocellular carcinoma, with loss of LFABP staining, raising the possibility that LFABP down-regulation may be associated with hepatocellular carcinogenesis. Our aim was to evaluate hepatocellular carcinomas arising in various backgrounds and with varying degrees of differentiation for loss of LFABP staining. Twenty total cases of hepatocellular carcinoma were examined. Thirteen cases arose in a background of cirrhosis due to hepatitis C (n = 8) or steatohepatitis (n = 5); 7 cases arose in a noncirrhotic background, with 2 cases arising within HNF1A-inactivated variant HCA and 2 cases arising within inflammatory variant HCA. Complete loss of expression of LFABP was seen in 6 of 20 cases, including 2 cases of hepatocellular carcinoma arising within HNF1A-inactivated variant HCA. Thus, loss of staining for LFABP appears to be common in hepatocellular carcinoma and may be seen in well-differentiated hepatocellular carcinoma. Therefore, LFABP loss should not be interpreted as evidence for hepatocellular adenoma over carcinoma, when other features support a diagnosis of hepatocellular carcinoma. The findings raise consideration for a role of HNF1A inactivation in hepatocellular carcinogenesis, particularly in less differentiated tumors. PMID:26997447

  11. Advances in protein-amino acid nutrition of poultry.

    PubMed

    Baker, David H

    2009-05-01

    The ideal protein concept has allowed progress in defining requirements as well as the limiting order of amino acids in corn, soybean meal, and a corn-soybean meal mixture for growth of young chicks. Recent evidence suggests that glycine (or serine) is a key limiting amino acid in reduced protein [23% crude protein (CP) reduced to 16% CP] corn-soybean meal diets for broiler chicks. Research with sulfur amino acids has revealed that small excesses of cysteine are growth depressing in chicks fed methionine-deficient diets. Moreover, high ratios of cysteine:methionine impair utilization of the hydroxy analog of methionine, but not of methionine itself. A high level of dietary L: -cysteine (2.5% or higher) is lethal for young chicks, but a similar level of DL: -methionine, L: -cystine or N-acetyl-L: -cysteine causes no mortality. A supplemental dietary level of 3.0% L: -cysteine (7x requirement) causes acute metabolic acidosis that is characterized by a striking increase in plasma sulfate and decrease in plasma bicarbonate. S-Methylmethionine, an analog of S-adenosylmethionine, has been shown to have choline-sparing activity, but it only spares methionine when diets are deficient in choline and(or) betaine. Creatine, or its precursor guanidinoacetic acid, can spare dietary arginine in chicks. PMID:19009229

  12. Interaction of Ku protein and DNA-dependent protein kinase catalytic subunit with nucleic acids.

    PubMed Central

    Dynan, W S; Yoo, S

    1998-01-01

    The Ku protein-DNA-dependent protein kinase system is one of the major pathways by which cells of higher eukaryotes respond to double-strand DNA breaks. The components of the system are evolutionarily conserved and homologs are known from a number of organisms. The Ku protein component binds directly to DNA ends and may help align them for ligation. Binding of Ku protein to DNA also nucleates formation of an active enzyme complex containing the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). The interaction between Ku protein, DNA-PKcs and nucleic acids has been extensively investigated. This review summarizes the results of these biochemical investigations and relates them to recent molecular genetic studies that reveal highly characteristic repair and recombination defects in mutant cells lacking Ku protein or DNA-PKcs. PMID:9512523

  13. Leukocyte Protease Binding to Nucleic Acids Promotes Nuclear Localization and Cleavage of Nucleic Acid Binding Proteins

    PubMed Central

    Thomas, Marshall P.; Whangbo, Jennifer; McCrossan, Geoffrey; Deutsch, Aaron; Martinod, Kimberly; Walch, Michael; Lieberman, Judy

    2014-01-01

    Killer lymphocyte granzyme (Gzm) serine proteases induce apoptosis of pathogen-infected cells and tumor cells. Many known Gzm substrates are nucleic acid binding proteins, and the Gzms accumulate in the target cell nucleus by an unknown mechanism. Here we show that human Gzms bind to DNA and RNA with nanomolar affinity. Gzms cleave their substrates most efficiently when both are bound to nucleic acids. RNase treatment of cell lysates reduces Gzm cleavage of RNA binding protein (RBP) targets, while adding RNA to recombinant RBP substrates increases in vitro cleavage. Binding to nucleic acids also influences Gzm trafficking within target cells. Pre-incubation with competitor DNA and DNase treatment both reduce Gzm nuclear localization. The Gzms are closely related to neutrophil proteases, including neutrophil elastase (NE) and cathepsin G (CATG). During neutrophil activation, NE translocates to the nucleus to initiate DNA extrusion into neutrophil extracellular traps (NETs), which bind NE and CATG. These myeloid cell proteases, but not digestive serine proteases, also bind DNA strongly and localize to nuclei and NETs in a DNA-dependent manner. Thus, high affinity nucleic acid binding is a conserved and functionally important property specific to leukocyte serine proteases. Furthermore, nucleic acid binding provides an elegant and simple mechanism to confer specificity of these proteases for cleavage of nucleic acid binding protein substrates that play essential roles in cellular gene expression and cell proliferation. PMID:24771851

  14. Modeling nucleic acid structure in the presence of single-stranded binding proteins

    NASA Astrophysics Data System (ADS)

    Forties, Robert; Bundschuh, Ralf

    2009-03-01

    There are many important proteins which bind single-stranded nucleic acids, such as the nucleocapsid protein in HIV, the RecA DNA repair protein in bacteria, and all proteins involved in mRNA splicing and translation. We extend the Vienna Package for quantitatively modeling the secondary structure of nucleic acids to include proteins which bind to unpaired portions of the nucleic acid. All parameters needed to model nucleic acid secondary structures in the absence of proteins have been previously measured. This leaves the footprint and sequence dependent binding affinity of the protein as adjustable parameters of our model. Using this model we are able to predict the probability of the protein binding at any position in the nucleic acid sequence, the impact of the protein on nucleic acid base pairing, the end-to-end distance distribution for the nucleic acid, and FRET distributions for fluorophores attached to the nucleic acid.

  15. 40 CFR 79.67 - Glial fibrillary acidic protein assay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... addition to information meeting the requirements stated under 40 CFR 79.60, the following specific...), 5 mM Hepes, pH 7.4, 0.7 percent Triton X-100) to a final concentration of 0.25 mg total protein per... the desired dilution in blocking solution containing 0.1 percent Triton X-100). Serum anti-bovine...

  16. 40 CFR 79.67 - Glial fibrillary acidic protein assay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... addition to information meeting the requirements stated under 40 CFR 79.60, the following specific...), 5 mM Hepes, pH 7.4, 0.7 percent Triton X-100) to a final concentration of 0.25 mg total protein per... the desired dilution in blocking solution containing 0.1 percent Triton X-100). Serum anti-bovine...

  17. 40 CFR 79.67 - Glial fibrillary acidic protein assay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... addition to information meeting the requirements stated under 40 CFR 79.60, the following specific...), 5 mM Hepes, pH 7.4, 0.7 percent Triton X-100) to a final concentration of 0.25 mg total protein per... the desired dilution in blocking solution containing 0.1 percent Triton X-100). Serum anti-bovine...

  18. 40 CFR 79.67 - Glial fibrillary acidic protein assay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... addition to information meeting the requirements stated under 40 CFR 79.60, the following specific...), 5 mM Hepes, pH 7.4, 0.7 percent Triton X-100) to a final concentration of 0.25 mg total protein per... the desired dilution in blocking solution containing 0.1 percent Triton X-100). Serum anti-bovine...

  19. 40 CFR 79.67 - Glial fibrillary acidic protein assay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... addition to information meeting the requirements stated under 40 CFR 79.60, the following specific...), 5 mM Hepes, pH 7.4, 0.7 percent Triton X-100) to a final concentration of 0.25 mg total protein per... the desired dilution in blocking solution containing 0.1 percent Triton X-100). Serum anti-bovine...

  20. Effect of altered eating pattern on serum fructosamine: total protein ratio and plasma glucose level.

    PubMed

    Ch'ng, S L; Cheah, S H; Husain, R; Duncan, M T

    1989-05-01

    The effect of alteration of eating pattern during Ramadan on body mass index (BMI), serum fructosamine: total protein ratio (F/TP), and glucose level in 18 healthy male Asiatic Moslems were studied. The results showed a significant decrease (p less than 0.025) in F/TP at the second week of Ramadan in 11 subjects who experienced continuous decrease in BMI throughout Ramadan. The remaining 7 subjects showed no significant changes in BMI and F/TP. No evidence of hypoglycaemia was observed in the subjects during the study. Serum fructosamine: total protein ratio in subjects with altered eating pattern preferably should be interpreted along with the change in body mass index. PMID:2774480

  1. Tranexamic acid for the reduction of blood loss in total knee arthroplasty.

    PubMed

    Oremus, Kresimir

    2015-05-01

    The Journal of Arthroplasty recently published a paper entitled "The Efficacy of Combined Use of Intraarticular and Intravenous Tranexamic Acid on Reducing Blood Loss and Transfusion Rate in Total Knee Arthroplasty". Tranexamic acid (TXA) is an antifibrinolytic drug whose administration during the perioperative period either by intravenous route or topically applied to the surgical field has been shown to reliably reduce blood loss and need for transfusion in patients undergoing total knee arthroplasty (TKA). Although randomized trials and meta-analyses did not show an increase in thromboembolic events, concerns remain about its repeated systemic application. The authors of the study introduced a novel regimen of TXA administration combining a preoperative intravenous bolus followed by local infiltration at the end of surgery with the idea of maximizing drug concentration at the surgical site while minimizing systemic antifibrinolytic effects. The combined dosage regimen appears to be more effective than single dose local application in reducing blood loss and transfusion rate without any complications noted. PMID:26046088

  2. Tranexamic acid for the reduction of blood loss in total knee arthroplasty

    PubMed Central

    2015-01-01

    The Journal of Arthroplasty recently published a paper entitled “The Efficacy of Combined Use of Intraarticular and Intravenous Tranexamic Acid on Reducing Blood Loss and Transfusion Rate in Total Knee Arthroplasty”. Tranexamic acid (TXA) is an antifibrinolytic drug whose administration during the perioperative period either by intravenous route or topically applied to the surgical field has been shown to reliably reduce blood loss and need for transfusion in patients undergoing total knee arthroplasty (TKA). Although randomized trials and meta-analyses did not show an increase in thromboembolic events, concerns remain about its repeated systemic application. The authors of the study introduced a novel regimen of TXA administration combining a preoperative intravenous bolus followed by local infiltration at the end of surgery with the idea of maximizing drug concentration at the surgical site while minimizing systemic antifibrinolytic effects. The combined dosage regimen appears to be more effective than single dose local application in reducing blood loss and transfusion rate without any complications noted. PMID:26046088

  3. Polyunsaturated Branched-Chain Fatty Acid Geranylgeranoic Acid Induces Unfolded Protein Response in Human Hepatoma Cells

    PubMed Central

    Iwao, Chieko; Shidoji, Yoshihiro

    2015-01-01

    The acyclic diterpenoid acid geranylgeranoic acid (GGA) has been reported to induce autophagic cell death in several human hepatoma-derived cell lines; however, the molecular mechanism for this remains unknown. In the present study, several diterpenoids were examined for ability to induce XBP1 splicing and/or lipotoxicity for human hepatoma cell lines. Here we show that three groups of diterpenoids emerged: 1) GGA, 2,3-dihydro GGA and 9-cis retinoic acid induce cell death and XBP1 splicing; 2) all-trans retinoic acid induces XBP1 splicing but little cell death; and 3) phytanic acid, phytenic acid and geranylgeraniol induce neither cell death nor XBP1 splicing. GGA-induced ER stress/ unfolded protein response (UPR) and its lipotoxicity were both blocked by co-treatment with oleic acid. The blocking activity of oleic acid for GGA-induced XBP1 splicing was not attenuated by methylation of oleic acid. These findings strongly suggest that GGA at micromolar concentrations induces the so-called lipid-induced ER stress response/UPR, which is oleate-suppressive, and shows its lipotoxicity in human hepatoma cells. PMID:26186544

  4. Evaluation of oxidative stress via total antioxidant status, sialic acid, malondialdehyde and RT-PCR findings in sheep affected with bluetongue

    PubMed Central

    Aytekin, I.; Aksit, H.; Sait, A.; Kaya, F.; Aksit, D.; Gokmen, M.; Baca, A. Unsal

    2015-01-01

    Introduction Bluetongue (BT) is a non-contagious infectious disease of ruminants. The disease agent bluetongue virus (BTV) is classified in the Reoviridae family Orbivirus. Aims and objectives The aim of this study was to determine serum malondialdehyde (MDA), total antioxidative stres (TAS), total sialic acid (TSA), ceruloplasmin, triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), cholesterol, creatinine, albumin, and total protein levels in sheep with and without bluetongue (BT). Materials and Methods The study included 13 Sakiz crossbreed sheep, aged 1–4 years and usually in the last stage of pregnancy, as the BT group and a control group consisting of 10 healthy sheep. All sheep were clinically examined before collecting blood samples. Serum ALT, AST, cholesterol, triglyceride, albumin, GGT, total protein, creatinine and TAS levels were measured using commercially available kits as per manufacturer's recommendations using a Biochemistry Auto Analyzer (Sinnowa D280, China). Serum lipid peroxidation was estimated through a previously described method in which MDA reacts with thiobarbituric acid (TBA) to form a coloured complex at a maximum absorbance of 535 nm. The TSA value was measured at 549 nm using the method described by Warren (1959): sialic acid was oxidised to formyl-pyruvic acid, which reacts with TBA to form a pink product. The ceruloplasmin concentration was measured according to Sunderman and Nomoto (1970): ceruloplasmin and p-phenylenediamine formed a coloured oxidation product that was proportional to the concentration of serum ceruloplasmin. Real time RT-PCR and conventional RT-PCR were performed as described by Shaw and others (2007). Results Biochemistry analysis of serum showed that in the BT group, TSA, MDA, triglyceride and ALT and AST were higher and that ceruloplasmin and TAS were lower than in the control group. Serum albumin, cholesterol, creatinine, total protein and GGT did

  5. Seasonal and spatial changes of free and bound organic acids in total suspended particles in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Bi, Xinhui; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

    2010-12-01

    The concentrations and compositions of free and bound organic acids in total suspended particles from typical urban, suburban and forest park sites of Guangzhou were determined in this study. The free form of organic acids (solvent extractable) in aerosols in Guangzhou varied with site and season. The suburban samples contained the highest contents of alkanoic, alkenoic and dicarboxylic acids. These findings were consistent with a higher supply of hydrocarbons and NOx in the suburban area. However, concentrations of aromatic acids were similar in the urban, suburban and forest park sites. Generally, winter season samples of the acids from anthropogenic sources contained more organic acids than summer season samples due to stronger removal by wet deposition in the summer. For the acids from botanic sources, the summer season samples were higher. In addition to the free acids, bound acids (solvent non-extractable) mainly formed by esterification of free acids were also found in the samples. In general, bound acids were higher than free acids. Esterification is mainly controlled by the pKa of organic acids and the atmospheric pH value. This explains why aromatic and dicarboxylic acids occur mainly as bound forms and why the samples from urban sites contained high levels of bound acids as the pH of rain water can reach 4.53. Concentrations of alkanoic and alkenoic acids in the aerosols of Guangzhou were much higher than those in the other areas studied.

  6. Analysis of total oil and fatty acids composition by near infrared reflectance spectroscopy in edible nuts

    NASA Astrophysics Data System (ADS)

    Kandala, Chari V.; Sundaram, Jaya

    2014-10-01

    Near Infrared (NIR) Reflectance spectroscopy has established itself as an important tool in quantifying water and oil present in various food materials. It is rapid and nondestructive, easier to use, and does not require processing the samples with corrosive chemicals that would render them non-edible. Earlier, the samples had to be ground into powder form before making any measurements. With the development of new soft ware packages, NIR techniques could now be used in the analysis of intact grain and nuts. While most of the commercial instruments presently available work well with small grain size materials such as wheat and corn, the method present here is suitable for large kernel size products such as shelled or in-shell peanuts. Absorbance spectra were collected from 400 nm to 2500 nm using a NIR instrument. Average values of total oil contents (TOC) of peanut samples were determined by standard extraction methods, and fatty acids were determined using gas chromatography. Partial least square (PLS) analysis was performed on the calibration set of absorption spectra, and models were developed for prediction of total oil and fatty acids. The best model was selected based on the coefficient of determination (R2), Standard error of prediction (SEP) and residual percent deviation (RPD) values. Peanut samples analyzed showed RPD values greater than 5.0 for both absorbance and reflectance models and thus could be used for quality control and analysis. Ability to rapidly and nondestructively measure the TOC, and analyze the fatty acid composition, will be immensely useful in peanut varietal improvement as well as in the grading process of grain and nuts.

  7. Total synthesis and biological evaluation of (+)-gambieric acid A and its analogues.

    PubMed

    Ishigai, Kazuya; Fuwa, Haruhiko; Hashizume, Keisuke; Fukazawa, Ryo; Cho, Yuko; Yotsu-Yamashita, Mari; Sasaki, Makoto

    2013-04-22

    In this study, we report the first total synthesis and complete stereostructure of gambieric acid A, a potent antifungal polycyclic ether metabolite, in detail. The A/B-ring exocyclic enol ether 32 was prepared through a Suzuki-Miyaura coupling of the B-ring vinyl iodide 18 and the alkylborate 33 and subsequent closure of the A-ring by using diastereoselective bromoetherification as the key transformation. Suzuki-Miyaura coupling of 32 with acetate-derived enol phosphate 49, followed by ring-closing metathesis of the derived diene, produced the D-ring. Subsequent closure of the C-ring through a mixed thioacetalization completed the synthesis of the A/BCD-ring fragment 8. The A/BCD- and F'GHIJ-ring fragments (i.e., 8 and 9) were assembled through Suzuki-Miyaura coupling. The C25 stereogenic center was elaborated by exploiting the intrinsic conformational property of the seven-membered F'-ring. After the oxidative cleavage of the F'-ring, the E-ring was formed as a cyclic mixed thioacetal (i.e., 70) and then stereoselectively allylated by using glycosylation chemistry. Ring-closing metathesis of the diene 3 thus obtained closed the F-ring and completed the polycyclic ether skeleton. Finally, the J-ring side chain was introduced by using a Julia-Kocienski olefination in the presence of CeCl3 to complete the total synthesis of gambieric acid A (1), thereby unambiguously establishing its complete stereostructure. The present total synthesis enabled us to evaluate the antifungal and antiproliferative activities of 1 and several synthetic analogues. PMID:23554126

  8. Hyperdimensional analysis of amino acid pair distributions in proteins.

    PubMed

    Henriksen, Svend B; Mortensen, Rasmus J; Geertz-Hansen, Henrik M; Neves-Petersen, Maria Teresa; Arnason, Omar; Söring, Jón; Petersen, Steffen B

    2011-01-01

    Our manuscript presents a novel approach to protein structure analyses. We have organized an 8-dimensional data cube with protein 3D-structural information from 8706 high-resolution non-redundant protein-chains with the aim of identifying packing rules at the amino acid pair level. The cube contains information about amino acid type, solvent accessibility, spatial and sequence distance, secondary structure and sequence length. We are able to pose structural queries to the data cube using program ProPack. The response is a 1, 2 or 3D graph. Whereas the response is of a statistical nature, the user can obtain an instant list of all PDB-structures where such pair is found. The user may select a particular structure, which is displayed highlighting the pair in question. The user may pose millions of different queries and for each one he will receive the answer in a few seconds. In order to demonstrate the capabilities of the data cube as well as the programs, we have selected well known structural features, disulphide bridges and salt bridges, where we illustrate how the queries are posed, and how answers are given. Motifs involving cysteines such as disulphide bridges, zinc-fingers and iron-sulfur clusters are clearly identified and differentiated. ProPack also reveals that whereas pairs of Lys residues virtually never appear in close spatial proximity, pairs of Arg are abundant and appear at close spatial distance, contrasting the belief that electrostatic repulsion would prevent this juxtaposition and that Arg-Lys is perceived as a conservative mutation. The presented programs can find and visualize novel packing preferences in proteins structures allowing the user to unravel correlations between pairs of amino acids. The new tools allow the user to view statistical information and visualize instantly the structures that underpin the statistical information, which is far from trivial with most other SW tools for protein structure analysis. PMID:22174733

  9. Probing interactions between plant virus movement proteins and nucleic acids.

    PubMed

    Tzfira, Tzvi; Citovsky, Vitaly

    2008-01-01

    Most plant viruses move between plant cells with the help of their movement proteins (MPs). MPs are multifunctional proteins, and one of their functions is almost invariably binding to nucleic acids. Presumably, the MP-nucleic acid interaction is directly involved in formation of nucleoprotein complexes that function as intermediates in the cell-to-cell transport of many plant viruses. Thus, when studying a viral MP, it is important to determine whether or not it binds nucleic acids, and to characterize the hallmark parameters of such binding, i.e., preference for single- or double-stranded nucleic acids and binding cooperativity and sequence specificity. Here, we present two major experimental approaches, native gel mobility shift assay and ultra violet (UV) light cross-linking, for detection and characterization of MP binding to DNA and RNA molecules. We also describe protocols for purification of recombinant viral MPs over-expressed in bacteria and production of different DNA and RNA probes for these binding assays. PMID:18370264

  10. Fatty acids exacerbate tubulointerstitial injury in protein-overload proteinuria.

    PubMed

    Thomas, Mark E; Harris, Kevin P G; Walls, John; Furness, Peter N; Brunskill, Nigel J

    2002-10-01

    The role of the albumin-carried fatty acids in the induction of tubulointerstitial injury was studied in protein-overload proteinuria. Rats were injected with fatty acid-carrying BSA [FA(+)BSA], fatty acid-depleted BSA [FA(-)BSA], or saline. Macrophage infiltration was measured by immunohistochemical staining, apoptotic cells were detected by in situ end labeling, and proliferating cells were identified by in situ hybridization for histone mRNA. Macrophage infiltration was significantly greater in the FA(+)BSA group than in the FA(-)BSA and saline groups. The infiltrate was largely restricted to the outer cortex. Apoptosis was greater in the FA(+)BSA group than in the FA(-)BSA and saline groups. Compared with the saline group, apoptosis was significantly increased in the FA(+)BSA group but not in the FA(-)BSA group. Cortical cells proliferated significantly more in the FA(+)BSA and FA(-)BSA groups than in the saline group. FA(+)BSA is therefore a more potent inducer of macrophage infiltration and cell death than FA(-)BSA. The fatty acids carried on albumin may be the chief instigators of tubulointerstitial injury in protein-overload proteinuria. PMID:12217854

  11. Intra-articular injection of tranexamic acid reduce blood loss in cemented total knee arthroplasty.

    PubMed

    Digas, G; Koutsogiannis, I; Meletiadis, G; Antonopoulou, E; Karamoulas, V; Bikos, Ch

    2015-10-01

    The purpose of this study was to compare the efficacy of intravenous and topical tranexamic acid (TXA) versus control group for reduction in blood loss following primary total knee arthroplasty (TKA). A total of 90 patients were prospectively allocated to each of three groups (control, intravenous IV and intra-articular) and underwent unilateral total knee arthroplasty. In the IV group, patients received one dose of TXA of 15 mg/kg before deflation of the tourniquet, while in the intra-articular group patients received 2 g TXA via the drain retrogradely after closure of the wound. The mean drained blood loss in control, IV and intra-articular groups was 415 ± 24, 192 ± 21 and 121 ± 17 ml, respectively. About 43 % (control), 23 % (IV) and 17 % (intra-articular) of each group required transfusion, and the mean transfusion was 338, 168 and 79 ml, respectively. Preoperative hemoglobin values decreased at 24 h by 2.80 ± 0.14, 2.24 ± 0.17 and 2.26 ± 0.18 mg/dl, respectively. TXA reduced blood loss and transfusion requirement. Compared with one-dose intravenous administration, intra-articular administration of TXA seems to be more effective in terms of reducing drained blood loss and transfusion frequency. We recommend administration of topical TXA in primary TKA in healthy patients to decrease perioperative blood loss. PMID:26169991

  12. The biological activities of protein/oleic acid complexes reside in the fatty acid.

    PubMed

    Fontana, Angelo; Spolaore, Barbara; Polverino de Laureto, Patrizia

    2013-06-01

    A complex formed by human α-lactalbumin (α-LA) and oleic acid (OA), named HAMLET, has been shown to have an apoptotic activity leading to the selective death of tumor cells. In numerous publications it has been reported that in the complex α-LA is monomeric and adopts a partly folded or "molten globule" state, leading to the idea that partly folded proteins can have "beneficial effects". The protein/OA molar ratio initially has been reported to be 1:1, while recent data have indicated that the OA-complex is given by an oligomeric protein capable of binding numerous OA molecules per protein monomer. Proteolytic fragments of α-LA, as well as other proteins unrelated to α-LA, can form OA-complexes with biological activities similar to those of HAMLET, thus indicating that a generic protein can form a cytotoxic complex under suitable experimental conditions. Moreover, even the selective tumoricidal activity of HAMLET-like complexes has been questioned. There is recent evidence that the biological activity of long chain unsaturated fatty acids, including OA, can be ascribed to their effect of perturbing the structure of biological membranes and consequently the function of membrane-bound proteins. In general, it has been observed that the cytotoxic effects exerted by HAMLET-like complexes are similar to those reported for OA alone. Overall, these findings can be interpreted by considering that the protein moiety does not have a toxic effect on its own, but merely acts as a solubilising agent for the inherently toxic fatty acid. PMID:23499846

  13. Determination of total protein content in white wines by solid phase spectrometry in a SI-LOV system.

    PubMed

    Vidigal, Susana S M P; Tóth, Ildikó V; Rangel, António O S S

    2012-07-15

    Although present at low concentration in wine samples, proteins, have considerable technological importance, due to their capability of haze formation. The present work presents a methodology for the quantification of total protein in white wine in a sequential injection lab-on-valve system, exploiting the bead injection concept for solid phase extraction with spectrophotometric detection. The method is based on the retention of the proteins in the solid support, NTA (nitrilotriacetic acid) superflow beads, charged by Cu(2+). The change in the absorbance is monitored at 500nm at the surface of the beads after addition of the Folin-Ciocalteu's reagent (FCr). The developed method presented a sample consumption of 400μL per assay and a consumption of FCr and Cu(2+) solution of 25μL and 100μL per assay, respectively. It was possible to achieve a linear range up to 0.30g/L with a limit of detection and quantification of 0.03 and 0.10g/L, respectively. The proposed method was successfully applied to white wine samples. PMID:22817935

  14. Effect of degree of hydrolysis of whey protein on in vivo plasma amino acid appearance in humans.

    PubMed

    Farup, Jean; Rahbek, Stine Klejs; Storm, Adam C; Klitgaard, Søren; Jørgensen, Henry; Bibby, Bo M; Serena, Anja; Vissing, Kristian

    2016-01-01

    Whey protein is generally found to be faster digested and to promote faster and higher increases in plasma amino acid concentrations during the immediate ~60 min following protein ingestion compared to casein. The aim of the present study was to compare three different whey protein hydrolysates with varying degrees of hydrolysis (DH, % cleaved peptide bonds) to evaluate if the degree of whey protein hydrolysis influences the rate of amino acid plasma appearance in humans. A casein protein was included as reference. The three differentially hydrolysed whey proteins investigated were: High degree of hydrolysis (DH, DH = 48 %), Medium DH (DH = 27 %), and Low DH (DH = 23 %). The casein protein was intact. Additionally, since manufacturing of protein products may render some amino acids unavailable for utilisation in the body the digestibility and the biological value of all four protein fractions were evaluated in a rat study. A two-compartment model for the description of the postprandial plasma amino acid kinetics was applied to investigate the rate of postprandial total amino acid plasma appearance of the four protein products. The plasma amino acid appearance rates of the three whey protein hydrolysates (WPH) were all significantly higher than for the casein protein, however, the degree of hydrolysis of the WPH products did not influence plasma total amino acid appearance rate (estimates of DH and 95 % confidence intervals [CI] (mol L(-1) min(-1)): High DH 0.0585 [0.0454, 0.0754], Medium DH 0.0594 [0.0495, 0.0768], Low DH 0.0560 [0.0429, 0.0732], Casein 0.0194 [0.0129, 0.0291]). The four protein products were all highly digestible, while the biological value decreased with increasing degree of hydrolysis. In conclusion, the current study does not provide evidence that the degree of whey protein hydrolysis is a strong determinant for plasma amino acid appearance rate within the studied range of hydrolysis and protein dose. PMID:27065230

  15. Role of Ingested Amino Acids and Protein in the Promotion of Resistance Exercise-Induced Muscle Protein Anabolism.

    PubMed

    Reidy, Paul T; Rasmussen, Blake B

    2016-02-01

    The goal of this critical review is to comprehensively assess the evidence for the molecular, physiologic, and phenotypic skeletal muscle responses to resistance exercise (RE) combined with the nutritional intervention of protein and/or amino acid (AA) ingestion in young adults. We gathered the literature regarding the translational response in human skeletal muscle to acute exposure to RE and protein/AA supplements and the literature describing the phenotypic skeletal muscle adaptation to RE and nutritional interventions. Supplementation of protein/AAs with RE exhibited clear protein dose-dependent effects on translational regulation (protein synthesis) through mammalian target of rapamycin complex 1 (mTORC1) signaling, which was most apparent through increases in p70 ribosomal protein S6 kinase 1 (S6K1) phosphorylation, compared with postexercise recovery in the fasted or carbohydrate-fed state. These acute findings were critically tested via long-term exposure to RE training (RET) and protein/AA supplementation, and it was determined that a diminishing protein/AA supplement effect occurs over a prolonged exposure stimulus after exercise training. Furthermore, we found that protein/AA supplements, combined with RET, produced a positive, albeit minor, effect on the promotion of lean mass growth (when assessed in >20 participants/treatment); a negligible effect on muscle mass; and a negligible to no additional effect on strength. A potential concern we discovered was that the majority of the exercise training studies were underpowered in their ability to discern effects of protein/AA supplementation. Regardless, even when using optimal methodology and large sample sizes, it is clear that the effect size for protein/AA supplementation is low and likely limited to a subset of individuals because the individual variability is high. With regard to nutritional intakes, total protein intake per day, rather than protein timing or quality, appears to be more of a factor on

  16. Protein turnover, amino acid requirements and recommendations for athletes and active populations.

    PubMed

    Poortmans, J R; Carpentier, A; Pereira-Lancha, L O; Lancha Jr, A

    2012-10-01

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ((13)C-lysine, (15)N-glycine, ²H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g · kg(-1) · day(-1) compared to 0.8 g · kg(-1) · day(-1) in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h. PMID:22666780

  17. Protein turnover, amino acid requirements and recommendations for athletes and active populations

    PubMed Central

    Poortmans, J.R.; Carpentier, A.; Pereira-Lancha, L.O.; Lancha, A.

    2012-01-01

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers (13C-lysine, 15N-glycine, 2H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg−1·day−1 compared to 0.8 g·kg−1·day−1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h. PMID:22666780

  18. A Platform for Combined DNA and Protein Microarrays Based on Total Internal Reflection Fluorescence

    PubMed Central

    Asanov, Alexander; Zepeda, Angélica; Vaca, Luis

    2012-01-01

    We have developed a novel microarray technology based on total internal reflection fluorescence (TIRF) in combination with DNA and protein bioassays immobilized at the TIRF surface. Unlike conventional microarrays that exhibit reduced signal-to-background ratio, require several stages of incubation, rinsing and stringency control, and measure only end-point results, our TIRF microarray technology provides several orders of magnitude better signal-to-background ratio, performs analysis rapidly in one step, and measures the entire course of association and dissociation kinetics between target DNA and protein molecules and the bioassays. In many practical cases detection of only DNA or protein markers alone does not provide the necessary accuracy for diagnosing a disease or detecting a pathogen. Here we describe TIRF microarrays that detect DNA and protein markers simultaneously, which reduces the probabilities of false responses. Supersensitive and multiplexed TIRF DNA and protein microarray technology may provide a platform for accurate diagnosis or enhanced research studies. Our TIRF microarray system can be mounted on upright or inverted microscopes or interfaced directly with CCD cameras equipped with a single objective, facilitating the development of portable devices. As proof-of-concept we applied TIRF microarrays for detecting molecular markers from Bacillus anthracis, the pathogen responsible for anthrax. PMID:22438738

  19. The acid tolerance response of Salmonella typhimurium involves transient synthesis of key acid shock proteins.

    PubMed Central

    Foster, J W

    1993-01-01

    Although Salmonella typhimurium prefers neutral-pH environments, it can adapt to survive conditions of severe low-pH stress (pH 3.3). The process, termed the acid tolerance response (ATR), includes two distinct stages. The first stage, called pre-acid shock, is induced at pH 5.8 and involves the production of an inducible pH homeostasis system functional at external pH values below 4.0. The second stage occurs following an acid shock shift to pH 4.5 or below and is called the post-acid shock stage. During this stage of the ATR, 43 acid shock proteins (ASPs) are synthesized. The present data reveal that several ASPs important for pH 3.3 acid tolerance are only transiently produced. Their disappearance after 30 to 40 min of pH 4.4 acid shock coincides with an inability to survive subsequent pH 3.3 acid challenge. Clearly, an essential feature of inducible acid tolerance is an ability to synthesize these key ASPs. The pre-acid shock stage, with its inducible pH homeostasis system, offers the cell an enhanced ability to synthesize ASPs following rapid shifts to conditions below pH 4.0, an external pH that normally prevents ASP synthesis. The data also address possible signals for ASP synthesis. The inducing signal for 22 ASPs appears to be internal acidification, while external pH serves to induce 13 others. Of the 14 transient ASPs, 10 are induced in response to changes in internal pH. Mutations in the fur (ferric uptake regulator) locus that produce an Atr- acid-sensitive phenotype also eliminate induction of six transiently induced ASPs. Images PMID:8458840

  20. Comparison of Neuroprotective Effects of Melissa officinalis Total Extract and Its Acidic and Non-Acidic Fractions against A β-Induced Toxicity

    PubMed Central

    Sepand, Mohammad Reza; Soodi, Maliheh; Hajimehdipoor, Homa; Soleimani, Masoud; Sahraei, Ehsan

    2013-01-01

    Alzheimer’s disease (AD) is a neurodegenerative disease that was characterized with deposit of beta amyloid (Aβ) aggregate in senile plaque. Oxidative damage to neurons and loss of cholinergic neurons in forebrain region are observed in this disease. Melissa officinalis is a medicinal plant from Lamiaceae family, used traditionally in the treatment of cognitive disorders. It has cholinomimetic and potent antioxidant activity. In the present study, we investigated the possible neuroprotective effects of total ethanolic extract, acidic and nonacidic fraction of Melissa officinalis on Aβ-induced cytotoxicity and oxidative stress in PC12 cells and also measured their in-vitro anticholinesterase activity. PC12 cells were incubated with the extract and fractions prior to the incubation with Aβ and cell toxicity was assessed by MTT assay. In addition, productions of reactive oxygen species (ROS), Malondialdehyde (MDA) as a biomarker of lipid peroxidation and glutathione peroxidase activity were measured. Pretreatment of cells with total extract and acidic fraction (not non-acidic fraction) had protective effect against Aβ-induced oxidative changes and cell death. In concentrations in which both total extracts of an acidic fraction showed neuroprotective effects, inhibition of cholinesterase activity was not significant. Then, the protective effects of Melissa officinalis total extract and acidic fraction were not attributed to their anticholinesterase activity. Acidic fraction showed more potent protective effect compared to the total extract, leading to the fact that polyphenolic compounds and terpenoic acids are the most effective components in the total extract concentrated in this fraction. PMID:24250617

  1. A high-performance direct transmethylation method for total fatty acids assessment in biological and foodstuff samples.

    PubMed

    Castro-Gómez, Pilar; Fontecha, Javier; Rodríguez-Alcalá, Luis M

    2014-10-01

    Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods. PMID:25059195

  2. Novel approach to the zaragozic acids. Enantioselective total synthesis of 6,7-dideoxysqualestatin H5.

    PubMed

    Naito, Satoru; Escobar, Maya; Kym, Philip R; Liras, Spiros; Martin, Stephen F

    2002-06-14

    The total synthesis of 6,7-dideoxysqualestatin H5 (3) has been completed by a concise approach that features the stereoselective intramolecular vinylogous aldol reaction of the furoic ester 25a to give 30 or its trimethylsilyl ether derivative 34, which possess the requisite absolute stereochemistry at C(3)-C(5) of 3. Compound 34 was reduced to the saturated bislactone 39, and the C(1) side chain subunit 47 was introduced leading to a mixture of the hemiacetals 48 and the corresponding ketone 49. When this mixture was stirred with methanolic acid, transketalization occurred to give a mixture of 50 and the spirocyclic methyl acetals 51a,b. Oxidation of the primary alcohol group in 50 followed by saponification of the two remaining ester groups gave 3. The longest linear sequence in the synthesis commences with commercially available erythronolactone (26) and requires 17 chemical steps with only 10 isolated intermediates. PMID:12054955

  3. Recovery of total microbial RNA from lactic acid fermented foods with a high starch content.

    PubMed

    Ampe, F; ben Omar, N; Guyot, J P

    1998-11-01

    An optimized procedure for the recovery of RNA from micro-organisms involved in the fermentation of starchy foods (mainly hard-to-lyse lactic acid bacteria) is reported. Critical steps for the extraction were: cell recovery by differential centrifugation; cell wall digestion with both mutanolysin and lysozyme; and CTAB treatment for the elimination of starch. Digestion of starch with alpha-amylase did not improve extraction yields. The method yielded high amounts of RNA from pozol, a Mexican maize-based fermented food, and was found to extract total RNA efficiently from all the micro-organisms potentially present in these ecosystems. Both rRNA and mRNA recovered were of high quality and suitable for hybridization studies. PMID:9830143

  4. Dietary total fat and fatty acids intake, serum fatty acids and risk of breast cancer: A meta-analysis of prospective cohort studies.

    PubMed

    Cao, Yi; Hou, Lin; Wang, Weijing

    2016-04-15

    Results from prospective cohort studies on the association between dietary total fat and fatty acids intake and risk of breast cancer remain controversial. Pertinent prospective cohort studies were identified by a search of Embase and PubMed from inception to September 2015. Study-specific relative risks (RRs) with 95% confidence intervals were pooled using a random-effect model. Between-study heterogeneity and publication bias were assessed, and sensitivity analysis was conducted. Twenty-four independent studies on dietary total fat and fatty acids intake and seven studies on serum fatty acids were included. The pooled RR of breast cancer for the highest vs. lowest category of dietary total fat intake was 1.10 (1.02-1.19); however, no association was observed in studies adjusting for traditional risk factors of breast cancer. No association was observed between animal fat, vegetable fat, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-3 PUFA, n-6 PUFA, eicosapentaenoic acid, docosahexaenoic acid, alpha-linolenic acid, oleic acid, linoleic acid and arachidonic acid and risk of breast cancer. The pooled RRs of breast cancer for the highest vs. lowest category of serum SFA, MUFA, PUFA, n-3 PUFA and n-6 PUFA were 1.00 (0.78-1.28), 1.41 (0.99-2.03), 0.59 (0.27-1.30), 0.81 (0.60-1.10) and 0.84 (0.60-1.18), respectively. Results from this meta-analysis suggested that dietary total fat and fatty acids might be not associated with risk of breast cancer. PMID:26595162

  5. Total Protein Profile and Drug Resistance in Candida albicans Isolated from Clinical Samples

    PubMed Central

    Thawani, Vijay; Mehra, Arti

    2016-01-01

    This study was done to assess the antifungal susceptibility of clinical isolates of Candida albicans and to evaluate its total protein profile based on morphological difference on drug resistance. Hundred and twenty clinical isolates of C. albicans from various clinical specimens were tested for susceptibility against four antifungal agents, namely, fluconazole, itraconazole, amphotericin B, and ketoconazole. A significant increase of drug resistance in clinical isolates of C. albicans was observed. The study showed 50% fluconazole and itraconazole resistance at 32 μg mL−1 with a MIC50 and MIC90 values at 34 and 47 and 36 and 49 μg mL−1, respectively. All isolates were sensitive to amphotericin B and ketoconazole. The SDS-PAGE protein profile showed a prevalent band of ~52.5 kDa, indicating overexpression of gene in 72% strains with fluconazole resistance. Since the opportunistic infections of Candida spp. are increasing along with drug resistance, the total protein profile will help in understanding the evolutionary changes in drug resistance and also to characterize them. PMID:27478638

  6. Fermentation Characteristics and Lactic Acid Bacteria Succession of Total Mixed Ration Silages Formulated with Peach Pomace

    PubMed Central

    Hu, Xiaodong; Hao, Wei; Wang, Huili; Ning, Tingting; Zheng, Mingli; Xu, Chuncheng

    2015-01-01

    The objective of this study was to assess the use of peach pomace in total mixed ration (TMR) silages and clarify the differences in aerobic stability between TMR and TMR silages caused by lactic acid bacteria (LAB). The TMR were prepared using peach pomace, alfalfa hay or Leymus chinensis hay, maize meal, soybean meal, cotton meal, limestone, a vitamin-mineral supplement, and salt in a ratio of 6.0:34.0:44.4:7.0:5.0:2.5:1.0:0.1 on a dry matter (DM) basis. Fermentation quality, microbial composition, and the predominant LAB were examined during ensiling and aerobic deterioration. The results indicated that the TMR silages with peach pomace were well fermented, with low pH and high lactic acid concentrations. The aerobic stability of TMR silages were significantly higher than that of TMR. Compared with TMR silages with alfalfa hay, TMR silage with Leymus chinensis hay was much more prone to deterioration. Although the dominant LAB were not identical in TMR, the same dominant species, Lactobacillus buchneri and Pediococcus acidilactici, were found in both types of TMR silages after 56 d of ensiling, and they may play an important role in the aerobic stability of TMR silages. PMID:25656205

  7. Heavy metals and acidic components in total deposited matter in Sibenik and National Park Kornati, Croatia.

    PubMed

    Cacković, Mirjana; Kalinić, Natasa; Vadjić, Vladimira; Pehnec, Gordana

    2009-01-01

    This article presents the results of 6 years (1999-2004) of monitoring acidic components (fluoride, chloride, nitrate, sulfate) and heavy metals (lead, cadmium, thallium) in total deposited matter (TDM) in the town of Sibenik and the National Park Kornati, Croatia, in order to determine their levels, spatial and temporal variations, and possible emission source. Bulk deposition samples were collected using the Bergerhoff samplers. TDM matter was determined gravimetrically. Acidic anions were analyzed using ion chromatography. Metallic components were determined by atomic absorption spectrometry. Results show that the levels of measured pollutants were relatively low compared to those reported in other investigations. Statistical analysis indicates that the measured pollutants originate from several sources such as resuspended soil, industry, road dust, traffic, and secondary aerosols as the most important. The levels of TDM show a slightly increasing trend at all sampling sites. A significant increasing trend in the levels of nitrate and sulfate in TDM could be the consequence of increasing traffic activity and urbanization. The significant increasing trend in the ratio between nitrate and sulfate in TDM indicates that the nitrate and sulfate relative contribution to acidification is increasing. The level of heavy metals in TDM was in order of lead > thallium > cadmium at all sampling sites with slightly decreasing trend. PMID:18414927

  8. vProtein: Identifying Optimal Amino Acid Complements from Plant-Based Foods

    PubMed Central

    Woolf, Peter J.; Fu, Leeann L.; Basu, Avik

    2011-01-01

    Background Indispensible amino acids (IAAs) are used by the body in different proportions. Most animal-based foods provide these IAAs in roughly the needed proportions, but many plant-based foods provide different proportions of IAAs. To explore how these plant-based foods can be better used in human nutrition, we have created the computational tool vProtein to identify optimal food complements to satisfy human protein needs. Methods vProtein uses 1251 plant-based foods listed in the United States Department of Agriculture standard release 22 database to determine the quantity of each food or pair of foods required to satisfy human IAA needs as determined by the 2005 daily recommended intake. The quantity of food in a pair is found using a linear programming approach that minimizes total calories, total excess IAAs, or the total weight of the combination. Results For single foods, vProtein identifies foods with particularly balanced IAA patterns such as wheat germ, quinoa, and cauliflower. vProtein also identifies foods with particularly unbalanced IAA patterns such as macadamia nuts, degermed corn products, and wakame seaweed. Although less useful alone, some unbalanced foods provide unusually good complements, such as Brazil nuts to legumes. Interestingly, vProtein finds no statistically significant bias toward grain/legume pairings for protein complementation. These analyses suggest that pairings of plant-based foods should be based on the individual foods themselves instead of based on broader food group-food group pairings. Overall, the most efficient pairings include sweet corn/tomatoes, apple/coconut, and sweet corn/cherry. The top pairings also highlight the utility of less common protein sources such as the seaweeds laver and spirulina, pumpkin leaves, and lambsquarters. From a public health perspective, many of the food pairings represent novel, low cost food sources to combat malnutrition. Full analysis results are available online at http

  9. Effect of Ethionine on the Ribonucleic Acid, Deoxyribonucleic Acid, and Protein Content of Escherichia coli

    PubMed Central

    Smith, Robert C.; Salmon, W. D.

    1965-01-01

    Smith, Robert C. (Auburn University, Auburn, Ala.), and W. D. Salmon. Effect of ethionine on the ribonucleic acid, deoxyribonucleic acid, and protein content of Escherichia coli. J. Bacteriol. 89:687–692. 1965.—The addition of ethionine to cultures of Escherichia coli K-12 W6, a methionine-requiring auxotroph, led to inhibition of the rate of increase in optical density when the ratio of ethionine to methionine was 200:1. When the ratio was 600:1, the increase in optical density became linear. When ethionine was substituted for methionine in the medium, the optical density of the culture increased, and there was a parallel increase in protein content. There was no cell division in these cultures. The rate of synthesis of ribonucleic acid (RNA) in a culture containing ethionine was similar to that of a culture deprived of methionine, but the synthesis of deoxyribonucleic acid in a culture with ethionine was about twice that of a culture deprived of methionine. No detectable radioactivity from ethionine-ethyl-1-C14 was incorporated into RNA. Ethionine-ethyl-1-C14 was readily incorporated into the protein fraction. PMID:14273646

  10. Effect of Acidic pH on Expression of Surface-Associated Proteins of Streptococcus oralis

    PubMed Central

    Wilkins, Joanna C.; Beighton, David; Homer, Karen A.

    2003-01-01

    Streptococcus oralis, a member of the mitis group of oral streptococci, is implicated in the pathogenesis of infective endocarditis and is the predominant aciduric non-mutans-group streptococcus in dental plaque. We undertook to identify the most abundant surface-associated proteins of S. oralis and to investigate changes in protein expression when the organism was grown under acidic culture conditions. Surface-associated proteins were extracted from cells grown in batch culture, separated by two-dimensional gel electrophoresis, excised, digested with trypsin, and analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry. Putative functions were assigned by homology to a translated genomic database of Streptococcus pneumoniae. A total of 27 proteins were identified; these included a lipoprotein, a ribosome recycling factor, and the glycolytic enzymes phosphoglycerate kinase, fructose bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and enolase. The most abundant protein, phosphocarrier protein HPr, was present as three isoforms. Neither lactate dehydrogenase nor pyruvate oxidase, dominant intracellular proteins, were present among the proteins on the gels, demonstrating that proteins in the surface-associated pool did not arise as a result of cell lysis. Eleven of the proteins identified were differentially expressed when cells were grown at pH 5.2 versus pH 7.0, and these included superoxide dismutase, a homologue of dipeptidase V from Lactococcus lactis, and the protein translation elongation factors G, Tu, and Ts. This study has extended the range of streptococcal proteins known to be expressed at the cell surface. Further investigations are required to ascertain their functions at this extracellular location and determine how their expression is influenced by other environmental conditions. PMID:12957916

  11. Total RNA and protein content, Cyclin B1 expression and developmental competence of prepubertal goat oocytes.

    PubMed

    Anguita, Begoña; Paramio, Maria-Teresa; Jiménez-Macedo, Ana R; Morató, Roser; Mogas, Teresa; Izquierdo, Dolors

    2008-01-30

    The aim of this study was to examine the relationship between the developmental competence of oocytes and their total RNA and protein contents, and the level of Cyclin B1 transcription. Ovaries from prepubertal goats were collected from a slaughterhouse. Oocytes were recovered by slicing and those with two or more layers of cumulus cells and homogenous cytoplasm were matured in vitro (20-25 oocytes per drop) for 27 h. Both before and after IVM, samples of oocytes were denuded and categorised into four group treatments by diameter (<110 microm, 110-125 microm, 125-135 microm; >135 microm), separated into sub-groups of 10 oocytes per treatment-replicate and stored in liquid nitrogen until total RNA content analysis by spectophotometry, total protein content analysis by a colorimetric assay and Cyclin B1 transcription analysis by RT-PCR. For the study of developmental competence, the rest of the matured oocytes were fertilised in vitro in groups of 20-25 for 24 h. Presumptive zygotes were denuded, sorted into the four categories of diameter noted above, and placed into culture drops in groups of 18-25 for in vitro culture. Cleavage rate was evaluated at 48 hpi and embryo development at 8 d post-insemination. There were four replicates of each treatment for each assay or evaluation point of the experiment. There were no significant differences between the size categories of oocytes at collection in total RNA content, total protein content and Cyclin B1 mRNA. There were significant differences (P<0.05) in the expression of Cyclin B1 before IVM with oocytes in the >135 mm diameter category having the highest value for this variant. There were no significant differences in these characteristics between the categories of oocyte diameter after IVM except in respect of total RNA content, which was lower for the largest size of oocytes (>135 microm; mean+/-S.D.=12.3+/-1.84 ng/oocyte) than the other three size groups (19.2+/-1.38-22.1+/-4.44 ng/oocyte; P<0.05). Significant

  12. Application of Near Infrared Reflectance Spectroscopy on Determination of Moisture, Total oil and Protein Contents of In-shell Peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture, total oil and protein content of peanuts are important factors in peanut grading. A method that could rapidly and nondestructively measure these parameters for in-shell peanuts would be extremely useful. NIR reflectance spectroscopy was used to analyze the moisture, total oil and protein ...

  13. The requirements of protein & amino acid during acute & chronic infections.

    PubMed

    Kurpad, Anura V

    2006-08-01

    Nutrition and infection interact with each other in a synergistic vicious cycle, leading to an adverse nutritional status and increased susceptibility to infection. Infectious episodes result in hypermetabolism and a negative nitrogen balance which is modulated by hormones, cytokines and other pro-inflammatory mediators, and is compounded by a reduced food intake. The extent of the negative nitrogen balance varies with the type of infection and its duration; however, it is reasonable to suggest that the loss of body protein could be minimized by the provision of dietary nitrogen, although anorexia will limit this. Further, distinctions need to be made about the provision of nutrients or protein during the catabolic and anabolic or recovery phase of the infection, since the capacity of the body to retain protein is enhanced in the anabolic recovery phase. Meeting the increased requirement for protein (and other nutrients) in infection does not imply a complete therapeutic strategy. Infections need to be treated appropriately, with nutrition as an adjunct to the treatment. Prior undernutrition could also impair the body's response to infection, although the weight of the evidence would suggest that this happens more particularly in oedematous undernutrition. In general, the amount of extra protein that would appear to be needed is of the order of 20-25 per cent of the recommended intake, for most infections. In acute infections, this is particularly relevant during the convalescence period. Community trials have suggested that lysine supplementation to the level required for normal daily nutriture, in predominantly wheat eating or potentially lysine deficient communities, improves immune function among other functional nutritional parameters; however, there is as yet insufficient evidence to suggest a specific requirement for amino acids in infections over and above the normal daily requirement as based on recent evidence. Some clinical studies that have showed

  14. Retinoic acid binding protein in normal and neopolastic rat prostate.

    PubMed

    Gesell, M S; Brandes, M J; Arnold, E A; Isaacs, J T; Ueda, H; Millan, J C; Brandes, D

    1982-01-01

    Sucrose density gradient analysis of cytosol from normal and neoplastic rat prostatic tissues exhibited a peak of (3H) retinoic acid binding in the 2S region, corresponding to the cytoplasmic retinoic acid binding protein (cRABP). In the Fisher-Copenhagen F1 rat, cRABP was present in the lateral lobe, but could not be detected in the ventral nor in the dorsal prostatic lobes. Four sublines of the R-3327 rat prostatic tumor contained similar levels of this binding protein. The absence of cRABP in the normal tissue of origin of the R-3327 tumor, the rat dorsal prostate, and reappearance in the neoplastic tissues follows a pattern described in other human and animal tumors. The occurrence of cRABP in the well-differentiated as well as in the anaplastic R-3327 tumors in which markers which reflect a state of differentiation and hormonal regulation, such as androgen receptor, 5 alpha reductase, and secretory acid phosphatase are either markedly reduced or absent, points to cRABP as a marker of malignant transformation. PMID:6283503

  15. EFFECT OF TRANEXAMIC ACID ON BLEEDING CONTROL IN TOTAL KNEE ARTHROPLASTY

    PubMed Central

    SADIGURSKY, DAVID; ANDION, DANIEL; BOUREAU, PÉRICLES; FERREIRA, MARIA CORDULINA; CARNEIRO, ROGÉRIO JAMIL FERNANDES; COLAVOLPE, PAULO OLIVEIRA

    2016-01-01

    ABSTRACT Objectives: To analyze the effectiveness of intravenous (IV) tranexamic acid (TA) in reducing blood loss in total knee arthroplasty (TKA). Method: The population sample was composed of patients with a diagnosis of primary knee osteoarthritis. The patients undergoing TKA were divided in two groups. Group A: comprised patients who used IV TA and B group, formed by patients who did not use TA in the intra or post-operative period. For descriptive analysis, quantitative variables were represented by mean and standard deviations when their distribution was normal and interquartile ranges and medians for non-normal variables. Results: The mean age of patients was 68 years old, most of them were female and with involvement of the left knee. Postoperatively patients who had used IV TA showed less bleeding rate and less hemoglobin rate reduction. Conclusion: The use of IV TA in TKA reduces blood loss in peri- and postoperative periods. Regarding total blood loss reduction, hemoglobin rate and need for blood transfusions, IV TA should be used routinely during TKA since it has been shown to be safe with no increase in side effects as thromboembolic events. Level of Evidence III. Retrospective Comparative Study. PMID:27217813

  16. Use of liposomal amplifiers in total internal reflection fluorescence fiber-optic biosensors for protein detection.

    PubMed

    Chang, Ying-Feng; Fu, Chen; Chen, Yi-Ting; Fang-Ju Jou, Amily; Chen, Chii-Chang; Chou, Chien; Annie Ho, Ja-An

    2016-03-15

    Evanescent-wave excited fluorescence technology has been demonstrated to enhance sensitivity and reduce matrix effects, making it suitable for biosensor development. In this study, we developed a liposome-based, total internal reflection fluorescence, fiber-optic biosensor (TIRF-FOB) for protein detection, which integrates a liposomal amplifier and sandwich immunoassay format with TIRF-FOB. In addition, the antibody-tagged and fluorophore-entrapped liposomes for heterogeneous detection of target molecules were designed and synthesized. This biosensor successfully detected the target protein (model analyzed here is IgG) with a limit of detection (LOD) of 2.0 attomoles for the target protein (equivalent to 2.0 pg/mL of protein presented in 150 μL of sample solution). The features of this ultra-sensitive liposomal TIRF-FOB are (i) fluorescence is excited via evanescent waves and amplified via liposomes; (ii) the use of two polyclonal antibodies in the sandwich assay format increases the specificity and lowers the cost of our assay. Based on the exceptional detection sensitivity and cost-effectiveness, we believe that the proposed biosensor has great potential as a practical, clinical diagnostic tool in the near future. PMID:26595485

  17. Effect of dietary fatty acid supplements, varying in fatty acid composition, on milk fat secretion in dairy cattle fed diets supplemented to less than 3% total fatty acids.

    PubMed

    Stoffel, C M; Crump, P M; Armentano, L E

    2015-01-01

    Dietary fatty acids can affect both milk fat yield and fatty acid (FA) composition. This relationship is well established when the dietary level of FA exceeds 3% of diet dry matter (DM). We could find no reports directly examining the effects of dietary FA profile on milk fat at levels below 3%. Twenty-four primiparous and 36 multiparous lactating cows were paired by production (1 high with 1 low, within parity) to form 30 experimental units. Pairs were fed 6 diets in five 6×6 balanced Latin squares with 21-d periods, and data were collected during the last 5d of each period. Two control diets were fed: a corn control diet (CC; 29% corn silage, 16% alfalfa silage, 19% corn grain, and 8% distillers grain on a DM basis) containing 1.8% FA; and a low-oil control diet (LOC; 9% corn silage, 35% alfalfa silage, 20% food-grade corn starch, and 8% corn gluten feed on a DM basis) containing 1.2% FA. A portion of the food-grade corn starch in LOC was replaced with 4 different FA supplements to create the 4 treatment diets. Treatments were 1.7% (DM basis) of a 50:50 blend of corn oil and high-linoleic safflower oil (LO), 1.7% high-oleic sunflower oil (OO), 1.7% palm oil (PO), or 1.8% calcium salts of palm fatty acids (PFA). The resultant diets were thus enriched in linoleic (LO), oleic (OO), or palmitic acid (PO and PFA). Dietary treatments did not affect dry matter intake. Addition of any of the fat sources to LOC resulted in increased milk yield, but milk fat yields and milk FA composition were variable for the different treatments. The LO treatment resulted in lower milk fat yield, fat concentration, and C16:0 yield but increased both trans-10 C18:1 and trans-10,cis-12 C18:2 yields compared with the other added FA treatments. Diets PO and PFA resulted in increased milk C16:0 yield and decreased total milk C18 yield compared with OO. Regression analysis revealed a negative coefficient for dietary linoleic acid content over basal (LOC) for both milk short-chain FA yield and

  18. The nutrient composition of European ready meals: protein, fat, total carbohydrates and energy.

    PubMed

    Kanzler, Sonja; Manschein, Martin; Lammer, Guido; Wagner, Karl-Heinz

    2015-04-01

    Despite the increasing social importance of ready meals, only few studies have been conducted on their nutrient composition. Therefore, 32 chilled, frozen and heat-treated ready meals (only main dishes) from the continental European market were analysed for protein, fat, total carbohydrate and energy. Half of the meals were nutritionally imbalanced by providing elevated fat (>30% of energy) and low carbohydrate levels (<50% of energy). Protein was generally above recommendations and ranged from 8.0 to 47.2g per serving. The inter-package variation was high, reaching 19.04 ± 2.90 g/package for fat. After proposing understandable guidelines to improve nutritional quality for the food industry, seven "nutritionally optimised" ready meals were created at the European level and analysed, however success was limited. If product labelling is to be useful for consumers, our results also indicate a need for better quality control to reduce the differences between content and labelling. PMID:25442542

  19. Foamy Virus Protein-Nucleic Acid Interactions during Particle Morphogenesis.

    PubMed

    Hamann, Martin V; Lindemann, Dirk

    2016-01-01

    Compared with orthoretroviruses, our understanding of the molecular and cellular replication mechanism of foamy viruses (FVs), a subfamily of retroviruses, is less advanced. The FV replication cycle differs in several key aspects from orthoretroviruses, which leaves established retroviral models debatable for FVs. Here, we review the general aspect of the FV protein-nucleic acid interactions during virus morphogenesis. We provide a summary of the current knowledge of the FV genome structure and essential sequence motifs required for RNA encapsidation as well as Gag and Pol binding in combination with details about the Gag and Pol biosynthesis. This leads us to address open questions in FV RNA engagement, binding and packaging. Based on recent findings, we propose to shift the point of view from individual glycine-arginine-rich motifs having functions in RNA interactions towards envisioning the FV Gag C-terminus as a general RNA binding protein module. We encourage further investigating a potential new retroviral RNA packaging mechanism, which seems more complex in terms of the components that need to be gathered to form an infectious particle. Additional molecular insights into retroviral protein-nucleic acid interactions help us to develop safer, more specific and more efficient vectors in an era of booming genome engineering and gene therapy approaches. PMID:27589786

  20. Human Skeletal Muscle Protein Metabolism Responses to Amino Acid Nutrition.

    PubMed

    Mitchell, W Kyle; Wilkinson, Daniel J; Phillips, Bethan E; Lund, Jonathan N; Smith, Kenneth; Atherton, Philip J

    2016-07-01

    Healthy individuals maintain remarkably constant skeletal muscle mass across much of adult life, suggesting the existence of robust homeostatic mechanisms. Muscle exists in dynamic equilibrium whereby the influx of amino acids (AAs) and the resulting increases in muscle protein synthesis (MPS) associated with the intake of dietary proteins cancel out the efflux of AAs from muscle protein breakdown that occurs between meals. Dysregulated proteostasis is evident with aging, especially beyond the sixth decade of life. Women and men aged 75 y lose muscle mass at a rate of ∼0.7% and 1%/y, respectively (sarcopenia), and lose strength 2- to 5-fold faster (dynapenia) as muscle "quality" decreases. Factors contributing to the disruption of an otherwise robust proteostatic system represent targets for potential therapies that promote healthy aging. Understanding age-related impairments in anabolic responses to AAs and identifying strategies to mitigate these factors constitute major areas of interest. Numerous studies have aimed to identify 1) the influence of distinct protein sources on absorption kinetics and muscle anabolism, 2) the latency and time course of MPS responses to protein/AAs, 3) the impacts of protein/AA intake on muscle microvascular recruitment, and 4) the role of certain AAs (e.g., leucine) as signaling molecules, which are able to trigger anabolic pathways in tissues. This review aims to discuss these 4 issues listed, to provide historical and modern perspectives of AAs as modulators of human skeletal muscle protein metabolism, to describe how advances in stable isotope/mass spectrometric approaches and instrumentation have underpinned these advances, and to highlight relevant differences between young adults and older individuals. Whenever possible, observations are based on human studies, with additional consideration of relevant nonhuman studies. PMID:27422520

  1. Studies on fatty acid-binding proteins. The detection and quantification of the protein from rat liver by using a fluorescent fatty acid analogue.

    PubMed Central

    Wilkinson, T C; Wilton, D C

    1986-01-01

    Fatty acid-binding protein from rat liver is shown to bind the fluorescent fatty acid probe dansyl undecanoic acid. Binding is accompanied by a shift in the fluorescence emission maximum from 550 nm to 500 nm and a 60-fold fluorescence enhancement at 500 nm. These spectral properties have allowed the use of this probe to detect and quantify microgram amounts of liver fatty acid-binding protein during purification procedures. In conjunction with h.p.l.c. the method allows the rapid estimation of liver fatty acid-binding protein in biological samples. The validity of the method is demonstrated by measuring the concentration of fatty acid-binding protein in livers from control and hypolipidaemic-drug-treated rats. The dramatic diurnal rhythm previously reported for this protein [Dempsey (1984) Curr. Top. Cell. Regul. 24, 63-86] was not observed with this method. Images Fig. 1. PMID:3800946

  2. Amino acid racemization reveals differential protein turnover in osteoarthritic articular and meniscal cartilages

    PubMed Central

    Stabler, Thomas V; Byers, Samuel S; Zura, Robert D; Kraus, Virginia Byers

    2009-01-01

    Introduction Certain amino acids within proteins have been reported to change from the L form to the D form over time. This process is known as racemization and is most likely to occur in long-lived low-turnover tissues such as normal cartilage. We hypothesized that diseased tissue, as found in an osteoarthritic (OA) joint, would have increased turnover reflected by a decrease in the racemized amino acid content. Methods Using high-performance liquid chromatography methods, we quantified the L and D forms of amino acids reported to racemize in vivo on a biological timescale: alanine, aspartate (Asp), asparagine (Asn), glutamate, glutamine, isoleucine, leucine (Leu), and serine (Ser). Furthermore, using a metabolically inactive control material (tooth dentin) and a control material with normal metabolism (normal articular cartilage), we developed an age adjustment in order to make inferences about the state of protein turnover in cartilage and meniscus. Results In the metabolically inactive control material (n = 25, ages 13 to 80 years) and the normal metabolizing control material (n = 19, ages 17 to 83 years), only Asp + Asn (Asx), Ser, and Leu showed a significant change (increase) in racemization with age (P < 0.01). The age-adjusted proportions of racemized to total amino acid (D/D+L expressed as a percentage of the control material) for Asx, Ser, and Leu when compared with the normal articular cartilage control were 97%, 74%, and 73% in OA meniscal cartilage and 97%, 70%, and 78% in OA articular cartilage. We also observed lower amino acid content in OA articular and meniscal cartilages compared with normal articular cartilage as well as a loss of total amino acids with age in the OA meniscal but not the OA articular cartilage. Conclusions These data demonstrate comparable anabolic responses for non-lesioned OA articular cartilage and OA meniscal cartilage but an excess of catabolism over anabolism for the meniscal cartilage. PMID:19267899

  3. Uric acid or 1-methyl uric acid in the urinary bladder increases serum glucose, insulin, true triglyceride, and total cholesterol levels in Wistar rats.

    PubMed

    Balasubramanian, T

    2003-10-01

    In animals deprived of food for a long period, a drop in the fat mass below 5% of the total body mass results in an increase in blood glucocorticoids and uric acid levels, followed by foraging activity. Since the glucocorticoids increase the uric acid excretion, an increase in the level of uric acid in the bladder urine could be the signal for this feeding behaviour and subsequent fat storage. Accumulation of fat is associated with hyperglycaemia, hyperinsulinaemia, hyperlipidaemia, and hypercholesterolaemia as seen in the metabolic syndrome or hibernation. It is hypothesized that uric acid or its structurally related compound, 1-methyl uric acid (one of the metabolites of the methyl xanthines namely caffeine, theophylline, and theobromine present in coffee, tea, cocoa, and some drugs), can act on the urinary bladder mucosa and increases the blood glucose, insulin, triglyceride, and cholesterol levels. In rats, perfusion of the urinary bladder with saturated aqueous solution of uric acid or 1-methyl uric acid results in a significant increase in the serum levels of glucose, insulin, true triglyceride, and total cholesterol in comparison with perfusion of the bladder with distilled water at 20, 40, and 80 min. The uric acid or the 1-methyl uric acid acts on the urinary bladder mucosa and increases the serum glucose, insulin, true triglyceride, and total cholesterol levels. PMID:15241498

  4. Perinatal protein restriction affects milk free amino acid and fatty acid profile in lactating rats: potential role on pup growth and metabolic status.

    PubMed

    Martin Agnoux, Aurore; Antignac, Jean-Philippe; Boquien, Clair-Yves; David, Agnes; Desnots, Emmanuelle; Ferchaud-Roucher, Veronique; Darmaun, Dominique; Parnet, Patricia; Alexandre-Gouabau, Marie-Cécile

    2015-07-01

    Perinatal undernutrition affects not only fetal and neonatal growth but also adult health outcome, as suggested by the metabolic imprinting concept. Although maternal milk is the only channel through which nutrients are transferred from mother to offspring during the postnatal period, the impact of maternal undernutrition on milk composition is poorly understood. The present study investigates, in a rat model of nutritional programming, the effects of feeding an isocaloric, low-protein diet throughout gestation and lactation on milk composition and its possible consequences on offspring's growth and metabolic status. We used an integrated methodological approach that combined targeted analyses of macronutrients, free amino acid and fatty acid content throughout lactation, with an untargeted mass-spectrometric-based metabolomic phenotyping. Whereas perinatal dietary protein restriction failed to alter milk protein content, it dramatically decreased the concentration of most free amino acids at the end of lactation. Interestingly, a decrease of several amino acids involved in insulin secretion or gluconeogenesis was observed, suggesting that maternal protein restriction during the perinatal period may impact the insulinotrophic effect of milk, which may, in turn, account for the slower growth of the suckled male offspring. Besides, the decrease in sulfur amino acids may alter redox status in the offspring. Maternal undernutrition was also associated with an increase in milk total fatty acid content, with modifications in their pattern. Altogether, our results show that milk composition is clearly influenced by maternal diet and suggest that alterations in milk composition may play a role in offspring growth and metabolic programming. PMID:25935308

  5. Total-body protein turnover in parenterally fed neonates: effects of energy source studied by using [15N]glycine and [1-13C]leucine.

    PubMed

    Pencharz, P; Beesley, J; Sauer, P; Van Aerde, J; Canagarayar, U; Renner, J; McVey, M; Wesson, D; Swyer, P

    1989-12-01

    The effects of nonprotein energy source (ie, glucose only vs glucose and lipid) on nitrogen retention and total-body protein turnover were studied in 20 parenterally fed newborn infants. All infants received approximately 3 g amino acids and 80-90 kcal.kg body wt.d. Total-body protein synthesis was estimated by using three constant-infusion, end-product methods: enrichment of urinary urea and ammonia in response to a [15N]glycine label and exhaled carbon dioxide enrichment in response to a [1-13C]leucine label. No differences were seen in nitrogen retention between the two energy sources. The estimate of total-body protein turnover obtained from the 13C label was similar to that obtained with the [15N]urea label. No differences in turnover rates were observed between the two diet groups. Use of the glucose-plus-lipid fuel system enhanced energy storage and the reutilization of amino acid for protein synthesis. PMID:2512806

  6. Amino acid sequence of the Amur tiger prion protein.

    PubMed

    Wu, Changde; Pang, Wanyong; Zhao, Deming

    2006-10-01

    Prion diseases are fatal neurodegenerative disorders in human and animal associated with conformational conversion of a cellular prion protein (PrP(C)) into the pathologic isoform (PrP(Sc)). Various data indicate that the polymorphisms within the open reading frame (ORF) of PrP are associated with the susceptibility and control the species barrier in prion diseases. In the present study, partial Prnp from 25 Amur tigers (tPrnp) were cloned and screened for polymorphisms. Four single nucleotide polymorphisms (T423C, A501G, C511A, A610G) were found; the C511A and A610G nucleotide substitutions resulted in the amino acid changes Lysine171Glutamine and Alanine204Threoine, respectively. The tPrnp amino acid sequence is similar to house cat (Felis catus ) and sheep, but differs significantly from other two cat Prnp sequences that were previously deposited in GenBank. PMID:16780982

  7. Simplified protein design biased for prebiotic amino acids yields a foldable, halophilic protein.

    PubMed

    Longo, Liam M; Lee, Jihun; Blaber, Michael

    2013-02-01

    A compendium of different types of abiotic chemical syntheses identifies a consensus set of 10 "prebiotic" α-amino acids. Before the emergence of biosynthetic pathways, this set is the most plausible resource for protein formation (i.e., proteogenesis) within the overall process of abiogenesis. An essential unsolved question regarding this prebiotic set is whether it defines a "foldable set"--that is, does it contain sufficient chemical information to permit cooperatively folding polypeptides? If so, what (if any) characteristic properties might such polypeptides exhibit? To investigate these questions, two "primitive" versions of an extant protein fold (the β-trefoil) were produced by top-down symmetric deconstruction, resulting in a reduced alphabet size of 12 or 13 amino acids and a percentage of prebiotic amino acids approaching 80%. These proteins show a substantial acidification of pI and require high salt concentrations for cooperative folding. The results suggest that the prebiotic amino acids do comprise a foldable set within the halophile environment. PMID:23341608

  8. Simplified protein design biased for prebiotic amino acids yields a foldable, halophilic protein

    PubMed Central

    Longo, Liam M.; Lee, Jihun; Blaber, Michael

    2013-01-01

    A compendium of different types of abiotic chemical syntheses identifies a consensus set of 10 “prebiotic” α-amino acids. Before the emergence of biosynthetic pathways, this set is the most plausible resource for protein formation (i.e., proteogenesis) within the overall process of abiogenesis. An essential unsolved question regarding this prebiotic set is whether it defines a “foldable set”—that is, does it contain sufficient chemical information to permit cooperatively folding polypeptides? If so, what (if any) characteristic properties might such polypeptides exhibit? To investigate these questions, two “primitive” versions of an extant protein fold (the β-trefoil) were produced by top-down symmetric deconstruction, resulting in a reduced alphabet size of 12 or 13 amino acids and a percentage of prebiotic amino acids approaching 80%. These proteins show a substantial acidification of pI and require high salt concentrations for cooperative folding. The results suggest that the prebiotic amino acids do comprise a foldable set within the halophile environment. PMID:23341608

  9. The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan.

    PubMed

    Huang, Ru-Yi; Yang, Kuen-Cheh; Chang, Hao-Hsiang; Lee, Long-Teng; Lu, Chia-Wen; Huang, Kuo-Chin

    2016-01-01

    Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance. Our objective was to investigate whether pre-sarcopenia status was associated with lower protein intake. A total of 327 community-dwelling elderly people were recruited for a cross-sectional study. We adopted the multivariate nutrient density model to identify associations between low muscle mass and dietary protein intake. The general linear regression models were applied to estimate skeletal muscle mass index across the quartiles of total protein and vegetable protein density. Participants with diets in the lowest quartile of total protein density (<13.2%) were at a higher risk for low muscle mass (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.37-6.72) than those with diets in the highest quartile (≥17.2%). Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8%) were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14-4.83) than those with diets in the highest quartile (≥9.4%). Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023) and vegetable protein density (p = 0.025). Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status. PMID:27322317

  10. The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan

    PubMed Central

    Huang, Ru-Yi; Yang, Kuen-Cheh; Chang, Hao-Hsiang; Lee, Long-Teng; Lu, Chia-Wen; Huang, Kuo-Chin

    2016-01-01

    Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance. Our objective was to investigate whether pre-sarcopenia status was associated with lower protein intake. A total of 327 community-dwelling elderly people were recruited for a cross-sectional study. We adopted the multivariate nutrient density model to identify associations between low muscle mass and dietary protein intake. The general linear regression models were applied to estimate skeletal muscle mass index across the quartiles of total protein and vegetable protein density. Participants with diets in the lowest quartile of total protein density (<13.2%) were at a higher risk for low muscle mass (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.37–6.72) than those with diets in the highest quartile (≥17.2%). Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8%) were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14–4.83) than those with diets in the highest quartile (≥9.4%). Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023) and vegetable protein density (p = 0.025). Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status. PMID:27322317

  11. Photolabeling of brain membrane proteins by lysergic acid diethylamide.

    PubMed

    Mahon, A C; Hartig, P R

    1982-04-01

    3H-Lysergic acid diethylamide (3H-LSD) is irreversibly incorporated into bovine caudate membranes during ultraviolet light illumination. The incorporated radioligand apparently forms a covalent bond with a subpopulation of the membrane proteins. Although the photolabeling pattern differs significantly from the Coomassie blue staining pattern on SDS gels, the photolabeling is apparently not specific for LSD binding sites associated with neurotransmitter receptors. 3H-LSD photolabeling can occur during prolonged exposure of membrane samples to room lighting and thus may introduce artifacts into receptor binding assays. PMID:7087658

  12. Photolabeling of brain membrane proteins by lysergic acid diethylamide

    SciTech Connect

    Mahon, A.C.; Hartig, P.R.

    1982-04-05

    /sup 3/H-Lysergic acid diethylamide (/sup 3/H-LSD) is irreversibly incorporated into bovine caudate membranes during ultraviolet light illumination. The incorporated radioligand apparently forms a covalent bond with a sub-population of the membrane proteins. Although the photolabeling pattern differs significantly from the Coomassie blue staining pattern on SDS gels, the photolabeling is apparently not specific for LSD binding sites associated with neurotransmitter receptors. /sup 3/H-LSD photolabeling can occur during prolonged exposure of membrane samples to room lighting and thus may introduce artifacts into receptor binding assays.

  13. Acid-base chemistry of frustrated water at protein interfaces.

    PubMed

    Fernández, Ariel

    2016-01-01

    Water molecules at a protein interface are often frustrated in hydrogen-bonding opportunities due to subnanoscale confinement. As shown, this condition makes them behave as a general base that may titrate side-chain ammonium and guanidinium cations. Frustration-based chemistry is captured by a quantum mechanical treatment of proton transference and shown to remove same-charge uncompensated anticontacts at the interface found in the crystallographic record and in other spectroscopic information on the aqueous interface. Such observations are untenable within classical arguments, as hydronium is a stronger acid than ammonium or guanidinium. Frustration enables a directed Grotthuss mechanism for proton transference stabilizing same-charge anticontacts. PMID:26762189

  14. Non-standard amino acid incorporation into proteins using Escherichia coli cell-free protein synthesis

    NASA Astrophysics Data System (ADS)

    Hong, Seok Hoon; Kwon, Yong-Chan; Jewett, Michael

    2014-06-01

    Incorporating non-standard amino acids (NSAAs) into proteins enables new chemical properties, new structures, and new functions. In recent years, improvements in cell-free protein synthesis (CFPS) systems have opened the way to accurate and efficient incorporation of NSAAs into proteins. The driving force behind this development has been three-fold. First, a technical renaissance has enabled high-yielding (>1 g/L) and long-lasting (>10 h in batch operation) CFPS in systems derived from Escherichia coli. Second, the efficiency of orthogonal translation systems has improved. Third, the open nature of the CFPS platform has brought about an unprecedented level of control and freedom of design. Here, we review recent developments in CFPS platforms designed to precisely incorporate NSAAs. In the coming years, we anticipate that CFPS systems will impact efforts to elucidate structure/function relationships of proteins and to make biomaterials and sequence-defined biopolymers for medical and industrial applications.

  15. DNA binding proteins that alter nucleic acid flexibility

    NASA Astrophysics Data System (ADS)

    McCauley, Micah; Hardwidge, Philip R.; Maher, L. J., III; Williams, Mark C.

    2007-09-01

    Dual - beam optical tweezers experiments subject single molecules of DNA to high forces (~ 300 pN) with 0.1 pN accuracy, probing the energy and specificity of nucleic acid - ligand structures. Stretching phage λ-DNA reveals an increase in the applied force up to a critical force known as the overstretching transition. In this region, base pairing and stacking are disrupted as double stranded DNA (dsDNA) is melted. Proteins that bind to the double strand will tend to stabilize dsDNA, and melting will occur at higher forces. Proteins that bind to single stranded DNA (ssDNA) destabilize melting, provided that the rate of association is comparable to the pulling rate of the experiment. Many proteins, however, exhibit some affinity for both dsDNA and ssDNA. We describe experiments upon DNA + HMGB2 (box A), a nuclear protein that is believed to facilitate transcription. By characterizing changes in the structure of dsDNA with a polymer model of elasticity, we have determined the equilibrium association constant for HMGB2 to be K ds = 0.15 +/- 0.7 10 9 M -1 for dsDNA binding. Analysis of the melting transition reveals an equilibrium association constant for HMGB2 to ssDNA to be K ss = 0.039 +/- 0.019 10 9 M -1 for ssDNA binding.

  16. Salicylic acid interferes with clathrin-mediated endocytic protein trafficking.

    PubMed

    Du, Yunlong; Tejos, Ricardo; Beck, Martina; Himschoot, Ellie; Li, Hongjiang; Robatzek, Silke; Vanneste, Steffen; Friml, Jirí

    2013-05-01

    Removal of cargos from the cell surface via endocytosis is an efficient mechanism to regulate activities of plasma membrane (PM)-resident proteins, such as receptors or transporters. Salicylic acid (SA) is an important plant hormone that is traditionally associated with pathogen defense. Here, we describe an unanticipated effect of SA on subcellular endocytic cycling of proteins. Both exogenous treatments and endogenously enhanced SA levels repressed endocytosis of different PM proteins. The SA effect on endocytosis did not involve transcription or known components of the SA signaling pathway for transcriptional regulation. SA likely targets an endocytic mechanism that involves the coat protein clathrin, because SA interfered with the clathrin incidence at the PM and clathrin-deficient mutants were less sensitive to the impact of SA on the auxin distribution and root bending during the gravitropic response. By contrast, SA did not affect the ligand-induced endocytosis of the flagellin sensing2 (FLS2) receptor during pathogen responses. Our data suggest that the established SA impact on transcription in plant immunity and the nontranscriptional effect of SA on clathrin-mediated endocytosis are independent mechanisms by which SA regulates distinct aspects of plant physiology. PMID:23613581

  17. Dependence of intestinal amino acid uptake on dietary protein or amino acid levels

    SciTech Connect

    Karasov, W.H.; Solberg, D.H.; Diamond, J.M.

    1987-05-01

    To understand how intestinal amino acid (AA) transport is regulated by dietary substrate levels, the authors measured uptake of seven radioactively-labelled AAs and glucose across the jejunal brush-border membrane of mice kept on one of three isocaloric rations differing in nitrogen content. In the high-protein ration, uptake increased by 77-81% for the nonessential, less toxic AAs, proline, and aspartate but only by 32-61% for the more toxic essential AAs tested. In the nitrogen-deficient ration, uptake decreased for the nonessential aspartate and proline but stayed constant or increased for essential AAs and for the nonessential alanine. These patterns imply independent regulation of the intestine's various AA transporters. With decreasing dietary AA (or protein), the imino acid and acidic AA private transporters are repressed, while activities of the basic AA transporter and the neutral AA public transporter decrease to an asymptote or else go through a minimum. These regulatory patterns can be understood as a compromise among conflicting constraints imposed by protein's multiple roles as a source of calories, nitrogen, and essential AAs and by the toxicity of essential AAs at high concentrations.

  18. Ribonucleic Acid Regulation in Permeabilized Cells of Escherichia coli Capable of Ribonucleic Acid and Protein Synthesis1

    PubMed Central

    Atherly, Alan G.

    1974-01-01

    A cell permeabilization procedure is described that reduces viability less than 10% and does not significantly reduce the rates of ribonucleic acid and protein synthesis when appropriately supplemented. Permeabilization abolishes the normal stringent coupling of protein and ribonucleic acid synthesis. PMID:4364330

  19. Topology of RNA-protein nucleobase-amino acid π-π interactions and comparison to analogous DNA-protein π-π contacts.

    PubMed

    Wilson, Katie A; Holland, Devany J; Wetmore, Stacey D

    2016-05-01

    The present work analyzed 120 high-resolution X-ray crystal structures and identified 335 RNA-protein π-interactions (154 nonredundant) between a nucleobase and aromatic (W, H, F, or Y) or acyclic (R, E, or D) π-containing amino acid. Each contact was critically analyzed (including using a visual inspection protocol) to determine the most prevalent composition, structure, and strength of π-interactions at RNA-protein interfaces. These contacts most commonly involve F and U, with U:F interactions comprising one-fifth of the total number of contacts found. Furthermore, the RNA and protein π-systems adopt many different relative orientations, although there is a preference for more parallel (stacked) arrangements. Due to the variation in structure, the strength of the intermolecular forces between the RNA and protein components (as determined from accurate quantum chemical calculations) exhibits a significant range, with most of the contacts providing significant stability to the associated RNA-protein complex (up to -65 kJ mol(-1)). Comparison to the analogous DNA-protein π-interactions emphasizes differences in RNA- and DNA-protein π-interactions at the molecular level, including the greater abundance of RNA contacts and the involvement of different nucleobase/amino acid residues. Overall, our results provide a clearer picture of the molecular basis of nucleic acid-protein binding and underscore the important role of these contacts in biology, including the significant contribution of π-π interactions to the stability of nucleic acid-protein complexes. Nevertheless, more work is still needed in this area in order to further appreciate the properties and roles of RNA nucleobase-amino acid π-interactions in nature. PMID:26979279

  20. Specific high-affinity binding of fatty acids to epidermal cytosolic proteins

    SciTech Connect

    Raza, H.; Chung, W.L.; Mukhtar, H. )

    1991-08-01

    Cytosol from rat, mouse, and human skin or rat epidermis was incubated with (3H)arachidonic acid, (14C)retinoic acid, (14C)oleic acid, (3H)leukotriene A4, (3H)prostaglandin E2 (PGE2) or (3H) 15-hydroxyeicosatetraenoic acid (15-HETE), and protein-bound ligands were separated using Lipidex-1000 at 4C to assess the binding specificity. The binding of oleic acid and arachidonic acid with rat epidermal cytosol was rapid, saturable, and reversible. Binding of oleic acid was competed out with the simultaneous addition of other ligands and found to be in the following order: arachidonic acid greater than oleic acid greater than linoleic acid greater than lauric acid greater than leukotriene A4 greater than 15-HETE = PGE1 greater than PGE2 = PGF2. Scatchard analysis of the binding with arachidonic acid, oleic acid, and retinoic acid revealed high-affinity binding sites with the dissociation constant in the nM range. SDS-PAGE analysis of the oleic acid-bound epidermal cytosolic protein(s) revealed maximum binding at the 14.5 kDa region. The presence of the fatty acid-binding protein in epidermal cytosol and its binding to fatty acids and retinoic acid may be of significance both in the trafficking and the metabolism of fatty acids and retinoids across the skin.

  1. Shedding light on proteins, nucleic acids, cells, humans and fish.

    PubMed

    Setlow, Richard B

    2002-03-01

    I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma. PMID:11906839

  2. Shedding light on proteins, nucleic acids, cells, humans and fish

    NASA Technical Reports Server (NTRS)

    Setlow, Richard B.

    2002-01-01

    I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma.

  3. Are Convergent and Parallel Amino Acid Substitutions in Protein Evolution More Prevalent Than Neutral Expectations?

    PubMed Central

    Zou, Zhengting; Zhang, Jianzhi

    2015-01-01

    Convergent and parallel amino acid substitutions in protein evolution, collectively referred to as molecular convergence here, have small probabilities under neutral evolution. For this reason, molecular convergence is commonly viewed as evidence for similar adaptations of different species. The surge in the number of reports of molecular convergence in the last decade raises the intriguing question of whether molecular convergence occurs substantially more frequently than expected under neutral evolution. We here address this question using all one-to-one orthologous proteins encoded by the genomes of 12 fruit fly species and those encoded by 17 mammals. We found that the expected amount of molecular convergence varies greatly depending on the specific neutral substitution model assumed at each amino acid site and that the observed amount of molecular convergence is explainable by neutral models incorporating site-specific information of acceptable amino acids. Interestingly, the total number of convergent and parallel substitutions between two lineages, relative to the neutral expectation, decreases with the genetic distance between the two lineages, regardless of the model used in computing the neutral expectation. We hypothesize that this trend results from differences in the amino acids acceptable at a given site among different clades of a phylogeny, due to prevalent epistasis, and provide simulation as well as empirical evidence for this hypothesis. Together, our study finds no genomic evidence for higher-than-neutral levels of molecular convergence, but suggests the presence of abundant epistasis that decreases the likelihood of molecular convergence between distantly related lineages. PMID:25862140

  4. Total Acid Value Titration of Hydrotreated Biomass Fast Pyrolysis Oil: Determination of Carboxylic Acids and Phenolics with Multiple End-Point Detection

    SciTech Connect

    Christensen, E.; Alleman, T. L.; McCormick, R. L.

    2013-01-01

    Total acid value titration has long been used to estimate corrosive potential of petroleum crude oil and fuel oil products. The method commonly used for this measurement, ASTM D664, utilizes KOH in isopropanol as the titrant with potentiometric end point determination by pH sensing electrode and Ag/AgCl reference electrode with LiCl electrolyte. A natural application of the D664 method is titration of pyrolysis-derived bio-oil, which is a candidate for refinery upgrading to produce drop in fuels. Determining the total acid value of pyrolysis derived bio-oil has proven challenging and not necessarily amenable to the methodology employed for petroleum products due to the different nature of acids present. We presented an acid value titration for bio-oil products in our previous publication which also utilizes potentiometry using tetrabutylammonium hydroxide in place of KOH as the titrant and tetraethylammonium bromide in place of LiCl as the reference electrolyte to improve the detection of these types of acids. This method was shown to detect numerous end points in samples of bio-oil that were not detected by D664. These end points were attributed to carboxylic acids and phenolics based on the results of HPLC and GC-MS studies. Additional work has led to refinement of the method and it has been established that both carboxylic acids and phenolics can be determined accurately. Use of pH buffer calibration to determine half-neutralization potentials of acids in conjunction with the analysis of model compounds has allowed us to conclude that this titration method is suitable for the determination of total acid value of pyrolysis oil and can be used to differentiate and quantify weak acid species. The measurement of phenolics in bio-oil is subject to a relatively high limit of detection, which may limit the utility of titrimetric methodology for characterizing the acidic potential of pyrolysis oil and products.

  5. Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process.

    PubMed

    Wang, Huijiao; Yuan, Shi; Zhan, Juhong; Wang, Yujue; Yu, Gang; Deng, Shubo; Huang, Jun; Wang, Bin

    2015-09-01

    Electro-peroxone (E-peroxone) is a novel electrocatalytic ozonation process that combines ozonation and electrolysis process to enhance pollutant degradation during water and wastewater treatment. This enhancement has been mainly attributed to several mechanisms that increase O3 transformation to ·OH in the E-peroxone system, e.g., electro-generation of H2O2 from O2 at a carbon-based cathode and its subsequent peroxone reaction with O3 to ·OH, electro-reduction of O3 to ·OH at the cathode, and O3 decomposition to ·OH at high local pH near the cathode. To get more insight how these mechanisms contribute respectively to the enhancement, this study investigated total organic carbon (TOC) elimination from oxalic acid (OA) solutions by the E-peroxone process. Results show that the E-peroxone process significantly increased TOC elimination rate by 10.2-12.5 times compared with the linear addition of the individual rates of corresponding ozonation and electrolysis process. Kinetic analyses reveal that the electrochemically-driven peroxone reaction is the most important mechanism for the enhanced TOC elimination rate, while the other mechanisms contribute minor to the enhancement by a factor of 1.6-2.5. The results indicate that proper selection of electrodes that can effectively produce H2O2 at the cathode is critical to maximize TOC elimination in the E-peroxone process. PMID:25989593

  6. Ileal apical sodium-dependent bile acid transporter protein levels are down-regulated through ubiquitin-dependent protein degradation induced by bile acids.

    PubMed

    Miyata, Masaaki; Yamakawa, Hiroki; Hayashi, Kenjiro; Kuribayashi, Hideaki; Yamazoe, Yasushi; Yoshinari, Kouichi

    2013-08-15

    The ileal apical sodium-dependent bile acid transporter (ASBT or SLC10A2) has a crucial role in intestinal bile acid absorption. We previously reported that enterobacteria-mediated bile acid conversion was involved in the alteration of ileal ASBT expression levels. In the present study, to investigate the hypothesis that ileal ASBT protein levels are post-translationally regulated by enterobacteria-associated bile acids, alteration of ileal ASBT protein levels was analysed in mice 12 h and 24 h after anti-bacterial drug ampicillin (ABPC) treatment (100 mg/kg, single shot) that altered bile acid composition in the intestinal lumen. In ABPC-treated mice, enterobacteria-biotransformed bile acid, taurodeoxycholic acid (TDCA) and cholic acid (CA) levels were decreased, whereas taurocholic acid (TCA) and tauro-β-muricholic acid levels were increased in the intestinal lumen. Ileal ASBT protein levels in brush-border membrane vesicles (BBMVs), but not ileal Asbt mRNA levels, were significantly increased in the ABPC-treated mice, and the extent of ubiquitination of the ileal ASBT protein was reduced in the ABPC-treated mice. Treatment of ABPC-pretreated mice with CA or TDCA, but not TCA, significantly decreased ileal ASBT protein levels and increased the extent of ubiquitination of ileal ASBT protein. Treatment of mice with the lysosome inhibitor, chloroquine, or the proteasome inhibitor, MG132, increased ileal ASBT protein levels in BBMVs. CA-mediated reduction of ASBT protein levels in the ABPC-pretreated mice was attenuated by co-treatment with chloroquine or MG132. These results suggest that ileal ASBT protein is degraded by a ubiquitin-dependent pathway in response to enterobacteria-associated bile acids. PMID:23872411

  7. Mutagenesis Mapping of the Protein-Protein Interaction Underlying FusB-Type Fusidic Acid Resistance

    PubMed Central

    Cox, Georgina; Edwards, Thomas A.

    2013-01-01

    FusB-type proteins represent the predominant mechanism of resistance to fusidic acid in staphylococci and act by binding to and modulating the function of the drug target (elongation factor G [EF-G]). To gain further insight into this antibiotic resistance mechanism, we sought to identify residues important for the interaction of FusB with EF-G and thereby delineate the binding interface within the FusB–EF-G complex. Replacement with alanine of any one of four conserved residues within the C-terminal domain of FusB (F156, K184, Y187, and F208) abrogated the ability of the protein to confer resistance to fusidic acid; the purified mutant proteins also lost the ability to bind S. aureus EF-G in vitro. E. coli EF-G, which is not ordinarily able to bind FusB-type proteins, was rendered competent for binding to FusB following deletion of a 3-residue tract (529SNP531) from domain IV of the protein. This study has identified key regions of both FusB and EF-G that are important for the interaction between the proteins, findings which corroborate our previous in silico prediction for the architecture of the complex formed between the resistance protein and the drug target (G. Cox, G. S. Thompson, H. T. Jenkins, F. Peske, A. Savelsbergh, M. V. Rodnina, W. Wintermeyer, S. W. Homans, T. A. Edwards, and A. J. O'Neill, Proc. Natl. Acad. Sci. U. S. A. 109:2102-2107, 2012). PMID:23836182

  8. Mutagenesis mapping of the protein-protein interaction underlying FusB-type fusidic acid resistance.

    PubMed

    Cox, Georgina; Edwards, Thomas A; O'Neill, Alex J

    2013-10-01

    FusB-type proteins represent the predominant mechanism of resistance to fusidic acid in staphylococci and act by binding to and modulating the function of the drug target (elongation factor G [EF-G]). To gain further insight into this antibiotic resistance mechanism, we sought to identify residues important for the interaction of FusB with EF-G and thereby delineate the binding interface within the FusB-EF-G complex. Replacement with alanine of any one of four conserved residues within the C-terminal domain of FusB (F156, K184, Y187, and F208) abrogated the ability of the protein to confer resistance to fusidic acid; the purified mutant proteins also lost the ability to bind S. aureus EF-G in vitro. E. coli EF-G, which is not ordinarily able to bind FusB-type proteins, was rendered competent for binding to FusB following deletion of a 3-residue tract (529SNP531) from domain IV of the protein. This study has identified key regions of both FusB and EF-G that are important for the interaction between the proteins, findings which corroborate our previous in silico prediction for the architecture of the complex formed between the resistance protein and the drug target (G. Cox, G. S. Thompson, H. T. Jenkins, F. Peske, A. Savelsbergh, M. V. Rodnina, W. Wintermeyer, S. W. Homans, T. A. Edwards, and A. J. O'Neill, Proc. Natl. Acad. Sci. U. S. A. 109:2102-2107, 2012). PMID:23836182

  9. Bile salt recognition by human liver fatty acid binding protein.

    PubMed

    Favretto, Filippo; Santambrogio, Carlo; D'Onofrio, Mariapina; Molinari, Henriette; Grandori, Rita; Assfalg, Michael

    2015-04-01

    Fatty acid binding proteins (FABPs) act as intracellular carriers of lipid molecules, and play a role in global metabolism regulation. Liver FABP (L-FABP) is prominent among FABPs for its wide ligand repertoire, which includes long-chain fatty acids as well as bile acids (BAs). In this work, we performed a detailed molecular- and atomic-level analysis of the interactions established by human L-FABP with nine BAs to understand the binding specificity for this important class of cholesterol-derived metabolites. Protein-ligand complex formation was monitored using heteronuclear NMR, steady-state fluorescence spectroscopy, and mass spectrometry. BAs were found to interact with L-FABP with dissociation constants in the narrow range of 0.6-7 μm; however, the diverse substitution patterns of the sterol nucleus and the presence of side-chain conjugation resulted in complexes endowed with various degrees of conformational heterogeneity. Trihydroxylated BAs formed monomeric complexes in which single ligand molecules occupied similar internal binding sites, based on chemical-shift perturbation data. Analysis of NMR line shapes upon progressive addition of taurocholate indicated that the binding mechanism departed from a simple binary association equilibrium, and instead involved intermediates along the binding path. The co-linear chemical shift behavior observed for L-FABP complexes with cholate derivatives added insight into conformational dynamics in the presence of ligands. The observed spectroscopic features of L-FABP/BA complexes, discussed in relation to ligand chemistry, suggest possible molecular determinants of recognition, with implications regarding intracellular BA transport. Our findings suggest that human L-FABP is a poorly selective, universal BA binder. PMID:25639618

  10. Bile acids influence the growth, oestrogen receptor and oestrogen-regulated proteins of MCF-7 human breast cancer cells.

    PubMed Central

    Baker, P. R.; Wilton, J. C.; Jones, C. E.; Stenzel, D. J.; Watson, N.; Smith, G. J.

    1992-01-01

    The effects of the major human serum bile acid, glycochenodeoxycholic acid (GCDC), as well as unconjugated chenodeoxycholic acid (CDC), on the MCF-7 human breast cancer cell line have been studied in vitro under oestrogen and bile acid deprived culture conditions. GCDC increased the growth of the breast cancer cells over the range 10-300 microM. At concentrations in excess of the bile acid binding capacity of the medium cell growth was prevented. In contrast 10 microM CDC tended to reduce cell growth. Oestrogen (ER) and progesterone (PgR) receptors, pS2 and total cathepsin D were quantified by monoclonal antibody based immunoassays. Ten to 100 microM GCDC and 10 microM CDC down-regulated ER protein and this was accompanied by induction of the oestrogen-regulated proteins PgR, pS2 and possibly cathepsin D, including increased secretion of the latter two proteins into the culture medium. All these changes were quantitatively similar to those observed with 10 nM oestradiol. The bile acid effects on ER and PgR were not due to interference with the assay procedures. Cells incubated with 50 microM GCDC or 10 microM CDC had higher pmolar concentrations of the bile acids than controls. This study suggests that naturally occurring bile acids influence the growth and steroid receptor function of human breast cancer cells. PMID:1562465

  11. Sex Differences in Long Chain Fatty Acid Utilization and Fatty Acid Binding Protein Concentration in Rat Liver

    PubMed Central

    Ockner, Robert K.; Burnett, David A.; Lysenko, Nina; Manning, Joan A.

    1979-01-01

    Female sex and estrogen administration are associated with increased hepatic production of triglyceride-rich lipoproteins; the basis for this has not been fully elucidated. Inasmuch as hepatic lipoprotein production is also influenced by FFA availability and triglyceride biosynthesis, we investigated sex differences in FFA utilization in rat hepatocyte suspensions and in the components of the triglyceride biosynthetic pathway. Isolated adult rat hepatocyte suspensions were incubated with albumin-bound [14C]oleate for up to 15 min. At physiological and low oleate concentrations, cells from females incorporated significantly more 14C into glycerolipids, especially triglycerides, and into oxidation products than did male cells, per milligram cell protein. At 0.44 mM oleate, incorporation into triglycerides in female cells was approximately twice that in male cells. Comparable sex differences were observed in cells from fasted animals and when [14C]-glycerol incorporation was measured. At higher oleate concentrations, i.e., fatty acid:albumin mole ratios in excess of 2:1, these sex differences were no longer demonstrable, suggesting that maximal rates of fatty acid esterification and oxidation were similar in female and male cells. In female and male hepatic microsomes, specific activities of long chain acyl coenzyme A synthetase, phosphatidate phosphohydrolase, and diglyceride acyltransferase were similar, but glycerol-3-phosphate acyltransferase activity was slightly greater in females at certain substrate concentrations. Microsomal incorporation of [14C]oleate into total glycerolipids was not significantly greater in females. In further contrast to intact cells, microsomal incorporation of [14C]oleate into triglycerides, although significantly greater in female microsomes, accounted for only a small fraction of the fatty acid esterified. The binding affinity and stoichiometry of partially purified female hepatic fatty acid binding protein (FABP) were similar to

  12. Prediction of protein-protein interactions with clustered amino acids and weighted sparse representation.

    PubMed

    Huang, Qiaoying; You, Zhuhong; Zhang, Xiaofeng; Zhou, Yong

    2015-01-01

    With the completion of the Human Genome Project, bioscience has entered into the era of the genome and proteome. Therefore, protein-protein interactions (PPIs) research is becoming more and more important. Life activities and the protein-protein interactions are inseparable, such as DNA synthesis, gene transcription activation, protein translation, etc. Though many methods based on biological experiments and machine learning have been proposed, they all spent a long time to learn and obtained an imprecise accuracy. How to efficiently and accurately predict PPIs is still a big challenge. To take up such a challenge, we developed a new predictor by incorporating the reduced amino acid alphabet (RAAA) information into the general form of pseudo-amino acid composition (PseAAC) and with the weighted sparse representation-based classification (WSRC). The remarkable advantages of introducing the reduced amino acid alphabet is being able to avoid the notorious dimensionality disaster or overfitting problem in statistical prediction. Additionally, experiments have proven that our method achieved good performance in both a low- and high-dimensional feature space. Among all of the experiments performed on the PPIs data of Saccharomyces cerevisiae, the best one achieved 90.91% accuracy, 94.17% sensitivity, 87.22% precision and a 83.43% Matthews correlation coefficient (MCC) value. In order to evaluate the prediction ability of our method, extensive experiments are performed to compare with the state-of-the-art technique, support vector machine (SVM). The achieved results show that the proposed approach is very promising for predicting PPIs, and it can be a helpful supplement for PPIs prediction. PMID:25984606

  13. Major phenolic acids and total antioxidant activity in mamaki leaves, Pipturus albidus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three phenolic acids, (+) catechins, chlorogenic acid, and rutin, were identified and quantified in mamaki leaves (Pipturus albidus) using a liquid chromatograph-mass spectrometer technique. Concentrations of (+) catechins, chlorogenic acid, and rutin varied from 1.1 mg to 5.0 mg per gram of mamaki...

  14. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  15. Fatty Acid-Binding Protein 5 Facilitates the Blood-Brain Barrier Transport of Docosahexaenoic Acid.

    PubMed

    Pan, Yijun; Scanlon, Martin J; Owada, Yuji; Yamamoto, Yui; Porter, Christopher J H; Nicolazzo, Joseph A

    2015-12-01

    The brain has a limited ability to synthesize the essential polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) from its omega-3 fatty acid precursors. Therefore, to maintain brain concentrations of this PUFA at physiological levels, plasma-derived DHA must be transported across the blood-brain barrier (BBB). While DHA is able to partition into the luminal membrane of brain endothelial cells, its low aqueous solubility likely limits its cytosolic transfer to the abluminal membrane, necessitating the requirement of an intracellular carrier protein to facilitate trafficking of this PUFA across the BBB. As the intracellular carrier protein fatty acid-binding protein 5 (FABP5) is expressed at the human BBB, the current study assessed the putative role of FABP5 in the brain endothelial cell uptake and BBB transport of DHA in vitro and in vivo, respectively. hFAPB5 was recombinantly expressed and purified from Escherichia coli C41(DE3) cells and the binding affinity of DHA to hFABP5 assessed using isothermal titration calorimetry. The impact of FABP5 siRNA on uptake of (14)C-DHA into immortalized human brain microvascular endothelial (hCMEC/D3) cells was assessed. An in situ transcardiac perfusion method was optimized in C57BL/6 mice and subsequently used to compare the BBB influx rate (Kin) of (14)C-DHA between FABP5-deficient (FABP5(-/-)) and wild-type (FABP5(+/+)) C57BL/6 mice. DHA bound to hFABP5 with an equilibrium dissociation constant of 155 ± 8 nM (mean ± SEM). FABP5 siRNA transfection decreased hCMEC/D3 mRNA and protein expression of FABP5 by 53.2 ± 5.5% and 44.8 ± 13.7%, respectively, which was associated with a 14.1 ± 2.7% reduction in (14)C-DHA cellular uptake. By using optimized conditions for the in situ transcardiac perfusion (a 1 min preperfusion (10 mL/min) followed by perfusion of (14)C-DHA (1 min)), the Kin of (14)C-DHA was 0.04 ± 0.01 mL/g/s. Relative to FABP5(+/+) mice, the Kin of (14)C-DHA decreased 36.7 ± 12.4% in FABP5(-/-) mice

  16. Proteins, dietary acid load, and calcium and risk of postmenopausal fractures in the E3N French women prospective study.

    PubMed

    Dargent-Molina, Patricia; Sabia, Sèverine; Touvier, Mathilde; Kesse, Emmanuelle; Bréart, Gérard; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine

    2008-12-01

    Excess dietary proteins and "acid ash" diets have been suspected to increase the risk of osteoporosis, but experimental and epidemiological evidence is mixed. We aimed to determine whether the association between protein intake and the overall acid-base equilibrium of the diet (as renal net acid excretion [RNAE] estimate) and fracture risk vary according to calcium intake. During an average of 8.37 +/- 1.73 yr of follow-up, 2408 women reported a fracture (excluding high-impact trauma) among 36,217 postmenopausal women from the E3N prospective study. We used Cox regression models to study the interaction between calcium and, respectively, proteins and RNAE, from the 1993 dietary questionnaire for fracture risk determination, adjusting for potential confounders. There was no overall association between fracture risk and total protein or RNAE. However, in the lowest quartile of calcium (<400 mg/1000 kcal), high protein intake was associated with a significant increased fracture risk (RR = 1.51 for highest versus lowest quartile; 95% CI, 1.17-1.94). An increasing fracture risk with increasing animal protein intake was also observed (trend, p < 0.0001). A similar pattern of interaction for fracture risk was observed between RNAE and calcium. In this Western population of postmenopausal women with normal to high protein intake and fairly high calcium intake, there was no overall association between total protein or RNAE and fracture risk. However, there was some evidence that high protein-high acid ash diets were associated with an increased risk of fracture when calcium intake was low (<400 mg/1000 kcal). PMID:18665794

  17. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men

    PubMed Central

    Churchward-Venne, Tyler A; Burd, Nicholas A; Mitchell, Cameron J; West, Daniel W D; Philp, Andrew; Marcotte, George R; Baker, Steven K; Baar, Keith; Phillips, Stuart M

    2012-01-01

    Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P = 0.001). MPS was increased above FAST at 1–3 h post-exercise in both FED (P < 0.001) and EX-FED (P < 0.001) conditions with no treatment effect. At 3–5 h, only WHEY remained significantly elevated above FAST in EX-FED (WHEY 184%vs. LEU 55% and EAA-LEU 35%; P = 0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion. PMID:22451437

  18. Site-specific incorporation of redox active amino acids into proteins

    DOEpatents

    Alfonta, Lital; Schultz, Peter G.; Zhang, Zhiwen

    2011-08-30

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  19. Site-specific incorporation of redox active amino acids into proteins

    DOEpatents

    Alfonta, Lital; Schultz, Peter G.; Zhang, Zhiwen

    2009-02-24

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  20. Site-specific incorporation of redox active amino acids into proteins

    DOEpatents

    Alfonta, Lital; Schultz, Peter G.; Zhang, Zhiwen

    2012-02-14

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  1. Site-specific incorporation of redox active amino acids into proteins

    DOEpatents

    Alfonta; Lital , Schultz; Peter G. , Zhang; Zhiwen

    2010-10-12

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  2. The role of total fats, saturated/unsaturated fatty acids and cholesterol content in chicken meat as cardiovascular risk factors

    PubMed Central

    2014-01-01

    Background The objective of the study was to present information about the chemical composition, the fatty acids profile, and cholesterol content of chicken meat in order to investigate the impact of chicken meat consumption on cardiovascular risk in the general population. Methods A total of 48 6-wk-old broiler chickens broilers from two farms in June to November of 2012, and February of 2013, were used in this trial. Total lipid content was determined by extraction of fat by petrol ether (Soxhlet) after acid hydrolysis of samples. Fatty acids were determined by capillary gas chromatography. Cholesterol determination was performed by using HPLC/PDA system. Results The results indicate that the total free cholesterol content in raw breast and drumstick of chickens was in the range of 37,41–79,9 mg/100 g and 48,35-99,5 mg/100 g, respectively. The main fatty acids identified in all cuts were C18:1c9, C18:2n6, C16:0, C18:0, and C16:1. Decreasing the dietary n-6/n-3 clearly decreased the content in breast and drumstick muscle of C18:2n6, C18:3n3, and C20: 3n6, but increased that of C16:0, C18:0, and C20:2. Also, the major saturated fatty acid (SFA) (C16:0 and C18:0) was significantly differ among the four treatments. Conclusion Our study shows that dietary fat and fatty acid composition influence the concentrations of total cholesterol content, total fat content, and fatty acid composition in broiler muscle. This information will aid in determining the burden of chicken meat as a cardiovascular risk factors disease and act as a planning tool for public-health Programmes. PMID:24588940

  3. Determination of total mercury in seafood and other protein-rich products

    SciTech Connect

    Landi, S.; Fagioli, F.; Locatelli, C.

    1992-11-01

    A previously developed wet-digestion method for the determination of total mercury in plants by cold vapor atomic absorption spectroscopy (CVAAS) was extended to the analysis of seafood and other products rich in proteins. Oxidation of matrixes is accomplished by K{sub 2}Cr{sub 2}O{sub 7} in the presence of diluted H{sub 2}SO{sub 4}; a simple air condenser is used to reflux vapors released from the boiling mixture. The original procedure (A) and 2 modifications (B and C), which differ with respect to the mode of acidification and/or digestion time and the types of condensers used, were compared for precision and accuracy by means of National Institute of Standards and Technology Research Material 50 Albacore Tuna and proved to be reliable (Hg present, 0.95{plus_minus}0.1 {mu}g/g; Hg found, 0.97 {plus_minus} 0.029 {mu}g/g [A], 0.98 {plus_minus} 0.018 {mu}g/g [B], and 0.94 {plus_minus} 0.025 {mu}g/g [C]). The modified procedures were tested further in Hg recovery experiments on a variety of biological matrixes with different spiking substances and again showed good analytical characteristics (overall average recoveries = 98 {plus_minus} 5.1% for seafood and 100 {plus_minus} 3.6 for protein-rich baby foods). 22 refs., 1 fig., 5 tabs.

  4. Physicochemical and sensory characteristics of whey protein hydrolysates generated at different total solids levels.

    PubMed

    Spellman, David; O'Cuinn, Gerard; FitzGerald, Richard J

    2005-05-01

    Whey protein hydrolysates were generated at different total solids (TS) levels (50-300 g/l) using the commercially available proteolytic preparation Debitrase HYW20, while enzyme to substrate ratio, pH and temperature were maintained constant. Hydrolysis proceeded at a faster rate at lower TS reaching a degree of hydrolysis (DH) of 16.6% at 300 g TS/l, compared with a DH of 22.7% at 50 g TS/l after 6 h hydrolysis. The slower breakdown of intact whey proteins at high TS was quantified by gel-permeation HPLC. Reversed-phase (RP) HPLC of hydrolysate samples of equivalent DH (approximately 15%) generated at different TS levels indicated that certain hydrophobic peptide peaks were present at higher levels in hydrolysates generated at low TS. Sensory evaluation showed that hydrolysates with equivalent DH values were significantly (P < 0.0005) less bitter when generated at 300 g TS/l (mean bitterness score = 25.4%) than hydrolysates generated at 50 g TS/l (mean bitterness score = 39.9%). A specific hydrophobic peptide peak present at higher concentrations in hydrolysates generated at low TS was isolated and identified as beta-lactoglobulin f(43-57), a fragment having the physical and chemical characteristics of a bitter peptide. PMID:15909678

  5. Use of Dimedone-Based Chemical Probes for Sulfenic Acid Detection: Methods to Visualize and Identify Labeled Proteins

    PubMed Central

    Nelson, Kimberly J.; Klomsiri, Chananat; Codreanu, Simona G.; Soito, Laura; Liebler, Daniel C.; Rogers, LeAnn C.; Daniel, Larry W.; Poole, Leslie B.

    2013-01-01

    Reversible thiol modification is a major component of the modulation of cell-signaling pathways by reactive oxygen species. Hydrogen peroxide, peroxynitrite, or lipid hydroperoxides are all able to oxidize cysteines to form cysteine sulfenic acids; this reactive intermediate can be directly reduced to thiol by cellular reductants such as thioredoxin or further participate in disulfide bond formation with glutathione or cysteine residues in the same or another protein. To identify the direct protein targets of cysteine modification and the conditions under which they are oxidized, a series of dimedone-based reagents linked to affinity or fluorescent tags have been developed that specifically alkylate and trap cysteine sulfenic acids. In this chapter, we provide detailed methods using one of our biotin-tagged reagents, DCP-Bio1, to identify and monitor proteins that are oxidized in vitro and in vivo. Using streptavidin-linked agarose beads, this biotin-linked reagent can be used to affinity capture labeled proteins. Stringent washing of the beads prior to elution minimizes the contamination of the enriched material with unlabeled proteins through coimmunoprecipitation or nonspecific binding. In particular, we suggest including DTT in one of the washes to remove proteins covalently linked to biotinylated proteins through a disulfide bond, except in cases where these linked proteins are of interest. We also provide methods for targeted approaches monitoring cysteine oxidation in individual proteins, global approaches to follow total cysteine oxidation in the cell, and guidelines for proteomic analyses to identify novel proteins with redox sensitive cysteines. PMID:20513473

  6. Abundant class III acidic chitinase homologue in tamarind (Tamarindus indica) seed serves as the major storage protein.

    PubMed

    Rao, Devavratha H; Gowda, Lalitha R

    2008-03-26

    The phyla Leguminosae contains protease inhibitors, lectins, chitinases, and glycohydrolases as major defense proteins in their seeds. Electrophoretic analysis of the seed proteins of tamarind ( Tamarindus indica L.), an agri-waste material, indicated the unusual presence of two major proteins comparable to overexpression of recombinant proteins. These proteins were identified by amino-terminal analysis to be (1) Kunitz-type trypsin inhibitor and (2) class III endochitinase (34000 Da). These two proteins were purified to apparent homogeneity by a single-step chitin bead affinity chromatography and characterized. The Kunitz inhibitor was specific toward inhibiting trypsin with a stoichiometry of 1:1. The 33000 +/- 1000 Da protein, accounting for >50% of the total seed protein, is an acidic glycoprotein exhibiting a very low endotype hydrolytic activity toward chitin derivatives. SDS-PAGE followed by densitometry of tamarind seed germination indicates the disappearance of the chitinase with the concomitant appearance of a cysteine endopeptidase. On the basis of its abundance, accumulation without any pathogenesis-related stimulus, temporal regulation, amino acid composition, and very low enzyme activity, this 34000 Da protein designated "tamarinin" physiologically serves as the major storage protein. PMID:18298067

  7. Ileal and total tract nutrient digestibilities and fecal characteristics of dogs as affected by soybean protein inclusion in dry, extruded diets.

    PubMed

    Clapper, G M; Grieshop, C M; Merchen, N R; Russett, J C; Brent, J L; Fahey, G C

    2001-06-01

    Plant-based protein sources are generally less variable in chemical composition than animal-based protein sources. However, relatively few data are available on the nutrient digestibilities of plant-based protein sources by companion animals. The effects of including selected soybean protein sources in dog diets on nutrient digestion at the ileum and in the total tract, as well as on fecal characteristics, were evaluated. Six protein sources were used: soybean meal (SBM), Soyafluff 200W (soy flour), Profine F (traditional aqueous-alcohol extracted soy protein concentrate [SPC 1]), Profine E (extruded SPC [SPC 2]), Soyarich I (modified molecular weight SPC [SPC 3]), and poultry meal (PM). All diets were extruded and kibbled. Test ingredients varied in CP and fat contents; however, diets were formulated to be isonitrogenous and isocaloric. Nutrient intakes were similar, except for total dietary fiber (TDF), which was lower (P < 0.01) for dogs fed the PM diet. Apparent ileal digestibilities of DM, OM, fat, and TDF were not different among treatments; however, CP digestibility at the terminal ileum was higher (P < 0.01) for diets containing soy protein sources than for PM. Total tract CP digestibility was greater (P < 0.01) for soy protein-containing diets than for PM. Apparent total tract digestibilities of DM, OM, fat, and TDF were not different among treatments. Apparent amino acid digestibilities at the terminal ileum, excluding methionine, threonine, alanine, and glycine, were higher (P < 0.01) for soy protein-containing diets than for PM. Dogs fed SPC diets had lower (P < 0.01) fecal outputs (g asis feces/g DMI) than dogs fed the SF diet, and dogs fed SBM tended (P < 0.11) to have lower fecal outputs than dogs fed the SF diet. However, dogs fed the PM diet had lower (P < 0.03) fecal outputs than dogs fed SPC-containing diets. Fecal outputs and scores reflected the TDF and nonstructural carbohydrate contents of the soy protein fraction. Soy protein sources are

  8. [Dynamics of fatty acid composition of total lipids during embryonic development of Atlantic salmon Salmo salar L].

    PubMed

    Murzina, S A; Nefedova, Z A; Ripatti, P O; Nemova, N N; Markova, L V

    2012-01-01

    Dynamics of fatty acid composition of total lipids was studied for freshwater salmon Salmo salar L. during its embryonic development from blastula (3 hours) up to hatching (108 days) as well as in unfertilized eggs. Stable amount of total and some saturated, monounsaturated and polyunsaturated fatty acids (PUFA) of total lipids was observed during embryonic development. Considerable changes in fatty acid composition were observed at the stage of prelarvae hatching, i.e., significant decrease of (n-6) PUFA (18:2(n-6) and 20:4(n-6)) and (n-3) PUFA and increase of total and some saturated and monounsaturated fatty acids was registered. Change in saturation ratio of membrane lipids justifies the presence of the biochemical mechanism forwarded on regulation of cell membrane enzymes in accordance with the changes of internal physiological processes taking place in the organism and fluctuations of external environmental conditions or the preparation period (as reproduction). Data on peculiarities of transformation and utilization of fatty acids during salmon embryonic development may be used for understanding of their functional role in the developing organism as well as for assessing the quality of the caviar. PMID:22650081

  9. An attenuated total reflectance IR study of silicic acid adsorbed onto a ferric oxyhydroxide surface

    NASA Astrophysics Data System (ADS)

    Swedlund, Peter J.; Miskelly, Gordon M.; McQuillan, A. James

    2009-07-01

    Silicic acid (H 4SiO 4) can have significant effects on the properties of iron oxide surfaces in both natural and engineered aquatic systems. Understanding the reactions of H 4SiO 4 on these surfaces is therefore necessary to describe the aquatic chemistry of iron oxides and the elements that associate with them. This investigation uses attenuated total reflectance infrared spectroscopy (ATR-IR) to study silicic acid in aqueous solution and the products formed when silicic acid adsorbs onto the surface of a ferrihydrite film in 0.01 M NaCl at pH 4. A spectrum of 1.66 mM H 4SiO 4 at pH 4 (0.01 M NaCl) has an asymmetric Si-O stretch at 939 cm -1 and a weak Si-O-H deformation at 1090 cm -1. ATR-IR spectra were measured over time (for up to 7 days) for a ferrihydrite film (≈1 mg) approaching equilibrium with H 4SiO 4 at concentrations between 0.044 and 0.91 mM. Adsorbed H 4SiO 4 had a broad spectral feature between 750 and 1200 cm -1 but the shape of the spectra changed as the amount of H 4SiO 4 adsorbed on the ferrihydrite increased. When the solid phase Si/Fe mole ratio was less than ≈0.01 the ATR-IR spectra had a maximum intensity at 943 cm -1 and the spectral shape suggests that a monomeric silicate species was formed via a bidentate linkage. As the solid phase Si/Fe mole ratio increased to higher values a discrete oligomeric silicate species was formed which had maximum intensity in the ATR-IR spectra at 1001 cm -1. The spectrum of this species suggests that it is larger than a dimer and it was tentatively identified as a cyclic tetramer. A small amount of a polymeric silica phase with a broad spectral feature centered at ≈1110 cm -1 was also observed at high surface coverage. The surface composition was estimated from the relative contribution of each species to the area of the ATR-IR spectra using multivariate curve resolution with alternating least squares. For a ferrihydrite film approaching equilibrium with 0.044, 0.14, 0.40 and 0.91 mM H 4SiO 4 the

  10. Suitability of methylmalonic acid and total homocysteine analysis in dried bloodspots.

    PubMed

    de Sain-van der Velden, Monique G M; van der Ham, Maria; Jans, Judith J; Visser, Gepke; van Hasselt, Peter M; Prinsen, Hubertus C M T; Verhoeven-Duif, Nanda M

    2015-01-01

    Methylmalonic acid (MMA) and total homocysteine (tHCYS) concentrations are used to detect acquired and inborn errors of cobalamin (vitamin B12, Cbl) metabolism and to evaluate the effect of therapeutic interventions. Dried blood spot sampling offers a patient-friendly and easy alternative to plasma sampling. However, dried blood spot concentrations are not necessarily equal to plasma concentrations. Therefore, the objective of this work was to establish the relationship between MMA and tHYS dried blood spot and plasma concentrations to facilitate clinical implementation of dried blood spot sampling. MMA and tHCYS in both plasma and DBS were validated on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). While position of the punch (in DBS) did affect tHCYS concentration, no influence of hematocrit (Ht) and blood volume on both MMA and tHCYS concentrations was observed. The plasma assay performed better than the DBS assay by most criteria. However, the DBS matrix was superior for tHCYS stability. Paired plasma and DBS samples were obtained from patients suspected for Cbl deficiency and from patients with a known inborn error of metabolism affecting MMA or tHCYS concentration. Based on the strong correlation of tHCYS in both matrices (y=0.46±1.12 (r(2)=0.91)), determination of tHCYS in plasma can be replaced by tHCYS in DBS. However, for MMA, a correlation in the higher (pathological) range of MMA exist, but no correlation was observed in the lower ranges. Therefore the added value of MMA concentrations in DBS is currently unknown and should be further investigated. PMID:25467488

  11. Which Route of Tranexamic Acid Administration is More Effective to Reduce Blood Loss Following Total Knee Arthroplasty?

    PubMed Central

    Keyhani, Sohrab; Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad

    2016-01-01

    Background: The most appropriate route of tranexamic acid administration is controversial. In the current study, we compared the efficacy of intravenous (IV) and topical intra-articular tranexamic acid in reducing blood loss and transfusion rate in patients who underwent primary total knee arthroplasty. Methods: One hundred twenty 120 patients were scheduled to undergo primary total knee arthroplasty. Patients were randomly allocated to three equal groups: IV tranexamic acid (500 mg), topical tranexamic acid (3 g in 100 mL normal saline) and the control. In the topical group, half of the volume was used to irrigate the joint and the other half was injected intra-articularly. The volume of blood loss, hemoglobin (Hb) level at 24 hours postoperative, and rate of transfusion was compared between groups. Results: The blood loss and Hb level were significantly greater and lower in the control group, respectively (P=0.031). Also, the rate of transfusion was significantly greater in the control group (P=0.013). However, IV and topical groups did not differ significantly in terms of measured variables. No patient experienced a thromboembolic event in our study. Conclusion: Tranexamic acid is a useful antifibrinolytic drug to reduce postoperative blood loss, Hb drop, and rate of blood transfusion in patients undergoing total knee arthroplasty. The route of tranexamic acid administration did not affect the efficacy and safety. PMID:26894222

  12. Screening of immunomodulatory activity of total and protein extracts of some Moroccan medicinal plants.

    PubMed

    Daoudi, Abdeljlil; Aarab, Lotfi; Abdel-Sattar, Essam

    2013-04-01

    Herbal and traditional medicines are being widely used in practice in many countries for their benefits of treating different ailments. A large number of plants in Morocco were used in folk medicine to treat immune-related disorders. The objective of this study is to evaluate the immunomodulatory activity of protein extracts (PEs) of 14 Moroccan medicinal plants. This activity was tested on the proliferation of immune cells. The prepared total and PEs of the plant samples were tested using MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assay on the splenocytes with or without stimulation by concanavalin-A (Con-A), a mitogenic agent used as positive control. The results of this study indicated different activity spectra. Three groups of activities were observed. The first group represented by Citrullus colocynthis, Urtica dioica, Elettaria cardamomum, Capparis spinosa and Piper cubeba showed a significant immunosuppressive activity. The second group that showed a significant immunostimulatory activity was represented by Aristolochia longa, Datura stramonium, Marrubium vulgare, Sinapis nigra, Delphynium staphysagria, Lepidium sativum, Ammi visnaga and Tetraclinis articulata. The rest of the plant extracts did not alter the proliferation induced by Con-A. This result was more important for the PE than for the total extract. In conclusion, this study revealed an interesting immunomodulating action of certain PEs, which could explain their traditional use. The results of this study may also have implications in therapeutic treatment of infections, such as prophylactic and adjuvant with cancer chemotherapy. PMID:22301818

  13. Blood count and C-reactive protein evolution in gastric cancer patients with total gastrectomy surgery

    PubMed Central

    CSENDES J., Attila; MUÑOZ Ch., Andrea; BURGOS L., Ana María

    2014-01-01

    Background The complete blood count (CBC) and C-reactive protein (CRP) are useful inflammatory parameters for ruling out acute postoperative inflammatory complications. Aim To determine their changes in gastric cancer patients submitted to total gastrectomy. Methods This is a prospective study, with 36 patients with gastric cancer who were submitted to elective total gastrectomy. On the first, third and fifth postoperative day (POD), blood count and CRP changes were assessed. Patients with postoperative complications were excluded. Results Twenty-one (58%) were men and 15 (42%) women. The mean age was 65 years. The leukocytes peaked on the 1st POD with a mean of 13,826 u/mm³, and decreased to 8,266 u/mm³ by the 5th POD. The bacilliforms peaked on the 1st POD with a maximum value of 1.48%. CRP reached its maximum level on the 3rd POD with a mean of 144.64 mg/l±44.84. Preoperative hematocrit (HCT) was 35% and 33.67% by the 5th POD. Hemoglobin, showed similar values. Conclusions Leukocytes increased during the 1st POD but reached normal values by the 5th POD. CRP peaked on the 3rd POD but did not reach normal values by the 5th POD. PMID:25626929

  14. Okadaic acid mimics multiple changes in early protein phosphorylation and gene expression induced by tumor necrosis factor or interleukin-1.

    PubMed

    Guy, G R; Cao, X; Chua, S P; Tan, Y H

    1992-01-25

    Okadaic acid, a phosphatase inhibitor from a marine organism, mimics tumor necrosis factor/interleukin-1 (TNF/IL-1) in inducing changes in early cellular protein phosphorylation. A total of approximately 116 proteins exhibit significant and concordant changes in phosphorylation or dephosphorylation within 15 min in human fibroblasts activated by either okadaic acid, TNF, or IL-1. The fidelity of this mimicry by okadaic acid extends to the phosphorylation of the 27 hsp complex, stathmin, eIF-4E, myosin light chain, nucleolin, epidermal growth factor receptor, and other cdc2-kinase substrates (c-abl, RB, and p53). The okadaic acid-induced pattern of protein phosphorylation is distinct from that observed in cells treated with phorbol 12-myristate 13-acetate or with ligands like epidermal growth factor, cyclic AMP agonists, bradykinin, or interferons. Like TNF, okadaic acid also induces the transcription of immediate early response genes like c-jun and Egr-1 as well as the interleukin-6 genes. The overall early effects of okadaic acid uniquely parallel those of TNF/IL-1 and not those of other cytokines or ligands. Regulation of protein phosphatase inhibition is discussed as a mechanism for TNF/IL-1 signal transduction. PMID:1370482

  15. Decarboxylation of malonyl-(acyl carrier protein) by 3-oxoacyl-(acyl carrier protein) synthases in plant fatty acid biosynthesis.

    PubMed Central

    Winter, E; Brummel, M; Schuch, R; Spener, F

    1997-01-01

    In order to identify regulatory steps in fatty acid biosynthesis, the influence of intermediate 3-oxoacyl-(acyl carrier proteins) (3-oxoacyl-ACPs) and end-product acyl-ACPs of the fatty acid synthase reaction on the condensation reaction was investigated in vitro, using total fatty acid synthase preparations and purified 3-oxoacyl-ACP synthases (KASs; EC 2.3.1.41) from Cuphea lanceolata seeds. KAS I and II in the fatty acid synthase preparations were assayed for the elongation of octanoyl- and hexadecanoyl-ACP respectively, and the accumulation of the corresponding condensation product 3-oxoacyl-ACP was studied by modulating the content of the reducing equivalentS NADH and NADPH. Complete omission of reducing equivalents resulted with either KAS in the abnormal synthesis of acetyl-ACP from malonyl-ACP by a decarboxylation reaction. Supplementation with NADPH or NADH, separately or in combination with recombinant 3-oxoacyl-ACP reductase (EC 1.1.1.100), led to a decrease in the amount of acetyl-ACP and a simultaneous increase in elongation products. This demonstrates that the accumulation of 3-oxoacyl-ACP inhibits the condensation reaction on the one hand, and induces the decarboxylation of malonyl-ACP on the other. By carrying out similar experiments with purified enzymes, this decarboxylation was attributed to the action of KAS. Our data point to a regulatory mechanism for the degradation of malonyl-ACP in plants which is activated by the accumulation of the fatty acid synthase intermediate 3-oxoacyl-ACP. PMID:9020860

  16. Conditions optimising on the yield of biomass, total lipid, and valuable fatty acids in two strains of Skeletonema menzelii.

    PubMed

    Jiang, Xiamin; Han, Qingxi; Gao, Xiuzhi; Gao, Guang

    2016-03-01

    Polyunsaturated fatty acids (PUFA) and eicosapentaenoic acid (EPA) are essential for the health of aquaculture organisms and human beings. A total of 9 species of diatoms were screened and two strains of Skeletonema menzelii were selected for further study due to their high growth rates, PUFA and EPA contents. The culture conditions for the yield of biomass, total lipid, EPA and PUFA were optimised. The quickest growth rates (0.28-0.41d(-1)) were achieved with moderate supplement of nitrogen, phosphorus, iron and silicon. The accumulation of total lipid (17.85-22.70% of dry weight) benefitted from deprivation of nitrogen, phosphorus and silicon, but a moderate iron supplement. Highest PUFA (38.26-50.48% of total fatty acids) or EPA (14.26-18.39% of total fatty acids) contents were observed under high nitrogen and phosphorus supplement, moderate available iron but deprivation of silicon. These findings make tangible contributions to culture S. menzelii for commercial production of PUFA or EPA. PMID:26471612

  17. Bile acids and pH values in total feces and in fecal water from habitually omnivorous and vegetarian subjects.

    PubMed

    van Faassen, A; Hazen, M J; van den Brandt, P A; van den Bogaard, A E; Hermus, R J; Janknegt, R A

    1993-12-01

    Twenty habitually omnivorous subjects and 19 habitually lactoovovegetarian subjects aged 59-65 y collected feces during 4 consecutive days. The concentrations of bile acids in total feces did not differ between the omnivores and vegetarians, but the bile acid concentrations in fecal water were significantly lower in the vegetarians. The concentration of the colorectal cancer-predicting bile acid deoxycholic acid in fecal water was explained by the intake of saturated fat and the daily fecal wet weight (r2 = 0.50). Fecal pH did not differ between the omnivores and vegetarians. This variable was significantly (P < 0.05) explained by the intake of calcium (r2 = 0.30); 24-h fecal wet weight and defecation frequency were significantly higher in the vegetarians. In conclusion, our vegetarian subjects had a lower concentration of deoxycholic acid in fecal water, higher fecal wet weight, and higher defecation frequency than the omnivorous subjects. PMID:8249879

  18. Effects of one-seed juniper on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the effect of feeding one-seed juniper on total intake, VFA profile, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and a basal diet with no protein supplement (Control; 5% CP) or rumen degradable (SBM; RDP 15% CP) or undegradable (FM; RUP 15% CP) protein supplement. Aft...

  19. A fast liquid chromatographic tandem mass spectrometric method for the simultaneous determination of total homocysteine and methylmalonic acid.

    PubMed

    Hempen, Christel; Wanschers, Harry; van der Sluijs Veer, Gertjan

    2008-05-01

    A liquid chromatography(LC)/electrospray ionization tandem mass spectrometry (MS) method for the quantitative determination of total homocysteine and methylmalonic acid and the monitoring of methionine, homocystine and succinic acid in plasma has been developed. The analytes are determined under the presence of the deuterated internal standards methylmalonic acid-d (3) and homocystine-d (8). Although methylmalonic acid can be determined directly, a reduction step has to be carried out to ensure the measurement of total homocysteine. Ultrafiltration was applied afterwards to deproteinize the samples prior to LC/MS injection. LC/MS analysis is carried out isocratically using a mobile phase consisting of 5% methanol and 95% of a 0.06 M formic acid solution on a reversed-phase C18 column at a flow rate of 0.5 mL/min. The MS measurement was separated into several periods: homocysteine, homocystine and methionine were determined in the positive-ion mode, whereas the determinations of methylmalonic acid and succinic acid were carried out in the negative-ion mode. The intraday coefficients of variation (CVs) were 2.9% or less and 3.2% or less for homocysteine and methylmalonic acid, respectively. Interday CVs ranged from 3.8 to 5.9% for homocysteine and from 3.5 to 6.3% for methylmalonic acid. Analyte concentrations could reliably be determined, also far below the reference values. Furthermore, the linearity was determined and a correlation study with respect to the existing homocysteine and methylmalonic acid methods at Medisch Spectrum Twente Hospital was carried out. PMID:18368393

  20. Human odontoblasts express transient receptor protein and acid-sensing ion channel mechanosensor proteins.

    PubMed

    Solé-Magdalena, Antonio; Revuelta, Enrique G; Menénez-Díaz, Ivan; Calavia, Marta G; Cobo, Teresa; García-Suárez, Olivia; Pérez-Piñera, Pablo; De Carlos, Felix; Cobo, Juan; Vega, Jose A

    2011-05-01

    Diverse proteins of the denegerin/epithelial sodium channel (DEG/ENa(+) C) superfamily, in particular those belonging to the acid-sensing ion channel (ASIC) family, as well as some members of the transient receptor protein (TRP) channel, function as mechanosensors or may be required for mechanosensation in a diverse range of species and cell types. Therefore, we investigated the putative mechanosensitive function of human odontoblasts using immunohistochemistry to detect ENa(+) C subunits (α, β, and γ) and ASIC (1, 2, 3, and 4) proteins, as well as TRPV4, in these cells. Positive and specific immunoreactivity in the odontoblast soma and/or processes was detected for all proteins studied except α-ENa(+) C. The intensity of immunostaining was high for β-ENa(+) C and ASIC2, whereas it was low for ASIC1, ASIC3, γ-ENa(+) C, and TRPV4, being absent for α-ENa(+) C and ASIC4. These results suggest that human odontoblasts in situ express proteins related to mechanosensitive channels that probably participate in the mechanisms involved in teeth sensory transmission. PMID:20836083

  1. DBBP: database of binding pairs in protein-nucleic acid interactions

    PubMed Central

    2014-01-01

    Background Interaction of proteins with other molecules plays an important role in many biological activities. As many structures of protein-DNA complexes and protein-RNA complexes have been determined in the past years, several databases have been constructed to provide structure data of the complexes. However, the information on the binding sites between proteins and nucleic acids is not readily available from the structure data since the data consists mostly of the three-dimensional coordinates of the atoms in the complexes. Results We analyzed the huge amount of structure data for the hydrogen bonding interactions between proteins and nucleic acids and developed a database called DBBP (DataBase of Binding Pairs in protein-nucleic acid interactions, http://bclab.inha.ac.kr/dbbp). DBBP contains 44,955 hydrogen bonds (H-bonds) of protein-DNA interactions and 77,947 H-bonds of protein-RNA interactions. Conclusions Analysis of the huge amount of structure data of protein-nucleic acid complexes is labor-intensive, yet provides useful information for studying protein-nucleic acid interactions. DBBP provides the detailed information of hydrogen-bonding interactions between proteins and nucleic acids at various levels from the atomic level to the residue level. The binding information can be used as a valuable resource for developing a computational method aiming at predicting new binding sites in proteins or nucleic acids. PMID:25474259

  2. Spaceflight effects on adult rat muscle protein, nucleic acids, and amino acids

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Musacchia, X. J.

    1986-01-01

    Exposure to conditions of weightlessness has been associated with decrements in muscle mass and strength. The present studies were undertaken to determine muscle responses at the cellular level. Male Sprague-Dawley rats (360-410 g) were exposed to 7 days of weightlessness during the Spacelab-3 shuttle flight (May 1985). Animals were killed 12 h postflight, and soleus (S), gastrocnemius (G), and extensor digitorum longus (EDL) muscles were excised. Muscle protein, RNA, and DNA were extracted and quantified. Differential muscle atrophy was accompanied by a significant (P less than 0.05) reduction in total protein only in S muscles. There were no significant changes in protein concentration (mg/g) in the muscles examined. In S muscles from flight animals, sarcoplasmic protein accounted for a significantly greater proportion of total protein that in ground controls (37.5 vs. 32.5%). Tissue concentrations (nmol/g) of asparagine-aspartate, glutamine-glutamate, glycine, histidine, and lysine were significantly reduced (from 17 to 63%) in S muscles from flight animals, but only glutamine-glutamate levels were decreased in the G and EDL. Muscle DNA content (microgram) was unchanged in the tissues examined, but S muscle DNA concentration (micrograms/mg) increased 27%. RNA content (micrograms) was significantly (P less than 0.025) reduced in S (-28%) and G(-22%) muscles following spaceflight. These results identify specific alterations in rat skeletal muscle during short term (7-day) exposure to weightlessness and compare favorably with observations previously obtained from ground-based suspension simulations.

  3. Coagulant properties of Moringa oleifera protein preparations: application to humic acid removal.

    PubMed

    Santos, Andréa F S; Paiva, Patrícia M G; Teixeira, José A C; Brito, António G; Coelho, Luana C B B; Nogueira, Regina

    2012-01-01

    This work aimed to characterize the coagulant properties of protein preparations from Moringa oleifera seeds in the removal of humic acids from water. Three distinct preparations were assayed, namely extract (seeds homogenized with 0.15 M NaCl), fraction (extract precipitated with 60% w/v ammonium sulphate) and cMoL (protein purified with guar gel column chromatography). The extract showed the highest coagulant activity in a protein concentration between 1 mg/L and 180 mg/L at pH 7.0. The zeta potential of the extract (-10 mV to -15 mV) was less negative than that of the humic acid (-41 mV to -42 mV) in a pH range between 5.0 and 8.0; thus, the mechanism that might be involved in this coagulation activity is adsorption and neutralization of charges. Reduction of total organic carbon (TOC) and dissolved organic carbon (DOC) was observed in water samples containing 9 mg/L carbon as humic acid when treated with 1 mg/L of the extract. A decrease in colour and in the aromatic content of the treated water was also observed. These results suggested that the extract from M. oleifera seeds in a low concentration (1 mg/L) can be an interesting natural alternative for removing humic acid from water in developing countries. The extract dose determined in the present study does not impart odour or colour to the treated water. PMID:22519089

  4. Chemical cross-linking/mass spectrometry targeting acidic residues in proteins and protein complexes.

    PubMed

    Leitner, Alexander; Joachimiak, Lukasz A; Unverdorben, Pia; Walzthoeni, Thomas; Frydman, Judith; Förster, Friedrich; Aebersold, Ruedi

    2014-07-01

    The study of proteins and protein complexes using chemical cross-linking followed by the MS identification of the cross-linked peptides has found increasingly widespread use in recent years. Thus far, such analyses have used almost exclusively homobifunctional, amine-reactive cross-linking reagents. Here we report the development and application of an orthogonal cross-linking chemistry specific for carboxyl groups. Chemical cross-linking of acidic residues is achieved using homobifunctional dihydrazides as cross-linking reagents and a coupling chemistry at neutral pH that is compatible with the structural integrity of most protein complexes. In addition to cross-links formed through insertion of the dihydrazides with different spacer lengths, zero-length cross-link products are also obtained, thereby providing additional structural information. We demonstrate the application of the reaction and the MS identification of the resulting cross-linked peptides for the chaperonin TRiC/CCT and the 26S proteasome. The results indicate that the targeting of acidic residues for cross-linking provides distance restraints that are complementary and orthogonal to those obtained from lysine cross-linking, thereby expanding the yield of structural information that can be obtained from cross-linking studies and used in hybrid modeling approaches. PMID:24938783

  5. Chemical cross-linking/mass spectrometry targeting acidic residues in proteins and protein complexes

    PubMed Central

    Leitner, Alexander; Joachimiak, Lukasz A.; Unverdorben, Pia; Walzthoeni, Thomas; Frydman, Judith; Förster, Friedrich; Aebersold, Ruedi

    2014-01-01

    The study of proteins and protein complexes using chemical cross-linking followed by the MS identification of the cross-linked peptides has found increasingly widespread use in recent years. Thus far, such analyses have used almost exclusively homobifunctional, amine-reactive cross-linking reagents. Here we report the development and application of an orthogonal cross-linking chemistry specific for carboxyl groups. Chemical cross-linking of acidic residues is achieved using homobifunctional dihydrazides as cross-linking reagents and a coupling chemistry at neutral pH that is compatible with the structural integrity of most protein complexes. In addition to cross-links formed through insertion of the dihydrazides with different spacer lengths, zero-length cross-link products are also obtained, thereby providing additional structural information. We demonstrate the application of the reaction and the MS identification of the resulting cross-linked peptides for the chaperonin TRiC/CCT and the 26S proteasome. The results indicate that the targeting of acidic residues for cross-linking provides distance restraints that are complementary and orthogonal to those obtained from lysine cross-linking, thereby expanding the yield of structural information that can be obtained from cross-linking studies and used in hybrid modeling approaches. PMID:24938783

  6. Quality Control of Gamma Irradiated Dwarf Mallow (Malva neglecta Wallr.) Based on Color, Organic Acids, Total Phenolics and Antioxidant Parameters.

    PubMed

    Pinela, José; Barros, Lillian; Antonio, Amilcar L; Carvalho, Ana Maria; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2016-01-01

    This study addresses the effects of gamma irradiation (1, 5 and 8 kGy) on color, organic acids, total phenolics, total flavonoids, and antioxidant activity of dwarf mallow (Malva neglecta Wallr.). Organic acids were analyzed by ultra fast liquid chromatography (UFLC) coupled to a photodiode array (PDA) detector. Total phenolics and flavonoids were measured by the Folin-Ciocalteu and aluminium chloride colorimetric methods, respectively. The antioxidant activity was evaluated based on the DPPH(•) scavenging activity, reducing power, β-carotene bleaching inhibition and thiobarbituric acid reactive substances (TBARS) formation inhibition. Analyses were performed in the non-irradiated and irradiated plant material, as well as in decoctions obtained from the same samples. The total amounts of organic acids and phenolics recorded in decocted extracts were always higher than those found in the plant material or hydromethanolic extracts, respectively. The DPPH(•) scavenging activity and reducing power were also higher in decocted extracts. The assayed irradiation doses affected differently the organic acids profile. The levels of total phenolics and flavonoids were lower in the hydromethanolic extracts prepared from samples irradiated at 1 kGy (dose that induced color changes) and in decocted extracts prepared from those irradiated at 8 kGy. The last samples also showed a lower antioxidant activity. In turn, irradiation at 5 kGy favored the amounts of total phenolics and flavonoids. Overall, this study contributes to the understanding of the effects of irradiation in indicators of dwarf mallow quality, and highlighted the decoctions for its antioxidant properties. PMID:27070569

  7. Coffee bean arabinogalactans: acidic polymers covalently linked to protein.

    PubMed

    Redgwell, Robert J; Curti, Delphine; Fischer, Monica; Nicolas, Pierre; Fay, Laurent B

    2002-02-11

    The arabinogalactan content of green coffee beans (Coffea arabica var. Yellow Caturra) was released by a combination of chemical extraction and enzymatic hydrolysis of the mannan-cellulose component of the wall. Several arabinogalactan fractions were isolated, purified by gel-permeation and ion-exchange chromatography and characterised by compositional and linkage analysis. The AG fractions contained between 6 and 8% glucuronic acid, and gave a positive test for the beta-glucosyl-Yariv reagent, a stain specific for arabinogalactan-proteins. The protein component accounted for between 0.5 and 2.0% of the AGPs and contained between 7 and 12% hydroxyproline. The AG moieties displayed considerable heterogeneity with regard to their degree of arabinosylation and the extent and composition of their side-chains. They possessed a MW average of 650 kDa which ranged between 150 and 2000 kDa. An investigation of the structural features of the major AG fraction, released following enzymatic hydrolysis of the mannan-cellulose polymers, allowed a partial structure of coffee arabinogalactan to be proposed. PMID:11844494

  8. Small acid soluble proteins for rapid spore identification.

    SciTech Connect

    Branda, Steven S.; Lane, Todd W.; VanderNoot, Victoria A.; Jokerst, Amanda S.

    2006-12-01

    This one year LDRD addressed the problem of rapid characterization of bacterial spores such as those from the genus Bacillus, the group that contains pathogenic spores such as B. anthracis. In this effort we addressed the feasibility of using a proteomics based approach to spore characterization using a subset of conserved spore proteins known as the small acid soluble proteins or SASPs. We proposed developing techniques that built on our previous expertise in microseparations to rapidly characterize or identify spores. An alternative SASP extraction method was developed that was amenable to both the subsequent fluorescent labeling required for laser-induced fluorescence detection and the low ionic strength requirements for isoelectric focusing. For the microseparations, both capillary isoelectric focusing and chip gel electrophoresis were employed. A variety of methods were evaluated to improve the molecular weight resolution for the SASPs, which are in a molecular weight range that is not well resolved by the current methods. Isoelectric focusing was optimized and employed to resolve the SASPs using UV absorbance detection. Proteomic signatures of native wild type Bacillus spores and clones genetically engineered to produce altered SASP patterns were assessed by slab gel electrophoresis, capillary isoelectric focusing with absorbance detection as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection.

  9. Crystal growth of proteins, nucleic acids, and viruses in gels.

    PubMed

    Lorber, Bernard; Sauter, Claude; Théobald-Dietrich, Anne; Moreno, Abel; Schellenberger, Pascale; Robert, Marie-Claire; Capelle, Bernard; Sanglier, Sarah; Potier, Noëlle; Giegé, Richard

    2009-11-01

    Medium-sized single crystals with perfect habits and no defect producing intense and well-resolved diffraction patterns are the dream of every protein crystallographer. Crystals of biological macromolecules possessing these characteristics can be prepared within a medium in which mass transport is restricted to diffusion. Chemical gels (like polysiloxane) and physical gels (such as agarose) provide such an environment and are therefore suitable for the crystallisation of biological macromolecules. Instructions for the preparation of each type of gel are given to urge crystal growers to apply diffusive media for enhancing crystallographic quality of their crystals. Examples of quality enhancement achieved with silica and agarose gels are given. Results obtained with other substances forming gel-like media (such as lipidic phases and cellulose derivatives) are presented. Finally, the use of gels in combination with capillary tubes for counter-diffusion experiments is discussed. Methods and techniques implemented with proteins can also be applied to nucleic acids and nucleoprotein assemblies such as viruses. PMID:20005247

  10. Comparison of Blood Loss between Neutral Drainage with Tranexamic Acid and Negative Pressure Drainage without Tranexamic Acid Following Primary Total Knee Arthroplasty

    PubMed Central

    Lee, Gwang Chul; Lee, Sang Hong; Pak, Chi-Hyoung; Park, Sang Ha; Jung, Sung

    2016-01-01

    Purpose There are many methods to reduce massive bleeding during total knee arthroplasty (TKA). In our study, tranexamic acid and neutral drainage were used to decrease total blood loss. Materials and Methods The study was performed on 97 TKA patients from March 2012 to January 2013. In the study group, tranexamic acid was administered and neutral drainage was applied. The study group had group I (unilateral, n=29) and group III (bilateral, n=17). The control group had group II (unilateral, n=35) and group IV (bilateral, n=16). Results In group I, the drainage volume on the 1st and 2nd postoperative days and the total drainage decreased with statistical significance (p<0.05). Between group III and group IV, group III had less drainage volume. In group III, the drainage volume on the 1st postoperative day and total drainage volume decreased statistically significantly (p<0.05). Between groups I and II, total blood loss showed no statistically significant difference, whereas between groups III and IV, the value was significantly different. Conclusions Intravenous administration of tranexamic acid with neutral drainage for 3 postoperative hours is a recommendable method because it can be helpful in reducing total blood loss in bilateral TKA. PMID:27595072

  11. Latency, duration and dose response relationships of amino acid effects on human muscle protein synthesis.

    PubMed

    Rennie, Michael J; Bohé, Julien; Wolfe, Robert R

    2002-10-01

    The components of the stimulatory effect of food on net deposition of protein are beginning to be identified and separated. One of the most important of these appears to be the effect of amino acids per se in stimulating muscle anabolism. Amino acids appear to have a linear stimulatory effect within the range of normal diurnal plasma concentrations from postabsorptive to postprandial. Within this range, muscle protein synthesis (measured by incorporation of stable isotope tracers of amino acids into biopsied muscle protein) appears to be stimulated approximately twofold; however, little further increase occurs when very high concentrations of amino acids (>2.5 times the normal postabsorptive plasma concentration) are made available. Amino acids provided in surfeit of the ability of the system to synthesize protein are disposed of by oxidation, ureagenesis and gluconeogenesis. The stimulatory effect of amino acids appears to be time dependent; a square wave increase in the availability of amino acids causes muscle protein synthesis to be stimulated and to fall back to basal values, despite continued amino acid availability. The relationship between muscle protein synthesis and insulin availability suggests that most of the stimulatory effects occur at low insulin concentrations, with large increases having no effect. These findings may have implications for our understanding of the body's requirements for protein. The maximal capacity for storage of amino acids as muscle protein probably sets an upper value on the extent to which amino acids can be stored after a single meal. PMID:12368422

  12. Reducing protein adsorption with polymer-grafted hyaluronic acid coatings.

    PubMed

    Ramadan, Mohamed H; Prata, Joseph E; Karácsony, Orsolya; Dunér, Gunnar; Washburn, Newell R

    2014-07-01

    We report a thermoresponsive chemical modification strategy of hyaluronic acid (HA) for coating onto a broad range of biomaterials without relying on chemical functionalization of the surface. Poly(di(ethylene glycol) methyl ether methacrylate) (PMEO2MA), a polymer with a lower critical solution temperature of 26 °C in water, was grafted onto HA to allow facile formation of biopolymer coatings. While the mechanism for film formation appears to involve a complex combination of homogeneous nucleation followed by heterogeneous film growth, we demonstrate that it resulted in hydrophilic coatings that significantly reduce protein adsorption despite the high fraction of hydrophobic (PMEO2MA). Structural characterization was performed using atomic force microscopy (AFM), which showed the formation of a dense, continuous coating based on 200 nm domains that were stable in protein solutions for at least 15 days. The coatings had a water contact angle of 16°, suggesting the formation of hydrophilic but not fully wetting films. Quartz crystal microbalance with dissipation monitoring (QCM-D) as well as biolayer interferometry (BLI) techniques were used to measure adsorption of bovine serum albumin (BSA), fibrinogen (Fbg), and human immunoglobulin (IgG), with results indicating that HA-PMEO2MA-coated surfaces effectively inhibited adsorption of all three serum proteins. These results are consistent with previous studies demonstrating that this degree of hydrophilicity is sufficient to generate an effectively nonfouling surface and suggest that segregation during the solubility transition resulted in a surface that presented the hydrophilic HA component of the hybrid biopolymer. We conclude that PMEO2MA-grafted HA is a versatile platform for the passivation of hydrophobic biomaterial surfaces without need for substrate functionalization. PMID:24892924

  13. ASSESSMENT OF NEUROTOXICITY: USE OF GLIAL FIBRILLARY ACIDIC PROTEIN AS A BIOMARKER

    EPA Science Inventory

    Diverse neurotoxic insults results in proliferation and hypertrophy of astrocytes. he hallmark of this response is enhanced expression of the major intermediate filament protein of astrocytes, glial fibrillary acidic protein (GFAP). hese observations suggest that GFAP may be a us...

  14. Detection of Multiple Autoantibodies in Patients with Ankylosing Spondylitis Using Nucleic Acid Programmable Protein Arrays*

    PubMed Central

    Wright, Cynthia; Sibani, Sahar; Trudgian, David; Fischer, Roman; Kessler, Benedikt; LaBaer, Joshua; Bowness, Paul

    2012-01-01

    Ankylosing spondylitis (AS) is a common, inflammatory rheumatic disease that primarily affects the axial skeleton and is associated with sacroiliitis, uveitis, and enthesitis. Unlike other autoimmune rheumatic diseases, such as rheumatoid arthritis or systemic lupus erythematosus, autoantibodies have not yet been reported to be a feature of AS. We therefore wished to determine whether plasma from patients with AS contained autoantibodies and, if so, characterize and quantify this response in comparison to patients with rheumatoid arthritis (RA) and healthy controls. Two high density nucleic acid programmable protein arrays expressing a total of 3498 proteins were screened with plasma from 25 patients with AS, 17 with RA, and 25 healthy controls. Autoantigens identified were subjected to Ingenuity Pathway Analysis to determine the patterns of signaling cascades or tissue origin. 44% of patients with ankylosing spondylitis demonstrated a broad autoantibody response, as compared with 33% of patients with RA and only 8% of healthy controls. Individuals with AS demonstrated autoantibody responses to shared autoantigens, and 60% of autoantigens identified in the AS cohort were restricted to that group. The autoantibody responses in the AS patients were targeted toward connective, skeletal, and muscular tissue, unlike those of RA patients or healthy controls. Thus, patients with AS show evidence of systemic humoral autoimmunity and multispecific autoantibody production. Nucleic acid programmable protein arrays constitute a powerful tool to study autoimmune diseases. PMID:22311593

  15. Solvent accessible surface area-based hot-spot detection methods for protein-protein and protein-nucleic acid interfaces.

    PubMed

    Munteanu, Cristian R; Pimenta, António C; Fernandez-Lozano, Carlos; Melo, André; Cordeiro, Maria N D S; Moreira, Irina S

    2015-05-26

    Due to the importance of hot-spots (HS) detection and the efficiency of computational methodologies, several HS detecting approaches have been developed. The current paper presents new models to predict HS for protein-protein and protein-nucleic acid interactions with better statistics compared with the ones currently reported in literature. These models are based on solvent accessible surface area (SASA) and genetic conservation features subjected to simple Bayes networks (protein-protein systems) and a more complex multi-objective genetic algorithm-support vector machine algorithms (protein-nucleic acid systems). The best models for these interactions have been implemented in two free Web tools. PMID:25845030

  16. Experimental Evolution of a Green Fluorescent Protein Composed of 19 Unique Amino Acids without Tryptophan

    NASA Astrophysics Data System (ADS)

    Kawahara-Kobayashi, Akio; Hitotsuyanagi, Mitsuhiro; Amikura, Kazuaki; Kiga, Daisuke

    2014-04-01

    At some stage of evolution, genes of organisms may have encoded proteins that were synthesized using fewer than 20 unique amino acids. Similar to evolution of the natural 19-amino-acid proteins GroEL/ES, proteins composed of 19 unique amino acids would have been able to evolve by accumulating beneficial mutations within the 19-amino-acid repertoire encoded in an ancestral genetic code. Because Trp is thought to be the last amino acid included in the canonical 20-amino-acid repertoire, this late stage of protein evolution could be mimicked by experimental evolution of 19-amino-acid proteins without tryptophan (Trp). To further understand the evolution of proteins, we tried to mimic the evolution of a 19-amino-acid protein involving the accumulation of beneficial mutations using directed evolution by random mutagenesis on the whole targeted gene sequence. We created active 19-amino-acid green fluorescent proteins (GFPs) without Trp from a poorly fluorescent 19-amino-acid mutant, S1-W57F, by using directed evolution with two rounds of mutagenesis and selection. The N105I and S205T mutations showed beneficial effects on the S1-W57F mutant. When these two mutations were combined on S1-W57F, we observed an additive effect on the fluorescence intensity. In contrast, these mutations showed no clear improvement individually or in combination on GFPS1, which is the parental GFP mutant composed of 20 amino acids. Our results provide an additional example for the experimental evolution of 19-amino-acid proteins without Trp, and would help understand the mechanisms underlying the evolution of 19-amino-acid proteins. (236 words)

  17. Indirect and direct effects of salinity on the quantity and quality of total amino acids in Ulva ohnoi (Chlorophyta).

    PubMed

    Angell, Alex R; Mata, Leonardo; de Nys, Rocky; Paul, Nicholas A

    2015-06-01

    Salinity can affect the quantity and quality of total amino acids (TAAs) in seaweeds indirectly by altering growth rates and thereby diluting or concentrating the amino acid content of the biomass, or directly by altering the synthesis of specific amino acids and osmolytes. This study attempted to partition the indirect and direct effects of salinity on the quantity and quality of TAAs in the green seaweed Ulva ohnoi by culturing it under a range of salinities without nutrient limitation. Both the quantity and quality of TAAs varied across the salinity treatments. Quantity was most strongly related to the growth rate of the seaweed and was highest in the slowest growing seaweed. In contrast, the quality of TAAs (individual amino acids as a proportion of total content) was most strongly related to salinity for all amino acids, although this varied substantially among individual amino acids. Increases in salinity were positively correlated with the proportion of proline (46% increase), tyrosine (36% increase), and histidine (26% increase), whereas there was a negative correlation with alanine (29% decrease). The proportion of methionine, with strong links to the synthesis of the osmolyte dimethylsulfoniopropionate, did not correlate linearly with salinity and instead was moderately higher at the optimal salinities for growth. These results show that salinity simultaneously affects the quantity and quality of TAAs in seaweed through both indirect and direct mechanisms, with growth rates playing the overarching role in determining the quantity of TAAs. PMID:26986668

  18. Dietary influence on the m. longissimus dorsi fatty acid composition of lambs in relation to protein source.

    PubMed

    Turner, T D; Karlsson, L; Mapiye, C; Rolland, D C; Martinsson, K; Dugan, M E R

    2012-08-01

    Dietary lipid effect, as a consequence of protein supplement, on lamb m. longissimus dorsi fatty acid composition was investigated, with emphasis on biohydrogenation intermediates. Crossbred lambs (White Swedish Landrace × Texel) were fed a barley-based diet without (CON) or with protein supplements including peas (PEA), rapeseed cake (RC) or hempseed cake (HC). The HC diet resulted in the highest muscle 22:6n-3 proportion, with the RC diet being similar (P<0.05). Protein supplement did not affect the c9,t11 conjugated linoleic acid (CLA) proportion, however the HC diet increased some minor CLA isomers, including t10,c12 CLA (P<0.05). The t10-18:1 and total trans-18:1 were lowest for the RC diet (P<0.05), likely relating to rumen conditions and precursor availability. The saturated, monounsaturated and branched-chain fatty acids were largely unaffected by protein supplement. In conclusion, feeding the RC diet lowered the t10-18:1 and total trans-18:1 in meat, and modestly increased 22:6n-3 content. The direction of these changes would be beneficial, making the RC diet the preferred protein supplement; however the magnitude of the changes in the present experiment may not be sufficient to have an impact on human health. PMID:22459498

  19. Hydroxyindole Carboxylic Acid-Based Inhibitors for Receptor-Type Protein Tyrosine Protein Phosphatase Beta

    PubMed Central

    Zeng, Li-Fan; Zhang, Ruo-Yu; Bai, Yunpeng; Wu, Li; Gunawan, Andrea M.

    2014-01-01

    Abstract Aims: Protein tyrosine phosphatases (PTPs) play an important role in regulating a wide range of cellular processes. Understanding the role of PTPs within these processes has been hampered by a lack of potent and selective PTP inhibitors. Generating potent and selective probes for PTPs remains a significant challenge because of the highly conserved and positively charged PTP active site that also harbors a redox-sensitive Cys residue. Results: We describe a facile method that uses an appropriate hydroxyindole carboxylic acid to anchor the inhibitor to the PTP active site and relies on the secondary binding elements introduced through an amide-focused library to enhance binding affinity for the target PTP and to impart selectivity against off-target phosphatases. Here, we disclose a novel series of hydroxyindole carboxylic acid-based inhibitors for receptor-type tyrosine protein phosphatase beta (RPTPβ), a potential target that is implicated in blood vessel development. The representative RPTPβ inhibitor 8b-1 (L87B44) has an IC50 of 0.38 μM and at least 14-fold selectivity for RPTPβ over a large panel of PTPs. Moreover, 8b-1 also exhibits excellent cellular activity and augments growth factor signaling in HEK293, MDA-MB-468, and human umbilical vein endothelial cells. Innovation: The bicyclic salicylic acid pharmacophore-based focused library approach may provide a potential solution to overcome the bioavailability issue that has plagued the PTP drug discovery field for many years. Conclusion: A novel method is described for the development of bioavailable PTP inhibitors that utilizes bicyclic salicylic acid to anchor the inhibitors to the active site and peripheral site interactions to enhance binding affinity and selectivity. Antioxid. Redox Signal. 20, 2130–2140. PMID:24180557

  20. Fatty acid transport protein 1 can compensate for fatty acid transport protein 4 in the developing mouse epidermis.

    PubMed

    Lin, Meei-Hua; Miner, Jeffrey H

    2015-02-01

    Fatty acid transport protein (FATP) 4 is one of a family of six FATPs that facilitate long- and very-long-chain fatty acid uptake. Mice lacking FATP4 are born with tight, thick skin and a defective barrier; they die neonatally because of dehydration and restricted movements. Mutations in SLC27A4, the gene encoding FATP4, cause ichthyosis prematurity syndrome (IPS), characterized by premature birth, respiratory distress, and edematous skin with severe ichthyotic scaling. Symptoms of surviving patients become mild, although atopic manifestations are common. We previously showed that suprabasal keratinocyte expression of a Fatp4 transgene in Fatp4 mutant skin rescues the lethality and ameliorates the skin phenotype. Here we tested the hypothesis that FATP1, the closest FATP4 homolog, can compensate for the lack of FATP4 in our mouse model of IPS, as it might do postnatally in IPS patients. Transgenic expression of FATP1 in suprabasal keratinocytes rescued the phenotype of Fatp4 mutants, and FATP1 sorted to the same intracellular organelles as endogenous FATP4. Thus, FATP1 and FATP4 likely have overlapping substrate specificities, enzymatic activities, and biological functions. These results suggest that increasing expression of FATP1 in suprabasal keratinocytes could normalize the skin of IPS patients and perhaps prevent the atopic manifestations. PMID:25184958

  1. Effect of total hepatectomy and administration of branched-chain amino acids on regional norepinephrine, dopamine, and amino acids in rat brain.

    PubMed Central

    Herlin, P M; James, J H; Nachbauer, C A; Fischer, J E

    1983-01-01

    In rats after total hepatectomy, the effect of infusing glucose alone or combined with branched-chain amino acids on amino acid concentrations in plasma and cerebral cortex and on catecholamine levels in eight different regions of the brain was studied. Infusion of branched-chain amino acids reduced the accumulation of tryptophan, phenylalanine, and tyrosine in plasma, while in cerebral cortex, the concentrations of phenylalanine and tyrosine were normalized and that of tryptophan was reduced greatly. In rats with hepatectomy and glucose infusion alone, norepinephrine levels were decreased in seven of eight brain regions with the exception of striatum, while dopamine was reduced significantly in striatum only. Infusion of branched-chain amino acids resulted in higher norepinephrine in cortex, mesencephalon, and hypothalamus and higher striatal dopamine 18 hours after hepatectomy. Thus, infusing branched-chain amino acids and reducing the accumulation of various neutral amino acids in brain may partially prevent the loss of norepinephrine from brain after total hepatectomy. PMID:6870374

  2. Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality.

    PubMed

    Sarwar Gilani, G; Wu Xiao, Chao; Cockell, Kevin A

    2012-08-01

    Dietary antinutritional factors have been reported to adversely affect the digestibility of protein, bioavailability of amino acids and protein quality of foods. Published data on these negative effects of major dietary antinutritional factors are summarized in this manuscript. Digestibility and the quality of mixed diets in developing countries are considerably lower than of those in developed regions. For example, the digestibility of protein in traditional diets from developing countries such as India, Guatemala and Brazil is considerably lower compared to that of protein in typical North American diets (54-78 versus 88-94 %). Poor digestibility of protein in the diets of developing countries, which are based on less refined cereals and grain legumes as major sources of protein, is due to the presence of less digestible protein fractions, high levels of insoluble fibre, and/or high concentrations of antinutritional factors present endogenously or formed during processing. Examples of naturally occurring antinutritional factors include glucosinolates in mustard and canola protein products, trypsin inhibitors and haemagglutinins in legumes, tannins in legumes and cereals, gossypol in cottonseed protein products, and uricogenic nucleobases in yeast protein products. Heat/alkaline treatments of protein products may yield Maillard reaction compounds, oxidized forms of sulphur amino acids, D-amino acids and lysinoalanine (LAL, an unnatural nephrotoxic amino acid derivative). Among common food and feed protein products, soyabeans are the most concentrated source of trypsin inhibitors. The presence of high levels of dietary trypsin inhibitors from soyabeans, kidney beans or other grain legumes have been reported to cause substantial reductions in protein and amino acid digestibility (up to 50 %) and protein quality (up to 100 %) in rats and/or pigs. Similarly, the presence of high levels of tannins in sorghum and other cereals, fababean and other grain legumes can cause

  3. Prebiotic Synthesis of Hydrophobic and Protein Amino Acids

    PubMed Central

    Ring, David; Wolman, Yecheskel; Friedmann, Nadav; Miller, Stanley L.

    1972-01-01

    The formation of amino acids by the action of electric discharges on a mixture of methane, nitrogen, and water with traces of ammonia was studied in detail. The presence of glycine, alanine, α-amino-n-butyric acid, α-aminoisobutyric acid, valine, norvaline, isovaline, leucine, isoleucine, alloisoleucine, norleucine, proline, aspartic acid, glutamic acid, serine, threonine, allothreonine, α-hydroxy-γ-aminobutyric acid, and α,γ-diaminobutyric acid was confirmed by ion-exchange chromatography and gas chromatography-mass spectrometry. All of the primary α-amino acids found in the Murchison Meteorite have been synthesized by this electric discharge experiment. PMID:4501592

  4. Gene Activation in Eukaryotes: Are Nuclear Acidic Proteins the Cause or the Effect?

    PubMed Central

    Pederson, Thoru

    1974-01-01

    Nuclear acidic proteins have been implicated in the positive control of gene transcription in eukaryotes. This hypothesis was examined in greater detail by analysis of these proteins during experimental gene activation by a technique for fractionating nuclei into chromatin and the ribonucleoprotein particles that contain heterogeneous nuclear RNA. When synthesis of rat-liver heterogeneous nuclear RNA was stimulated by administration of hydrocortisone, there was a parallel increase in the labeling of acidic proteins in ribonucleoprotein particles. However, there was no detectable effect on the labeling of either acidic chromatin proteins or histones. Thus, the nuclear acidic proteins that respond to the hormone are concerned with a post-transcriptional event, namely the assembly and processing of ribonucleoprotein particles that contain heterogeneous RNA, rather than with direct gene activation. Increases in synthesis of “chromatin” acidic proteins during gene activation observed by others may reflect the presence of these ribonucleoprotein particles in crude chromatin preparations. Images PMID:4522777

  5. Protein content and amino acids profile of pseudocereals.

    PubMed

    Mota, Carla; Santos, Mariana; Mauro, Raul; Samman, Norma; Matos, Ana Sofia; Torres, Duarte; Castanheira, Isabel

    2016-02-15

    Quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus) and buckwheat (Fagopyrum esculentum) represent the main protein source in several diets, although these pseudocereals are not currently present in the FCDB nutrient profile information. The aim of this work is to characterise the AA profile of these pseudocereals and compare them with rice. Total protein content revealed to vary from 16.3g/100g (quinoa Salta) to 13.1g/100g (buckwheat) and lower values were found in rice samples (6.7g/100g). For pseudocereals the most abundant essential AA was leucine. Quinoa-Salta evidences the highest leucine content (1013mg/100g) and the minor methionine content (199mg/100g). Buckwheat was the cereal with the highest phenylalanine content (862mg/100g). Rice (Oryza sativa) presents the lowest content for all AA. Results showed pseudocereals as the best source of AA. EuroFIR guidelines where strictly followed and proved to be a crucial tool to guarantee data interchangeability and comparability. PMID:26433287

  6. Dilute oxalic acid pretreatment for high total sugar recovery in pretreatment and subsequent enzymatic hydrolysis.

    PubMed

    Qing, Qing; Huang, Meizi; He, Yucai; Wang, Liqun; Zhang, Yue

    2015-12-01

    Oxalic acid was evaluated as an alternative reagent to mineral inorganic acid in pretreatment of corncob to achieve high xylose yield in addition to highly digestible solid residue. A quadratic polynomial model of xylose formation was developed for optimization of pretreatment process by the response surface methodology based on the impact factors of pretreatment temperature, reaction time, acid concentration, and solid-to-liquid ratio. The highest xylose yield was 94.3 % that was obtained under the pretreatment condition of 140 °C for 40 min with 0.5 wt% oxalic acid at a solid loading of 7.5 %. Under these conditions, the xylose yield results of verification experiments were very close to the model prediction, which indicated that the model was applicable. The solid residue generated under this condition also demonstrated a satisfactory enzymatic digestibility and fermentability. PMID:26494137

  7. Synthesis of alanyl nucleobase amino acids and their incorporation into proteins.

    PubMed

    Talukder, Poulami; Dedkova, Larisa M; Ellington, Andrew D; Yakovchuk, Petro; Lim, Jaebum; Anslyn, Eric V; Hecht, Sidney M

    2016-09-15

    Proteins which bind to nucleic acids and regulate their structure and functions are numerous and exceptionally important. Such proteins employ a variety of strategies for recognition of the relevant structural elements in their nucleic acid substrates, some of which have been shown to involve rather subtle interactions which might have been difficult to design from first principles. In the present study, we have explored the preparation of proteins containing unnatural amino acids having nucleobase side chains. In principle, the introduction of multiple nucleobase amino acids into the nucleic acid binding domain of a protein should enable these modified proteins to interact with their nucleic acid substrates using Watson-Crick and other base pairing interactions. We describe the synthesis of five alanyl nucleobase amino acids protected in a fashion which enabled their attachment to a suppressor tRNA, and their incorporation into each of two proteins with acceptable efficiencies. The nucleobases studied included cytosine, uracil, thymine, adenine and guanine, i.e. the major nucleobase constituents of DNA and RNA. Dihydrofolate reductase was chosen as one model protein to enable direct comparison of the facility of incorporation of the nucleobase amino acids with numerous other unnatural amino acids studied previously. The Klenow fragment of DNA polymerase I was chosen as a representative DNA binding protein whose mode of action has been studied in detail. PMID:27452282

  8. Interference of Cerebrospinal Fluid Total Protein Measurement by Povidone-Iodine Contamination

    PubMed Central

    Gounden, Verena; Sacks, David B; Zhao, Zhen

    2014-01-01

    Background A falsely high cerebrospinal fluid (CSF) total protein (TP) result measured by pyrogallol red (PGR) method was suspected to be caused by preparation of the collection site with povidone-iodine (PVP-iodine) solution. Methods CSF TP was evaluated for interference in samples with different final concentrations of PVP-iodine (up to 0.25% PVP and 0.025% iodine) or iodine alone (up to 0.025% iodine) using three methods: PGR, modified biuret and benzethonium chloride (BZTC). Interference exceeding ±20% of the baseline value is considered clinically significant according the criterion defined by College of American Pathologists. Results There was a positive interference with the PGR method and a negative inference for the BZTC method in CSF samples spiked with PVP-iodine. The PVP-iodine (up to 0.25% PVP and 0.025% iodine) did not cause a clinically significant interference with the modified biuret method. PVP alone without iodine caused a positive interference with the PGR method but did not interfere with the modified biuret or the BZTC method. When the samples were spiked with iodine alone, none of the three methods was affected (change < 20%) by iodine concentration up to 0.025%. Conclusions Contamination of CSF specimens with PVP-iodine can lead to interference with CSF TP measurements using PGR or BZTC methods. PMID:25446880

  9. Changes in IgG and total plasma protein glycomes in acute systemic inflammation

    PubMed Central

    Novokmet, Mislav; Lukić, Edita; Vučković, Frano; –Durić, Željko; Keser, Toma; Rajšl, Katarina; Remondini, Daniel; Castellani, Gastone; Gašparović, Hrvoje; Gornik, Olga; Lauc, Gordan

    2014-01-01

    Recovery after cardiac surgery is a complex process that has to compensate for both individual variability and extensive tissue damage in the context of systemic inflammation. Protein glycosylation is essential in many steps of the inflammatory cascade, but due to technological limitations the role of individual variation in glycosylation in systemic inflammation has not been addressed until now. We analysed composition of the total plasma and IgG N-glycomes in 107 patients undergoing cardiac surgery. In nearly all individuals plasma N-glycome underwent the same pattern of changes in the first 72 h, revealing a general mechanism of glycosylation changes. To the contrary, changes in the IgG glycome were very individualized. Bi-clustering analysis revealed the existence of four distinct patterns of changes. One of them, characterized by a rapid increase in galactosylated glycoforms, was associated with nearly double mortality risk measured by EuroSCORE II. Our results indicate that individual variation in IgG glycosylation changes during acute systemic inflammation associates with increased mortality risk and indicates new avenues for the development of personalized diagnostic and therapeutic approach. PMID:24614541

  10. Identification of Dynamic Changes in Proteins Associated with the Cellular Cytoskeleton after Exposure to Okadaic Acid

    PubMed Central

    Opsahl, Jill A.; Ljostveit, Sonja; Solstad, Therese; Risa, Kristin; Roepstorff, Peter; Fladmark, Kari E.

    2013-01-01

    Exposure of cells to the diarrhetic shellfish poison, okadaic acid, leads to a dramatic reorganization of cytoskeletal architecture and loss of cell-cell contact. When cells are exposed to high concentrations of okadaic acid (100–500 nM), the morphological rearrangement is followed by apoptotic cell death. Okadaic acid inhibits the broad acting Ser/Thr protein phosphatases 1 and 2A, which results in hyperphosphorylation of a large number of proteins. Some of these hyperphosphorylated proteins are most likely key players in the reorganization of the cell morphology induced by okadaic acid. We wanted to identify these phosphoproteins and searched for them in the cellular lipid rafts, which have been found to contain proteins that regulate cytoskeletal dynamics and cell adhesion. By using stable isotope labeling by amino acids in cell culture cells treated with okadaic acid (400 nM) could be combined with control cells before the isolation of lipid rafts. Protein phosphorylation events and translocations induced by okadaic acid were identified by mass spectrometry. Okadaic acid was shown to regulate the phosphorylation status and location of proteins associated with the actin cytoskeleton, microtubules and cell adhesion structures. A large number of these okadaic acid-regulated proteins have previously also been shown to be similarly regulated prior to cell proliferation and migration. Our results suggest that okadaic acid activates general cell signaling pathways that induce breakdown of the cortical actin cytoskeleton and cell detachment. PMID:23708184

  11. Anesthesia with halothane and nitrous oxide alters protein and amino acid metabolism in dogs

    SciTech Connect

    Horber, F.F.; Krayer, S.; Rehder, K.; Haymond, M.W.

    1988-09-01

    General anesthesia in combination with surgery is known to result in negative nitrogen balance. To determine whether general anesthesia without concomitant surgery decreases whole body protein synthesis and/or increases whole body protein breakdown, two groups of dogs were studied: Group 1 (n = 6) in the conscious state and Group 2 (n = 8) during general anesthesia employing halothane (1.5 MAC) in 50% nitrous oxide and oxygen. Changes in protein metabolism were estimated by isotope dilution techniques employing simultaneous infusions of (4,53H)leucine and alpha-(1-14C)-ketoisocaproate (KIC). Total leucine carbon flux was unchanged or slightly increased in the anesthetized animals when compared to the conscious controls, indicating only a slight increase in the rate of proteolysis. However, leucine oxidation was increased (P less than 0.001) by more than 80% in the anesthetized animals when compared with their conscious controls, whereas whole body nonoxidative leucine disappearance, an indicator of whole body protein synthesis, was decreased. The ratio of leucine oxidation to the nonoxidative rate of leucine disappearance, which provides an index of the catabolism of at least one essential amino acid in the postabsorptive state, was more than twofold increased (P less than 0.001) in the anesthetized animals regardless of the tracer employed. These studies suggest that the administration of anesthesia alone, without concomitant surgery, is associated with a decreased rate of whole body protein synthesis and increased leucine oxidation, resulting in increased leucine and protein catabolism, which may be underlying or initiating some of the protein wasting known to occur in patients undergoing surgery.

  12. Amino Acid Flux from Metabolic Network Benefits Protein Translation: the Role of Resource Availability

    PubMed Central

    Hu, Xiao-Pan; Yang, Yi; Ma, Bin-Guang

    2015-01-01

    Protein translation is a central step in gene expression and affected by many factors such as codon usage bias, mRNA folding energy and tRNA abundance. Despite intensive previous studies, how metabolic amino acid supply correlates with protein translation efficiency remains unknown. In this work, we estimated the amino acid flux from metabolic network for each protein in Escherichia coli and Saccharomyces cerevisiae by using Flux Balance Analysis. Integrated with the mRNA expression level, protein abundance and ribosome profiling data, we provided a detailed description of the role of amino acid supply in protein translation. Our results showed that amino acid supply positively correlates with translation efficiency and ribosome density. Moreover, with the rank-based regression model, we found that metabolic amino acid supply facilitates ribosome utilization. Based on the fact that the ribosome density change of well-amino-acid-supplied genes is smaller than poorly-amino-acid-supply genes under amino acid starvation, we reached the conclusion that amino acid supply may buffer ribosome density change against amino acid starvation and benefit maintaining a relatively stable translation environment. Our work provided new insights into the connection between metabolic amino acid supply and protein translation process by revealing a new regulation strategy that is dependent on resource availability. PMID:26056817

  13. BILE ACIDS REGULATE THE ONTOGENIC EXPRESSION OF ILEAL BILE ACID BINDING PROTEIN IN THE RAT VIA THE FARNESOID X RECEPTOR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the rat, an increase in ileal bile acid binding protein (IBABP) expression occurs during the third postnatal week. In vitro studies suggest that bile acids (BAs) increase IBABP transcription by activating the BA receptor, farnesoid X receptor (FXR). Thus, we investigated the role of BAs on the on...

  14. [Effect of proteolysis inhibitors on the incorporation of labelled amino acids into proteins].

    PubMed

    Konikova, A S; Korotkina, R N

    1975-01-01

    Role of peptide bond breaks in the incorporation of amino acids into proteins in a "protein--amino acid" system is investigated. For this purpose the incorporation of labelled amino acids into trypsin under the inhibition of its autolysis by a specific inhibitor from soybean and epsilon-amino-caproic acid is studied. The trypsin inhibitor from soybean is found to suppress considerably the incorporation of 14C-glycine, 14C-lysine and 14C-methionine into crystal trypsin and not to affect the incorporation of labelled amino acids into chomotrypsin, papain and carboxypeptidase. Epsilon-Aminocaproic acid inhibited 14C-glycine incorporation into crystal trypsin by 40% and did not change its incorporation level into serum albumin. The dependency of amino acid incorporation level into trypsin on the activity of autolysis in the "protein--amino acid" system is demonstrated. PMID:1212456

  15. Retinoic acid-binding protein, rhombomeres and the neural crest.

    PubMed

    Maden, M; Hunt, P; Eriksson, U; Kuroiwa, A; Krumlauf, R; Summerbell, D

    1991-01-01

    We have investigated by immunocytochemistry the spatial and temporal distribution of cellular retinoic acid-binding protein (CRABP) in the developing nervous system of the chick embryo in order to answer two specific questions: do neural crest cells contain CRABP and where and when do CRABP-positive neuroblasts first arise in the neural tube? With regard to the neural crest, we have compared CRABP staining with HNK-1 staining (a marker of migrating neural crest) and found that they do indeed co-localise, but cephalic and trunk crest behave slightly differently. In the cephalic region in tissues such as the frontonasal mass and branchial arches, HNK-1 immunoreactivity is intense at early stages, but it disappears as CRABP immunoreactivity appears. Thus the two staining patterns do not overlap, but are complementary. In the trunk, HNK-1 and CRABP stain the same cell populations at the same time, such as those migrating through the anterior halves of the somites. In the neural tube, CRABP-positive neuroblasts first appear in the rhombencephalon just after the neural folds close and then a particular pattern of immunoreactivity appears within the rhombomeres of the hindbrain. Labelled cells are present in the future spinal cord, the posterior rhombencephalon up to rhombomere 6 and in rhombomere 4 thus producing a single stripe pattern. This pattern is dynamic and gradually changes as anterior rhombomeres begin to label. The similarity of this initial pattern to the arrangement of certain homeobox genes in the mouse stimulated us to examine the expression of the chicken Hox-2.9 gene. We show that at stage 15 the pattern of expression of this gene is closely related to that of CRABP. The relationship between retinoic acid, CRABP and homeobox genes is discussed. PMID:1707786

  16. Effects of dietary cottonseed oil and tannin supplements on protein and fatty acid composition of bovine milk.

    PubMed

    Aprianita, Aprianita; Donkor, Osaana N; Moate, Peter J; Williams, S Richard O; Auldist, Martin J; Greenwood, Jae S; Hannah, Murray C; Wales, William J; Vasiljevic, Todor

    2014-05-01

    This experiment was conducted to determine the effects of diets supplemented with cottonseed oil, Acacia mearnsii-condensed tannin extract, and a combination of both on composition of bovine milk. Treatment diets included addition of cottonseed oil (800 g/d; CSO), condensed tannin from Acacia mearnsii (400 g/d; TAN) or a combination of cottonseed oil (800 g/d) and condensed tannin (400 g/d; CPT) with a diet consisting of 6·0 kg dry matter (DM) of concentrates and alfalfa hay ad libitum, which also served as the control diet (CON). Relative to the CON diet, feeding CSO and CPT diets had a minor impact on feed intake and yield of lactose in milk. These diets increased yields of milk and protein in milk. In contrast to the TAN diet, the CSO and CPT diets significantly decreased milk fat concentration and altered milk fatty acid composition by decreasing the proportion of saturated fatty acids but increasing proportions of monounsaturated and polyunsaturated fatty acids. The CPT diet had a similar effect to the CSO diet in modifying fatty acid profile. Overall, reduction in milk fat concentration and changes in milk fatty acid profile were probably due to supplementation of linoleic acid-rich cottonseed oil. The TAN diet had no effect on feed intake, milk yield and milk protein concentration. However, a reduction in the yields of protein and lactose occurred when cows were fed this diet. Supplemented tannin had no significant effect on fat concentration and changes in fatty acid profile in milk. All supplemented diets did not affect protein concentration or composition, nitrogen concentration, or casein to total protein ratio of the resulting milk. PMID:24594257

  17. The amino acid sequence of protein CM-3 from Dendroaspis polylepis polylepis (black mamba) venom.

    PubMed

    Joubert, F J

    1985-01-01

    Protein CM-3 from Dendroaspis polylepis polylepis venom was purified by gel filtration and ion exchange chromatography. It comprises 65 amino acids including eight half-cystines. The complete amino acid sequence of protein CM-3 has been elucidated. The sequence (residues 1-50) resembles that of the N-terminal sequence of the subunits of a synergistic type protein and residues 51-65 that of the C-terminal sequence of an angusticeps type protein. Mixtures of protein CM-3 and angusticeps type proteins showed no apparent synergistic effect, in that their toxicity in combination was no greater than the sum of their individual toxicities. PMID:4029488

  18. Sorption behavior of polyaramides in relation to isolation of nucleic acids and proteins.

    PubMed

    Liaw, Der-Jang; Yagudaeva, Elena; Prostyakova, Anna; Lazov, Michael; Zybin, Dmitry; Ischenko, Anatoly; Zubov, Vitaly; Chang, Cheng-Hung; Huang, Ying-Chi; Kapustin, Dmitry

    2016-09-01

    The effect of chemical composition and morphology of the surface layers of new polyaramide-containing sorbents on the mechanism of selective sorption of nucleic acids and proteins was investigated as compared to the previously studied sorbents modified with fluoropolymers and polyaniline (high-throughput materials providing one-step isolation of DNA from biological mixtures). A series of silica-based sorbents modified with polyaramides having consistently varying structure and containing the set of "key" structural elements (aromatic units and nitrogen atoms in the backbone, fluorinated groups), and various donor and acceptor moieties was prepared. The chemical composition of the polymer coatings was evaluated by X-ray photoelectron spectroscopy. The surface morphology was studied by scanning probe microscopy. The sorption properties were investigated by passing the mixtures containing DNA, RNA and proteins of different nature through the cartridges containing the obtained sorbents. All the investigated materials weakly retain double-stranded DNA but effectively retain RNA and proteins. The sorption capacity of the sorbents depends on the protein nature. The observed sorption behavior was shown to be determined by the chemical structure and not by the morphology of the polymer coating. It was proposed that similarity of the sorption properties of the series of chemically different polymers could be determined by similar total input of different sorption mechanisms. PMID:27341305

  19. Effects of antinutritional factors on protein digestibility and amino acid availability in foods.

    PubMed

    Gilani, G Sarwar; Cockell, Kevin A; Sepehr, Estatira

    2005-01-01

    Digestibility of protein in traditional diets from developing countries such as India, Guatemala, and Brazil is considerably lower compared to that of protein in typical North American diets (54-78 versus 88-94%). The presence of less digestible protein fractions, high levels of insoluble fiber, and high concentrations of antinutritional factors in the diets of developing countries, which are based on less refined cereals and grain legumes as major sources of protein, are responsible for poor digestibility of protein. The effects of the presence of some of the important antinutritional factors on protein and amino digestibilities of food and feed products are reviewed in this chapter. Food and feed products may contain a number of antinutritional factors that may adversely affect protein digestibility and amino acid availability. Antinutritional factors may occur naturally, such as glucosinolates in mustard and rapeseed protein products, trypsin inhibitors and hemagglutinins in legumes, tannins in legumes and cereals, phytates in cereals and oilseeds, and gossypol in cottonseed protein products. Antinutritional factors may also be formed during heat/alkaline processing of protein products, yielding Maillard compounds, oxidized forms of sulfur amino acids, D-amino acids, and lysinoalanine (LAL, an unnatural amino acid derivative). The presence of high levels of dietary trypsin inhibitors from soybeans, kidney beans, or other grain legumes can cause substantial reductions in protein and amino acid digestibilities (up to 50%) in rats and pigs. Similarly, the presence of high levels of tannins in cereals, such as sorghum, and grain legumes, such as fababean (Vicia faba L.), can result in significantly reduced protein and amino acid digestibilities (up to 23%) in rats, poultry, and pigs. Studies involving phytase supplementation of production rations for swine or poultry have provided indirect evidence that normally encountered levels of phytates in cereals and legumes

  20. Quantification of total content of non-esterified fatty acids bound to human serum albumin.

    PubMed

    Pavićević, Ivan D; Jovanović, Vesna B; Takić, Marija M; Aćimović, Jelena M; Penezić, Ana Z; Mandić, Ljuba M

    2016-09-10

    Non-esterified fatty acids bound to the human serum albumin (HSA) contribute to several HSAs properties of special concern in pathologies, for instance to the reactivity of the free HSA-Cys34 thiol group (important antioxidative thiol pool in plasma), and to the affinity for binding of molecules and ions (for example cobalt as a prominent biomarker in heart ischemia). Therefore, the method for determination of FAs bound to HSA was developed. FAs were released from HSA (previously isolated from serum by ammonium sulfate precipitation) using acidic copper(II) sulfate in phosphoric acid, extracted by n-heptane-chloroform (4:1, v/v) mixture, spotted on TL silica-gel and then developed with n-heptane-chloroform-acetic acid (5:3:0.3, v/v/v). Common office flatbed scanner and software solution for densitometric image analysis, developed in R, were used. The linearity of calibration curve in concentration range from 0.1 to 5.0mmol/L stearic acid was achieved. The method was proved to be precise (with RSD of 1.4-4.7%) and accurate. Accuracy was examined by standard addition method (recoveries 97.2-102.5%) and by comparison to results of GC. The method is sample saving, technically less demanding, and cheap, and therefore suitable for determination of FAs/HSA ratio when elevated concentrations of free FAs are reliable diagnostic/risk parameter of pathological states. PMID:27394177

  1. Effect of branched-chain amino acid supplementation during unloading on regulatory components of protein synthesis in atrophied soleus muscles.

    PubMed

    Bajotto, Gustavo; Sato, Yuzo; Kitaura, Yasuyuki; Shimomura, Yoshiharu

    2011-08-01

    Maintenance of skeletal muscle mass depends on the equilibrium between protein synthesis and protein breakdown; diminished functional demand during unloading breaks this balance and leads to muscle atrophy. The current study analyzed time-course alterations in regulatory genes and proteins in the unloaded soleus muscle and the effects of branched-chain amino acid (BCAA) supplementation on muscle atrophy and abundance of molecules that regulate protein turnover. Short-term (6 days) hindlimb suspension of rats resulted in significant losses of myofibrillar proteins, total RNA, and rRNAs and pronounced atrophy of the soleus muscle. Muscle disuse induced upregulation and increases in the abundance of the eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), increases in gene and protein amounts of two ubiquitin ligases (muscle RING-finger protein 1 and muscle atrophy F-box protein), and decreases in the expression of cyclin D1, the ribosomal protein S6 kinase 1, the mammalian target of rapamycin (mTOR), and ERK1/2. BCAA addition to the diet did not prevent muscle atrophy and had no apparent effect on regulators of proteasomal protein degradation. However, BCAA supplementation reduced the loss of myofibrillar proteins and RNA, attenuated the increases in 4E-BP1, and partially preserved cyclin D1, mTOR and ERK1 proteins. These results indicate that BCAA supplementation alone does not oppose protein degradation but partly preserves specific signal transduction proteins that act as regulators of protein synthesis and cell growth in the non-weight-bearing soleus muscle. PMID:21222129

  2. The effect of tranexamic acid on blood coagulation in total hip replacement arthroplasty: rotational thromboelastographic (ROTEM®) analysis.

    PubMed

    Na, H S; Shin, H J; Lee, Y J; Kim, J H; Koo, K H; Do, S H

    2016-01-01

    We evaluated changes in rotational thromboelastometry (ROTEM(®) ) parameters and clinical outcomes in patients undergoing total hip replacement arthroplasty, with concomitant infusions of tranexamic acid and of 6% hydroxyethyl starch 130/0.4. Fifty-five patients were randomly assigned to either the tranexamic acid (n = 29) or the control (n = 26) group. Hydroxyethyl starch was administered in the range of 10-15 ml.kg(-1) during the operation in both groups. In the control group, the clot formation time and maximum clot firmness of APTEM showed significant differences when compared with those of EXTEM at one hour postoperatively, suggestive of fibrinolysis. In the tranexamic acid group, there was no significant difference between each postoperative EXTEM and APTEM parameter. In the tranexamic acid and control group, postoperative blood loss was 308 ml (210-420 [106-745]) and 488 ml (375-620 [170-910], p = 0.002), respectively, and total blood loss was 1168 ml (922-1470 [663-2107]) and 1563 ml (1276-1708 [887-1494], p = 0.003). Haemoglobin concentration was higher in the tranexamic acid group on the second postoperative day (10.5 (9.4-12.1 [7.9-14.0]) vs. 9.6 (8.9-10.5[7.3-16.0]) g.dl(-1) , p = 0.027). In patients undergoing total hip replacement arthroplasty, postoperative fibrinolysis aggravated by hydroxyethyl starch was attenuated by co-administration of 10 mg.kg(-1) tranexamic acid, which may have led to less postoperative blood loss. PMID:26559015

  3. Competition effects in cation binding to humic acid: Conditional affinity spectra for fixed total metal concentration conditions

    NASA Astrophysics Data System (ADS)

    David, Calin; Mongin, Sandrine; Rey-Castro, Carlos; Galceran, Josep; Companys, Encarnació; Garcés, José Luis; Salvador, José; Puy, Jaume; Cecilia, Joan; Lodeiro, Pablo; Mas, Francesc

    2010-09-01

    Information on the Pb and Cd binding to a purified Aldrich humic acid (HA) is obtained from the influence of different fixed total metal concentrations on the acid-base titrations of this ligand. NICA (Non-Ideal Competitive Adsorption) isotherm has been used for a global quantitative description of the binding, which has then been interpreted by plotting the Conditional Affinity Spectra of the H + binding at fixed total metal concentrations (CAScTM). This new physicochemical tool, here introduced, allows the interpretation of binding results in terms of distributions of proton binding energies. A large increase in the acidity of the phenolic sites as the total metal concentration increases, especially in presence of Pb, is revealed from the shift of the CAScTM towards lower affinities. The variance of the CAScTM distribution, which can be used as a direct measure of the heterogeneity, also shows a significant dependence on the total metal concentration. A discussion of the factors that influence the heterogeneity of the HA under the conditions of each experiment is provided, so that the smoothed pattern exhibited by the titration curves can be justified.

  4. 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. PMID:17264222

  5. Experimentally Testing the Hypothesis of a Limited Amino Acid Repertoire in Primitive Proteins

    NASA Astrophysics Data System (ADS)

    Akanuma, S.; Nakajima, Y.; Yokobori, S.; Yamagishi, A.

    2013-11-01

    It has been argued that a fewer amino acids were used in primitive proteins and later the repertoire increased up to 20. To test this hypothesis experimentally, we restricted the amino acid usage of a reconstructed, ancestral protein to reduced sets.

  6. Temporal profile of intestinal tissue expression of intestinal fatty acid-binding protein in a rat model of necrotizing enterocolitis

    PubMed Central

    Simões, Ana Leda Bertoncini; Figueira, Rebeca Lopes; Gonçalves, Frances Lilian Lanhellas; Mitidiero, Luís Felipe Tsuyoshi; Silva, Orlando Castro e; Peiró, José Luis; Sbragia, Lourenço

    2016-01-01

    OBJECTIVES: Necrotizing enterocolitis is a severe multifactorial intestinal disorder that primarily affects preterm newborns, causing 20-40% mortality and morbidity. Intestinal fatty acid-binding protein has been reported to be a biomarker for the detection of intestinal injuries. Our aim was to assess intestinal tissue injury and the molecular expression of intestinal fatty acid-binding protein over time in a necrotizing enterocolitis model. METHODS: A total of 144 Newborn rats were divided into two groups: 1) Control, which received breastfeeding (n=72) and 2) Necrotizing Enterocolitis, which received formula feeding and underwent hypoxia and hypothermia (n=72). A total of six time points of ischemia (2 times a day for 3 days; 12 pups for each time point) were examined. Samples were collected for analysis of body weight, morphological and histological characteristics, intestinal weight, intestinal weight/body weight ratio, injury grade, and intestinal fatty acid-binding protein levels. RESULTS: Body and intestinal weights were lower in the Necrotizing Enterocolitis group than in the Control group (p<0.005 and p<0.0005, respectively). The intestinal weight/body weight ratio was higher in the Necrotizing Enterocolitis group than in the Control group (p<0.005) only at the sixth ischemia time point. The Necrotizing Enterocolitis group displayed higher expression of intestinal fatty acid-binding protein (p<0.0005) and showed greater tissue damage than the Control group. CONCLUSION: Intestinal fatty acid-binding protein was an efficient marker of ischemic injury to the intestine and a good correlation was demonstrated between the time of ischemic injury and the grade of intestinal injury. PMID:27464299

  7. Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination

    DOEpatents

    Xie, Jianming; Wang, Lei; Wu, Ning; Schultz, Peter G.

    2008-07-15

    Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.

  8. Total protein, animal protein, and physical activity in relation to muscle mass in middle-aged and older Americans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance training is recognized as a good strategy for retarding age-related declines in muscle mass and strength. Recent studies have also highlighted the potential value of protein intakes in excess of current recommendations. The roles that leisure-time physical activity and protein quality mig...

  9. Interaction of perfluoroalkyl acids with human liver fatty acid-binding protein.

    PubMed

    Sheng, Nan; Li, Juan; Liu, Hui; Zhang, Aiqian; Dai, Jiayin

    2016-01-01

    Perfluoroalkyl acids (PFAAs) are highly persistent and bioaccumulative, resulting in their broad distribution in humans and the environment. The liver is an important target for PFAAs, but the mechanisms behind PFAAs interaction with hepatocyte proteins remain poorly understood. We characterized the binding of PFAAs to human liver fatty acid-binding protein (hL-FABP) and identified critical structural features in their interaction. The binding interaction of PFAAs with hL-FABP was determined by fluorescence displacement and isothermal titration calorimetry (ITC) assay. Molecular simulation was conducted to define interactions at the binding sites. ITC measurement revealed that PFOA/PFNA displayed a moderate affinity for hL-FABP at a 1:1 molar ratio, a weak binding affinity for PFHxS and no binding for PFHxA. Moreover, the interaction was mainly mediated by electrostatic attraction and hydrogen bonding. Substitution of Asn111 with Asp caused loss of binding affinity to PFAA, indicating its crucial role for the initial PFAA binding to the outer binding site. Substitution of Arg122 with Gly caused only one molecule of PFAA to bind to hL-FABP. Molecular simulation showed that substitution of Arg122 increased the volume of the outer binding pocket, making it impossible to form intensive hydrophobic stacking and hydrogen bonds with PFOA, and highlighting its crucial role in the binding process. The binding affinity of PFAAs increased significantly with their carbon number. Arg122 and Asn111 played a pivotal role in these interactions. Our findings may help understand the distribution pattern, bioaccumulation, elimination, and toxicity of PFAAs in humans. PMID:25370009

  10. Amino Acid and Protein Metabolism in Bermuda Grass During Water Stress 12

    PubMed Central

    Barnett, N. M.; Naylor, A. W.

    1966-01-01

    The ability of Arizona Common and Coastal Bermuda grass [Cynodon dactylon (L.) Pers.] to synthesize amino acids and proteins during water stress was investigated. Amino acids were continually synthesized during the water stress treatments, but protein synthesis was inhibited and protein levels decreased. Water stress induced a 10- to 100-fold accumulation of free proline in shoots and a 2- to 6-fold accumulation of free asparagine, both of which are characteristic responses of water-stressed plants. Valine levels increased, and glutamic acid and alanine levels decreased. 14C labeling experiments showed that free proline turns over more slowly than any other free amino acid during water stress. This proline is readily synthesized and accumulated from glutamic acid. It is suggested that during water stress free proline functions as a storage compound. No significant differences were found in the amino acid and protein metabolism of the 2 varieties of Bermuda grass. PMID:16656387

  11. Total volatile fatty acid concentrations are unreliable estimators of treatment effects on ruminal fermentation in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile fatty acid concentrations ([VFA], mM) have long been used to assess impact of dietary treatments on ruminal fermentation in vivo. However, discrepancies in statistical results between VFA and VFA pool size (VFAmol), possibly related to ruminal digesta liquid amount (LIQ, kg), suggest issues...

  12. The effect of monensin concentration on dry matter intake, ruminal fermentation, short-chain fatty acid absorption, total tract digestibility, and total gastrointestinal barrier function in beef heifers.

    PubMed

    Wood, K M; Pinto, A C J; Millen, D D; Kanafany Guzman, R; Penner, G B

    2016-06-01

    In a 4 × 4 Latin square design (24-d periods), 4 ruminally cannulated Hereford × Angus/Simmental heifers were used to evaluate the effect of increasing levels of monensin concentration on DMI, ruminal fermentation, short-chain fatty acid (SCFA) absorption across the reticulorumen, and total tract barrier function. Heifers were fed a barley-based finishing diet (76% rolled barley grain, 12% barley silage, 8% mineral and vitamin supplement, and 4% canola meal) containing 0, 22, 33 or 48 mg/kg monensin. Urinary recovery of Cr-EDTA was used as an indicator of total tract barrier function (d 18 to 20). Days 20 to 23 were used to evaluate ruminal fermentation and total tract digestibility measurements, and SCFA absorption was measured using the temporarily isolated and washed reticulorumen technique on d 24. Data were analyzed using PROC MIXED of SAS with linear and quadratic contrasts to evaluate the effect of increasing monensin dose. Increasing monensin linearly decreased DMI (10.0, 9.9, 9.3, and 9.1 kg/d for diets containing 0, 22, 33 or 48 mg/kg monensin, respectively; = 0.01) but did not affect the variation in DMI among days. Urinary Cr-EDTA recovery was not ( ≥ 0. 61) affected by increasing dose of monensin, nor was ruminal pH (mean, minimum, maximum, duration less than 5.5, and area under curve; ≥ 0.21). The acetate-to-propionate ratio linearly decreased (1.9, 1.8, 1.4, and 1.3 for diets containing 0, 22, 33 or 48 mg/kg monensin, respectively; = 0.03) with increasing monensin. There was no response ( ≥ 0. 17) for the rate of SCFA absorption with monensin concentration. Total tract ethanol soluble carbohydrate digestibility linearly increased (77.2, 84.7, 88.0, and 94.0% for diets containing 0, 22, 33 or 48 mg/kg monensin, respectively; = 0.003) whereas starch digestibility quadratically responded (93.8, 93.9, 88.0, and 94.0% for diets containing 0, 22, 33 or 48 mg/kg monensin, respectively; < 0.001), where 33 mg/kg inclusion of monensin had a minimal

  13. Snake venom. The amino acid sequence of protein A from Dendroaspis polylepis polylepis (black mamba) venom.

    PubMed

    Joubert, F J; Strydom, D J

    1980-12-01

    Protein A from Dendroaspis polylepis polylepis venom comprises 81 amino acids, including ten half-cystine residues. The complete primary structures of protein A and its variant A' were elucidated. The sequences of proteins A and A', which differ in a single position, show no homology with various neurotoxins and non-neurotoxic proteins and represent a new type of elapid venom protein. PMID:7461607

  14. Expression of cationic amino acid transporters, carcass traits, and performance of growing pigs fed low-protein amino acid-supplemented versus high protein diets.

    PubMed

    Morales, A; Grageola, F; García, H; Araiza, A; Zijlstra, R T; Cervantes, M

    2013-01-01

    Free amino acids (AA) appear to be absorbed faster than protein-bound AA (PB-AA). We conducted an experiment to assess the effect of feeding pigs with a partially free (F-AA) or totally PB-AA diet on expression of selected genes and performance of pigs. The expression of cationic AA transporters b(0,+) and CAT-1 in intestinal mucosa, liver, and longissimus (LM) and semitendinosus (SM) muscles, as well as that of myosin in LM and SM, was analyzed. Twelve pigs (31.7 ± 2.7 kg) were used. The F-AA diet was based on wheat, supplemented with 0.59% L-Lys, 0.33% L-Thr, and 0.10% DL-Met. The PB-AA diet was formulated with wheat-soybean meal. Average daily feed intake was 1.53 kg per pig. The expression of b(0,+) and CAT-1 was analyzed in jejunal and ileal mucosa, liver, LM, and SM; myosin expression was also analyzed in both muscles. Pigs fed the PB-AA diet tended to have higher weight gain and feed efficiency (P < 0.10), and had thinner back fat (P = 0.02). The expression of b(0,+) was higher (P < 0.01) in jejunum but lower (P < 0.01) in the liver of pigs fed the F-AA diet; CAT-1 tended to be lower in liver but higher in LM of PB-AA pigs. Myosin expression was not affected. Intestinal AA absorption was faster in pigs fed the F-AA diet, but AA uptake by the liver seemed to be faster in pigs fed the PB-AA. Performance and expression of AA transporters and myosin suggest that the dietary content of free or protein-bound AA does not affect their availability for protein synthesis in pigs. PMID:24222247

  15. Urea, creatinine, uric acid, and phosphate spaces and their relationship to total body water during chronic hemodialysis

    SciTech Connect

    Ericsson, F.; Odar-Cederloef, I.E.; Eriksson, C.G.; Lindgren, S.; Kjellstrand, C.M.

    1988-07-01

    The authors determined total body water (TBW) with tritium in 11 patients on chronic hemodialysis and compared this space to that estimated by 60% of body weight, and removal spaces of urea, creatinine, uric acid, and phosphate (PO4). The latter spaces were determined by dividing the total amount of substance (measured in total dialysate) by pre- minus post-dialysis concentrations. Body water X 0.6 was more than 10% less than the tritium space, and showed a maximal variation of 10 liters, or 24%. The removal space of urea was 80% of the tritium space, but correlated closely with it. The difference between total body water and urea removal space was variable and dependent on fluid excess (edema) in the patients. Creatinine, uric acid, and phosphate removal spaces were highly variable and not correlated to total body water. The authors suggest that actual measured TBW should be used, rather than estimations using BW X 0.6, for V in K X T/V, where K = clearance, T = duration of dialysis, and V = the removal space of urea. Furthermore, one may need to introduce a correction factor for urea removal space over TBW in the equation to allow better quantification of dialysis in edematous patients and during very fast dialyses.

  16. Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  17. Studies on the high-sulphur proteins of reduced Merino wool. Amino acid sequence of protein SCMKB-IIIB4

    PubMed Central

    Swart, L. S.; Haylett, T.

    1971-01-01

    The complete amino acid sequence of protein SCMKB-IIIB4 is presented. It is closely related to the sequence of protein SCMKB-IIIB3 (Haylett, Swart & Parris, 1971) differing in only four positions. The peptic and thermolysin peptides of protein SCMKB-IIIB4 were analysed by the dansyl–Edman method (Gray, 1967) and by tritium-labelling of C-terminal residues (Matsuo, Fujimoto & Tatsuno, 1966). This protein is the third member of a group of high-sulphur wool proteins with molecular weight of about 11400. It consists of 98 residues and has acetylalanine and carboxymethylcysteine as N- and C-terminal residues respectively. PMID:4942536

  18. Total synthesis and complete structural assignment of gambieric acid A, a large polycyclic ether marine natural product.

    PubMed

    Sasaki, Makoto; Fuwa, Haruhiko

    2014-08-01

    More than thirty years after the discovery of polycyclic ether marine natural products, they continue to receive intense attention from the chemical, biological, and pharmacological communities because of their potent biological activities and highly complex molecular architectures. Gambieric acids are intriguing polycyclic ethers that exhibit potent antifungal activity with minimal toxicity against mammals. Despite the recent advances in the synthesis of this class of natural products, gambieric acids remain unconquered due to their daunting structural complexity, which poses a formidable synthetic challenge to organic chemists. This paper reviews our long-term studies on the total synthesis, complete configurational reassignment, and structure-activity relationships of gambieric acid A over the last decade. PMID:25092231

  19. Allied Health Chemistry Laboratory: Amino Acids, Insulin, Proteins, and Skin

    ERIC Educational Resources Information Center

    Dever, David F.

    1975-01-01

    Presents a laboratory experiment specifically designed for allied health students. The students construct molecular models of amino acids, extract amino acids from their skin with hot water, and chromatographically analyze the skin extract and hydrolyzed insulin. (MLH)

  20. Secretion of whey acidic protein and cystatin is down regulated at mid-lactation in the red kangaroo (Macropus rufus)

    USGS Publications Warehouse

    Nicholas, K.R.; Fisher, J.A.; Muths, E.; Trott, J.; Janssens, P.A.; Reich, C.; Shaw, D.C.

    2001-01-01

    Milk collected from the red kangaroo (Macropus rufus) between day 100 and 260 of lactation showed major changes in milk composition at around day 200 of lactation, the time at which the pouch young begins to temporarily exit the pouch and eat herbage. The carbohydrate content of milk declined abruptly at this time and although there was only a small increase in total protein content, SDS PAGE analysis of milk revealed asynchrony in the secretory pattern of individual proteins. The levels of ??-lactalbumin, ??-lactoglobulin, serum albumin and transferrin remain unchanged during lactation. In contrast, the protease inhibitor cystatin, and the putative protease inhibitor whey acidic protein (WAP) first appeared in milk at elevated concentrations after approximately 150 days of lactation and then ceased to be secreted at approximately 200 days. In addition, a major whey protein, late lactation protein, was first detected in milk around the time whey acidic protein and cystatin cease to be secreted and was present at least until day 260 of lactation. The co-ordinated, but asynchronous secretion of putative protease inhibitors in milk may have several roles during lactation including tissue remodelling in the mammary gland and protecting specific proteins in milk required for physiological development of the dependent young. ?? 2001 Elsevier Science Inc.

  1. Seed storage protein deficiency improves sulfur amino acid content in common bean (Phaseolus vulgaris L.): redirection of sulfur from gamma-glutamyl-S-methyl-cysteine.

    PubMed

    Taylor, Meghan; Chapman, Ralph; Beyaert, Ronald; Hernández-Sebastià, Cinta; Marsolais, Frédéric

    2008-07-23

    The contents of sulfur amino acids in seeds of common bean ( Phaseolus vulgaris L.) are suboptimal for nutrition. They accumulate large amounts of a gamma-glutamyl dipeptide of S-methyl-cysteine, a nonprotein amino acid that cannot substitute for methionine or cysteine in the diet. Protein accumulation and amino acid composition were characterized in three genetically related lines integrating a progressive deficiency in major seed storage proteins, phaseolin, phytohemagglutinin, and arcelin. Nitrogen, carbon, and sulfur contents were comparable among the three lines. The contents of S-methyl-cysteine and gamma-glutamyl-S-methyl-cysteine were progressively reduced in the mutants. Sulfur was shifted predominantly to the protein cysteine pool, while total methionine was only slightly elevated. Methionine and cystine contents (mg per g protein) were increased by up to ca. 40%, to levels slightly above FAO guidelines on amino acid requirements for human nutrition. These findings may be useful to improve the nutritional quality of common bean. PMID:18588315

  2. The human ubiquitin-52 amino acid fusion protein gene shares several structural features with mammalian ribosomal protein genes.

    PubMed Central

    Baker, R T; Board, P G

    1991-01-01

    Complementary DNA clones encoding ubiquitin fused to a 52 amino acid tail protein were isolated from human placental and adrenal gland cDNA libraries. The deduced human 52 amino acid tail protein is very similar to the homologous protein from other species, including the conservation of the putative metal-binding, nucleic acid-binding domain observed in these proteins. Northern blot analysis with a tail-specific probe indicated that the previously identified UbA mRNA species most likely represents comigrating transcripts of the 52 amino acid tail (UbA52) and 80 amino acid tail (UbA80) ubiquitin fusion genes. The UbA52 gene was isolated from a human genomic library and consists of five exons distributed over 3400 base pairs. One intron is in the 5' non-coding region, two interrupt the single ubiquitin coding unit, and the fourth intron is within the tail coding region. Several members of the Alu family of repetitive DNA are associated with the gene. The UbA52 promoter has several features in common with mammalian ribosomal protein genes, including its location in a CpG-rich island, initiation of transcription within a polypyrimidine tract, the lack of a consensus TATA motif, and the presence of Sp1 binding sites, observations that are consistent with the recent identification of the ubiquitin-free tail proteins as ribosomal proteins. Thus, in spite of its unusual feature of being translationally fused to ubiquitin, the 52 amino acid tail ribosomal protein is expressed from a structurally typical ribosomal protein gene. Images PMID:1850507

  3. Classification of pseudo pairs between nucleotide bases and amino acids by analysis of nucleotide–protein complexes

    PubMed Central

    Kondo, Jiro; Westhof, Eric

    2011-01-01

    Nucleotide bases are recognized by amino acid residues in a variety of DNA/RNA binding and nucleotide binding proteins. In this study, a total of 446 crystal structures of nucleotide–protein complexes are analyzed manually and pseudo pairs together with single and bifurcated hydrogen bonds observed between bases and amino acids are classified and annotated. Only 5 of the 20 usual amino acid residues, Asn, Gln, Asp, Glu and Arg, are able to orient in a coplanar fashion in order to form pseudo pairs with nucleotide bases through two hydrogen bonds. The peptide backbone can also form pseudo pairs with nucleotide bases and presents a strong bias for binding to the adenine base. The Watson–Crick side of the nucleotide bases is the major interaction edge participating in such pseudo pairs. Pseudo pairs between the Watson–Crick edge of guanine and Asp are frequently observed. The Hoogsteen edge of the purine bases is a good discriminatory element in recognition of nucleotide bases by protein side chains through the pseudo pairing: the Hoogsteen edge of adenine is recognized by various amino acids while the Hoogsteen edge of guanine is only recognized by Arg. The sugar edge is rarely recognized by either the side-chain or peptide backbone of amino acid residues. PMID:21737431

  4. Optimizing Scoring Function of Protein-Nucleic Acid Interactions with Both Affinity and Specificity

    PubMed Central

    Yan, Zhiqiang; Wang, Jin

    2013-01-01

    Protein-nucleic acid (protein-DNA and protein-RNA) recognition is fundamental to the regulation of gene expression. Determination of the structures of the protein-nucleic acid recognition and insight into their interactions at molecular level are vital to understanding the regulation function. Recently, quantitative computational approach has been becoming an alternative of experimental technique for predicting the structures and interactions of biomolecular recognition. However, the progress of protein-nucleic acid structure prediction, especially protein-RNA, is far behind that of the protein-ligand and protein-protein structure predictions due to the lack of reliable and accurate scoring function for quantifying the protein-nucleic acid interactions. In this work, we developed an accurate scoring function (named as SPA-PN, SPecificity and Affinity of the Protein-Nucleic acid interactions) for protein-nucleic acid interactions by incorporating both the specificity and affinity into the optimization strategy. Specificity and affinity are two requirements of highly efficient and specific biomolecular recognition. Previous quantitative descriptions of the biomolecular interactions considered the affinity, but often ignored the specificity owing to the challenge of specificity quantification. We applied our concept of intrinsic specificity to connect the conventional specificity, which circumvents the challenge of specificity quantification. In addition to the affinity optimization, we incorporated the quantified intrinsic specificity into the optimization strategy of SPA-PN. The testing results and comparisons with other scoring functions validated that SPA-PN performs well on both the prediction of binding affinity and identification of native conformation. In terms of its performance, SPA-PN can be widely used to predict the protein-nucleic acid structures and quantify their interactions. PMID:24098651

  5. Serum Glial Fibrillary Acidic Protein Predicts Tissue Glial Fibrillary Acidic Protein Break-Down Products and Therapeutic Efficacy after Penetrating Ballistic-Like Brain Injury.

    PubMed

    Boutté, Angela M; Deng-Bryant, Ying; Johnson, David; Tortella, Frank C; Dave, Jitendra R; Shear, Deborah A; Schmid, Kara E

    2016-01-01

    Acute traumatic brain injury (TBI) is associated with neurological dysfunction, changes in brain proteins, and increased serum biomarkers. However, the relationship between these brain proteins and serum biomarkers, and the ability of these serum biomarkers to indicate a neuroprotective/therapeutic response, remains elusive. Penetrating ballistic-like brain injury (PBBI) was used to systematically analyze several key TBI biomarkers, glial fibrillary acidic protein (GFAP) and its break-down products (BDPs)-ubiquitin C-terminal hydrolase-L1 (UCH-L1), α-II spectrin, and α-II spectrin BDPs (SBDPs)-in brain tissues and serum during an extended acute-subacute time-frame. In addition, neurological improvement and serum GFAP theranostic value was evaluated after neuroprotective treatment. In brain tissues, total GFAP increased more than three-fold 2 to 7 d after PBBI. However, this change was primarily due to GFAP-BDPs which increased to 2.7-4.8 arbitrary units (AU). Alpha-II spectrin was nearly ablated 3 d after PBBI, but somewhat recovered after 7 d. In conjunction with α-II spectrin loss, SBDP-145/150 increased approximately three-fold 2 to 7 d after PBBI (vs. sham, p<0.05). UCH-L1 protein levels were slightly decreased 7 d after PBBI but otherwise were unaffected. Serum GFAP was elevated by 3.2- to 8.8-fold at 2 to 4 h (vs. sham; p<0.05) and the 4 h increase was strongly correlated to 3 d GFAP-BDP abundance (r=0.66; p<0.05). Serum GFAP showed such a strong injury effect that it also was evaluated after therapeutic intervention with cyclosporin A (CsA). Administration of 2.5 mg/kg CsA significantly reduced serum GFAP elevation by 22.4-fold 2 h after PBBI (vs. PBBI+vehicle; p<0.05) and improved neurological function 1 d post-injury. Serum biomarkers, particularly GFAP, may be correlative tools of brain protein changes and feasible theranostic markers of TBI progression and recovery. PMID:25789543

  6. The "Jekyll and Hyde" Actions of Nucleic Acids on the Prion-like Aggregation of Proteins.

    PubMed

    Silva, Jerson L; Cordeiro, Yraima

    2016-07-22

    Protein misfolding results in devastating degenerative diseases and cancer. Among the culprits involved in these illnesses are prions and prion-like proteins, which can propagate by converting normal proteins to the wrong conformation. For spongiform encephalopathies, a real prion can be transmitted among individuals. In other disorders, the bona fide prion characteristics are still under investigation. Besides inducing misfolding of native proteins, prions bind nucleic acids and other polyanions. Here, we discuss how nucleic acid binding might influence protein misfolding for both disease-related and benign, functional prions and why the line between bad and good amyloids might be more subtle than previously thought. PMID:27288413

  7. Biophysical and computational methods to analyze amino acid interaction networks in proteins.

    PubMed

    O'Rourke, Kathleen F; Gorman, Scott D; Boehr, David D

    2016-01-01

    Globular proteins are held together by interacting networks of amino acid residues. A number of different structural and computational methods have been developed to interrogate these amino acid networks. In this review, we describe some of these methods, including analyses of X-ray crystallographic data and structures, computer simulations, NMR data, and covariation among protein sequences, and indicate the critical insights that such methods provide into protein function. This information can be leveraged towards the design of new allosteric drugs, and the engineering of new protein function and protein regulation strategies. PMID:27441044

  8. Genetically programmed expression of proteins containing the unnatural amino acid phenylselenocysteine

    DOEpatents

    Wang, Jiangyun; Schultz, Peter G.

    2012-07-10

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the unnatural amino acid phenylselenocysteine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal aminoacyl-tRNA synthetases, polynucleotides encoding the novel synthetase molecules, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid phenylselenocysteine and translation systems. The invention further provides methods for producing modified proteins (e.g., lipidated proteins) through targeted modification of the phenylselenocysteine residue in a protein.

  9. Genetically programmed expression of proteins containing the unnatural amino acid phenylselenocysteine

    DOEpatents

    Wang, Jiangyun; Schultz, Peter G.

    2010-09-07

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the unnatural amino acid phenylselenocysteine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal aminoacyl-tRNA synthetases, polynucleotides encoding the novel synthetase molecules, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid phenylselenocysteine and translation systems. The invention further provides methods for producing modified proteins (e.g., lipidated proteins) through targeted modification of the phenylselenocysteine residue in a protein.

  10. Comparison of Bile Acids and Acetaminophen Protein Adducts in Children and Adolescents with Acetaminophen Toxicity

    PubMed Central

    James, Laura; Yan, Ke; Pence, Lisa; Simpson, Pippa; Bhattacharyya, Sudeepa; Gill, Pritmohinder; Letzig, Lynda; Kearns, Gregory; Beger, Richard

    2015-01-01

    Metabolomics approaches have enabled the study of new mechanisms of liver injury in experimental models of drug toxicity. Disruption of bile acid homeostasis is a known mechanism of drug induced liver injury. The relationship of individual bile acids to indicators of oxidative drug metabolism (acetaminophen protein adducts) and liver injury was examined in children with acetaminophen overdose, hospitalized children with low dose exposure to acetaminophen, and children with no recent exposure to acetaminophen. Nine bile acids were quantified through targeted metabolomic analysis in the serum samples of the three groups. Bile acids were compared to serum levels of acetaminophen protein adducts and alanine aminotransferase. Glycodeoxycholic acid, taurodeoxycholic acid, and glycochenodeoxycholic acid were significantly increased in children with acetaminophen overdose compared to healthy controls. Among patients with acetaminophen overdose, bile acids were higher in subjects with acetaminophen protein adduct values > 1.0 nmol/mL and modest correlations were noted for three bile acids and acetaminophen protein adducts as follows: taurodeoxycholic acid (R=0.604; p<0.001), glycodeoxycholic acid (R=0.581; p<0.001), and glycochenodeoxycholic acid (R=0.571; p<0.001). Variability in bile acids was greater among hospitalized children receiving low doses of acetaminophen than in healthy children with no recent acetaminophen exposure. Compared to bile acids, acetaminophen protein adducts more accurately discriminated among children with acetaminophen overdose, children with low dose exposure to acetaminophen, and healthy control subjects. In children with acetaminophen overdose, elevations of conjugated bile acids were associated with specific indicators of acetaminophen metabolism and non-specific indicators of liver injury. PMID:26208104

  11. Comparison of Bile Acids and Acetaminophen Protein Adducts in Children and Adolescents with Acetaminophen Toxicity.

    PubMed

    James, Laura; Yan, Ke; Pence, Lisa; Simpson, Pippa; Bhattacharyya, Sudeepa; Gill, Pritmohinder; Letzig, Lynda; Kearns, Gregory; Beger, Richard

    2015-01-01

    Metabolomics approaches have enabled the study of new mechanisms of liver injury in experimental models of drug toxicity. Disruption of bile acid homeostasis is a known mechanism of drug induced liver injury. The relationship of individual bile acids to indicators of oxidative drug metabolism (acetaminophen protein adducts) and liver injury was examined in children with acetaminophen overdose, hospitalized children with low dose exposure to acetaminophen, and children with no recent exposure to acetaminophen. Nine bile acids were quantified through targeted metabolomic analysis in the serum samples of the three groups. Bile acids were compared to serum levels of acetaminophen protein adducts and alanine aminotransferase. Glycodeoxycholic acid, taurodeoxycholic acid, and glycochenodeoxycholic acid were significantly increased in children with acetaminophen overdose compared to healthy controls. Among patients with acetaminophen overdose, bile acids were higher in subjects with acetaminophen protein adduct values > 1.0 nmol/mL and modest correlations were noted for three bile acids and acetaminophen protein adducts as follows: taurodeoxycholic acid (R=0.604; p<0.001), glycodeoxycholic acid (R=0.581; p<0.001), and glycochenodeoxycholic acid (R=0.571; p<0.001). Variability in bile acids was greater among hospitalized children receiving low doses of acetaminophen than in healthy children with no recent acetaminophen exposure. Compared to bile acids, acetaminophen protein adducts more accurately discriminated among children with acetaminophen overdose, children with low dose exposure to acetaminophen, and healthy control subjects. In children with acetaminophen overdose, elevations of conjugated bile acids were associated with specific indicators of acetaminophen metabolism and non-specific indicators of liver injury. PMID:26208104

  12. AMINO ACIDS AUGMENT MUSCLE PROTEIN SYNTHESIS IN NEONATAL PIGS DURING ENDOTOXEMIA BY MODULATING TRANSLATION INITIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In adults, sepsis reduces protein synthesis in skeletal muscle by restraining translation. The effect of sepsis on amino acid-stimulated muscle protein synthesis has not been determined in neonates, a population who is highly anabolic and whose muscle protein synthesis rates are uniquely sensitive ...

  13. Enteral obeticholic acid prevents hepatic cholestasis in total parenteral nutrition-fed neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total parenteral nutrition (TPN) is a vital support for neonatal infants with congenital or acquired gastrointestinal (GI) disorders and requiring small bowel resection. An adverse outcome associated with prolonged TPN use is parenteral nutrition associated cholestasis (PNAC). We previously showed t...

  14. Improved method for simultaneous isolation of proteins and nucleic acids.

    PubMed

    Chey, Soroth; Claus, Claudia; Liebert, Uwe Gerd

    2011-04-01

    Guanidinium thiocyanate-phenol-chloroform extraction (GTPC extraction) is widely used in molecular biology for isolating DNA, RNA, and proteins. Protein isolation by commercially available GTPC solutions is time consuming and the resulting pellets are only incompletely soluble. In this study ethanol-bromochloropropane-water was used for precipitation of proteins from the phenol-ethanol phase after GTPC extraction of RNA and DNA. The precipitated proteins can be readily dissolved in 4% SDS for subsequent analysis. This technique allows a fast (30min) and efficient (with a protein recovery of up to 95%) extraction of proteins for the study of transcriptional and posttranscriptional events from the same sample. PMID:21094121

  15. Novel humic acid-bonded magnetite nanoparticles for protein immobilization.

    PubMed

    Bayrakci, Mevlut; Gezici, Orhan; Bas, Salih Zeki; Ozmen, Mustafa; Maltas, Esra

    2014-09-01

    The present paper is the first report that introduces (i) a useful methodology for chemical immobilization of humic acid (HA) to aminopropyltriethoxysilane-functionalized magnetite iron oxide nanoparticles (APS-MNPs) and (ii) human serum albumin (HSA) binding to the obtained material (HA-APS-MNPs). The newly prepared magnetite nanoparticle was characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and elemental analysis. Results indicated that surface modification of the bare magnetite nanoparticles (MNPs) with aminopropyltriethoxysilane (APS) and HA was successfully performed. The protein binding studies that were evaluated in batch mode exhibited that HA-APS-MNPs could be efficiently used as a substrate for the binding of HSA from aqueous solutions. Usually, recovery values higher than 90% were found to be feasible by HA-APS-MNPs, while that value was around 2% and 70% in the cases of MNPs and APS-MNPs, respectively. Hence, the capacity of MNPs was found to be significantly improved by immobilization of HA. Furthermore, thermal degradation of HA-APS-MNPs and HSA bonded HA-APS-MNPs was evaluated in terms of the Horowitz-Metzger equation in order to determine kinetic parameters for thermal decomposition. Activation energies calculated for HA-APS-MNPs (20.74 kJmol(-1)) and HSA bonded HA-APS-MNPs (33.42 kJmol(-1)) implied chemical immobilization of HA to APS-MNPs, and tight interactions between HA and HA-APS-MNPs. PMID:25063152

  16. Role of a liver fatty acid-binding protein gene in lipid metabolism in chicken hepatocytes.

    PubMed

    Gao, G L; Na, W; Wang, Y X; Zhang, H F; Li, H; Wang, Q G

    2015-01-01

    This study investigated the role of the chicken liver fatty acid-binding protein (L-FABP) gene in lipid metabolism in hepatocytes, and the regulatory relationships between L-FABP and genes related to lipid metabolism. The short hairpin RNA (shRNA) interference vector with L-FABP and an eukaryotic expression vector were used. Chicken hepatocytes were subjected to shRNA-mediated knockdown or L-FABP cDNA overexpression. Expression levels of lipid metabolism-related genes and biochemical parameters were detected 24, 36, 48, 60, and 72 h after transfection with the interference or overexpression plasmids for L-FABP, PPARα and L-BABP expression levels, and the total amount of cholesterol, were significantly affected by L-FABP expression. L-FABP may affect lipid metabolism by regulating PPARα and L-BABP in chicken hepatocytes. PMID:25966259

  17. Fast computational methods for predicting protein structure from primary amino acid sequence

    DOEpatents

    Agarwal, Pratul Kumar

    2011-07-19

    The present invention provides a method utilizing primary amino acid sequence of a protein, energy minimization, molecular dynamics and protein vibrational modes to predict three-dimensional structure of a protein. The present invention also determines possible intermediates in the protein folding pathway. The present invention has important applications to the design of novel drugs as well as protein engineering. The present invention predicts the three-dimensional structure of a protein independent of size of the protein, overcoming a significant limitation in the prior art.

  18. Changes in the absorption of bile acids after total colectomy in patients with an ileostomy or pouch-anal anastomosis

    SciTech Connect

    Nasmyth, D.G.; Johnston, D.; Williams, N.S.; King, R.F.; Burkinshaw, L.; Brooks, K.

    1989-03-01

    Bile acid absorption was investigated using /sup 75/Se Taurohomocholate (SeHCAT) in controls and patients who had undergone total colectomy with either conventional ileostomy or pouch-anal anastomosis for ulcerative colitis or adenomatous polyposis. Whole-body retention of SeHCAT after 168 hours was greater in the controls than the patients who had undergone colectomy (P less than .05). Retention of SeHCAT did not differ significantly between patients with an ileostomy and patients with pouch-anal anastomosis, but patients with an ileostomy and ileal resection of more than 20 cm retained less SeHCAT than patients with a pouch-anal anastomosis (P less than .01). Analysis of fecal bile acids from ileostomies and pouches showed that bacterial metabolism of primary conjugated bile acids was greater in patients with a pouch. It was concluded that bile acid absorption was not significantly impaired by construction of a pouch compared with conventional ileostomy, but bacterial metabolism of bile acids was greater in the pouches.

  19. Blood zinc protoporphyrin, serum total protein, and total cholesterol levels in automobile workshop workers in relation to lead toxicity: Our experience.

    PubMed

    Pachathundikandi, Suneesh Kumar; Varghese, Earaly Thomas

    2006-09-01

    Blood zinc protoporphyrin (ZPP), serum total protein (TP), and total cholesterol (TC) levels in automobile workshop workers in relation to lead toxicity were analysed. In the present study, automobile workshop workers (healthy male workers at an age between 28 and 35 from four major automobile workshops in Kottayam, Kerala State, India) and the control (male healthy adults at an age between 28 and 35 residing at Aymanam, a distant village at Kottayam District, Kerala having reduced or no chance of lead exposure) displayed significant difference in blood lead (BPb) and blood ZZP (BZPP) level. The mean value of BPb in automobile workshop workers was 15.76±0.33 μg/dl, while in the control it was 8.20±0.15 μg/dl. In automobile workshop workers, the mean value of BZPP was 34.2±0.62 μg/dl. The control group exhibited a mean of 11.5±0.22 μg/dl. Automobile workshop workers exhibited significant increase in BZPP was corresponding to the increase in BPb level. The total protein levels estimated in automobile workshop workers showed significant decrease compared to control individuals, but was within the reference range of healthy individuals. The mean value of TP level in automobile workshop workers and control was 6.9±0.13 g/dl and 7.71±0.18 g/dl, respectively. There was no significant difference in blood haemoglobin (BHb) level among the automobile workshop workers and control. The serum TC level in automobile workshop workers showed significant decrease compared to the control individuals, but was with in the reference range of healthy individuals. The mean level of serum TC in automobile workshop workers was 162.00±3.44 mg/dl and the same in control was 172.86±4.32 mg/dl. The present study affirms occupational lead toxicity in automobile workshop workers and its effect on serum protein and cholesterol levels. PMID:23105626

  20. Development of a total maximum daily load (TMDL) for acid-impaired lakes in the Adirondack region of New York

    NASA Astrophysics Data System (ADS)

    Fakhraei, Habibollah; Driscoll, Charles T.; Selvendiran, Pranesh; DePinto, Joseph V.; Bloomfield, Jay; Quinn, Scott; Rowell, H. Chandler

    2014-10-01

    Acidic deposition has impaired acid-sensitive surface waters in the Adirondack region of New York by decreasing pH and acid neutralizing capacity (ANC). In spite of air quality programs over past decades, 128 lakes in the Adirondacks were classified as “impaired” under Section 303(d) of the Clean Water Act in 2010 due to elevated acidity. The biogeochemical model, PnET-BGC, was used to relate decreases in atmospheric sulfur (S) and nitrogen (N) deposition to changes in lake water chemistry. The model was calibrated and confirmed using observed soil and lake water chemistry data and then was applied to calculate the maximum atmospheric deposition that the impaired lakes can receive while still achieving ANC targets. Two targets of ANC were used to characterize the recovery of acid-impaired lakes: 11 and 20 μeq L-1. Of the 128 acid-impaired lakes, 97 currently have ANC values below the target value of 20 μeq L-1 and 83 are below 11 μeq L-1. This study indicates that a moderate control scenario (i.e., 60% decrease from the current atmospheric S load) is projected to recover the ANC of lakes at a mean rate of 0.18 and 0.05 μeq L-1 yr-1 during the periods 2022-2050 and 2050-2200, respectively. The total maximum daily load (TMDL) of acidity corresponding to this moderate control scenario was estimated to be 7.9 meq S m-2 yr-1 which includes a 10% margin of safety.

  1. Longtime soaking of high concentration tranexamic acid in total hip arthroplasty: A prospective randomized controlled trial in 224 patients

    PubMed Central

    Xu, Xingming; Li, Xiaofeng; Liu, Wei; Wang, Zhenyu

    2015-01-01

    Objectives: To evaluate the efficacy and safety of intra-articular Soaking of high concentration Tranexamic Acid (TXA) in total hip arthroplasty. Methods: From March 2013 to March 2014, 224 patients who underwent unilateral primary THA in our hospital was enrolled in this randomized, prospective double-blinded study. The patients were allocated into two groups according to intra-articular solution received: Intra-articular soaking of TXA group, Control group (physiologic saline). The solution was injected from intermuscular space following fixation of the implants and closure of articular capsule, short external rotators. Total blood loss, total volume of drainage and transfusion were recorded. Postoperative deep vein thrombosis and other complications was also measured. Results: The mean total blood loss was 730±296 ml in intra-articular soaking of TXA group compared with 1048±295ml in control group (P<0.05). The postoperative mean total volume of drainage was 93±50 mL in intra-articular soaking of TXA group versus 312±136 mL in control group.22 patients (19.8%, control) and 6 patients (5.3%, Intra-articular soaking of TXA) required transfusion (P=0.001). Postoperative deep vein thrombosis and other complications were no statistical significance between the two groups. Conclusions: Intra-articular soaking of high concentration TXA with 2-hour clamping drain can reduce the total blood loss and transfusion rates in primary THA without significant increase in postoperative thrombotic complications. PMID:26870087

  2. Prediction of nucleic acid binding probability in proteins: a neighboring residue network based score.

    PubMed

    Miao, Zhichao; Westhof, Eric

    2015-06-23

    We describe a general binding score for predicting the nucleic acid binding probability in proteins. The score is directly derived from physicochemical and evolutionary features and integrates a residue neighboring network approach. Our process achieves stable and high accuracies on both DNA- and RNA-binding proteins and illustrates how the main driving forces for nucleic acid binding are common. Because of the effective integration of the synergetic effects of the network of neighboring residues and the fact that the prediction yields a hierarchical scoring on the protein surface, energy funnels for nucleic acid binding appear on protein surfaces, pointing to the dynamic process occurring in the binding of nucleic acids to proteins. PMID:25940624

  3. Prediction of nucleic acid binding probability in proteins: a neighboring residue network based score

    PubMed Central

    Miao, Zhichao; Westhof, Eric

    2015-01-01

    We describe a general binding score for predicting the nucleic acid binding probability in proteins. The score is directly derived from physicochemical and evolutionary features and integrates a residue neighboring network approach. Our process achieves stable and high accuracies on both DNA- and RNA-binding proteins and illustrates how the main driving forces for nucleic acid binding are common. Because of the effective integration of the synergetic effects of the network of neighboring residues and the fact that the prediction yields a hierarchical scoring on the protein surface, energy funnels for nucleic acid binding appear on protein surfaces, pointing to the dynamic process occurring in the binding of nucleic acids to proteins. PMID:25940624

  4. Anion-π interactions in complexes of proteins and halogen-containing amino acids.

    PubMed

    Borozan, Sunčica Z; Zlatović, Mario V; Stojanović, Srđan Đ

    2016-06-01

    We analyzed the potential influence of anion-π interactions on the stability of complexes of proteins and halogen-containing non-natural amino acids. Anion-π interactions are distance and orientation dependent and our ab initio calculations showed that their energy can be lower than -8 kcal mol(-1), while most of their interaction energies lie in the range from -1 to -4 kcal mol(-1). About 20 % of these interactions were found to be repulsive. We have observed that Tyr has the highest occurrence among the aromatic residues involved in anion-π interactions, while His made the least contribution. Furthermore, our study showed that 67 % of total interactions in the dataset are multiple anion-π interactions. Most of the amino acid residues involved in anion-π interactions tend to be buried in the solvent-excluded environment. The majority of the anion-π interacting residues are located in regions with helical secondary structure. Analysis of stabilization centers for these complexes showed that all of the six residues capable of anion-π interactions are important in locating one or more of such centers. We found that anion-π interacting residues are sometimes involved in simultaneous interactions with halogens as well. With all that in mind, we can conclude that the anion-π interactions can show significant influence on molecular organization and on the structural stability of the complexes of proteins and halogen-containing non-natural amino acids. Their influence should not be neglected in supramolecular chemistry and crystal engineering fields as well. PMID:26910415

  5. Total syntheses of zaragozic acids A and C by a carbonyl ylide cycloaddition strategy.

    PubMed

    Hirata, Yuuki; Nakamura, Seiichi; Watanabe, Nobuhide; Kataoka, Osamu; Kurosaki, Takahiro; Anada, Masahiro; Kitagaki, Shinji; Shiro, Motoo; Hashimoto, Shunichi

    2006-12-01

    A carbonyl ylide cycloaddition approach to the squalene synthase inhibitors zaragozic acids A and C is described. The carbonyl ylide precursor 8 was synthesized starting from di-tert-butyl D-tartrate (47) via an eleven-step sequence involving the regioselective reduction of the mono-MPM (MPM=4-methoxybenzyl) ether 48 with LiBH4 and the diastereoselective addition of sodium tert-butyl diazoacetate to alpha-keto ester 10. The reaction of alpha-diazo ester 8 with 3-butyn-2-one (40) in the presence of a catalytic amount of [Rh2(OAc)4] gave the desired cycloadduct 59 as a single diastereomer. The dihydroxylation of enone 59 followed by sequential transformations permitted the construction of the fully functionalized 2,8-dioxabicyclo[3.2.1]octane core 5. Alkene 79 derived from 5 serves as a common precursor to zaragozic acids A (1) and C (2), since the elongation of the C1 alkyl side chain can be attained by olefin cross-metathesis, especially under the influence of Blechert's catalyst (85). PMID:17106907

  6. Total Synthesis of the Aristolochic Acids, Their Major Metabolites, and Related Compounds

    PubMed Central

    2015-01-01

    Plants from the Aristolochia genus have been recommended for the treatment of a variety of human ailments since the time of Hippocrates. However, many species produce the highly toxic aristolochic acids (AAs), which are both nephrotoxic and carcinogenic. For the purposes of extensive biological studies, a versatile approach to the synthesis of the AAs and their major metabolites was devised based primarily on a Suzuki–Miyaura coupling reaction. The key to success lies in the preparation of a common ring-A precursor, namely, the tetrahydropyranyl ether of 2-nitromethyl-3-iodo-4,5-methylendioxybenzyl alcohol (27), which was generated in excellent yield by oxidation of the aldoxime precursor 26. Suzuki–Miyaura coupling of 27 with a variety of benzaldehyde 2-boronates was accompanied by an aldol condensation/elimination reaction to give the desired phenanthrene intermediate directly. Deprotection of the benzyl alcohol followed by two sequential oxidation steps gave the desired phenanthrene nitrocarboxylic acids. This approach was used to synthesize AAs I–IV and several other related compounds, including AA I and AA II bearing an aminopropyloxy group at position-6, which were required for further conversion to fluorescent biological probes. Further successful application of the Suzuki–Miyaura coupling reaction to the synthesis of the N-hydroxyaristolactams of AA I and AA II then allowed the synthesis of the putative, but until now elusive, N-acetoxy- and N-sulfonyloxy-aristolactam metabolites. PMID:24877584

  7. Electrophoretic Mobility Shift Assay (EMSA) for Detecting Protein-Nucleic Acid Interactions

    PubMed Central

    Hellman, Lance M.; Fried, Michael G.

    2009-01-01

    The gel electrophoresis mobility shift assay (EMSA) is used to detect protein complexes with nucleic acids. It is the core technology underlying a wide range of qualitative and quantitative analyses for the characterization of interacting systems. In the classical assay, solutions of protein and nucleic acid are combined and the resulting mixtures are subjected to electrophoresis under native conditions through polyacrylamide or agarose gel. After electrophoresis, the distribution of species containing nucleic acid is determined, usually by autoradiography of 32P-labeled nucleic acid. In general, protein-nucleic acid complexes migrate more slowly than the corresponding free nucleic acid. In this article, we identify the most important factors that determine the stabilities and electrophoretic mobilities of complexes under assay conditions. A representative protocol is provided and commonly used variants are discussed. Expected outcomes are briefly described. References to extensions of the method and a troubleshooting guide are provided. PMID:17703195

  8. Effect of liver fatty acid binding protein on fatty acid movement between liposomes and rat liver microsomes.

    PubMed Central

    McCormack, M; Brecher, P

    1987-01-01

    Although movement of fatty acids between bilayers can occur spontaneously, it has been postulated that intracellular movement is facilitated by a class of proteins named fatty acid binding proteins (FABP). In this study we have incorporated long chain fatty acids into multilamellar liposomes made of phosphatidylcholine, incubated them with rat liver microsomes containing an active acyl-CoA synthetase, and measured formation of acyl-CoA in the absence or presence of FABP purified from rat liver. FABP increased about 2-fold the accumulation of acyl-CoA when liposomes were the fatty acid donor. Using fatty acid incorporated into liposomes made either of egg yolk lecithin or of dipalmitoylphosphatidylcholine, it was found that the temperature dependence of acyl-CoA accumulation in the presence of FABP correlated with both the physical state of phospholipid molecules in the liposomes and the binding of fatty acid to FABP, suggesting that fatty acid must first desorb from the liposomes before FABP can have an effect. An FABP-fatty acid complex incubated with microsomes, in the absence of liposomes, resulted in greater acyl-CoA formation than when liposomes were present, suggesting that desorption of fatty acid from the membrane is rate-limiting in the accumulation of acyl-CoA by this system. Finally, an equilibrium dialysis cell separating liposomes from microsomes on opposite sides of a Nuclepore filter was used to show that liver FABP was required for the movement and activation of fatty acid between the compartments. These studies show that liver FABP interacts with fatty acid that desorbs from phospholipid bilayers, and promotes movement to a membrane-bound enzyme, suggesting that FABP may act intracellularly by increasing net desorption of fatty acid from cell membranes. PMID:3446187

  9. Relation of plasma calcium to total protein and albumin in African grey (Psittacus erithacus) and Amazon (Amazona spp.) parrots.

    PubMed

    Lumeij, J T

    1990-10-01

    A significant correlation was found between total calcium and albumin concentration in the plasma of 70 African grey parrots (r=0.37; P<0.05). A correlation formula for plasma calcium concentration in the African grey parrot was derived on the basis of the concentration of albumin: Adjusted Ca (mmol/1) = Ca (mmol/1) - 0.015 Albumin (g/1) + 0.4. About 14% of the variability in calcium was attributable to the change in the concentration of plasma albumin concentration (R2=0.137). The correlation between calcium and total protein in African greys and between calcium and albumin and calcium and total protein in Amazons was not significant. PMID:18679980

  10. Interactions of Dietary Fats and Proteins on Fatty Acid Composition of Immune Cells and LTB4 Production by Peritoneal Exudate Cells of Rats.

    PubMed

    Kaku, S; Yunoki, S; Ohkura, K; Sugano, M; Nonaka, M; Tachibana, H; Yamada, K

    2001-01-01

    The interaction of dietary fats and proteins on lipid parameters of rats was studied using safflower oil (linoleic acid-rich), borage oil (γ-linolenic acid-rich) or perilla oil (α-linolenic acid-rich) in combination with casein or soybean protein. The experiment was focused on the fatty acid composition of immune cells and the leukotriene B4 production by peritoneal exudate cells. Serum total cholesterol, triglyceride, and phospholipid levels were low in perilla oil-fed or soybean protein-fed rats. Fatty acid compositions of serum and liver phospholipids reflected those of dietary fats. However, feeding borage oil resulted in a marked increase in the proportion of dihomo-γ-linolenic acid in phospholipids of peritoneal exudate cells, spleen lymphocytes, and mesenteric lymph node lymphocytes in relation to those of liver and serum. It is suggested that activities of metabolic n-6 polyunsaturated fatty acids are different between immune and other tissues. In addition, the magnitude of the reduction of the proportion of linoleic acid of perilla oil in immune cells was considerably more moderate than serum and liver, indicating a different degree of interference of α-linolenic acid with linoleic acid metabolism. Leukotriene B4 release from peritoneal exudate cells was in the order of safflower oil>borage oil>perilla oil groups as reflecting the proportion of arachidonic acid, and tended to be lower in soybean protein-fed groups. These suggest an anti-inflammatory property of γ-linolenic acid as well as α-linolenic acid tended to be strengthened when they were combined with soybean protein than with casein. PMID:27374271

  11. Interactions of dietary fats and proteins on fatty acid composition of immune cells and LTB4 production by peritoneal exudate cells of rats.

    PubMed

    Kaku, S; Yunoki, S; Ohkura, K; Sugano, M; Nonaka, M; Tachibana, H; Yamada, K

    2001-02-01

    The interaction of dietary fats and proteins on lipid parameters of rats was studied using safflower oil (linoleic acid-rich), borage oil (gamma-linolenic acid-rich) or perilla oil (alpha-linolenic acid-rich) in combination with casein or soybean protein. The experiment was focused on the fatty acid composition of immune cells and the leukotriene B4 production by peritoneal exudate cells. Serum total cholesterol, triglyceride, and phospholipid levels were low in perilla oil-fed or soybean protein-fed rats. Fatty acid compositions of serum and liver phospholipids reflected those of dietary fats. However, feeding borage oil resulted in a marked increase in the proportion of dihomo-gamma-linolenic acid in phospholipids of peritoneal exudate cells, spleen lymphocytes, and mesenteric lymph node lymphocytes in relation to those of liver and serum. It is suggested that activities of metabolic n-6 polyunsaturated fatty acids are different between immune and other tissues. In addition, the magnitude of the reduction of the proportion of linoleic acid of perilla oil in immune cells was considerably more moderate than serum and liver, indicating a different degree of interference of alpha-linolenic acid with linoleic acid metabolism. Leukotriene release from peritoneal exudate cells was in the order of safflower oil > borage oil > perilla oil groups as reflecting the proportion of arachidonic acid, and tended to be lower in soybean protein-fed groups. These suggest an anti-inflammatory property of gamma-linolenic acid as well as alpha-linolenic acid tended to be strengthened when they were combined with soybean protein than with casein. PMID:11302164

  12. Tsetse Salivary Gland Proteins 1 and 2 Are High Affinity Nucleic Acid Binding Proteins with Residual Nuclease Activity

    PubMed Central

    Caljon, Guy; Ridder, Karin De; Stijlemans, Benoît; Coosemans, Marc; Magez, Stefan; De Baetselier, Patrick; Van Den Abbeele, Jan

    2012-01-01

    Analysis of the tsetse fly salivary gland EST database revealed the presence of a highly enriched cluster of putative endonuclease genes, including tsal1 and tsal2. Tsal proteins are the major components of tsetse fly (G. morsitans morsitans) saliva where they are present as monomers as well as high molecular weight complexes with other saliva proteins. We demonstrate that the recombinant tsetse salivary gland proteins 1&2 (Tsal1&2) display DNA/RNA non-specific, high affinity nucleic acid binding with KD values in the low nanomolar range and a non-exclusive preference for duplex. These Tsal proteins exert only a residual nuclease activity with a preference for dsDNA in a broad pH range. Knockdown of Tsal expression by in vivo RNA interference in the tsetse fly revealed a partially impaired blood digestion phenotype as evidenced by higher gut nucleic acid, hematin and protein contents. PMID:23110062

  13. Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

    PubMed Central

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-01-01

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control. PMID:24495932

  14. Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

    NASA Astrophysics Data System (ADS)

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-02-01

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control.

  15. Association of androgen with gender difference in serum adipocyte fatty acid binding protein levels

    PubMed Central

    Hu, Xiang; Ma, Xiaojing; Pan, Xiaoping; Luo, Yuqi; Xu, Yiting; Xiong, Qin; Bao, Yuqian; Jia, Weiping

    2016-01-01

    Clinical investigations have indicated women have higher levels of adipocyte fatty acid binding protein (A-FABP) than men. The present study aimed to identify factors related to gender difference in serum A-FABP levels. A total of 507 participants (194 men, 132 premenopausal women, and 181 postmenopausal women) were enrolled in the present study. Serum A-FABP levels increased in the order from men to premenopausal women to postmenopausal women in both body mass index categories (<25.0 and ≥25.0 kg/m2; all P < 0.05). Multiple stepwise regression analyses showed that after adjustment for factors related to serum A-FABP levels, the trunk fat mass was an independent and positive factor of serum A-FABP levels. For men, total testosterone was associated independently and inversely with serum A-FABP levels. For pre- and postmenopausal women, bioavailable testosterone and total testosterone were independent and positive factors associated with serum A-FABP levels, respectively. The present study demonstrated that the androgen was correlated with the serum A-FABP levels negatively in men, but positively in women. With these effects on the fat content, especially trunk fat, androgen might contribute to the gender difference in serum A-FABP levels. PMID:27270834

  16. Association of androgen with gender difference in serum adipocyte fatty acid binding protein levels.

    PubMed

    Hu, Xiang; Ma, Xiaojing; Pan, Xiaoping; Luo, Yuqi; Xu, Yiting; Xiong, Qin; Bao, Yuqian; Jia, Weiping

    2016-01-01

    Clinical investigations have indicated women have higher levels of adipocyte fatty acid binding protein (A-FABP) than men. The present study aimed to identify factors related to gender difference in serum A-FABP levels. A total of 507 participants (194 men, 132 premenopausal women, and 181 postmenopausal women) were enrolled in the present study. Serum A-FABP levels increased in the order from men to premenopausal women to postmenopausal women in both body mass index categories (<25.0 and ≥25.0 kg/m(2); all P < 0.05). Multiple stepwise regression analyses showed that after adjustment for factors related to serum A-FABP levels, the trunk fat mass was an independent and positive factor of serum A-FABP levels. For men, total testosterone was associated independently and inversely with serum A-FABP levels. For pre- and postmenopausal women, bioavailable testosterone and total testosterone were independent and positive factors associated with serum A-FABP levels, respectively. The present study demonstrated that the androgen was correlated with the serum A-FABP levels negatively in men, but positively in women. With these effects on the fat content, especially trunk fat, androgen might contribute to the gender difference in serum A-FABP levels. PMID:27270834

  17. Differential Occurrence of Interactions and Interaction Domains in Proteins Containing Homopolymeric Amino Acid Repeats.

    PubMed

    Pelassa, Ilaria; Fiumara, Ferdinando

    2015-01-01

    Homopolymeric amino acids repeats (AARs), which are widespread in proteomes, have often been viewed simply as spacers between protein domains, or even as "junk" sequences with no obvious function but with a potential to cause harm upon expansion as in genetic diseases associated with polyglutamine or polyalanine expansions, including Huntington disease and cleidocranial dysplasia. A growing body of evidence indicates however that at least some AARs can form organized, functional protein structures, and can regulate protein function. In particular, certain AARs can mediate protein-protein interactions, either through homotypic AAR-AAR contacts or through heterotypic contacts with other protein domains. It is still unclear however, whether AARs may have a generalized, proteome-wide role in shaping protein-protein interaction networks. Therefore, we have undertaken here a bioinformatics screening of the human proteome and interactome in search of quantitative evidence of such a role. We first identified the sets of proteins that contain repeats of any one of the 20 amino acids, as well as control sets of proteins chosen at random in the proteome. We then analyzed the connectivity between the proteins of the AAR-containing protein sets and we compared it with that observed in the corresponding control networks. We find evidence for different degrees of connectivity in the different AAR-containing protein networks. Indeed, networks of proteins containing polyglutamine, polyglutamate, polyproline, and other AARs show significantly increased levels of connectivity, whereas networks containing polyleucine and other hydrophobic repeats show lower degrees of connectivity. Furthermore, we observed that numerous protein-protein, -nucleic acid, and -lipid interaction domains are significantly enriched in specific AAR protein groups. These findings support the notion of a generalized, combinatorial role of AARs, together with conventional protein interaction domains, in shaping

  18. Bioconjugation of therapeutic proteins and enzymes using the expanded set of genetically encoded amino acids.

    PubMed

    Lim, Sung In; Kwon, Inchan

    2016-10-01

    The last decade has witnessed striking progress in the development of bioorthogonal reactions that are strictly directed towards intended sites in biomolecules while avoiding interference by a number of physical and chemical factors in biological environment. Efforts to exploit bioorthogonal reactions in protein conjugation have led to the evolution of protein translational machineries and the expansion of genetic codes that systematically incorporate a range of non-natural amino acids containing bioorthogonal groups into recombinant proteins in a site-specific manner. Chemoselective conjugation of proteins has begun to find valuable applications to previously inaccessible problems. In this review, we describe bioorthogonal reactions useful for protein conjugation, and biosynthetic methods that produce proteins amenable to those reactions through an expanded genetic code. We then provide key examples in which novel protein conjugates, generated by the genetic incorporation of a non-natural amino acid and the chemoselective reactions, address unmet needs in protein therapeutics and enzyme engineering. PMID:26036278

  19. Proximity-enabled protein crosslinking through genetically encoding haloalkane unnatural amino acids.

    PubMed

    Xiang, Zheng; Lacey, Vanessa K; Ren, Haiyan; Xu, Jing; Burban, David J; Jennings, Patricia A; Wang, Lei

    2014-02-17

    The selective generation of covalent bonds between and within proteins would provide new avenues for studying protein function and engineering proteins with new properties. New covalent bonds were genetically introduced into proteins by enabling an unnatural amino acid (Uaa) to selectively react with a proximal natural residue. This proximity-enabled bioreactivity was expanded to a series of haloalkane Uaas. Orthogonal tRNA/synthetase pairs were evolved to incorporate these Uaas, which only form a covalent thioether bond with cysteine when positioned in close proximity. By using the Uaa and cysteine, spontaneous covalent bond formation was demonstrated between an affibody and its substrate Z protein, thereby leading to irreversible binding, and within the affibody to increase its thermostability. This strategy of proximity-enabled protein crosslinking (PEPC) may be generally expanded to target different natural amino acids, thus providing diversity and flexibility in covalent bond formation for protein research and protein engineering. PMID:24449339

  20. Cellular retinol-binding protein and retinoic acid-binding protein in rat testes: effect of retinol depletion.

    PubMed

    Ong, D E; Tsai, C H; Chytil, F

    1976-02-01

    Testes of rats contain two cellular binding proteins of interest in vitamin A metabolism. One protein binds retinoic acid with high specificity; the other binds retinol with high specificity. When the cellular retinol-binding protein was partially purified from rat testes, it exhibited fluorescence excitation and emission spectra similar to that of all-trans-retinol in hexane. Exposure of this preparation to UV light destroyed this fluorescence but spectra identical to the original were obtained after addition of retinol. Hexane extracts of the binding protein had fluorescence spectra identical to all-trans-retinol, suggesting that this compound is bound to the protein in vivo. Extracts of testes from retinol depleted rats were submitted to gel filtration but failed to show a retinol-like fluorescence at the elution position of retinol binding protein. This fluorescence was observed in the preparations from pair fed control animals. However, after addition of all-trans-retinol to the extracts from the depleted rats, fluorescence at that elution position was observed. This indicates that in testes of retinol depleted rats the cellular retinol binding protein is present but without bound retinol, in contrast to the non-depleted rats where 30-43% of the binding protein had bound retinol. The amounts of cellular retinol binding protein and retinoic acid binding protein in testes, as determined by sucrose gradient centrifugation, were found to be similar for retinol depleted and pair fed control rats. PMID:942996

  1. Total tract nutrient digestion and milk fatty acid profile of dairy cows fed diets containing different levels of whole raw soya beans.

    PubMed

    Venturelli, B C; de Freitas Júnior, J E; Takiya, C S; de Araújo, A P C; Santos, M C B; Calomeni, G D; Gardinal, R; Vendramini, T H A; Rennó, F P

    2015-12-01

    Whole oilseeds such as soya beans have been utilized in dairy rations to supply additional fat and protein. However, antinutritional components contained in soya beans, such as trypsin inhibitors and haemagglutinins (lectins) may alter digestibility of nutrients and consequently affect animal performance. The objective of the present experiment was to quantify the effect of different levels of whole raw soya beans in diets of dairy cows on nutrient intake, total tract digestion, nutrient balances and milk yield and composition. Sixteen mid to late-lactation cows (228 ± 20 days in milk; mean ± SD) were used in four replicated 4 × 4 Latin square design experiment with 21-d periods. Cows were assigned to each square according to milk yield and DIM. The animals were randomly allocated to treatments: control (without soya beans addition; CO), WS9, WS18 and WS27, with addition of 9%, 18% and 27% of whole raw soya bean in diet on a dry matter (DM) basis respectively. All diets contained identical forage and concentrate components and consisted of maize silage and concentrate based on ground corn and soya beans at a ratio of 60:40. There were no differences in OM, CP, NDF and NEL intakes (kg/day and MJ/day) among the treatments (p > 0.05). However, DM and NFC intakes were negatively affected (p = 0.04 and p < 0.01, respectively) and ether extract (EE) intake was positively affected (p < 0.01). Total tract digestion increased linearly with whole raw soya beans for EE (p < 0.01) and NDF (p = 0.01). The excretion (kg/day) of digested soya beans grains increased linearly according to addition of whole raw soya beans. However, the nutritive characteristics of excreted grains were not altered. Milk (kg), milk lactose (kg) and protein (kg) yield decreased linearly (p < 0.01, p < 0.01 and p = 0.04, respectively) milk fat content (%) increased linearly (p < 0.01) with whole raw soya beans inclusion. Increasing addition of whole raw soya beans affected milk fatty acid profile

  2. Keloids in rural black South Africans. Part 2: dietary fatty acid intake and total phospholipid fatty acid profile in the blood of keloid patients.

    PubMed

    Louw, L; Dannhauser, A

    2000-11-01

    In the second part of this study, emphasis is placed on nutritional intakes (fatty acids and micronutrients) and fatty acid intake and metabolism in the blood, respectively, according to a combined 24 h recall and standardized food frequency questionnaire analyses of keloid prone patients (n=10), compared with normal black South Africans (n=80), and total phospholipid blood (plasma and red blood cell ) analyses of keloid patients (n=20), compared with normal individuals (n=20). Lipid extraction and fractionation by standard procedures, total phospholipid (TPL) separation with thin layer chromatography, and fatty acid methyl ester analyses with gas liquid chromatography techniques were used. Since nutrition may play a role in several disease disorders, the purpose of this study was to confirm or refute a role for essential fatty acids (EFAs) in the hypothesis of keloid formations stated in part 1 of this study. (1)According to the Canadian recommendation (1991), we observed that in keloid patients linoleic acid (LA) and arachidonic acid (AA) dietary intakes, as EFAs of the omega-6-series, are higher than the recommended 7-11 g/d. However, the a-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) dietary intakes, as EFAs of the omega-3 series, are lower than the recommendation of 1.1-1.5 g/d. This was also the case in the control group, where a higher dietary intake of the omega-6 fatty acids and a slightly lower dietary intake of the omega-3 fatty acids occurred. Thus, we confirm a high dietary intake of LA (as a product of organ meats, diary products and many vegetable oils) and AA (as a product of meats and egg yolks), as well as lower dietary intakes of ALA (as a product of grains, green leafy vegetables, soy oil, rapeseed oil and linseed), and EPA and DHA (as products of marine oils). Lower micronutrient intakes than the recommended dietary allowances were observed in the keloid group that may influence EFA metabolism and/or collagen

  3. Possible involvement of lipoic acid in binding protein-dependent transport systems in Escherichia coli.

    PubMed

    Richarme, G

    1985-04-01

    We describe the properties of the binding protein dependent-transport of ribose, galactose, and maltose and of the lactose permease, and the phosphoenolpyruvate-glucose phosphotransferase transport systems in a strain of Escherichia coli which is deficient in the synthesis of lipoic acid, a cofactor involved in alpha-keto acid dehydrogenation. Such a strain can grow in the absence of lipoic acid in minimal medium supplemented with acetate and succinate. Although the lactose permease and the phosphoenolypyruvate-glucose phosphotransferase are not affected by lipoic acid deprivation, the binding protein-dependent transports are reduced by 70% in conditions of lipoic acid deprivation when compared with their activity in conditions of lipoic acid supply. The remaining transport is not affected by arsenate but is inhibited by the uncoupler carbonylcyanide-m-chlorophenylhydrazone; however the lipoic acid-dependent transport is completely inhibited by arsenate and only weakly inhibited by carbonylcyanide-m-chlorophenylhydrazone. The known inhibitor of alpha-keto acid dehydrogenases, 5-methoxyindole-2-carboxylic acid, completely inhibits all binding protein-dependent transports whether in conditions of lipoic supply or deprivation; the results suggest a possible relation between binding protein-dependent transport and alpha-keto acid dehydrogenases and shed light on the inhibition of these transports by arsenicals and uncouplers. PMID:3920206

  4. Thyroid hormone responsive protein Spot14 enhances catalysis of fatty acid synthase in lactating mammary epithelium[S

    PubMed Central

    Rudolph, Michael C.; Wellberg, Elizabeth A.; Lewis, Andrew S.; Terrell, Kristina L.; Merz, Andrea L.; Maluf, N. Karl; Serkova, Natalie J.; Anderson, Steven M.

    2014-01-01

    Thyroid hormone responsive protein Spot 14 has been consistently associated with de novo fatty acid synthesis activity in multiple tissues, including the lactating mammary gland, which synthesizes large quantities of medium chain fatty acids (MCFAs) exclusively via FASN. However, the molecular function of Spot14 remains undefined during lactation. Spot14-null mice produce milk deficient in total triglyceride and de novo MCFA that does not sustain optimal neonatal growth. The lactation defect was rescued by provision of a high fat diet to the lactating dam. Transgenic mice overexpressing Spot14 in mammary epithelium produced total milk fat equivalent to controls, but with significantly greater MCFA. Spot14-null dams have no diminution of metabolic gene expression, enzyme protein levels, or intermediate metabolites that accounts for impaired de novo MCFA. When [13C] fatty acid products were quantified in vitro using crude cytosolic lysates, native FASN activity was 1.6-fold greater in control relative to Spot14-null lysates, and add back of Spot14 partially restored activity. Recombinant FASN catalysis increased 1.4-fold and C = 14:0 yield was enhanced 4-fold in vitro following addition of Spot14. These findings implicate Spot14 as a direct protein enhancer of FASN catalysis in the mammary gland during lactation when maximal MCFA production is needed. PMID:24771867

  5. Production of low chlorogenic and caffeic acid containing sunflower meal protein isolate and its use in functional wheat bread making.

    PubMed

    Shchekoldina, Tatiana; Aider, Mohammed

    2014-10-01

    Sunflower meal protein isolate (SMPI) is a promising food additive in different matrices. However, the uses of SMPI are limited because of the presence of antinutritional compounds like polyphenolic substances. Chlorogenic and caffeic acids are the dominants polyphenolics in the SMPI. These substances cause significant changes of the colour of the meal, proteins and food matrices during their extraction and use as food additives. Moreover, these substances lower the nutritional value of the end product due to their interaction with some amino acids such as lysine and methionine. Thus, the removal of these substances is important to enable the use of the SMPI and meal in general in a greater extent in food applications and replacing more expensive protein sources such as soy proteins. The aim of this work was to study the production of functional bread by supplementing wheat flour with sunflower meal protein isolate (SMPI). SMPI with low content of chlorogenic and caffeic acid was usefully produced following alkaline extraction and purification with succinic acid. Purified SMPI showed well balanced amino acid profile and was characterized by high water and fat absorption capacities. It was incorporated to dough formula at 8-12 % of the total wheat flour. The results showed that production of bread supplemented with SMPI was technologically feasible. The supplemented bread had high mass volume and nutritional quality compared to the control bread. The optimal SMPI to incorporate into dough formula without significant alteration of the final bread colour was established at 10 %. This study will be helpful to find economic ways to enhance the nutritional quality of wheat bread and to improve the profitability of sunflower meal residue. PMID:25328173

  6. Lower vegetable protein intake and higher dietary acid load associated with lower carbohydrate intake are risk factors for metabolic syndrome in patients with type 2 diabetes: Post-hoc analysis of a cross-sectional study

    PubMed Central

    Iwase, Hiroya; Tanaka, Muhei; Kobayashi, Yukiko; Wada, Sayori; Kuwahata, Masashi; Kido, Yasuhiro; Hamaguchi, Masahide; Asano, Mai; Yamazaki, Masahiro; Hasegawa, Goji; Nakamura, Naoto; Fukui, Michiaki

    2015-01-01

    Aims/Introduction A low-carbohydrate diet based on animal sources is associated with higher all-cause mortality, whereas a vegetable-based low-carbohydrate diet is associated with lower cardiovascular disease mortality. It has been suggested that acid/base imbalance might play an important role in some cardiometabolic abnormalities. The aims of the present study were to evaluate whether carbohydrate intake is associated with quality of dietary protein and acid load, and whether these are related to metabolic syndrome in patients with type 2 diabetes. Materials and Methods The present cross-sectional study involved 149 patients with type 2 diabetes. Dietary intake was assessed using a validated self-administered diet history questionnaire. Dietary acid load was assessed by potential renal acid load and net endogenous acid production. Results Mean daily total energy intake, carbohydrate intake, animal protein intake and vegetable protein intake were 1821.5 kcal, 248.8 g, 36.1 g and 31.1 g, respectively. Carbohydrate energy/total energy was negatively correlated with animal protein energy/total energy, potential renal acid load or net endogenous acid production score, and was positively correlated with vegetable protein energy/total energy. Logistic regression analyses showed that the subgroup of patients with a lower vegetable protein energy/total energy or higher potential renal acid load or net endogenous acid production score was significantly associated with the prevalence of metabolic syndrome. Conclusions The present study showed that carbohydrate intake was associated with the quality of dietary protein and dietary acid load. Furthermore, decreased vegetable protein intake and increased dietary acid load were associated with the prevalence of metabolic syndrome. PMID:26221526

  7. Proteins.

    ERIC Educational Resources Information Center

    Doolittle, Russell F.

    1985-01-01

    Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

  8. Intakes of total fat, saturated, monounsaturated and polyunsaturated fatty acids in Irish children, teenagers and adults.

    PubMed

    Joyce, Triona; Wallace, Alison J; McCarthy, Sinead N; Gibney, Michael J

    2009-02-01

    Recommendations limiting the intake of total fat, SFA, MUFA and PUFA have been established in several countries with the aim of reducing the risk of chronic diseases such as CVD. Studies have shown that intakes of total fat and SFA are above desired recommended intake levels across a wide range of age and sex groups. In addition, intakes of PUFA and MUFA are often reported to be less than the desired recommended intake levels. The aims of the present paper are to provide the first data on estimates of current intakes and main food sources of SFA, MUFA and PUFA in Irish children (aged 5-12 years), teenagers (aged 13-17 years) and adults (aged 18-64 years) and to analyse compliance with current dietary recommendations. Data for this analysis were based on the North/South Ireland Food Consumption Survey (n 1379, 18-64 years), the National Children's Food Survey (n 594, 5-12 years) and the National Teen Food Survey (n 441, 13-17 years). Results showed that SFA intakes in Irish children, teenagers and adults are high, with only 6 % of children, 11 % of teenagers and 21 % of adults in compliance with the recommended daily intake. The main food groups that contributed to SFA intakes were whole milk; fresh meat; meat products; biscuits, cakes, buns and pastries; and sugars, confectionery and preserves. PMID:19026091

  9. Apparent Consumption vs. Total Consumption--A Lead-Acid Battery Case Study

    USGS Publications Warehouse

    Wilburn, David R.; Buckingham, David A.

    2006-01-01

    Introduction: This report compares estimates of U.S. apparent consumption of lead with estimates of total U.S. consumption of this mineral commodity from a materials flow perspective. The difference, attributed to the amount of lead contained in imported and exported products, was found to be significant for this sector. The study also assesses the effects of including mineral commodities incorporated in manufactured products on the interpretation of observed trends in minerals consumption and trade. Materials flow is a systems approach to understanding what happens to the materials we use from the time a material is extracted, through its processing and manufacturing, to its ultimate disposition. The U.S. Geological Survey (USGS) provides accurate and detailed mineral production and mineral commodity consumption statistics that are essential for government, nongovernment organizations, and the public to gain a better understanding of how and where materials are used and their effect on the environment and society. Published statistics on mineral apparent consumption are limited to estimates of consumption of raw material forms (ore, concentrate, and [or] refined metal). For this study, apparent consumption is defined as mine production + secondary refined production + imports (concentrates and refined metal) ? exports (concentrates and refined metal) + adjustments for government and industry stock changes. These estimates do not account for the amount of mineral commodities contained in manufactured products that are imported to the United States, nor do they deduct the amount of these mineral commodities contained in manufactured products that are exported from the United States. When imports or exports of manufactured products contribute significantly to the total use of a particular raw material, an estimate of consumption that does not consider the incorporated forms of these mineral commodities within imported or exported manufactured products can be either

  10. Method for nucleic acid hybridization using single-stranded DNA binding protein

    DOEpatents

    Tabor, Stanley; Richardson, Charles C.

    1996-01-01

    Method of nucleic acid hybridization for detecting the presence of a specific nucleic acid sequence in a population of different nucleic acid sequences using a nucleic acid probe. The nucleic acid probe hybridizes with the specific nucleic acid sequence but not with other nucleic acid sequences in the population. The method includes contacting a sample (potentially including the nucleic acid sequence) with the nucleic acid probe under hybridizing conditions in the presence of a single-stranded DNA binding protein provided in an amount which stimulates renaturation of a dilute solution (i.e., one in which the t.sub.1/2 of renaturation is longer than 3 weeks) of single-stranded DNA greater than 500 fold (i.e., to a t.sub.1/2 less than 60 min, preferably less than 5 min, and most preferably about 1 min.) in the absence of nucleotide triphosphates.

  11. AFAL: a web service for profiling amino acids surrounding ligands in proteins.

    PubMed

    Arenas-Salinas, Mauricio; Ortega-Salazar, Samuel; Gonzales-Nilo, Fernando; Pohl, Ehmke; Holmes, David S; Quatrini, Raquel

    2014-11-01

    With advancements in crystallographic technology and the increasing wealth of information populating structural databases, there is an increasing need for prediction tools based on spatial information that will support the characterization of proteins and protein-ligand interactions. Herein, a new web service is presented termed amino acid frequency around ligand (AFAL) for determining amino acids type and frequencies surrounding ligands within proteins deposited in the Protein Data Bank and for assessing the atoms and atom-ligand distances involved in each interaction (availability: http://structuralbio.utalca.cl/AFAL/index.html ). AFAL allows the user to define a wide variety of filtering criteria (protein family, source organism, resolution, sequence redundancy and distance) in order to uncover trends and evolutionary differences in amino acid preferences that define interactions with particular ligands. Results obtained from AFAL provide valuable statistical information about amino acids that may be responsible for establishing particular ligand-protein interactions. The analysis will enable investigators to compare ligand-binding sites of different proteins and to uncover general as well as specific interaction patterns from existing data. Such patterns can be used subsequently to predict ligand binding in proteins that currently have no structural information and to refine the interpretation of existing protein models. The application of AFAL is illustrated by the analysis of proteins interacting with adenosine-5'-triphosphate. PMID:25085083

  12. Single molecule DNA interaction kinetics of retroviral nucleic acid chaperone proteins

    NASA Astrophysics Data System (ADS)

    Williams, Mark

    2010-03-01

    Retroviral nucleocapsid (NC) proteins are essential for several viral replication processes including specific genomic RNA packaging and reverse transcription. The nucleic acid chaperone activity of NC facilitates the latter process. In this study, we use single molecule biophysical methods to quantify the DNA interactions of wild type and mutant human immunodeficiency virus type 1 (HIV-1) NC and Gag and human T-cell leukemia virus type 1 (HTLV-1) NC. We find that the nucleic acid interaction properties of these proteins differ significantly, with HIV-1 NC showing rapid protein binding kinetics, significant duplex destabilization, and strong DNA aggregation, all properties that are critical components of nucleic acid chaperone activity. In contrast, HTLV-1 NC exhibits significant destabilization activity but extremely slow DNA interaction kinetics and poor aggregating capability, which explains why HTLV-1 NC is a poor nucleic acid chaperone. To understand these results, we developed a new single molecule method for quantifying protein dissociation kinetics, and applied this method to probe the DNA interactions of wild type and mutant HIV-1 and HTLV-1 NC. We find that mutations to aromatic and charged residues strongly alter the proteins' nucleic acid interaction kinetics. Finally, in contrast to HIV-1 NC, HIV-1 Gag, the nucleic acid packaging protein that contains NC as a domain, exhibits relatively slow binding kinetics, which may negatively impact its ability to act as a nucleic acid chaperone.

  13. Natural vs. random protein sequences: Discovering combinatorics properties on amino acid words.

    PubMed

    Santoni, Daniele; Felici, Giovanni; Vergni, Davide

    2016-02-21

    Casual mutations and natural selection have driven the evolution of protein amino acid sequences that we observe at present in nature. The question about which is the dominant force of proteins evolution is still lacking of an unambiguous answer. Casual mutations tend to randomize protein sequences while, in order to have the correct functionality, one expects that selection mechanisms impose rigid constraints on amino acid sequences. Moreover, one also has to consider that the space of all possible amino acid sequences is so astonishingly large that it could be reasonable to have a well tuned amino acid sequence indistinguishable from a random one. In order to study the possibility to discriminate between random and natural amino acid sequences, we introduce different measures of association between pairs of amino acids in a sequence, and apply them to a dataset of 1047 natural protein sequences and 10,470 random sequences, carefully generated in order to preserve the relative length and amino acid distribution of the natural proteins. We analyze the multidimensional measures with machine learning techniques and show that, to a reasonable extent, natural protein sequences can be differentiated from random ones. PMID:26656109

  14. One-Pot Procedure for Recovery of Gallic Acid from Wastewater and Encapsulation within Protein Particles.

    PubMed

    Nourbakhsh, Himan; Madadlou, Ashkan; Emam-Djomeh, Zahra; Wang, Yi-Cheng; Gunasekaran, Sundaram; Mousavi, Mohammad E

    2016-02-24

    A whey protein isolate solution was heat-denatured and treated with the enzyme transglutaminase, which cross-linked ≈26% of the amino groups and increased the magnitude of the ζ-potential value. The protein solution was microemulsified, and then the resulting water-in-oil microemulsion was dispersed within a gallic acid-rich model wastewater. Gallic acid extraction by the outlined microemulsion liquid membrane (MLM) from the exterior aqueous phase (wastewater) and accumulation within the internal aqueous nanodroplets induced protein cold-set gelation and resulted in the formation of gallic acid-enveloping nanoparticles. Measurements with a strain-controlled rheometer indicated a progressive increase in the MLM viscosity during gallic acid recovery corresponding to particle formation. The mean hydrodynamic size of the nanoparticles made from the heat-denatured and preheated enzymatically cross-linked proteins was 137 and 122 nm, respectively. The enzymatic cross-linking of whey proteins led to a higher gallic acid recovery yield and increased the glass transition enthalpy and temperature. A similar impact on glass transition indices was observed by the gallic acid-induced nanoparticulation of proteins. Scanning electron microscopy showed the existence of numerous jammed/fused nanoparticles. It was suggested on the basis of the results of Fourier transform infrared spectroscopy that the in situ nanoparticulation of proteins shifted the C-N stretching and C-H bending peaks to higher wavenumbers. X-ray diffraction results proposed a decreased β-sheet content for proteins because of the acid-induced particulation. The nanoparticles made from the enzymatically cross-linked protein were more stable against the in vitro gastrointestinal digestion and retained almost 19% of the entrapped gallic acid after 300 min sequential gastric and intestinal digestions. PMID:26862880

  15. Quantitative evaluation of proteins with bicinchoninic acid (BCA): resonance Raman and surface-enhanced resonance Raman scattering-based methods.

    PubMed

    Chen, Lei; Yu, Zhi; Lee, Youngju; Wang, Xu; Zhao, Bing; Jung, Young Mee

    2012-12-21

    A rapid and highly sensitive bicinchoninic acid (BCA) reagent-based protein quantitation tool was developed using competitive resonance Raman (RR) and surface-enhanced resonance Raman scattering (SERRS) methods. A chelation reaction between BCA and Cu(+), which is reduced by protein in an alkaline environment, is exploited to create a BCA-Cu(+) complex that has strong RR and SERRS activities. Using these methods, protein concentrations in solutions can be quantitatively measured at concentrations as low as 50 μg mL(-1) and 10 pg mL(-1). There are many advantages of using RR and SERRS-based assays. These assays exhibit a much wider linear concentration range and provide an additional one (RR method) to four (SERRS method) orders of magnitude increase in detection limits relative to UV-based methods. Protein-to-protein variation is determined using a reference to a standard curve at concentrations of BSA that exhibits excellent recoveries. These novel methods are extremely accurate in detecting total protein concentrations in solution. This improvement in protein detection sensitivity could yield advances in the biological sciences and medical diagnostic field and extend the applications of reagent-based protein assay techniques. PMID:23099478

  16. Proteomic analysis of cerebrospinal fluid in California sea lions (Zalophus californianus) with domoic acid toxicosis identifies proteins associated with neurodegeneration.

    PubMed

    Neely, Benjamin A; Soper, Jennifer L; Gulland, Frances M D; Bell, P Darwin; Kindy, Mark; Arthur, John M; Janech, Michael G

    2015-12-01

    Proteomic studies including marine mammals are rare, largely due to the lack of fully sequenced genomes. This has hampered the application of these techniques toward biomarker discovery efforts for monitoring of health and disease in these animals. We conducted a pilot label-free LC-MS/MS study to profile and compare the cerebrospinal fluid from California sea lions with domoic acid toxicosis (DAT) and without DAT. Across 11 samples, a total of 206 proteins were identified (FDR<0.1) using a composite mammalian database. Several peptide identifications were validated using stable isotope labeled peptides. Comparison of spectral counts revealed seven proteins that were elevated in the cerebrospinal fluid from sea lions with DAT: complement C3, complement factor B, dickkopf-3, malate dehydrogenase 1, neuron cell adhesion molecule 1, gelsolin, and neuronal cell adhesion molecule. Immunoblot analysis found reelin to be depressed in the cerebrospinal fluid from California sea lions with DAT. Mice administered domoic acid also had lower hippocampal reelin protein levels suggesting that domoic acid depresses reelin similar to kainic acid. In summary, proteomic analysis of cerebrospinal fluid in marine mammals is a useful tool to characterize the underlying molecular pathology of neurodegenerative disease. All MS data have been deposited in the ProteomeXchange with identifier PXD002105 (http://proteomecentral.proteomexchange.org/dataset/PXD002105). PMID:26364553

  17. Genetically programmed expression of proteins containing the unnatural amino acid phenylselenocysteine

    DOEpatents

    Wang, Jiangyun; Schultz, Peter G.

    2013-03-12

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetase that can incorporate the unnatural amino acid phenylselenocysteine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal aminoacyl-tRNA synthetases, polynucleotides encoding the novel sythetases molecules, methods for identifying and making the novel synthetases, methods for producing containing the unnatural amino acid phenylselenocysteine and translation systems. The invention further provides methods for producing modified proteins (e.g., lapidated proteins) through targeted modification of the phenylselenocysteine residue in a protein.

  18. First total synthesis and antileishmanial activity of (Z)-16-methyl-11-heptadecenoic acid, a new marine fatty acid from the sponge Dragmaxia undata

    PubMed Central

    Carballeira, Néstor M.; Montano, Nashbly; Cintrón, Gabriel A.; Márquez, Carmary; Rubio, Celia Fernández; Prada, Christopher Fernández; Balaña-Fouce, Rafael

    2010-01-01

    The first total synthesis for the (Z)-16-methyl-11-heptadecenoic acid, a novel fatty acid from the sponge Dragmaxia undata, was accomplished in seven steps and in a 44% overall yield. The use of (trimethylsilyl)acetylene was key in the synthesis. Based on a previous developed strategy in our laboratory the best synthetic route towards the title compound was first acetylide coupling of (trimethylsilyl)acetylene to the long-chain protected 10-bromo-1-decanol followed by a second acetylide coupling to the short-chain 1-bromo-4-methylpentane, which resulted in higher yields. Complete spectral data is also presented for the first time for this recently discovered fatty acid and the cis double bond stereochemistry of the natural acid was established. The title compound displayed antiprotozoal activity against Leishmania donovani (IC50 = 165.5 ± 23.4 µM) and inhibited the leishmania DNA topoisomerase IB enzyme (LdTopIB) with an IC50 = 62.3 ± 0.7 µM. PMID:21129369

  19. First total synthesis and antiprotozoal activity of (Z)-17-methyl-13-octadecenoic acid, a new marine fatty acid from the sponge Polymastia penicillus

    PubMed Central

    Carballeira, Néstor M.; Montano, Nashbly; Balaña-Fouce, Rafael; Prada, Christopher Fernández

    2009-01-01

    The first total synthesis for the (Z)-17-methyl-13-octadecenoic acid was accomplished in seven steps and in a 45% overall yield. The use of (trimethylsilyl)acetylene was key in the synthesis. Based on a previous developed strategy in our laboratory the best synthetic route towards the title compound was first acetylide coupling of (trimethylsilyl)acetylene to the long-chain protected 12-bromo-1-dodecanol followed by a second acetylide coupling to the short-chain 3-methyl-1-bromobutane, which resulted in higher yields. Complete spectral data is also presented for the first time for this recently discovered fatty acid. The title compound displayed antiprotozoal activity against Leishmania donovani (EC50 = 19.8 μg/ml) and inhibited the leishmania DNA topoisomerase IB at concentrations of 50 μM. PMID:19527698

  20. Fish protein hydrolysates: proximate composition, amino acid composition, antioxidant activities and applications: a review.

    PubMed

    Chalamaiah, M; Dinesh Kumar, B; Hemalatha, R; Jyothirmayi, T

    2012-12-15

    The fish processing industry produces more than 60% by-products as waste, which includes skin, head, viscera, trimmings, liver, frames, bones, and roes. These by-product wastes contain good amount of protein rich material that are normally processed into low market-value products, such as animal feed, fish meal and fertilizer. In view of utilizing these fish industry wastes, and for increasing the value to several underutilised fish species, protein hydrolysates from fish proteins are being prepared by several researchers all over the world. Fish protein hydrolysates are breakdown products of enzymatic conversion of fish proteins into smaller peptides, which normally contain 2-20 amino acids. In recent years, fish protein hydrolysates have attracted much attention of food biotechnologists due to the availability of large quantities of raw material for the process, and presence of high protein content with good amino acid balance and bioactive peptides (antioxidant, antihypertensive, immunomodulatory and antimicrobial peptides). PMID:22980905

  1. Single-molecule pull-down for investigating protein-nucleic acid interactions.

    PubMed

    Fareh, Mohamed; Loeff, Luuk; Szczepaniak, Malwina; Haagsma, Anna C; Yeom, Kyu-Hyeon; Joo, Chirlmin

    2016-08-01

    The genome and transcriptome are constantly modified by proteins in the cell. Recent advances in single-molecule techniques allow for high spatial and temporal observations of these interactions between proteins and nucleic acids. However, due to the difficulty of obtaining functional protein complexes, it remains challenging to study the interactions between macromolecular protein complexes and nucleic acids. Here, we combined single-molecule fluorescence with various protein complex pull-down techniques to determine the function and stoichiometry of ribonucleoprotein complexes. Through the use of three examples of protein complexes from eukaryotic cells (Drosha, Dicer, and TUT4 protein complexes), we provide step-by-step guidance for using novel single-molecule techniques. Our single-molecule methods provide sub-second and nanometer resolution and can be applied to other nucleoprotein complexes that are essential for cellular processes. PMID:27017911

  2. Conservation of Shannon's redundancy for proteins. [information theory applied to amino acid sequences

    NASA Technical Reports Server (NTRS)

    Gatlin, L. L.

    1974-01-01

    Concepts of information theory are applied to examine various proteins in terms of their redundancy in natural originators such as animals and plants. The Monte Carlo method is used to derive information parameters for random protein sequences. Real protein sequence parameters are compared with the standard parameters of protein sequences having a specific length. The tendency of a chain to contain some amino acids more frequently than others and the tendency of a chain to contain certain amino acid pairs more frequently than other pairs are used as randomness measures of individual protein sequences. Non-periodic proteins are generally found to have random Shannon redundancies except in cases of constraints due to short chain length and genetic codes. Redundant characteristics of highly periodic proteins are discussed. A degree of periodicity parameter is derived.

  3. Protecting-Group-Free Total Synthesis of (-)-Lycopodine via Phosphoric Acid Promoted Alkyne Aza-Prins Cyclization.

    PubMed

    Ma, Donghui; Zhong, Zhuliang; Liu, Zaimin; Zhang, Mingjie; Xu, Shiyan; Xu, Dengyu; Song, Dengpeng; Xie, Xingang; She, Xuegong

    2016-09-01

    A protecting-group-free route for the total synthesis of (-)-lycopodine was demonstrated in only 8 steps from Wade's fawcettimine enone (12 steps from commercial availiable (R)-(+)-pulegone). The key core of this alkaloid was constructed through a phosphoric acid promoted and highly stereocontrolled alkyne aza-Prins cyclization reaction, synchronously establishing the bridged B-ring and the C13 quaternary stereocenter. Importantly, the synthesis further features a new efficient approach for the preparation of other lycopodine-type alkaloids. PMID:27529730

  4. GLUCOCORTICOIDS REGULATE THE CONCENTRATION OF GLIAL FIBRILLARY ACIDIC PROTEIN THROUGHOUT THE BRAIN

    EPA Science Inventory

    The role of glucocorticoids in the in vivo regulation of glial fibrillary acidic protein was examined. orticosterone administration to adult rats resulted in decreased levels of GFAP throughout the brain whereas adrenalectomy caused levels of GFAP to increase. orticosterone admin...

  5. GONADAL STEROIDS REGULATED THE EXPRESSION OF GLIAL FIBRILLARY ACIDIC PROTEIN IN THE ADULT MALE RAT HIPPOCAMPUS

    EPA Science Inventory

    This study demonstrates that gonadal steroids (estradiol, testosterone, dihydrotestosterone) can inhibit the expression of glial fibrillary acidic protein and it MRNA in the adult male rat brain. esticular hormones may influence the activity of astrocytes in the intact and lesion...

  6. Identify Secretory Protein of Malaria Parasite with Modified Quadratic Discriminant Algorithm and Amino Acid Composition.

    PubMed

    Feng, Yong-E

    2016-06-01

    Malaria parasite secretes various proteins in infected red blood cell for its growth and survival. Thus identification of these secretory proteins is important for developing vaccine or drug against malaria. In this study, the modified method of quadratic discriminant analysis is presented for predicting the secretory proteins. Firstly, 20 amino acids are divided into five types according to the physical and chemical characteristics of amino acids. Then, we used five types of amino acids compositions as inputs of the modified quadratic discriminant algorithm. Finally, the best prediction performance is obtained by using 20 amino acid compositions, the sensitivity of 96 %, the specificity of 92 % with 0.88 of Mathew's correlation coefficient in fivefold cross-validation test. The results are also compared with those of existing prediction methods. The compared results shown our method are prominent in the prediction of secretory proteins. PMID:26286010

  7. Study of Stationary Phase Metabolism Via Isotopomer Analysis of Amino Acids from an Isolated Protein

    SciTech Connect

    Shaikh, AfshanS.; Tang, YinjieJ.; Mukhopadhyay, Aindrila; Martin, Hector Garcia; Gin, Jennifer; Benke, Peter; Keasling, Jay D.

    2009-09-14

    Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully 13C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.

  8. Probing Protein Structure by Amino Acid-Specific Covalent Labeling and Mass Spectrometry

    PubMed Central

    Mendoza, Vanessa Leah; Vachet, Richard W.

    2009-01-01

    For many years, amino acid-specific covalent labeling has been a valuable tool to study protein structure and protein interactions, especially for systems that are difficult to study by other means. These covalent labeling methods typically map protein structure and interactions by measuring the differential reactivity of amino acid side chains. The reactivity of amino acids in proteins generally depends on the accessibility of the side chain to the reagent, the inherent reactivity of the label and the reactivity of the amino acid side chain. Peptide mass mapping with ESI- or MALDI-MS and peptide sequencing with tandem MS are typically employed to identify modification sites to provide site-specific structural information. In this review, we describe the reagents that are most commonly used in these residue-specific modification reactions, details about the proper use of these covalent labeling reagents, and information about the specific biochemical problems that have been addressed with covalent labeling strategies. PMID:19016300

  9. Use of anaerobic green fluorescent protein versus green fluorescent protein as reporter in lactic acid bacteria.

    PubMed

    Landete, José M; Langa, Susana; Revilla, Concepción; Margolles, Abelardo; Medina, Margarita; Arqués, Juan L

    2015-08-01

    Lactic acid bacteria (LAB) are commonly used in the production of fermented and probiotic foods. Development of molecular tools to discriminate the strains of interest from the endogenous microbiota in complex environments like food or gut is of high interest. Green fluorescent protein (GFP)-like chromophores strictly requires molecular oxygen for maturation of fluorescence, which restrict the study of microorganisms in low-oxygen environments. In this work, we have developed a noninvasive cyan-green fluorescent based reporter system for real-time tracking of LAB that is functional under anoxic conditions. The evoglow-Pp1 was cloned downstream from the promoters D-alanyl-D-alanine carboxypeptidase and elongation factor Tu of Lactobacillus reuteri CECT925 using pNZ8048 and downstream of the lactococcal P1 promoter using pT1NX. The classical gfp was also cloned in pT1NX. These recombinant expression vectors were electroporated into Lactococccus, Lactobacillus, and Enterococcus strains with biotechnological and/or probiotic interests to assess and compare their functionality under different conditions of oxygen and pH. The expression was analyzed by imaging and fluorometric methods as well as by flow cytometry. We demonstrate that reporter systems pNZ:TuR-aFP and pT1-aFP are two versatile molecular markers for monitoring LAB in food and fecal environments without the potential problems caused by oxygen and pH limitations, which could be exploited for in vivo studies. Production of the fluorescent protein did not disturb any important physiological properties of the parental strains, such as growth rate, reuterin, or bacteriocin production. PMID:26129953

  10. Short communication: Intake, milk production, and milk fatty acid profile of dairy cows fed diets combining fresh forage with a total mixed ration.

    PubMed

    Mendoza, A; Cajarville, C; Repetto, J L

    2016-03-01

    To establish the effects of access time to high-quality temperate fresh forage (FF) on intake and performance of cows fed a total mixed ration (TMR), 9 Holstein cows were assigned to three 3 × 3 Latin squares with 20-d periods with sampling in the last 10 d. The following treatments were evaluated: 0 (T0), 4 (T4), and 8 (T8) h of daily access to FF. Forage (Lolium multiflorum) was cut daily and offered ad libitum beginning at 0800 h in individual stalls, and a TMR was offered ad libitum during the period when cows had no access to FF. Fresh forage dry matter intake (DMI) increased and TMR DMI decreased with the access time to FF, whereas total DMI was 3.0 kg higher for T4 than for T8; no differences were detected with T0. Compared with T0, 8h/d of access to FF decreased milk, protein, and casein yields, and tended to decrease fat and lactose yields, but treatment had no effect on milk composition or feed efficiency. The milk fatty acid profile in T8 had a higher content of rumenic, vaccenic, and linolenic acids compared with T0. We concluded that cows with 4h of access to high-quality FF had similar DMI and milk yields as cows fed only the TMR, but more than 4h of access reduced DMI and performance without changes in feed efficiency, although milk fat had enhanced levels of beneficial fatty acids. PMID:26778319

  11. The primary structure of fatty-acid-binding protein from nurse shark liver. Structural and evolutionary relationship to the mammalian fatty-acid-binding protein family.

    PubMed

    Medzihradszky, K F; Gibson, B W; Kaur, S; Yu, Z H; Medzihradszky, D; Burlingame, A L; Bass, N M

    1992-02-01

    The primary structure of a fatty-acid-binding protein (FABP) isolated from the liver of the nurse shark (Ginglymostoma cirratum) was determined by high-performance tandem mass spectrometry (employing multichannel array detection) and Edman degradation. Shark liver FABP consists of 132 amino acids with an acetylated N-terminal valine. The chemical molecular mass of the intact protein determined by electrospray ionization mass spectrometry (Mr = 15124 +/- 2.5) was in good agreement with that calculated from the amino acid sequence (Mr = 15121.3). The amino acid sequence of shark liver FABP displays significantly greater similarity to the FABP expressed in mammalian heart, peripheral nerve myelin and adipose tissue (61-53% sequence similarity) than to the FABP expressed in mammalian liver (22% similarity). Phylogenetic trees derived from the comparison of the shark liver FABP amino acid sequence with the members of the mammalian fatty-acid/retinoid-binding protein gene family indicate the initial divergence of an ancestral gene into two major subfamilies: one comprising the genes for mammalian liver FABP and gastrotropin, the other comprising the genes for mammalian cellular retinol-binding proteins I and II, cellular retinoic-acid-binding protein myelin P2 protein, adipocyte FABP, heart FABP and shark liver FABP, the latter having diverged from the ancestral gene that ultimately gave rise to the present day mammalian heart-FABP, adipocyte FABP and myelin P2 protein sequences. The sequence for intestinal FABP from the rat could be assigned to either subfamily, depending on the approach used for phylogenetic tree construction, but clearly diverged at a relatively early evolutionary time point. Indeed, sequences proximately ancestral or closely related to mammalian intestinal FABP, liver FABP, gastrotropin and the retinoid-binding group of proteins appear to have arisen prior to the divergence of shark liver FABP and should therefore also be present in elasmobranchs

  12. Relationship of Circulating Total Homocysteine and C-Reactive Protein to Trabecular Bone in Postmenopausal Women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homocysteine (Hcy) and C-reactive protein (CRP) are novel risk factors for osteoporosis. The purpose of this analysis was to determine the relationship of Hcy and CRP to volumetric trabecular bone, but also to assess their relationship to areal composite bone in healthy postmenopausal women (N=184)....

  13. Hypochlorite-induced oxidation of amino acids, peptides and proteins.

    PubMed

    Hawkins, C L; Pattison, D I; Davies, M J

    2003-12-01

    Activated phagocytes generate the potent oxidant hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is known to react with a number of biological targets including proteins, DNA, lipids and cholesterol. Proteins are likely to be major targets for reaction with HOCl within a cell due to their abundance and high reactivity with HOCl. This review summarizes information on the rate of reaction of HOCl with proteins, the nature of the intermediates formed, the mechanisms involved in protein oxidation and the products of these reactions. The predicted targets for reaction with HOCl from kinetic modeling studies and the consequences of HOCl-induced protein oxidation are also discussed. PMID:14661089

  14. Simple, Fast, and Simultaneous Detection of Plasma Total Homocysteine, Methylmalonic Acid, Methionine, and 2-Methylcitric Acid Using Liquid Chromatography and Mass Spectrometry (LC/MS/MS).

    PubMed

    Fu, Xiaowei; Xu, Yan-Kang; Chan, Penny; Pattengale, Paul K

    2013-01-01

    Cobalamin (Vitamin B12) plays an essential role both in the conversion of methylmalonyl-CoA to succinyl-CoA and in the synthesis of methionine (Met) from homocysteine (Hcy). Elevations of total homocysteine (tHcy), Met, methylmalonic acid (MMA), and 2-methylcitric acid (2MCA) are indicative of disorders in these related pathways, and can clinically present as methylmalonic acidemia, cobalamin defects or deficiency, propionic acidemia, homocystinuria, and hypermethioninemia. We have developed a fast, sensitive, and simple method for the simultaneous detection of plasma tHcy, MMA, Met, and 2MCA using liquid chromatography mass spectrometry (LC/MS/MS). All analytes were directly determined without the need of derivatization. Both positive and negative modes were used to achieve the best sensitivity and specificity. The two stereo isomers of 2MCA (2S, 3S) and (2R, 3S) were successfully separated and were designated as 2MCA1 and 2MCA2. The assays were linear up to a concentration of 800 μMol/l for tHcy, 2,000 μMol/l for Met, 80 μMol/l for MMA, 40 μMol/l for 2MCA1, and 40 μMol/l for 2MCA2 (80 μMol/l for total 2MCA), respectively. The recovery was between 84.42 % and 120.05 %. The intra-assay coefficient of variations (CVs) ranged from 2.1 % to 6.9 % (n = 20), and the inter-assay CVs ranged from 2.7 % to 11.6 % (n = 20). Reference intervals were established and verified (n = 125). A total of 15 patients with variable disorders in related pathway were successfully confirmed. The assay can be performed either in diagnostic laboratories or as second-tier, follow-up test in newborn screening laboratories.A fast, sensitive, and simple LC/MS/MS method was developed successfully for the simultaneous detection of plasma total homocysteine, methylmalonic acid, methionine, and 2-methylcitric acid for diagnosis of disorders in related pathways. PMID:23430805

  15. A novel method to identify nucleic acid binding sites in proteins by scanning mutagenesis: application to iron regulatory protein.

    PubMed Central

    Neupert, B; Menotti, E; Kühn, L C

    1995-01-01

    We describe a new procedure to identify RNA or DNA binding sites in proteins, based on a combination of UV cross-linking and single-hit chemical peptide cleavage. Site-directed mutagenesis is used to create a series of mutants with single Asn-Gly sequences in the protein to be analysed. Recombinant mutant proteins are incubated with their radiolabelled target sequence and UV irradiated. Covalently linked RNA- or DNA-protein complexes are digested with hydroxylamine and labelled peptides identified by SDS-PAGE and autoradiography. The analysis requires only small amounts of protein and is achieved within a relatively short time. Using this method we mapped the site at which human iron regulatory protein (IRP) is UV cross-linked to iron responsive element RNA to amino acid residues 116-151. Images PMID:7544459

  16. Tables of critical values for examining compositional non-randomness in proteins and nucleic acids

    NASA Technical Reports Server (NTRS)

    Laird, M.; Holmquist, R.

    1975-01-01

    A binomially distributed statistic is defined to show whether or not the proportion of a particular amino acid in a protein deviates from random expectation. An analogous statistic is derived for nucleotides in nucleic acids. These new statistics are simply related to the classical chi-squared test. They explicitly account for the compositional fluctuations imposed by the finite length of proteins, and they are more accurate than previous tables.

  17. Highly efficient extraction of cellular nucleic acid associated proteins in vitro with magnetic oxidized carbon nanotubes.

    PubMed

    Zhang, Yi; Hu, Zhengyan; Qin, Hongqiang; Wei, Xiaoluan; Cheng, Kai; Liu, Fangjie; Wu, Ren'an; Zou, Hanfa

    2012-12-01

    Nucleic acid associated proteins (NAaP) play the essential roles in gene regulation and protein expression. The global analysis of cellular NAaP would give a broad insight to understand the interaction between nucleic acids and the associated proteins, such as the important proteinous regulation factors on nucleic acids. Proteomic analysis presents a novel strategy to investigate a group of proteins. However, the large scale analysis of NAaP is yet impossible due to the lack of approaches to harvest target protein groups with a high efficiency. Herein, a simple and efficient method was developed to collect cellular NAaP using magnetic oxidized carbon nanotubes based on the strong interaction between carbon nanotubes and nucleic acids along with corresponding associated proteins. We found that the magnetic oxidized carbon nanotubes demonstrated a nearly 100% extraction efficiency for intracellular nucleic acids from cells in vitro. Importantly, the proteins associated on nucleic acids could be highly efficiently harvested using magnetic oxidized carbon nanotubes due to the binding of NAaP on nucleic acids. 1594 groups of nuclear NAaP and 2595 groups of cellular NAaP were extracted and identified from about 1,000,000 cells, and 803 groups of NAaP were analyzed with only about 10,000 cells, showing a promising performance for the proteomic analysis of NAaP from minute cellular samples. This highly efficient extraction strategy for NAaP is a simple approach to identify cellular nucleic acid associated proteome, and we believed this strategy could be further applied in systems biology to understand the gene expression and regulation. PMID:23121485

  18. Effects of one-seed juniper and polyethylene glycol on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein and tannins.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the effect of polyethylene glycol (PEG) on juniper and total intake, rumen fermentation, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and basal diets containing 10% quebracho tannins with no protein supplement (Control; 5% CP) or high rumen degradable (RDP 15% CP) or u...

  19. Glutathione peroxidase's reaction intermediate selenenic acid is stabilized by the protein microenvironment.

    PubMed

    Li, Fei; Liu, Jun; Rozovsky, Sharon

    2014-11-01

    Selenenic acids are highly reactive intermediates of selenoproteins' enzymatic reactions. Knowledge of how the protein environment protects and stabilizes them is fundamental not only to descriptions of selenoproteins' reactivity but also potentially for proteomics and therapeutics. However, selenenic acids are considered particularly short-lived and are not yet identified in wild-type selenoproteins. Here, we report trapping the selenenic acid in glutathione peroxidase, an antioxidant enzyme that efficiently eliminates hydroperoxides. It has long been thought that selenium-containing glutathione peroxidases form a selenenic acid intermediate. However, this putative species has eluded detection. Here, we report its identification. The selenenic acid in bovine glutathione peroxidase 1 was chemically trapped using dimedone, an alkylating agent specific to sulfenic and selenenic acids. The alkylation of the catalytic selenocysteine was verified by electrospray ionization mass spectrometry. In the presence of glutathione, the selenocysteine was not alkylated because the selenenic acid condenses faster with glutathione than the alkylation reaction. In the absence of thiols, the selenenic acid was surprisingly long-lived with 95% of the protein still able to react with dimedone 10 min after hydrogen peroxide was removed, indicating that the protein environment stabilizes the selenenic acid by shielding it from reactive groups in the protein. After 30 min, the selenocysteine was no longer modified but became accessible once the protein was exposed to reducing agents. This suggests that the selenenic acid reacted with a protein's amide or amine to form a selenylamide bond. Such a modification may play a role in protecting glutathione peroxidase׳' reactivity. PMID:25124921

  20. Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

    SciTech Connect

    Garrison, W. M.

    1981-12-01

    An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides, and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the ..cap alpha..,..cap alpha..'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The ..cap alpha..,..cap alpha..'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and bacterial products. All of the available data strongly suggest that the ..cap alpha..,..cap alpha..'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized.

  1. Enterocyte Fatty Acid Binding Proteins (FABPs): Different Functions of Liver- and Intestinal- FABPs in the Intestine

    PubMed Central

    Gajda, Angela M.; Storch, Judith

    2014-01-01

    SUMMARY Fatty acid binding proteins (FABP) are highly abundant cytosolic proteins that are expressed in most mammalian tissues. In the intestinal enterocyte, both Liver- (LFABP; FABP1) and Intestinal-fatty acid binding proteins (IFABP; FABP2) are expressed. These proteins display high affinity binding for long chain fatty acids (FA) and other hydrophobic ligands, thus they are believed to be involved with uptake and trafficking of lipids in the intestine. In vitro studies have identified differences in ligand binding stoichiometry and specificity, and in mechanisms of FA transfer to membranes, and it has been hypothesized that LFABP and IFABP have difference functions in the enterocyte. Studies directly comparing LFABP- and IFABP-null mice have revealed markedly different phenotypes, indicating that these proteins indeed have different functions in intestinal lipid metabolism and whole body energy homeostasis. In this review, we discuss the evolving knowledge of the functions of LFABP and IFABP in the intestinal enterocyte. PMID:25458898

  2. Total volatile fatty acid concentrations are unreliable estimators of treatment effects on ruminal fermentation in vivo.

    PubMed

    Hall, M B; Nennich, T D; Doane, P H; Brink, G E

    2015-06-01

    Volatile fatty acid concentrations ([VFA], mM) have long been used to assess the effect of dietary treatments on ruminal fermentation in vivo. However, discrepancies in statistical results between [VFA] and VFA pool size (VFAmol) possibly related to ruminal digesta liquid amount (LIQ, kg) indicate potential issues with the use of [VFA]. We investigated relationships among [VFA], VFAmol, and LIQ measured 2 h postfeeding using individual lactating cow data (n=175) from 7 separate feeding studies. Regression analyses were performed using mixed models with "study" as a discrete random variable. The mean across studies and average range of values within studies, respectively, were 151 and 75 for [VFA], 11.2 and 9.8 for VFAmol, 73.3 and 41.0 for LIQ, and 289 and 83 mmol/kg for rumen fluid osmolality. Liquid amount changed with VFAmol (3.76 VFAmol+31.2; average within-study R2=0.69), but the relationship was weak between [VFA] and LIQ (0.524 LIQ+112.8; average within-study R2=0.12). The relationship between LIQ and VFAmol was likely a function of the osmotic gradient between rumen liquid and blood. The VFA are a major ruminal solute; VFAmol amounts can affect water flux in the rumen as similar tonicities of rumen fluid and blood are maintained. This also has a damping effect on ruminal solute concentration, creating the weak relationship between [VFA] and LIQ. Within studies, similar [VFA] were found in LIQ differing by 30 kg or more. The difference between minimum and maximum LIQ within cow within study was 12.7 kg (standard deviation=7.1), so inclusion of "cow" in analyses did not correct for the variation in LIQ. To allow valid comparisons of experimental treatments, responses must be on an equivalent basis; concentrations in different LIQ are not on an equivalent basis and so are not valid to use for comparing treatment effects. The [VFA] changed with VFAmol (5.80 VFAmol+86.3; average within-study R2=0.56). However, the ratio of [VFA] to VFAmol ranged from 9.0 to 24

  3. Incorporation of glycine-2-C-14 in acid-insoluble proteins of rat bones and teeth during hypokinesia and administration of thyrocalcitonine

    NASA Technical Reports Server (NTRS)

    Volozhin, A. I.; Stekolnikov, L. I.; Uglova, N. N.; Potkin, V. Y.

    1979-01-01

    A forced limitation of the motor activity in rats (from 5 to 60 days) results in reduced incorporation of glycine 2-C14 in the total acid insoluble proteins of limb bones and its increase in the teeth and mandibular-maxillary bones. Daily administration of five micrograms of thyrocalcitonine together with polyvinylpyrrolidone normalizes the protein metabolism in the bone tissues during the 40 days of experimentation.

  4. Effect of Buddhist meditation on serum cortisol and total protein levels, blood pressure, pulse rate, lung volume and reaction time.

    PubMed

    Sudsuang, R; Chentanez, V; Veluvan, K

    1991-09-01

    Serum cortisol and total protein levels, blood pressure, heart rate, lung volume, and reaction time were studied in 52 males 20-25 years of age practicing Dhammakaya Buddhist meditation, and in 30 males of the same age group not practicing meditation. It was found that after meditation, serum cortisol levels were significantly reduced, serum total protein level significantly increased, and systolic pressure, diastolic pressure and pulse rate significantly reduced. Vital capacity, tidal volume and maximal voluntary ventilation were significantly lower after meditation than before. There were also significant decreases in reaction time after mediation practice. The percentage decrease in reaction time during meditation was 22%, while in subjects untrained in meditation, the percentage decrease was only 7%. Results from these studies indicate that practising Dhammakaya Buddhist meditation produces biochemical and physiological changes and reduces the reaction time. PMID:1801007

  5. Super-resolution Microscopy of Clickable Amino Acids Reveals the Effects of Fluorescent Protein Tagging on Protein Assemblies.

    PubMed

    Vreja, Ingrid C; Nikić, Ivana; Göttfert, Fabian; Bates, Mark; Kröhnert, Katharina; Outeiro, Tiago F; Hell, Stefan W; Lemke, Edward A; Rizzoli, Silvio O

    2015-11-24

    The advent of super-resolution microscopy (nanoscopy) has set high standards for fluorescence tagging. Fluorescent proteins (FPs) are convenient tags in conventional imaging, but their use in nanoscopy has been questioned due to their relatively large size and propensity to form multimers. Here, we compared the nanoscale organization of proteins with or without FP tags by introducing the unnatural amino acid propargyl-L-lysine (PRK) in 26 proteins known to form multimolecular arrangements and into their FP-tagged variants. We revealed the proteins by coupling synthetic fluorophores to PRK via click chemistry and visualized them using ground-state depletion microscopy followed by individual molecule return, as well as stimulated emission depletion microscopy. The arrangements formed by the FP-tagged and nontagged proteins were similar. Mild, but statistically significant differences were observed for only six proteins (23% of all proteins tested). This suggests that FP-based nanoscopy is generally reliable. Unnatural amino acids should be a reliable alternative for the few proteins that are sensitive to FP tagging. PMID:26498474

  6. Bacterial periplasmic sialic acid-binding proteins exhibit a conserved binding site

    SciTech Connect

    Gangi Setty, Thanuja; Cho, Christine; Govindappa, Sowmya; Apicella, Michael A.; Ramaswamy, S.

    2014-07-01

    Structure–function studies of sialic acid-binding proteins from F. nucleatum, P. multocida, V. cholerae and H. influenzae reveal a conserved network of hydrogen bonds involved in conformational change on ligand binding. Sialic acids are a family of related nine-carbon sugar acids that play important roles in both eukaryotes and prokaryotes. These sialic acids are incorporated/decorated onto lipooligosaccharides as terminal sugars in multiple bacteria to evade the host immune system. Many pathogenic bacteria scavenge sialic acids from their host and use them for molecular mimicry. The first step of this process is the transport of sialic acid to the cytoplasm, which often takes place using a tripartite ATP-independent transport system consisting of a periplasmic binding protein and a membrane transporter. In this paper, the structural characterization of periplasmic binding proteins from the pathogenic bacteria Fusobacterium nucleatum, Pasteurella multocida and Vibrio cholerae and their thermodynamic characterization are reported. The binding affinities of several mutations in the Neu5Ac binding site of the Haemophilus influenzae protein are also reported. The structure and the thermodynamics of the binding of sugars suggest that all of these proteins have a very well conserved binding pocket and similar binding affinities. A significant conformational change occurs when these proteins bind the sugar. While the C1 carboxylate has been identified as the primary binding site, a second conserved hydrogen-bonding network is involved in the initiation and stabilization of the conformational states.

  7. The distinct C-terminal acidic domains of HMGB proteins are functionally relevant in Schistosoma mansoni.

    PubMed

    de Abreu da Silva, Isabel Caetano; Carneiro, Vitor Coutinho; Vicentino, Amanda Roberta Revoredo; Aguilera, Estefania Anahi; Mohana-Borges, Ronaldo; Thiengo, Silvana; Fernandez, Monica Ammon; Fantappié, Marcelo Rosado

    2016-04-01

    The Schistosoma mansoni High Mobility Group Box (HMGB) proteins SmHMGB1, SmHMGB2 and SmHMGB3 share highly conserved HMG box DNA binding domains but have significantly different C-terminal acidic tails. Here, we used three full-length and tailless forms of the S. mansoni HMGB proteins to examine the functional roles of their acidic tails. DNA binding assays revealed that the different lengths of the acidic tails among the three SmHMGB proteins significantly and distinctively influenced their DNA transactions. Spectroscopic analyses indicated that the longest acidic tail of SmHMGB3 contributes to the structural stabilisation of this protein. Using immunohistochemical analysis, we showed distinct patterns of SmHMGB1, SmHMGB2 and SmHMGB3 expression in different tissues of adult worms. RNA interference approaches indicated a role for SmHMGB2 and SmHMGB3 in the reproductive system of female worms, whereas for SmHMGB1 no clear phenotype was observed. Schistosome HMGB proteins can be phosphorylated, acetylated and methylated. Importantly, the acetylation and methylation of schistosome HMGBs were greatly enhanced upon removal of the acidic tail. These data support the notion that the C-terminal acidic tails dictate the differences in the structure, expression and function of schistosome HMGB proteins. PMID:26820302

  8. First total syntheses of aeruginosin 298-A and aeruginosin 298-B, based on a stereocontrolled route to the new amino acid 6-hydroxyoctahydroindole-2-carboxylic acid.

    PubMed

    Valls, N; López-Canet, M; Vallribera, M; Bonjoch, J

    2001-08-17

    The first total syntheses of aeruginosin 298-A (1) and aeruginosin 298-B (3) are described. The syntheses of the alternative putative structures 2 and 4 were also accomplished. The key common strategic element is the stereo-controlled synthesis of (2S,3aS,6R,7aS)-6-hydroxyoctahydroindole-2-carboxylic acid (L-Choi, 5) from L-tyrosine. The synthesis of this new bicyclic alpha-amino acid, which is the core of aeruginosins, involves Birch reduction of O-methyl-L-tyrosine (6) and aminocyclization of the resulting dihydroanisole 7 in acid medium, followed by N-benzylation to give the diastereoisomers 12 and 13. Upon acid treatment with HCl-MeOH, the last two produce an equilibrium mixture in which the endo isomer 13 significantly predominates. Hydrogenation of 13 in the presence of (Boc)2O gives 16, which on reduction with LS-Selectride furnishes the alcohol 22, a protected L-Choi. Successive couplings of 22 with D-leucine, protected (R)-(4-hydroxyphenyl)lactic acid, and L-arginine fragments, followed by reduction to the argininol level and a deprotection end step complete the synthetic sequence to produce aeruginosin 298-A (1). Spectral comparison showed that peptide 2, with the structure previously proposed for aeruginosin 298-A, was different from the natural product. However, synthetic 1 was found to be identical to the isolated natural sample of aeruginosin 298-A. These results unequivocally establish that the absolute stereochemistry of aeruginosin 298-A, formerly assigned incorrectly, is D-Hpla-D-Leu-L-Choi-L-Argol, as shown by structure 1. Aeruginosin 298-B was also synthesized and shown to be a mixture of rotamers of D-Hpla-D-Leu-L-ChoiNH2 (3), rather than an epimeric mixture of 3 and the L-Leu-incorporating 4. PMID:11560314

  9. Distinctive amino acid composition profiles in salivary proteins of the tick Ixodes scapularis

    PubMed Central

    Hughes, Austin L.; Friedman, Robert

    2012-01-01

    Bioinformatic analysis of the amino acid composition of proteins of the tick Ixodes scapularis showed that, in comparison to other secreted proteins, salivary proteins in general have higher frequencies of polar residues and lower frequencies of the non-polar residues leucine and valine. Computer prediction of linear B-cell epitopes showed that polar residues were associated with the presence of high-quality epitopes and that tick salivary proteins included significantly more proteins with predicted high-quality epitopes than did other secreted proteins. The results provided no evidence that salivary proteins as a whole have evolved characteristics minimizing their antigenicity to the vertebrate host. Certain salivary proteins may indeed have evolved low antigenicity, but the I. scapularis sialome include at least some apparently antigenic proteins that might be tested experimentally to determine whether they would be suitable candidates for anti-tick vaccines. PMID:22108016

  10. Identification of Secretory Proteins in Mycobacterium tuberculosis Using Pseudo Amino Acid Composition.

    PubMed

    Yang, Huan; Tang, Hua; Chen, Xin-Xin; Zhang, Chang-Jian; Zhu, Pan-Pan; Ding, Hui; Chen, Wei; Lin, Hao

    2016-01-01

    Tuberculosis is killing millions of lives every year and on the blacklist of the most appalling public health problems. Recent findings suggest that secretory protein of Mycobacterium tuberculosis may serve the purpose of developing specific vaccines and drugs due to their antigenicity. Responding to global infectious disease, we focused on the identification of secretory proteins in Mycobacterium tuberculosis. A novel method called MycoSec was designed by incorporating g-gap dipeptide compositions into pseudo amino acid composition. Analysis of variance-based technique was applied in the process of feature selection and a total of 374 optimal features were obtained and used for constructing the final predicting model. In the jackknife test, MycoSec yielded a good performance with the area under the receiver operating characteristic curve of 0.93, demonstrating that the proposed system is powerful and robust. For user's convenience, the web server MycoSec was established and an obliging manual on how to use it was provided for getting around any trouble unnecessary. PMID:27597968

  11. Viability and Effects on Bacterial Proteins by Oral Rinses with Hypochlorous Acid as Active Ingredient.

    PubMed

    Castillo, Diana Marcela; Castillo, Yormaris; Delgadillo, Nathaly Andrea; Neuta, Yineth; Jola, Johana; Calderón, Justo Leonardo; Lafaurie, Gloria Inés

    2015-10-01

    This study investigated the effect of hypochlorous acid (HOCl) rinses and chlorhexidine (CHX) on the bacterial viability of S. mutans, A. israelii, P. gingivalis, A. actinomycetemcomitans, E. corrodens, C. rectus, K. oxytoca, K. pneumoniae and E. cloacae. The percentage of live bacteria was tested by fluorescence method using Live/Dead kit(r) and BacLight (Molecular Probes(r)) and compared between groups by the Kruskal-Wallis and U Mann-Whitney tests with Bonferroni correction (p value<0.012). The effect of HOCl and CHX on total proteins of P. gingivalis and S. mutans was determined by SDS-PAGE. CHX showed a higher efficacy than HOCl against S. mutans, A. israelii, E. corrodens and E. cloacae (p<0.001) while HOCl was more effective than CHX against P. gingivalis, A. actinomycetemcomitans, C. rectus and K. oxytoca (p=0.001). CHX and HOCl had similar efficacy against K. pneumoniae. Proteins of P. gingivalis and S. mutans were affected similarly by HOCl and CHX. HOCl reduced the bacterial viability especially in periodontopathic bacteria, which may support its use in the control of subgingival biofilm in periodontal patients. PMID:26647939

  12. Identification of Secretory Proteins in Mycobacterium tuberculosis Using Pseudo Amino Acid Composition

    PubMed Central

    Yang, Huan; Tang, Hua; Chen, Xin-Xin; Zhang, Chang-Jian; Zhu, Pan-Pan; Ding, Hui

    2016-01-01

    Tuberculosis is killing millions of lives every year and on the blacklist of the most appalling public health problems. Recent findings suggest that secretory protein of Mycobacterium tuberculosis may serve the purpose of developing specific vaccines and drugs due to their antigenicity. Responding to global infectious disease, we focused on the identification of secretory proteins in Mycobacterium tuberculosis. A novel method called MycoSec was designed by incorporating g-gap dipeptide compositions into pseudo amino acid composition. Analysis of variance-based technique was applied in the process of feature selection and a total of 374 optimal features were obtained and used for constructing the final predicting model. In the jackknife test, MycoSec yielded a good performance with the area under the receiver operating characteristic curve of 0.93, demonstrating that the proposed system is powerful and robust. For user's convenience, the web server MycoSec was established and an obliging manual on how to use it was provided for getting around any trouble unnecessary. PMID:27597968

  13. [Recombinant proteins containing amino acid sequences of two ectatomin chains].

    PubMed

    Esipov, R S; Gurevich, A I; Kaiushin, A L; Korosteleva, M D; Miroshnikov, A I; Shevchenko, L V; Pluzhnikov, K A; Grishin, E V

    1997-12-01

    Artificial genes for chains A and B of ectatomin, an Ectatomma tuberculatum ant toxin, were obtained by chemical and enzymic synthesis and cloned into new plasmid vectors. Expression plasmids with the genes of hybrid proteins were constructed containing human interleukin-3 or its terminal 63-mer fragment as well as chains A and B of ectatomin, which are linked via a region containing the cleavage site of specific protease, enterokinase (hybrid proteins IL3ETOXA, IL3ETOXB, ILETOXA, and ILETOXB). Escherichia coli producer strains providing a high yield of IL3ETOXA and IL3ETOXB proteins as inclusion bodies were obtained. PMID:9499370

  14. Fatty acid profile, total cholesterol, vitamin content, and TBARS value of turkey breast muscle cured with the addition of lycopene.

    PubMed

    Skiepko, N; Chwastowska-Siwiecka, I; Kondratowicz, J; Mikulski, D

    2016-05-01

    The aim of this study was to determine the effect of lycopene addition for curing turkey meat on the profile of fatty acids, total cholesterol, vitamin content, and the TBARS of the final products. The analyzed material comprised 64 breast muscles, of which 16 (RBM) were immediately transported to a laboratory. Another 16 (UBM) were heat treated in a convection steam oven, and 32 muscles were cured for 3 days in two types of curing mixture: without (CBM) and with (CBM+Lyc) tomato peel extract standardized for 5% lycopene content. After completed curing, samples were steamed and grilled under the same conditions as raw samples. Statistical analysis demonstrated the highest (P≤0.01) mean content of vitamin A (0.07 μg/g) in chilled muscles. The content of vitamin E was lower (P≤0.01) in UBM samples than in CBM+Lyc and RBM. The TBARS value was the lowest (P≤0.01) in RBM muscles (0.35 mg MDA/kg of meat). Although there were no differences between products, but lower TBARS were found in CBM+Lyc samples. The content of cholesterol was higher (P≤0.01) in CBM+Lyc products than in the RBM and UBM. RBM samples contained (P≤0.01) the lowest amount of saturated, monounsaturated, and hypercholesterolemic fatty acids, and the highest of unsaturated, polyunsaturated, and hypocholesterolemic fatty acids. CBM+Lyc samples contained (P≤0.01) less hypercholesterolemic and more hypocholesterolemic fatty acids than CBM group. Higher (P≤0.01) unsaturated/saturated and hypocholesterolemic/hypercholesterolemic fatty acid ratios were also found in CBM+Lyc products. The study demonstrated that the used processing technology caused reduction (P≤0.01) of n-3 and n-6 PUFA content. Findings suggest that the addition of lycopene in the process of meat curing and heat treatment in meat industry do not change the content of vitamins and cholesterol or alter the TBARS value in turkey meat products. Nevertheless, lycopene can be used to increase the content of essential

  15. Interference of salts used on aqueous two-phase systems on the quantification of total proteins.

    PubMed

    Golunski, Simone Maria; Sala, Luisa; Silva, Marceli Fernandes; Dallago, Rogério Marcos; Mulinari, Jéssica; Mossi, Altemir José; Brandelli, Adriano; Kalil, Susana Juliano; Di Luccio, Marco; Treichel, Helen

    2016-02-01

    In this study the interference of potassium phosphate, sodium citrate, sodium chloride and sodium nitrate salts on protein quantification by Bradford's method was assessed. Potassium phosphate and sodium citrate salts are commonly used in aqueous two-phase systems for enzyme purification. Results showed that the presence of potassium phosphate and sodium citrate salts increase the absorbance of the samples, when compared with the samples without any salt. The increase in absorptivity of the solution induces errors on protein quantification, which are propagated to the calculations of specific enzyme activity and consequently on purification factor. The presence of sodium chloride and sodium nitrate practically did not affect the absorbance of inulinase, probably the metals present in the enzyme extract did not interact with the added salts. PMID:26616454

  16. Long-chain n-3 fatty acids - New anabolic compounds improving protein metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous animal studies demonstrated that chronic feeding of long-chain n-3 polyunsaturated fatty acids (LCn-3PUFA) that modifies muscle membrane fatty acid composition promotes protein anabolism by blunting the age-associated deterioration in insulin sensitivity. The current study assessed, as a pr...

  17. Prolonged stimulation of muscle protein synthesis by leucine in neonates is dependent on amino acid availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rise in amino acids and insulin after a meal independently stimulate protein synthesis in skeletal muscle of neonates by activating the intracellular signalling pathways that regulate mRNA translation. Leucine, in particular, is important in mediating the response to amino acids. Previously, w...

  18. COMPARATIVE PATHOGENESIS OF HALOACETIC ACID AND PROTEIN KINASE INHIBITOR EMBRYOTOXICITY IN MOUSE WHOLE EMBRYO CULTURE

    EPA Science Inventory

    Comparative pathogenesis of haloacetic acid and protein kinase inhibitor embryotoxicity in mouse whole embryo culture.

    Ward KW, Rogers EH, Hunter ES 3rd.

    Curriculum in Toxicology, University of North Carolina at Chapel Hill, 27599-7270, USA.

    Haloacetic acids ...

  19. Protein Quantification by Derivatization-Free High-Performance Liquid Chromatography of Aromatic Amino Acids

    PubMed Central

    Hesse, Almut

    2016-01-01

    Amino acid analysis is considered to be the gold standard for quantitative peptide and protein analysis. Here, we would like to propose a simple HPLC/UV method based on a reversed-phase separation of the aromatic amino acids tyrosine (Tyr), phenylalanine (Phe), and optionally tryptophan (Trp) without any derivatization. The hydrolysis of the proteins and peptides was performed by an accelerated microwave technique, which needs only 30 minutes. Two internal standard compounds, homotyrosine (HTyr) and 4-fluorophenylalanine (FPhe) were used for calibration. The limit of detection (LOD) was estimated to be 0.05 µM (~10 µg/L) for tyrosine and phenylalanine at 215 nm. The LOD for a protein determination was calculated to be below 16 mg/L (~300 ng BSA absolute). Aromatic amino acid analysis (AAAA) offers excellent accuracy and a precision of about 5% relative standard deviation, including the hydrolysis step. The method was validated with certified reference materials (CRM) of amino acids and of a pure protein (bovine serum albumin, BSA). AAAA can be used for the quantification of aromatic amino acids, isolated peptides or proteins, complex peptide or protein samples, such as serum or milk powder, and peptides or proteins immobilized on solid supports. PMID:27559481

  20. Nucleic acid chaperons: a theory of an RNA-assisted protein folding

    PubMed Central

    Biro, Jan C

    2005-01-01

    Background Proteins are assumed to contain all the information necessary for unambiguous folding (Anfinsen's principle). However, ab initio structure prediction is often not successful because the amino acid sequence itself is not sufficient to guide between endless folding possibilities. It seems to be a logical to try to find the "missing" information in nucleic acids, in the redundant codon base. Results mRNA energy dot plots and protein residue contact maps were found to be rather similar. The structure of mRNA is also conserved if the protein structure is conserved, even if the sequence similarity is low. These observations led me to suppose that some similarity might exist between nucleic acid and protein folding. I found that amino acid pairs, which are co-located in the protein structure, are preferentially coded by complementary codons. This codon complementarity is not perfect; it is suboptimal where the 1st and 3rd codon residues are complementary to each other in reverse orientation, while the 2nd codon letters may be, but are not necessarily, complementary. Conclusion Partial complementary coding of co-locating amino acids in protein structures suggests that mRNA assists in protein folding and functions not only as a template but even as a chaperon during translation. This function explains the role of wobble bases and answers the mystery of why we have a redundant codon base. PMID:16137324

  1. Protein Quantification by Derivatization-Free High-Performance Liquid Chromatography of Aromatic Amino Acids.

    PubMed

    Hesse, Almut; Weller, Michael G

    2016-01-01

    Amino acid analysis is considered to be the gold standard for quantitative peptide and protein analysis. Here, we would like to propose a simple HPLC/UV method based on a reversed-phase separation of the aromatic amino acids tyrosine (Tyr), phenylalanine (Phe), and optionally tryptophan (Trp) without any derivatization. The hydrolysis of the proteins and peptides was performed by an accelerated microwave technique, which needs only 30 minutes. Two internal standard compounds, homotyrosine (HTyr) and 4-fluorophenylalanine (FPhe) were used for calibration. The limit of detection (LOD) was estimated to be 0.05 µM (~10 µg/L) for tyrosine and phenylalanine at 215 nm. The LOD for a protein determination was calculated to be below 16 mg/L (~300 ng BSA absolute). Aromatic amino acid analysis (AAAA) offers excellent accuracy and a precision of about 5% relative standard deviation, including the hydrolysis step. The method was validated with certified reference materials (CRM) of amino acids and of a pure protein (bovine serum albumin, BSA). AAAA can be used for the quantification of aromatic amino acids, isolated peptides or proteins, complex peptide or protein samples, such as serum or milk powder, and peptides or proteins immobilized on solid supports. PMID:27559481

  2. Enamel proteins mitigate mechanical and structural degradations in mature human enamel during acid attack

    NASA Astrophysics Data System (ADS)

    Lubarsky, Gennady V.; Lemoine, Patrick; Meenan, Brian J.; Deb, Sanjukta; Mutreja, Isha; Carolan, Patrick; Petkov, Nikolay

    2014-04-01

    A hydrazine deproteination process was used to investigate the role of enamel proteins in the acid erosion of mature human dental enamel. Bright field high resolution transmission electron micrographs and x-ray diffraction analysis show no crystallographic changes after the hydrazine treatment with similar nanoscale hydroxyapatite crystallite size and orientation for sound and de-proteinated enamel. However, the presence of enamel proteins reduces the erosion depth, the loss of hardness and the loss of structural order in enamel, following exposure to citric acid. Nanoindentation creep is larger for sound enamel than for deproteinated enamel but it reduces in sound enamel after acid attack. These novel results are consistent with calcium ion-mediated visco-elasticty in enamel matrix proteins as described previously for nacre, bone and dental proteins. They are also in good agreement with a previous double layer force spectroscopy study by the authors which found that the proteins electrochemically buffer enamel against acid attack. Finally, this suggests that acid attack, and more specifically dental erosion, is influenced by ionic permeation through the enamel layer and that it is mitigated by the enamel protein matrix.

  3. Impact of Altitudes and Habitats on Valerenic Acid, Total Phenolics, Flavonoids, Tannins, and Antioxidant Activity of Valeriana jatamansi.

    PubMed

    Jugran, Arun K; Bahukhandi, Amit; Dhyani, Praveen; Bhatt, Indra D; Rawal, Ranbeer S; Nandi, Shyamal K

    2016-07-01

    The changes in total phenolics, flavonoids, tannins, valerenic acid, and antioxidant activity were assessed in 25 populations of Valeriana jatamansi sampled from 1200 to 2775 m asl and four habitat types of Uttarakhand, West Himalaya. Significant (p < 0.05) variations in total phenolics, flavonoids, valerenic acid, and antioxidant activity in aerial and root portions and across the populations were observed. Antioxidant activity measured by three in vitro antioxidant assays, i.e., 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) (ABTS) radical scavenging, 2,2'-diphenyl-1-picryylhydrazyl (DPPH) free radical scavenging, and ferric-reducing antioxidant power (FRAP) assays, showed significant (p < 0.05) differences across the populations. However, no clear pattern was found in phytochemicals across the altitudinal range. Among habitat types, (pine, oak, mixed forest, and grassy land), variation in phytochemical content and antioxidant activity were observed. Equal class ranking, neighbor-joining cluster analysis, and principal component analysis (PCA) identified Talwari, Jaberkhet, Manjkhali, and Khirshu populations as promising sources with higher phytochemicals and antioxidant activity. The results recommended that the identified populations with higher value of phytochemicals and antioxidants can be utilized for mass multiplication and breeding program to meet the domestic as well as commercial demand. PMID:26971960

  4. Influence of oxalic acid on the agglomeration process and total soda content in precipitated Al(OH) 3

    NASA Astrophysics Data System (ADS)

    Nikolić, I.; Blec̆ić, D.; Blagojević, N.; Radmilović, V.; Kovac̆ević, K.

    2003-05-01

    Decomposition of caustic soda solutions is an important part of Bayer process for alumina production. The physico-chemical properties of precipitated Al(OH) 3 are dependent on several processes that take place simultaneously during the decomposition process and they are: nucleation, agglomeration and Al(OH) 3 crystals. An important industrial requirement is increase of Al(OH) 3 crystal grain size, and hence agglomeration and growth of Al(OH) 3 crystals become important processes and they enable increase of particle size. The influence of oxalic acid concentration on the agglomeration process and total soda content in precipitated Al(OH) 3 at different temperatures and caustic soda concentrations has been investigated. The results have shown that the agglomeration process is increased with increase of temperature and decrease of caustic soda concentration. Total soda content in precipitated Al(OH) 3 is changed in the same way. Besides, agglomeration process of Al(OH) 3 particles is favored in the presence of oxalic acid.

  5. Protein biomarkers for enhancement of radiation dose and injury assessment in nonhuman primate total-body irradiation model.

    PubMed

    Ossetrova, Natalia I; Sandgren, David J; Blakely, William F

    2014-06-01

    Development and validation of early-response radiation injury biomarkers are critical for effective triage and medical management of irradiated individuals. Plasma protein and haematological profiles were evaluated using multivariate linear-regression analysis to provide dose-response calibration curves for photon-radiation dose assessment in 30 rhesus macaques total-body-irradiated to 1-8.5 Gy with (60)Co gamma rays (0.55 Gy min(-1)). Equations for radiation dose received were established based on different combinations of protein biomarkers [i.e. C-reactive protein (CRP), serum amyloid A (SAA), interleukin 6 (IL-6) and Flt3 Ligand (Flt3L)] at samples collection time-points 6 h, 1, 2, 3, 4 and 7 d post-total-body irradiation. Dynamic changes in the levels of CRP, SAA, IL-6 and Flt3L may function as prognostic indicators of the time course and severity of acute radiation sickness (ARS). The combination of protein biomarkers provides greater accuracy for early radiation assessment than any one biomarker alone. PMID:24925901

  6. Fatty-acid profile of total and polar lipids in cultured rainbow trout (Oncorhynchus mykiss) raised in freshwater and seawater (Croatia) determined by transmethylation method.

    PubMed

    Staver, Mladenka Malenica; Jerković, Igor; Giacometti, Jasminka; Malenica, Ante; Marijanović, Zvonimir

    2012-08-01

    Fatty acids from total lipids and polar lipids in cultured rainbow trout (Oncorhynchus mykiss) raised in seawater (SW) and freshwater (FW) were identified and quantified from the muscle samples in January, April, and July. The highest total lipid and polar lipid amounts were found in April. July contents of total lipids were low, but percent of the polyunsaturated fatty acids (PUFAs) was high in SW and FW environment (particularly n-3 PUFAs). Variety of 17 fatty acids was identified by GC-FID after transmethylation. The predominant fatty acids in rainbow trout from SW and FW were: docosahexaenoic acid among n-3 PUFAs, palmitic acid among saturated fatty acids (SFAs), and oleic acid among monounsaturated fatty acids (MUFAs). Appreciably higher n-3/n-6 ratio was found in total lipids in April (6.40, FW fish) and in polar lipids in July (18.76; SW fish). High n-3/n-6 ratio in total lipids and polar lipids of rainbow trout from SW and FW, besides beneficial n-3/n-6 ratio in the commercial fish food, could be characteristic for the local environmental conditions (Croatia). PMID:22899619

  7. Reasons for the occurrence of the twenty coded protein amino acids

    NASA Technical Reports Server (NTRS)

    Weber, A. L.; Miller, S. L.

    1981-01-01

    Factors involved in the selection of the 20 protein L-alpha-amino acids during chemical evolution and the early stages of Darwinian evolution are discussed. The selection is considered on the basis of the availability in the primitive ocean, function in proteins, the stability of the amino acid and its peptides, stability to racemization, and stability on the transfer RNA. It is concluded that aspartic acid, glutamic acid, arginine, lysine, serine and possibly threonine are the best choices for acidic, basic and hydroxy amino acids. The hydrophobic amino acids are reasonable choices, except for the puzzling absences of alpha-amino-n-butyric acid, norvaline and norleucine. The choices of the sulfur and aromatic amino acids seem reasonable, but are not compelling. Asparagine and glutamine are apparently not primitive. If life were to arise on another planet, it would be expected that the catalysts would be poly-alpha-amino acids and that about 75% of the amino acids would be the same as on the earth.

  8. INCREASE IN GLIAL FIBRILLARY ACIDIC PROTEIN FOLLOWS BRAIN HYPERTHERMIA IN RATS

    EPA Science Inventory

    Previously, the authors have demonstrated that an increase in the astrocyte-associated protein, glial fibrillary acidic protein (GFAP), accompanies brain injury induced by a variety of chemical insults. In the present study the authors examined the effects of microwave-induced hy...

  9. Effect of microfluidized and stearic acid modified soy protein in natural rubber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microfluidized and stearic acid modified soy protein aggregates were used to reinforced natural rubber. The size of soy protein particles was reduced with a microfluidizing and ball milling process. Filler size reduction with longer ball milling time tends to increase tensile strength of the rubber ...

  10. Development of a Quantitative BRET Affinity Assay for Nucleic Acid-Protein Interactions

    PubMed Central

    Vickers, Timothy A.; Crooke, Stanley T.

    2016-01-01

    Protein-nucleic acid interactions play a crucial role in the regulation of diverse biological processes. Elucidating the roles that protein-nucleic acid complexes play in the regulation of transcription, translation, DNA replication, repair and recombination, and RNA processing continues to be a crucial aspect of understanding of cell biology and the mechanisms of disease. In addition, proteins have been demonstrated to interact with antisense oligonucleotide therapeutics in a sequence and chemistry dependent manner, influencing ASO potency and distribution in cells and in vivo. While many assays have been developed to measure protein-nucleic acid interactions, many suffer from lack of throughput and sensitivity, or challenges with protein purification and scalability. In this report we present a new BRET assay for the analysis of DNA-protein interactions which makes use of an extremely bright luciferase as a tag for the binding protein, along with a long-wavelength fluorophore conjugated to the nucleic acid. The resulting assay is high throughput, sensitive, does not require protein purification, and even allows for quantitative characterization of these interactions within the biologically relevant context of whole cells. PMID:27571227

  11. Isolation and partial characterization of a fatty acid binding protein in rat liver plasma membranes.

    PubMed Central

    Stremmel, W; Strohmeyer, G; Borchard, F; Kochwa, S; Berk, P D

    1985-01-01

    When [14C]oleate-bovine serum albumin complexes were incubated in vitro with rat liver plasma membranes (LPM), specific, saturable binding of oleate to the membranes was observed. Maximal heat-sensitive (i.e., specific) binding was 3.2 nmol/mg of membrane protein. Oleate-agarose affinity chromatography of Triton X-100-solubilized LPM was used to isolate a single 40-kDa protein with high affinity for oleate. On gel filtration, the protein comigrated with various fatty acids but not with [14C]bilirubin, [35S]sulfobromophthalein, [14C]taurocholate, [14C]phosphatidylcholine, or [14C]cholesteryloleate. A rabbit antibody to this membrane fatty acid-binding protein gave a single precipitin line with the antigen but no reactivity with concentrated cytosolic proteins, LPM bilirubin/sulfobromophthalein-binding protein, or rat albumin or other rat plasma proteins. The antibody selectively inhibited heat-sensitive binding of [14C]oleate to LPM. Immunofluorescence studies localized the antigen in liver-cell plasma membranes as well as in other major sites of fatty acid transport. These data are compatible with the hypothesis that this protein may act as a receptor in a hepatocellular uptake mechanism for fatty acids. Images PMID:3881757

  12. Long-term leucine induced stimulation of muscle protein synthesis is amino acid dependent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infusing leucine for 1 h increases skeletal muscle protein synthesis in the neonate, but this is not sustained for 2 h unless the corresponding fall in amino acids is prevented. This study aimed to determine whether a continuous leucine infusion can stimulate protein synthesis for a prolonged period...

  13. Acid diet (high meat protein) effects on calcium metabolism and bone health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose of review: Update recent advancements regarding the effect of high animal protein on calcium utilization and bone health. Recent findings: Increased potential renal acid load resulting from a high protein (meat) intake has been closely associated with increased urinary calcium excretion. How...

  14. Semisynthetic DNA-protein conjugates for fabrication of nucleic acid based nanostructures

    NASA Astrophysics Data System (ADS)

    Rabe, Kersten S.; Feldkamp, Udo; Niemeyer, Christof M.

    2008-10-01

    We here report on the developments of semisynthetic DNA-protein conjugates and their assembly into multi-component nanostructures. We describe the improvement of the DNA sequences embedded in such nanostructures by computational and analytical methods. Moreover, we report on the exploration of novel DNA conjugates of streptavidin or redox proteins with improved properties for the assembly of nucleic acid based nanostructures.

  15. CONCENTRATION OF GLIAL FIBRILLARY ACIDIC PROTEIN INCREASES WITH AGE IN THE MOUSE AND RAT BRAIN

    EPA Science Inventory

    The role of aging in the expression of the astrocyte protein, glial fibrillary acidic protein (GFAP), was examined. n both mice and rats the concentration of GFAP increased throughout the brain as a function of aging. he largest increase (2-fold) was observed in striatum for both...

  16. Insulin and amino acids stimulate whole body protein synthesis in neonates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insulin and amino acids (AA) stimulate muscle protein synthesis in neonatal pigs. To determine the effects of insulin and AA on whole body protein turnover, hyperinsulinemic (0 and 100 ng/(kg[0.66]/min))-euglycemic-AA clamps were performed during euaminoacidemia or hyperaminoacidemia in fasted 7-d-...

  17. Regulation of protein degradation pathways by amino acids and insulin in skeletal muscle of neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rapid gain in lean mass in neonates requires greater rates of protein synthesis than degradation. We previously delineated the molecular mechanisms by which insulin and amino acids, especially leucine, modulate skeletal muscle protein synthesis and how this changes with development. In the curre...

  18. Umami taste amino acids produced by hydrolyzing extracted protein from tomato seed meal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzymatic hydrolysis was performed for extracting protein to prepare umami taste amino acids from defatted tomato seed meal (DTSM) which is a by-product of tomato processing. Papain was used as an enzyme for the hydrolysis of DTSM. The particle size distribution of DTSM, protein concentration and fr...

  19. Development of a Quantitative BRET Affinity Assay for Nucleic Acid-Protein Interactions.

    PubMed

    Vickers, Timothy A; Crooke, Stanley T

    2016-01-01

    Protein-nucleic acid interactions play a crucial role in the regulation of diverse biological processes. Elucidating the roles that protein-nucleic acid complexes play in the regulation of transcription, translation, DNA replication, repair and recombination, and RNA processing continues to be a crucial aspect of understanding of cell biology and the mechanisms of disease. In addition, proteins have been demonstrated to interact with antisense oligonucleotide therapeutics in a sequence and chemistry dependent manner, influencing ASO potency and distribution in cells and in vivo. While many assays have been developed to measure protein-nucleic acid interactions, many suffer from lack of throughput and sensitivity, or challenges with protein purification and scalability. In this report we present a new BRET assay for the analysis of DNA-protein interactions which makes use of an extremely bright luciferase as a tag for the binding protein, along with a long-wavelength fluorophore conjugated to the nucleic acid. The resulting assay is high throughput, sensitive, does not require protein purification, and even allows for quantitative characterization of these interactions within the biologically relevant context of whole cells. PMID:27571227

  20. Isoelectric Point, Electric Charge, and Nomenclature of the Acid-Base Residues of Proteins

    ERIC Educational Resources Information Center

    Maldonado, Andres A.; Ribeiro, Joao M.; Sillero, Antonio

    2010-01-01

    The main object of this work is to present the pedagogical usefulness of the theoretical methods, developed in this laboratory, for the determination of the isoelectric point (pI) and the net electric charge of proteins together with some comments on the naming of the acid-base residues of proteins. (Contains 8 figures and 4 tables.)

  1. Intracellular Nucleic Acid Delivery by the Supercharged Dengue Virus Capsid Protein

    PubMed Central

    Freire, João Miguel; Veiga, Ana Salomé; Conceição, Thaís M.; Kowalczyk, Wioleta; Mohana-Borges, Ronaldo; Andreu, David; Santos, Nuno C.; Da Poian, Andrea T.; Castanho, Miguel A. R. B.

    2013-01-01

    Supercharged proteins are a recently identified class of proteins that have the ability to efficiently deliver functional macromolecules into mammalian cells. They were first developed as bioengineering products, but were later found in the human proteome. In this work, we show that this class of proteins with unusually high net positive charge is frequently found among viral structural proteins, more specifically among capsid proteins. In particular, the capsid proteins of viruses from the Flaviviridae family have all a very high net charge to molecular weight ratio (> +1.07/kDa), thus qualifying as supercharged proteins. This ubiquity raises the hypothesis that supercharged viral capsid proteins may have biological roles that arise from an intrinsic ability to penetrate cells. Dengue virus capsid protein was selected for a detailed experimental analysis. We showed that this protein is able to deliver functional nucleic acids into mammalian cells. The same result was obtained with two isolated domains of this protein, one of them being able to translocate lipid bilayers independently of endocytic routes. Nucleic acids such as siRNA and plasmids were delivered fully functional into cells. The results raise the possibility that the ability to penetrate cells is part of the native biological functions of some viral capsid proteins. PMID:24339931

  2. Beta-galactosidase and selective neutrality. [amino acid composition of proteins

    NASA Technical Reports Server (NTRS)

    Holmquist, R.

    1979-01-01

    Three hypotheses to explain the amino acid composition of proteins are inconsistent (about 10 to the minus 9th) with the experimental data for beta-galactosidase from Escherichia coli. The exceptional length of this protein, 1021 residues, permits rigorous tests of these hypotheses without complication from statistical artifacts. Either this protein is not at compositional equilibrium, which is unlikely from knowledge about other proteins, or the evolution of this protein and its coding gene have not been selectively neutral. However, the composition of approximately 60% of the molecule is consistent with either a selectively neutral or nonneutral evolutionary process.

  3. Nucleic acid encoding DS-CAM proteins and products related thereto

    SciTech Connect

    Korenberg, Julie R.

    2005-11-01

    In accordance with the present invention, there are provided Down Syndrome-Cell Adhesion Molecule (DS-CAM) proteins. Nucleic acid sequences encoding such proteins and assays employing same are also disclosed. The invention DS-CAM proteins can be employed in a variety of ways, for example, for the production of anti-DS-CAM antibodies thereto, in therapeutic compositions and methods employing such proteins and/or antibodies. DS-CAM proteins are also useful in bioassays to identify agonists and antagonists thereto.

  4. Adaptive Evolution of Eel Fluorescent Proteins from Fatty Acid Binding Proteins Produces Bright Fluorescence in the Marine Environment

    PubMed Central

    Gruber, David F.; Gaffney, Jean P.; Mehr, Shaadi; DeSalle, Rob; Sparks, John S.; Platisa, Jelena; Pieribone, Vincent A.

    2015-01-01

    We report the identification and characterization of two new members of a family of bilirubin-inducible fluorescent proteins (FPs) from marine chlopsid eels and demonstrate a key region of the sequence that serves as an evolutionary switch from non-fluorescent to fluorescent fatty acid-binding proteins (FABPs). Using transcriptomic analysis of two species of brightly fluorescent Kaupichthys eels (Kaupichthys hyoproroides and Kaupichthys n. sp.), two new FPs were identified, cloned and characterized (Chlopsid FP I and Chlopsid FP II). We then performed phylogenetic analysis on 210 FABPs, spanning 16 vertebrate orders, and including 163 vertebrate taxa. We show that the fluorescent FPs diverged as a protein family and are the sister group to brain FABPs. Our results indicate that the evolution of this family involved at least three gene duplication events. We show that fluorescent FABPs possess a unique, conserved tripeptide Gly-Pro-Pro sequence motif, which is not found in non-fluorescent fatty acid binding proteins. This motif arose from a duplication event of the FABP brain isoforms and was under strong purifying selection, leading to the classification of this new FP family. Residues adjacent to the motif are under strong positive selection, suggesting a further refinement of the eel protein’s fluorescent properties. We present a phylogenetic reconstruction of this emerging FP family and describe additional fluorescent FABP members from groups of distantly related eels. The elucidation of this class of fish FPs with diverse properties provides new templates for the development of protein-based fluorescent tools. The evolutionary adaptation from fatty acid-binding proteins to fluorescent fatty acid-binding proteins raises intrigue as to the functional role of bright green fluorescence in this cryptic genus of reclusive eels that inhabit a blue, nearly monochromatic, marine environment. PMID:26561348

  5. Glutathione Peroxidase’s Reaction Intermediate Selenenic Acid is Stabilized by the Protein Microenvironment

    PubMed Central

    Li, Fei; Liu, Jun; Rozovsky, Sharon

    2014-01-01

    Selenenic acids are highly reactive intermediates of selenoproteins’ enzymatic reactions. Knowledge of how the protein environment protects and stabilizes them is fundamental not only to descriptions of selenoproteins’ reactivity but also potentially for proteomics and therapeutics. However, selenenic acids are considered particularly short-lived and were not yet identified in wild-type selenoproteins. Here, we report trapping the selenenic acid in glutathione peroxidase, an anti-oxidant enzyme that efficiently eliminates hydroperoxides. It has long been thought that selenium-containing glutathione peroxidases form a selenenic acid intermediate. However, this putative species has eluded detection. Here, we report its identification. The selenenic acid in bovine glutathione peroxidase 1 was chemically trapped using dimedone, an alkylating agent specific to sulfenic and selenenic acids. The alkylation of the catalytic selenocysteine was verified by electrospray ionization mass spectrometry. In the presence of glutathione, the selenocysteine was not alkylated because the selenenic acid condenses faster with glutathione than the alkylation reaction. In the absence of thiols, the selenenic acid was surprisingly long-lived with 95% of the protein still able to react with dimedone 10 min after hydrogen peroxide was removed, indicating that the protein environment stabilizes the selenenic acid by shielding it from reactive groups in the protein. After 30 min, the selenocysteine was no longer modified but became accessible once the protein was exposed to reducing agents. This suggests that the selenenic acid reacted with a protein’s amide or amine to form a selenylamide bond. Such a modification may play a role in protecting glutathione peroxidase’s reactivity. PMID:25124921

  6. Assay of phenolic compounds from four species of ber (Ziziphus mauritiana L.) fruits: comparison of three base hydrolysis procedure for quantification of total phenolic acids.

    PubMed

    Memon, Ayaz Ali; Memon, Najma; Bhanger, Muhammad Iqbal; Luthria, Devanand L

    2013-08-15

    The present study was undertaken to investigate the flavonoid profile in four species of ber (Ziziphus mauritiana Lamk.) fruit. The 12 flavonoids identified were quercetin 3-O-robinobioside, quercetin 3-O-rutinoside, quercetin 3'-O-galactoside, quercetin 3'-O-glucoside, quercetin 3'-O-rhamnoside, quercetin 3'-O-pentosylhexoside, quercetin 3-O-6'malonylglucoside, quercetin 3'-O-malonylglucoside, luteolin 7-O-6'malonylglucoside, luteolin 7-O-malonylglucoside, myricetin 3-O-galactoside, and naringenin tri glycoside. This is the first report on extraction of nine additional flavonoids from the ber fruits. In addition, we also compared the impact of three different base hydrolysis techniques namely ultrasonic assisted base hydrolysis (UABH), microwave assisted base hydrolysis (MWABH), and pressurised liquid assisted base hydrolysis (PLABH) for the quantification of total phenolic acids. Nine phenolic acids, protocatechuic acid, p-hydroxybenzoic acid, ferulic acid, chlorogenic acid, vanillic acid, caffeic acid, vanillin, ortho- and para-coumaric acids, were identified and quantified. The three major phenolic acids identified in all four ber species were p-coumaric acid, vanillin and ferulic acids. Higher amounts (p<0.05) of total phenolic acids in all cultivars were obtained with the PLABH technique as compared to other two procedures (UABH and MWABH). PMID:23561136

  7. Effects of stress on serum triglycerides, nonsterified fatty acids, and total cholesterol levels in male rats after ethanol administration

    SciTech Connect

    Hershock, D.; Vogel, W.H. )

    1989-02-09

    Serum triglycerides, nonesterified fatty acids (NEFA), and total cholesterol were determined during one hour immobilization stress in adult male Sprague-Dawley rats after ethanol administration (2g/kg, i.p.). Stress and ethanol effects were evaluated in two experiments: (1) rats maintained on Purina Rodent Chow for six weeks and fasted for 24 hours; and (2) rats maintained on the same diet supplemented with 1% cholesterol and 10% peanut oil for six weeks and nonfasted prior to experimentation. Blood was obtained from indwelling jugular catheters. In each experiment, differences were seen in triglyceride and NEFA levels but not in total cholesterol. In the regular diet-fed rats (1), serum triglyceride levels were not affected by either stress or ethanol. However, NEFA levels did show differences in the response to ethanol and stress. A 63% decrease from baseline after 5{prime} of stress was partially abolished by ethanol; instead, a 24% increase was observed. Also, a stress-induced increase in NEFA which occurred after 15{prime} was not observed in the ethanol treated rats; rather, a decrease in NEFA was noted. Total cholesterol did not change in response to stress or ethanol. In the high cholesterol diet-fed rats (2), ethanol did not suppress a stress-induced increase in triglyceride levels. NEFA levels in ethanol-treated rats were higher during the first 15{prime} of stress as compared to stress alone. A decrease in NEFA was however seen in the ethanol-treated rats after 30{prime} of stress and these levels remained lower than the stress alone group. A diet-induced increase in total cholesterol levels was observed; however, no changes were seen due to either or ethanol. Thus, ethanol administration prior to acute immobilization stress did affect serum triglyceride and NEFA levels but did not change total cholesterol.

  8. Clinical significance of urinary liver-type fatty acid binding protein at various stages of nephropathy.

    PubMed

    Viswanathan, V; Sivakumar, S; Sekar, V; Umapathy, D; Kumpatla, S

    2015-01-01

    This cross-sectional study was to evaluate the levels of urinary liver-type fatty acid binding protein (u-LFABP pg/mg urine creatinine ratio) at different stages of diabetic nephropathy and to see its correlation with other clinical parameters in South Indian patients with type 2 diabetes mellitus (T2DM). A total of 65 (M: F; 42:23) T2DM subjects were divided into three groups, and were compared with 13 (M: F; 3:10) nondiabetic controls. The study groups were as follows: normoalbuminuric (n = 22), microalbuminuric (n = 22) and macroalbuminuric (n = 21). Estimated glomerular filtration rate (eGFR) was calculated using Cockcroft and Gault formula. u-LFABP levels in spot urine samples were measured with a solid phase enzyme linked immunosorbent assay. This study showed that u-LFABP levels were undetectable in healthy controls and was very low in the normoalbuminuric subjects. Elevated levels of u-LFABP are evident from the microalbuminuric stage indicating tubular damage. The levels of u-LFABP increased gradually with declining renal function. Geometric mean (95% confidence interval) for normoalbuminuria was 0.65 (0.47-0.97), microalbuminuria was 0.99 (0.55-1.97) and macroalbuminuria was 5.16 (1.8-14.5), (P = 0.005). In conclusion, u-LFABP levels were elevated in patients with reduced eGFR and showed a positive correlation with systolic blood pressure and protein to creatinine ratio in the total study subjects. PMID:26628791

  9. Clinical significance of urinary liver-type fatty acid binding protein at various stages of nephropathy

    PubMed Central

    Viswanathan, V.; Sivakumar, S.; Sekar, V.; Umapathy, D.; Kumpatla, S.

    2015-01-01

    This cross-sectional study was to evaluate the levels of urinary liver-type fatty acid binding protein (u-LFABP pg/mg urine creatinine ratio) at different stages of diabetic nephropathy and to see its correlation with other clinical parameters in South Indian patients with type 2 diabetes mellitus (T2DM). A total of 65 (M: F; 42:23) T2DM subjects were divided into three groups, and were compared with 13 (M: F; 3:10) nondiabetic controls. The study groups were as follows: normoalbuminuric (n = 22), microalbuminuric (n = 22) and macroalbuminuric (n = 21). Estimated glomerular filtration rate (eGFR) was calculated using Cockcroft and Gault formula. u-LFABP levels in spot urine samples were measured with a solid phase enzyme linked immunosorbent assay. This study showed that u-LFABP levels were undetectable in healthy controls and was very low in the normoalbuminuric subjects. Elevated levels of u-LFABP are evident from the microalbuminuric stage indicating tubular damage. The levels of u-LFABP increased gradually with declining renal function. Geometric mean (95% confidence interval) for normoalbuminuria was 0.65 (0.47–0.97), microalbuminuria was 0.99 (0.55–1.97) and macroalbuminuria was 5.16 (1.8–14.5), (P = 0.005). In conclusion, u-LFABP levels were elevated in patients with reduced eGFR and showed a positive correlation with systolic blood pressure and protein to creatinine ratio in the total study subjects. PMID:26628791

  10. Short communication: Evaluation of acid-insoluble ash and indigestible neutral detergent fiber as total-tract digestibility markers in dairy cows fed corn silage-based diets.

    PubMed

    Lee, C; Hristov, A N

    2013-08-01

    The objective of this experiment was to evaluate acid-insoluble ash (AIA) and indigestible NDF (iNDF) as intrinsic digestibility markers in comparison with total fecal collection (TC) in dairy cows fed corn silage- and alfalfa haylage-based diets. The experiment was part of a larger experiment, which involved 8 Holstein cows [102±28.4 d in milk, 26.4±0.27 kg/d of dry matter (DM) intake, and 43±5.3 kg/d milk yield]. The experimental design was a replicated 4×4 Latin square with the following treatments: metabolizable protein (MP)-adequate diet [15.6% crude protein (CP); high-CP], MP-deficient diet (14.0% CP; low-CP), and 2 other low-CP diets supplemented (top-dressed) with ruminally protected Lys or Lys and Met. Data for the 3 low-CP diets were combined for this analysis. Total feces were collected for 5 consecutive days during each period to estimate total-tract apparent digestibility. Digestibility was also estimated using AIA (digestion with 2 N HCl) and iNDF (12-d ruminal incubation in 25-μm-pore-size bags). Significant diet × digestibility method interactions were observed for fecal output of nutrients and digestibility. Fecal output of nutrients estimated using AIA or iNDF was lower compared with TC and fecal output of DM, organic matter, and CP tended to be higher for iNDF compared with AIA for the high-CP diet. For the low-CP diet, however, fecal output of all nutrients was lower for AIA compared with TC and was higher for iNDF compared with TC. Data from this experiment showed that, compared with TC, AIA underestimated fecal output and overestimated digestibility, particularly evident with the fiber fractions and the protein-deficient diet. Compared with TC, fecal output was overestimated and digestibility of the low-CP diet was underestimated when iNDF was used as a marker, although the magnitude of the difference was smaller compared with that for AIA. In the conditions of the current study, iNDF appeared to be a more reliable digestibility marker

  11. Protein adsorption on piezoelectric poly(L-lactic) acid thin films by scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Barroca, Nathalie; Vilarinho, Paula M.; Daniel-da-Silva, Ana Luisa; Wu, Aiying; Fernandes, Maria Helena; Gruverman, Alexei

    2011-03-01

    Up until now, no direct evidence of protein adsorption processes associated with polar activity of a piezoelectric has been reported. This work presents the experimental evidence of the protein adsorption process' dependence on the surface polarization of a piezoelectric by showing at the local scale that the process of protein adsorption is highly favored in the poled areas of a piezoelectric polymer such as poly(L-lactic) acid.

  12. Development of a Univariate Membrane-Based Mid-Infrared Method for Protein Quantitation and Total Lipid Content Analysis of Biological Samples

    PubMed Central

    Cappione, Amedeo; Lento, Joseph; Chernokalskaya, Elena

    2014-01-01

    Biological samples present a range of complexities from homogeneous purified protein to multicomponent mixtures. Accurate qualification of such samples is paramount to downstream applications. We describe the development of an MIR spectroscopy-based analytical method offering simultaneous protein quantitation (0.25–5 mg/mL) and analysis of total lipid or detergent species, as well as the identification of other biomolecules present in biological samples. The method utilizes a hydrophilic PTFE membrane engineered for presentation of aqueous samples in a dried format compatible with fast infrared analysis. Unlike classical quantification techniques, the reported method is amino acid sequence independent and thus applicable to complex samples of unknown composition. By comparison to existing platforms, this MIR-based method enables direct quantification using minimal sample volume (2 µL); it is well-suited where repeat access and limited sample size are critical parameters. Further, accurate results can be derived without specialized training or knowledge of IR spectroscopy. Overall, the simplified application and analysis system provides a more cost-effective alternative to high-throughput IR systems for research laboratories with minimal throughput demands. In summary, the MIR-based system provides a viable alternative to current protein quantitation methods; it also uniquely offers simultaneous qualification of other components, notably lipids and detergents. PMID:25371845

  13. Surface lysine residues modulate the collisional transfer of fatty acid from adipocyte fatty acid binding protein to membranes.

    PubMed

    Herr, F M; Matarese, V; Bernlohr, D A; Storch, J

    1995-09-19

    The transfer of unesterified fatty acids (FA) from adipocyte fatty acid binding protein (A-FABP) to phospholipid membranes is proposed to occur via a collisional mechanism involving transient ionic and hydrophobic interactions [Wootan & Storch (1994) J. Biol. Chem. 269, 10517-10523]. In particular, it was suggested that membrane acidic phospholipids might specifically interact with basic residues on the surface of A-FABP. Here we addressed whether lysine residues on the surface of the protein are involved in this collisional transfer mechanism. Recombinant A-FABP was acetylated to neutralize all positively charged surface lysine residues. Protein fluorescence, CD spectra, and chemical denaturant data indicate that acetylation did not substantially alter the conformational integrity of the protein, and nearly identical affinities were obtained for binding of the fluorescently labeled FA [12-(9-anthroyloxy)oleate] to native and acetylated protein. Transfer of 2-(9-anthroyloxy)palmitate (2AP) from acetylated A-FABP to small unilamellar vesicles (SUV) was 35-fold slower than from native protein. In addition, whereas the 2AP transfer rate from native A-FABP was directly dependent on SUV concentration, 2AP transfer from acetylated protein was independent on the concentration of acceptor membranes. Factors which alter aqueous-phase solubility of FA, such as ionic strength and acyl chain length and saturation, affected the AOFA transfer rate from acetylated but not native A-FABP. Finally, an increase in the negative charge density of the acceptor SUV resulted in a marked increase in the rate of transfer from native A-FABP but did not increase the rate from acetylated A-FABP.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7547918

  14. Shared Segment Analysis and Next-Generation Sequencing Implicates the Retinoic Acid Signaling Pathway in Total Anomalous Pulmonary Venous Return (TAPVR)

    PubMed Central

    Nash, Dustin; Arrington, Cammon B.; Kennedy, Brett J.; Yandell, Mark; Wu, Wilfred; Zhang, Wenying; Ware, Stephanie; Jorde, Lynn B.; Gruber, Peter J.; Yost, H. Joseph

    2015-01-01

    Most isolated congenital heart defects are thought to be sporadic and are often ascribed to multifactorial mechanisms with poorly understood genetics. Total Anomalous Pulmonary Venous Return (TAPVR) occurs in 1 in 15,000 live-born infants and occurs either in isolation or as part of a syndrome involving aberrant left-right development. Previously, we reported causative links between TAVPR and the PDGFRA gene. TAPVR has also been linked to the ANKRD1/CARP genes. However, these genes only explain a small fraction of the heritability of the condition. By examination of phased single nucleotide polymorphism genotype data from 5 distantly related TAPVR patients we identified a single 25 cM shared, Identical by Descent genomic segment on the short arm of chromosome 12 shared by 3 of the patients and their obligate-carrier parents. Whole genome sequence (WGS) analysis identified a non-synonymous variant within the shared segment in the retinol binding protein 5 (RBP5) gene. The RBP5 variant is predicted to be deleterious and is overrepresented in the TAPVR population. Gene expression and functional analysis of the zebrafish orthologue, rbp7, supports the notion that RBP5 is a TAPVR susceptibility gene. Additional sequence analysis also uncovered deleterious variants in genes associated with retinoic acid signaling, including NODAL and retinol dehydrogenase 10. These data indicate that genetic variation in the retinoic acid signaling pathway confers, in part, susceptibility to TAPVR. PMID:26121141

  15. Biological chemistry and functionality of protein sulfenic acids and related thiol modifications.

    PubMed

    Devarie-Baez, Nelmi O; Silva Lopez, Elsa I; Furdui, Cristina M

    2016-01-01

    Selective modification of proteins at cysteine residues by reactive oxygen, nitrogen or sulfur species formed under physiological and pathological states is emerging as a critical regulator of protein activity impacting cellular function. This review focuses primarily on protein sulfenylation (-SOH), a metastable reversible modification connecting reduced cysteine thiols to many products of cysteine oxidation. An overview is first provided on the chemistry principles underlining synthesis, stability and reactivity of sulfenic acids in model compounds and proteins, followed by a brief description of analytical methods currently employed to characterize these oxidative species. The following chapters present a selection of redox-regulated proteins for which the -SOH formation was experimentally confirmed and linked to protein function. These chapters are organized based on the participation of these proteins in the regulation of signaling, metabolism and epigenetics. The last chapter discusses the therapeutic implications of altered redox microenvironment and protein oxidation in disease. PMID:26340608

  16. Genetically Encoding an Electrophilic Amino Acid for Protein Stapling and Covalent Binding to Native Receptors

    PubMed Central

    2015-01-01

    Covalent bonds can be generated within and between proteins by an unnatural amino acid (Uaa) reacting with a natural residue through proximity-enabled bioreactivity. Until now, Uaas have been developed to react mainly with cysteine in proteins. Here we genetically encoded an electrophilic Uaa capable of reacting with histidine and lysine, thereby expanding the diversity of target proteins and the scope of the proximity-enabled protein cross-linking technology. In addition to efficient cross-linking of proteins inter- and intramolecularly, this Uaa permits direct stapling of a protein α-helix in a recombinant manner and covalent binding of native membrane receptors in live cells. The target diversity, recombinant stapling, and covalent targeting of endogenous proteins enabled by this versatile Uaa should prove valuable in developing novel research tools, biological diagnostics, and therapeutics by exploiting covalent protein linkages for specificity, irreversibility, and stability. PMID:25010185