Age characteristics of changes in invertase activity of the mucous membrane of the small intestine

NASA Technical Reports Server (NTRS)

Rakhimov, K. R.; Aleksandrova, N. V.

1980-01-01

Rats of varying ages were subjected to stress from heat, cold, and hydrocortisone injection. Invertase activity in homogenates of small intestine mucous membranes was studied following sacrifice. Invertase activity was low in young animals, but increased sharply in 30 day old ones, remaining at a relatively constant level until old age. The study concludes that the stress hormone (corticosteroids, etc.) levels in the blood, which affects the formation of enteric enzyme levels and activities, and that age related peculiarities in invertase activity are a consequence of altered hormone status and epitheliocyte sensitivity.

Molecular and functional characterization of novel fructosyltransferases and invertases from Agave tequilana.

PubMed

Cortés-Romero, Celso; Martínez-Hernández, Aída; Mellado-Mojica, Erika; López, Mercedes G; Simpson, June

2012-01-01

Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and structure/function relationships, two different genes were predicted to encode 1-SST and 6G-FFT type fructosyltransferases, in addition, 4 genes encoding putative cell wall invertases and 4 genes encoding putative vacuolar invertases were also identified. Probable functions for each gene, were assigned based on conserved amino acid sequences and confirmed for 2 fructosyltransferases and one invertase by analyzing the enzymatic activity of recombinant Agave protein s expressed and purified from Pichia pastoris. The genome organization of the fructosyltransferase/invertase genes, for which the corresponding cDNA contained the complete open reading frame, was found to be well conserved since all genes were shown to carry a 9 bp mini-exon and all showed a similar structure of 8 exons/7 introns with the exception of a cell wall invertase gene which has 7 exons and 6 introns. Fructosyltransferase genes were strongly expressed in the storage organs of the plants, especially in vegetative stages of development and to lower levels in photosynthetic tissues, in contrast to the invertase genes where higher levels of expression were observed in leaf tissues and in mature plants.

Molecular and Functional Characterization of Novel Fructosyltransferases and Invertases from Agave tequilana

PubMed Central

Cortés-Romero, Celso; Martínez-Hernández, Aída; Mellado-Mojica, Erika; López, Mercedes G.; Simpson, June

2012-01-01

Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and structure/function relationships, two different genes were predicted to encode 1-SST and 6G-FFT type fructosyltransferases, in addition, 4 genes encoding putative cell wall invertases and 4 genes encoding putative vacuolar invertases were also identified. Probable functions for each gene, were assigned based on conserved amino acid sequences and confirmed for 2 fructosyltransferases and one invertase by analyzing the enzymatic activity of recombinant Agave protein s expressed and purified from Pichia pastoris. The genome organization of the fructosyltransferase/invertase genes, for which the corresponding cDNA contained the complete open reading frame, was found to be well conserved since all genes were shown to carry a 9 bp mini-exon and all showed a similar structure of 8 exons/7 introns with the exception of a cell wall invertase gene which has 7 exons and 6 introns. Fructosyltransferase genes were strongly expressed in the storage organs of the plants, especially in vegetative stages of development and to lower levels in photosynthetic tissues, in contrast to the invertase genes where higher levels of expression were observed in leaf tissues and in mature plants. PMID:22558253

Purification and characterization of a trehalase-invertase enzyme with dual activity from Candida utilis.

PubMed

Lahiri, Sagar; Basu, Arghya; Sengupta, Shinjinee; Banerjee, Shakri; Dutta, Trina; Soren, Dhananjay; Chattopadhyay, Krishnananda; Ghosh, Anil K

2012-06-15

Trehalose and sucrose, two important anti-stress non-reducing natural disaccharides, are catabolized by two enzymes, namely trehalase and invertase respectively. In this study, a 175 kDa enzyme protein active against both substrates was purified from wild type Candida utilis and characterized in detail. Substrate specificity assay and activity staining revealed the enzyme to be specific for both sucrose and trehalose. The ratio between trehalase and invertase activity was found to be constant at 1:3.5 throughout the entire study. Almost 40-fold purification and 30% yield for both activities were achieved at the final step of purification. The presence of common enzyme inhibitors, thermal and pH stress had analogous effects on its trehalase and invertase activity. Km values for two activities were similar while Vmax and Kcat also differed by a factor of 3.5. Competition plot for both substrates revealed the two activities to be occurring at the single active site. N-terminal sequencing and MALDI-TOF data analysis revealed higher similarity of the purified protein to previously known neutral trehalases. While earlier workers mentioned independent purification of neutral trehalase or invertase from different sources, the present study reports the purification of a single protein showing dual activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Role of invertase activity in processing quality of potatoes: Effect of storage temperature and duration.

PubMed

Bandana; Sharma, Vineet; Singh, Brajesh; Raigond, Pinky; Kaushik, S K

2016-03-01

Invertase activity and processing attributes of three potato cultivars were studied to find the reason for deterioration of processing quality during their prolonged storage in commercial cold stores (4°C) as compared to elevated temperature storage (12 ± 0.5°C), with CIPC {Isopropyl-N-(3-Cholorophenyl) carbamate}. Lower storage temperature (4°C) tended to be more effective in increasing invertase activity of potato tubers than elevated temperature. Non-processing cultivar viz., Kufri Pukhraj resulted in accumulation of more invertase activity than relatively two processing cultivars. Kufri Chipsona-1 and Kufri Chipsona-3 at 12 ± 0.5°C possessed basal invertase activity ranging from 39.3 to 79.8 and 54.1 to 93.8 (pmoles hexose h⁻¹ g⁻¹ f.wt.) respectively, during two years. Total invertase activity at 4°C increased abruptly and remained high from 30 to 60 days of storage. The activity progressively reached 90.6 to 106.6 and 81.4 to 101.3 during both the years respectively, after 60 days of storage to that observed initially. Reducing sugar content increased from 23.3 to 105.7 and 389.0 to 1138.2 (mg 100g⁻¹ f.wt.) after 90 days of storage at 12 ± 0.5°C and 4°C, respectively. Studies concluded that basal and total invertase, were responsible for cold-induced sweetening and resulted in deterioration of processing quality of potatoes during storage at 4°C. Since this activity is low at 12 ± 0.5°C, the processing traits remained acceptable to industry and consumers.

Gene encoding a novel invertase from a xerophilic Aspergillus niger strain and production of the enzyme in Pichia pastoris.

PubMed

Veana, Fabiola; Fuentes-Garibay, José Antonio; Aguilar, Cristóbal Noé; Rodríguez-Herrera, Raúl; Guerrero-Olazarán, Martha; Viader-Salvadó, José María

2014-09-01

β-Fructofuranosidases or invertases (EC 3.2.1.26) are enzymes that are widely used in the food industry, where fructose is preferred over sucrose, because it is sweeter and does not crystallize easily. Since Aspergillus niger GH1, an xerophilic fungus from the Mexican semi-desert, has been reported to be an invertase producer, and because of the need for new enzymes with biotechnological applications, in this work, we describe the gene and amino acid sequence of the invertase from A. niger GH1, and the use of a synthetic gene to produce the enzyme in the methylotrophic yeast Pichia pastoris. In addition, the produced invertase was characterized biochemically. The sequence of the invertase gene had a length of 1770 bp without introns, encodes a protein of 589 amino acids, and presented an identity of 93% and 97% with invertases from Aspergillus kawachi IFO 4308 and A. niger B60, respectively. A 4.2 L culture with the constructed recombinant P. pastoris strain showed an extracellular and periplasmic invertase production at 72 h induction of 498 and 3776 invertase units (U), respectively, which corresponds to 1018 U/L of culture medium. The invertase produced had an optimum pH of 5.0, optimum temperature of 60 °C, and specific activity of 3389 U/mg protein, and after storage for 96 h at 4 °C showed 93.7% of its activity. This invertase could be suitable for producing inverted sugar used in the food industry. Copyright © 2014 Elsevier Inc. All rights reserved.

Production and characterization of a novel yeast extracellular invertase activity towards improved dibenzothiophene biodesulfurization.

PubMed

Arez, Bruno F; Alves, Luís; Paixão, Susana M

2014-11-01

The main goal of this work was the production and characterization of a novel invertase activity from Zygosaccharomyces bailii strain Talf1 for further application to biodesulfurization (BDS) in order to expand the exploitable alternative carbon sources to renewable sucrose-rich feedstock. The maximum invertase activity (163 U ml(-1)) was achieved after 7 days of Z. bailii strain Talf1 cultivation at pH 5.5-6.0, 25 °C, and 150 rpm in Yeast Malt Broth with 25 % Jerusalem artichoke pulp as inducer substrate. The optimum pH and temperature for the crude enzyme activity were 5.5 and 50 °C, respectively, and moreover, high stability was observed at 30 °C for pH 5.5-6.5. The application of Talf1 crude invertase extract (1 %) to a BDS process by Gordonia alkanivorans strain 1B at 30 °C and pH 7.5 was carried out through a simultaneous saccharification and fermentation (SSF) approach in which 10 g l(-1) sucrose and 250 μM dibenzothiophene were used as sole carbon and sulfur sources, respectively. Growth and desulfurization profiles were evaluated and compared with those of BDS without invertase addition. Despite its lower stability at pH 7.5 (loss of activity within 24 h), Talf1 invertase was able to catalyze the full hydrolysis of 10 g l(-1) sucrose in culture medium into invert sugar, contributing to a faster uptake of the monosaccharides by strain 1B during BDS. In SSF approach, the desulfurizing bacterium increased its μmax from 0.035 to 0.070 h(-1) and attained a 2-hydroxybiphenyl productivity of 5.80 μM/h in about 3 days instead of 7 days, corresponding to an improvement of 2.6-fold in relation to the productivity obtained in BDS process without invertase addition.

Comparative study of invertases of Streptococcus mutans.

PubMed

Tanzer, J M; Brown, A T; McInerney, M F; Woodiel, F N

1977-04-01

Sucrase activity was studied in 13 strains of Streptococcus mutans representing the five Bratthall serotypes. Sucrose-adapted cells have sucrase activity in the 37,000 x g-soluble fraction of all strains. The enzyme was identified as invertase (beta-d-fructofuranoside fructohydrolase; EC 3.2.1.26) because it hydrolyzed the beta-fructofuranoside trisaccharide raffinose, giving fructose and melibiose as its products, and because it hydrolyzed the beta-fructofuranoside dissacharide sucrose, giving equimolar glucose and fructose as its products. Invertases of c and e strains exhibit two activity peaks by molecular exclusion chromatography with molecular weights of 45,000 to 50,000 and about 180,000; those of serotypes a, b, and d strains exhibit only a single component of 45,000 to 50,000 molecular weight. The electrophoretic mobility of invertases is different between the serotypes and the same within them. Inorganic orthophosphate (P(i)) has a weak positive effect on the V(max) of invertases of serotypes c and e cells but a strong positive effect on the invertases of serotype b cells; P(i) has a strong positive effect on the apparent K(m) of the invertases of serotype d cells, but has no effect on the V(max); P(i) has a strong positive effect on both the apparent K(m) and V(max) of the invertases of serotype a cells. Thus, the invertases were different between all of the serotypes but similar within the serotypes. These findings support the taxonomic schemes of Coykendall and of Bratthall. It was additionally noted that 37,000 x g-soluble fractions of only serotypes b and c but not serotypes a, d, and e cells have melibiase activity, and it could be deduced that serotype d cells lack an intact raffinose permease system.

Effect of moisture content on the invertase activity of freeze-dried S. cerevisiae.

PubMed

Pitombo, R N; Spring, C; Passos, R F; Tonato, M; Vitolo, M

1994-08-01

The invertase activity of intact Saccharomyces cerevisiae submitted to freezing-thawing was affected by pH, the chemical nature of the buffer, and the freezing cooling rate (CR), leading in some cases to a complete invertase inactivation (acetate buffer, pH 4.0, CR = 0.5 degree C/min). Once established under adequate freezing conditions the invertase activity remained unchanged after freeze-drying. Nevertheless, in some cases the cell-growing capability after freeze-drying diminished around 70%, mainly if the frozen cell suspension was attained through freezing carried out at CR = 0.5 degree C/min. Water sorption isotherms of freeze-dried samples (freeze-dryer Edwards L-4KR; 30 degrees C and 0.1 mB) were determined at 10 and 25 degrees C. The monolayer moisture content (MMC) at each temperature (12.7 and 3.71 for 10 and 25 degrees C, respectively) was calculated from isotherms by applying BET and GAB models. Freeze-dried yeast with water activity (Aw) between 0 and 0.33 (about the MMC value) maintained at 25 degrees C for 235 days and at 89 degrees C for 15 min retained at least 85% of its original invertase activity (IA), whereas samples with Aw > MMC lost at least 60% of its IA. X ray diffraction showed that the freeze-dried cake before and after storage presented an amorphous structure.

Efficient stabilization of Saccharomyces cerevisiae external invertase by immobilisation on modified beidellite nanoclays.

PubMed

Andjelković, Uroš; Milutinović-Nikolić, Aleksandra; Jović-Jovičić, Nataša; Banković, Predrag; Bajt, Teja; Mojović, Zorica; Vujčić, Zoran; Jovanović, Dušan

2015-02-01

The external invertase isoform 1 (EINV1) was immobilised on eight differently modified beidellite nanoclays. Modifications were composed of organo-modification with different amounts of surfactant - hexadecyl trimethylammonium cation (HDTMA), pillaring with Al/Fe containing polyhydroxy cations and acid modification of Na-enriched and pillared clays. The modified nanoclays were characterised by XRD, N2-physisorption, SEM and FT-IR spectroscopy. The amount of bound enzyme activity was significantly influenced by the modification of beidellite ranging from 50 to remarkable 2200U/g. Biochemical characterization was performed for five modified nanoclays showing the highest enzyme activity after invertase immobilisation. The investigation demonstrated that after immobilisation the structure and the catalytic properties of invertase were preserved, while Km values were slightly increased from 26 to 37mM. immobilisation significantly improved thermal and storage stability of EINV1. Results indicate that beidellite nanoclays obtained by low cost modifications can be applied as a suitable support for the immobilisation of invertase. The immobilizate can be efficiently engaged in sucrose hydrolysis in batch reactor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Differential expression of vacuolar and defective cell wall invertase genes in roots and seeds of metalliferous and non-metalliferous populations of Rumex dentatus under copper stress.

PubMed

Xu, Zhong-Rui; Cai, Shen-Wen; Huang, Wu-Xing; Liu, Rong-Xiang; Xiong, Zhi-Ting

2018-01-01

Acid invertase activities in roots and young seeds of a metalliferous population (MP) of Rumex dentatus were previously observed to be significantly higher than those of a non-metalliferous population (NMP) under Cu stress. To date, no acid invertase gene has been cloned from R. dentatus. Here, we isolated four full-length cDNAs from the two populations of R. dentatus, presumably encoding cell wall (RdnCIN1 and RdmCIN1 from the NMP and MP, respectively) and vacuolar invertases (RdnVIN1 and RdmVIN1 from the NMP and MP, respectively). Unexpectedly, RdnCIN1 and RdmCIN1 most likely encode special defective invertases with highly attenuated sucrose-hydrolyzing capacity. The transcript levels of RdmCIN1 were significantly higher than those of RdnCIN1 in roots and young seeds under Cu stress, whereas under control conditions, the former was initially lower than the latter. Unexpected high correlations were observed between the transcript levels of RdnCIN1 and RdmCIN1 and the activity of cell wall invertase, even though RdnCIN1 and RdmCIN1 do not encode catalytically active invertases. Similarly, the transcript levels of RdmVIN1 in roots and young seeds were increased under Cu stress, whereas those of RdnVIN1 were decreased. The high correlations between the transcript levels of RdnVIN1 and RdmVIN1 and the activity of vacuolar invertase indicate that RdnVIN1 and RdmVIN1 might control distinct vacuolar invertase activities in the two populations. Moreover, a possible indirect role for acid invertases in Cu tolerance, mediated by generating a range of sugars used as nutrients and signaling molecules, is discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular cloning, structure, phylogeny and expression analysis of the invertase gene family in sugarcane.

PubMed

Wang, Liming; Zheng, Yuexia; Ding, Shihui; Zhang, Qing; Chen, Youqiang; Zhang, Jisen

2017-06-23

Invertases (INVs) are key enzymes regulating sucrose metabolism and are here revealed to be involved in responses to environmental stress in plants. To date, individual members of the invertase gene family and their expression patterns are unknown in sugarcane due to its complex genome despite their significance in sucrose metabolism. In this study, based on comparative genomics, eleven cDNA and twelve DNA sequences belonging to 14 non-redundant members of the invertase gene family were successfully cloned from sugarcane. A comprehensive analysis of the invertase gene family was carried out, including gene structures, phylogenetic relationships, functional domains, conserved motifs of proteins. The results revealed that the 14 invertase members from sugarcane could be clustered into three subfamilies, including 6 neutral/alkaline invertases (ShN/AINVs), and 8 acid invertases (ShAINVs). Faster divergence occurred in acid INVs than in neutral/alkaline INVs after the split of sugarcane and sorghum. At least a one-time gene duplication event was observed to have occurred in the four groups of acid INVs, whereas ShN/AINV1 and ShN/AINV2 in the β8 lineage were revealed to be the most recently duplicated genes among their paralogous genes in the β group of N/AINVs. Furthermore, comprehensive expression analysis of these genes was performed in sugarcane seedlings subjected to five abiotic stresses (drought, low temperature, glucose, fructose, and sucrose) using Quantitative Real-time PCR. The results suggested a functional divergence of INVs and their potential role in response to the five different treatments. Enzymatic activity in sugarcane seedlings was detected under five abiotic stresses treatments, and showed that the activities of all INVs were significantly inhibited in response to five different abiotic stresses, and that the neutral/alkaline INVs played a more prominent role in abiotic stresses than the acid INVs. In this study, we determined the INV gene family

Cell wall invertase in tobacco crown gall cells : enzyme properties and regulation by auxin.

PubMed

Weil, M; Rausch, T

1990-12-01

The cell wall invertase from an Agrobacterium tumefaciens-transformed Nicotiana tabacum cell line (SR1-C58) was purified. The heterogeneously glycosylated enzyme has the following properties: M(r) 63,000, pH optimum at 4.7, K(m sucrose) 0.6 millimolar (at pH 4.7), pl 9.5. Enzyme activity is inhibited by micromolar concentrations of HgCl(2) but is insensitive to H(2)O(2), N-ethylmaleimide and dithiothreitol. Upon transfer of transformed cells from the stationary phase to fresh medium, a cycloheximide- and tunicamycin-sensitive de novo formation of cell wall invertase is demonstrated in the absence or presence of sucrose. While in an auxin mutant (lacking gene 1;SR1-3845) 1 micromolar 1-naphthaleneacetic acid led to a further increased activity, the wild-type transformed cell line (SR1-C58) responded with a decreased activity compared to the control. An analysis of cell wall invertase in and around tumors initiated with Agrobacterium tumefaciens (strain C58) on Nicotiana tabacum stem and Kalanchoë daigremontiana leaves revealed gradients of activity. The results indicate that the auxin-stimulated cell wall invertase is essential for the establishment of the tumor sink.

RhVI1 is a membrane-anchored vacuolar invertase highly expressed in Rosa hybrida L. petals

PubMed Central

Farci, Domenica; Collu, Gabriella; Kirkpatrick, Joanna; Esposito, Francesca; Piano, Dario

2016-01-01

Invertases are a widespread group of enzymes that catalyse the conversion of sucrose into fructose and glucose. Plants invertases and their substrates are essential factors that play an active role in primary metabolism and in cellular differentiation and by these activities they sustain development and growth. Being naturally present in multiple isoforms, invertases are known to be highly differentiated and tissue specific in such a way that every isoform is characteristic of a specific part of the plant. In this work, we report the identification of the invertase RhVI1 that was found to be highly expressed in rose petals. A characterization of this protein revealed that RhVI1 is a glycosylated membrane-anchored protein associated with the cytosolic side of the vacuolar membrane which occurs in vivo in a monomeric form. Purification yields have shown that the levels of expression decreased during the passage of petals from buds to mature and pre-senescent flowers. Moreover, the activity assay indicates RhVI1 to be an acidic vacuolar invertase. The physiological implications of these findings are discussed, suggesting a possible role of this protein during anthesis. PMID:27083698

Catalytic efficiency and thermostability improvement of Suc2 invertase through rational site-directed mutagenesis.

PubMed

Mohandesi, Nooshin; Haghbeen, Kamahldin; Ranaei, Omid; Arab, Seyed Shahriar; Hassani, Sorour

2017-01-01

Engineering of invertases has come to attention because of increasing demand for possible applications of invertases in various industrial processes. Due to the known physicochemical properties, invertases from micro-organisms such as Saccharomyces cerevisiae carrying SUC2 gene are considered as primary models. To improve thermostability and catalytic efficiency of SUC2 invertase (SInv), six influential residues with Relative Solvent Accessibility<5% were selected through multiple-sequence alignments, molecular modelling, structural and computational analyses. Consequently, SInv and 5 mutants including three mutants with single point substitution [Mut1=P152V, Mut2=S85V and Mut3=K153F)], one mutant with two points [Mut4=S305V-N463V] and one mutant with three points [Mut5=S85V-K153F-T271V] were developed via site-directed mutagenesis and produced using Pichia pastoris as the host. Physicochemical studies on these enzymes indicated that the selected amino acids which were located in the active site region mainly influenced catalytic efficiency. The best improvement belonged to Mut1 (54% increase in K cat /K m ) and Mut3 exhibited the worst effect (90% increase in K m ). These results suggest that Pro152 and Lys153 play key role in preparation of the right substrate lodging in the active site of SInv. The best thermostability improvement (16%) was observed for Mut4 in which two hydrophilic residues located on the loops, far from the active site, were replaced by Valines. These results suggest that tactful simultaneous substitution of influential hydrophilic residues in both active site region and peripheral loops with hydrophobic amino acids could result in more thermostable invertases with enhanced catalytic efficiency. Copyright © 2016 Elsevier Inc. All rights reserved.

Vacuolar invertase gene silencing in potato (Solanum tuberosum L.) improves processing quality by decreasing the frequency of sugar-end defects

USDA-ARS?s Scientific Manuscript database

Sugar-end defect is a tuber quality disorder that causes unacceptable darkening of one end of French fries. This defect appears when environmental stress during tuber growth increases post-harvest vacuolar acid invertase activity at one end of the tuber. Reducing sugars produced by invertase form da...

RhVI1 is a membrane-anchored vacuolar invertase highly expressed in Rosa hybrida L. petals.

PubMed

Farci, Domenica; Collu, Gabriella; Kirkpatrick, Joanna; Esposito, Francesca; Piano, Dario

2016-05-01

Invertases are a widespread group of enzymes that catalyse the conversion of sucrose into fructose and glucose. Plants invertases and their substrates are essential factors that play an active role in primary metabolism and in cellular differentiation and by these activities they sustain development and growth. Being naturally present in multiple isoforms, invertases are known to be highly differentiated and tissue specific in such a way that every isoform is characteristic of a specific part of the plant. In this work, we report the identification of the invertase RhVI1 that was found to be highly expressed in rose petals. A characterization of this protein revealed that RhVI1 is a glycosylated membrane-anchored protein associated with the cytosolic side of the vacuolar membrane which occurs in vivo in a monomeric form. Purification yields have shown that the levels of expression decreased during the passage of petals from buds to mature and pre-senescent flowers. Moreover, the activity assay indicates RhVI1 to be an acidic vacuolar invertase. The physiological implications of these findings are discussed, suggesting a possible role of this protein during anthesis. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Effects of high pressure processing on activity and structure of soluble acid invertase in mango pulp, crude extract, purified form and model systems.

PubMed

Li, Renjie; Wang, Yongtao; Ling, Jiangang; Liao, Xiaojun

2017-09-15

The effects of high pressure processing (HPP) on the activity of soluble acid invertase (SAI) in mango pulp, crude extract, purified SAI and purified SAI in model systems (pectin, bovine serum albumin (BSA), sugars and pH 3-7) were investigated. The activity of SAI in mango pulp was increased after HPP, and that in crude extract stayed unchanged. The activity of purified SAI was decreased after HPP at 45 and 50°C. Pectin exhibited a concentration-dependent protection for purified SAI against HPP at 50°C/600MPa for 30min. Pectin that had an esterification degree (DE) of 85% exhibited a greater protection than pectin that had a DE of 20-34%. BSA, acidic pH (3-6) and sucrose also exhibited protection for purified SAI against HPP. HPP at 50°C/600MPa for 30min disrupted the secondary structure and tertiary structure of purified SAI, but no aggregation of purified SAI was observed after HPP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic Control of Tobacco Pollination by Sugars and Invertases1

PubMed Central

Goetz, Marc; Hirsche, Jörg; Bauerfeind, Martin Andreas; González, María-Cruz; Hyun, Tae Kyung; Eom, Seung Hee; Chriqui, Dominique; Engelke, Thomas; Großkinsky, Dominik K.; Roitsch, Thomas

2017-01-01

Pollination in flowering plants is initiated by germination of pollen grains on stigmas followed by fast growth of pollen tubes representing highly energy-consuming processes. The symplastic isolation of pollen grains and tubes requires import of Suc available in the apoplast. We show that the functional coupling of Suc cleavage by invertases and uptake of the released hexoses by monosaccharide transporters are critical for pollination in tobacco (Nicotiana tabacum). Transcript profiling, in situ hybridization, and immunolocalization of extracellular invertases and two monosaccharide transporters in vitro and in vivo support the functional coupling in supplying carbohydrates for pollen germination and tube growth evidenced by spatiotemporally coordinated expression. Detection of vacuolar invertases in maternal tissues by these approaches revealed metabolic cross talk between male and female tissues and supported the requirement for carbohydrate supply in transmitting tissue during pollination. Tissue-specific expression of an invertase inhibitor and addition of the chemical invertase inhibitor miglitol strongly reduced extracellular invertase activity and impaired pollen germination. Measurements of (competitive) uptake of labeled sugars identified two import pathways for exogenously available Suc into the germinating pollen operating in parallel: direct Suc uptake and via the hexoses after cleavage by extracellular invertase. Reduction of extracellular invertase activity in pollen decreases Suc uptake and severely compromises pollen germination. We further demonstrate that Glc as sole carbon source is sufficient for pollen germination, whereas Suc is supporting tube growth, revealing an important regulatory role of both the invertase substrate and products contributing to a potential metabolic and signaling-based multilayer regulation of pollination by carbohydrates. PMID:27923989

Kinetic Induction of Oat Shoot Pulvinus Invertase mRNA by Gravistimulation and Partial cDNA Cloning by the Polymerase Chain Reaction

NASA Technical Reports Server (NTRS)

Wu, Liu-Lai; Song, Il; Karuppiah, Nadarajah; Kaufman, Peter B.

1993-01-01

An asymmetric (top vs. bottom halves of pulvini) induction of invertase mRNA by gravistimulation was analyzed in oat shoot pulvini. Total RNA and poly(A)(+) RNA, isolated from oat pulvini, and two oli-gonucleotide primers, corresponding to two conserved amino acid sequences (NDPNG and WECPD) found in invertase from other species, were used for the polymerase chain reaction (PCR). A partial length cDNA (550 bp) was obtained and characterized. A 62% nucleotide sequence homology and 58% deduced amino acid sequence homology, as compared to beta-fructosidase of carrot cell wall, was found. Northern blot analysis showed that there was an obviously transient induction of invertase mRNA by gravistimulation in the oat pulvinus system. The mRNA was rapidly induced to a maximum level at 1 hour after gravistimulation treatment and gradually decreased afterwards. The mRNA level in the bottom half of the oat pulvinus was significantly higher than that in the top half of the pulvinus tissue. The kinetic induction of invertase mRNA was consistent with the transient accumulation of invertase activity during the graviresponse of the pulvinus. This indicates that the expression of the invertase gene(s) could be regulated by gravistimulation at the transcriptional level. Southern blot analysis showed that there were two to three genomic DNA fragments which hybridized with the partial-length invertase cDNA.

Physiological responses of biomass allocation, root architecture, and invertase activity to copper stress in young seedlings from two populations of Kummerowia stipulacea (maxim.) Makino.

PubMed

Zhang, Luan; Pan, Yuxue; Lv, Wei; Xiong, Zhi-ting

2014-06-01

In the current study, we hypothesize that mine (metallicolous) populations of metallophytes form a trade-off between the roots and shoots when under copper (Cu) stress to adapt themselves to heavy metal contaminated habitats, and thus, differ from normal (non-metallicolous) populations in biomass allocation. To test the hypothesis, two populations of the metallophyte Kummerowia stipulacea, one from an ancient Cu mine (MP) and the other from a non-contaminated site (NMP), were treated with Cu(2+) in hydroponic conditions. The results showed that MP plants had higher root/shoot biomass allocation and more complicated root system architecture compared to those of the NMP plants when under Cu stress. The net photosynthetic capacity was more inhibited in the NMP plants than in the MP plants when under Cu stress. The sugar (sucrose and hexose) contents and acid invertase activities of MP plants were elevated while those in NMP plants were inhibited after Cu treatment. The neutral/alkaline invertase activities and sucrose synthase level showed no significant differences between the two populations when under Cu stress. The results showed that acid invertase played an important role in biomass allocation and that the physiological responses were beneficial for the high root/shoot biomass allocation, which were advantageous during adaptive evolution to Cu-enriched mine soils. Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular and functional characterization of an invertase secreted by Ashbya gossypii.

PubMed

Aguiar, Tatiana Q; Dinis, Cláudia; Magalhães, Frederico; Oliveira, Carla; Wiebe, Marilyn G; Penttilä, Merja; Domingues, Lucília

2014-06-01

The repertoire of hydrolytic enzymes natively secreted by the filamentous fungus Ashbya (Eremothecium) gossypii has been poorly explored. Here, an invertase secreted by this flavinogenic fungus was for the first time molecularly and functionally characterized. Invertase activity was detected in A. gossypii culture supernatants and cell-associated fractions. Extracellular invertase migrated in a native polyacrylamide gel as diffuse protein bands, indicating the occurrence of at least two invertase isoforms. Hydrolytic activity toward sucrose was approximately 10 times higher than toward raffinose. Inulin and levan were not hydrolyzed. Production of invertase by A. gossypii was repressed by the presence of glucose in the culture medium. The A. gossypii invertase was demonstrated to be encoded by the AFR529W (AgSUC2) gene, which is highly homologous to the Saccharomyces cerevisiae SUC2 (ScSUC2) gene. Agsuc2 null mutants were unable to hydrolyze sucrose, proving that invertase is encoded by a single gene in A. gossypii. This mutation was functionally complemented by the ScSUC2 and AgSUC2 genes, when expressed from a 2-μm-plasmid. The signal sequences of both AgSuc2p and ScSuc2p were able to direct the secretion of invertase into the culture medium in A. gossypii.

Vacuolar invertase gene silencing in potato decreasing the frequency of sugar-end defects

USDA-ARS?s Scientific Manuscript database

Sugar-end defect is a tuber quality disorder and persistent problem for the French fry processing industry that causes unacceptable darkening of one end of French fries. This defect appears when environmental stress during tuber growth increases post-harvest vacuolar acid invertase activity at one e...

Interaction proteins of invertase and invertase inhibitor in cold-stored potato tubers suggested a protein complex underlying post-translational regulation of invertase.

PubMed

Lin, Yuan; Liu, Jun; Liu, Xun; Ou, Yongbin; Li, Meng; Zhang, Huiling; Song, Botao; Xie, Conghua

2013-12-01

The activity of vacuolar invertase (VI) is vital to potato cold-induced sweetening (CIS). A post-translational regulation of VI activity has been proposed which involves invertase inhibitor (VIH), but the mechanism for the interaction between VI and VIH has not been fully understood. To identify the potential partners of VI and VIH, two cDNA libraries were respectively constructed from CIS-resistant wild potato species Solanum berthaultii and CIS-sensitive potato cultivar AC035-01 for the yeast two-hybrid analysis. The StvacINV1 (one of the potato VIs) and StInvInh2B (one of the potato VIHs), previously identified to be associated with potato CIS, were used as baits to screen the two libraries. Through positive selection and sequencing, 27 potential target proteins of StvacINV1 and eight of StInvInh2B were clarified. The Kunitz-type protein inhibitors were captured by StvacINV1 in both libraries and the interaction between them was confirmed by bimolecular fluorescence complementation assay in tobacco cells, reinforcing a fundamental interaction between VI and VIH. Notably, a sucrose non-fermenting-1-related protein kinase 1 was captured by both the baits, suggesting that a protein complex could be necessary for fine turning of the invertase activity. The target proteins clarified in present research provide a route to elucidate the mechanism by which the VI activity can be subtly modulated. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Light modulated activity of root alkaline/neutral invertase involves the interaction with 14-3-3 proteins.

PubMed

Gao, Jing; van Kleeff, Paula J M; Oecking, Claudia; Li, Ka Wan; Erban, Alexander; Kopka, Joachim; Hincha, Dirk K; de Boer, Albertus H

2014-12-01

Alkaline/neutral invertases (A/N-Invs) are now recognized as essential proteins in plant life. They catalyze the irreversible breakdown of sucrose into glucose and fructose and thus supply the cells with energy as well as signaling molecules. In this study we report on a mechanism that affects the activity of the cytosolic invertase AtCINV1 (At-A/N-InvG or AT1G35580). We demonstrate that Ser547 at the extreme C-terminus of the AtCINV1 protein is a substrate of calcium-dependent kinases (CPK3 and 21) and that phosphorylation creates a high-affinity binding site for 14-3-3 proteins. The invertase as such has basal activity, but we provide evidence that interaction with 14-3-3 proteins enhances its activity. The analysis of three quadruple 14-3-3 mutants generated from six T-DNA insertion mutants of the non-epsilon family shows both specificity as well as redundancy for this function of 14-3-3 proteins. The strong reduction in hexose levels in the roots of one 14-3-3 quadruple mutant plant is in line with the activating function of 14-3-3 proteins. The physiological relevance of this mechanism that affects A/N-invertase activity is underscored by the light-induced activation and is another example of the central role of 14-3-3 proteins in mediating dark/light signaling. The nature of the light-induced signal that travels from the shoot to root and the question whether this signal is transmitted via cytosolic Ca(++) changes that activate calcium-dependent kinases, await further study. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Utilization of molasses and sugar cane bagasse for production of fungal invertase in solid state fermentation using Aspergillus niger GH1

PubMed Central

Veana, F.; Martínez-Hernández, J.L.; Aguilar, C.N.; Rodríguez-Herrera, R.; Michelena, G.

2014-01-01

Agro-industrial wastes have been used as substrate-support in solid state fermentation for enzyme production. Molasses and sugarcane bagasse are by-products of sugar industry and can be employed as substrates for invertase production. Invertase is an important enzyme for sweeteners development. In this study, a xerophilic fungus Aspergillus niger GH1 isolated of the Mexican semi-desert, previously reported as an invertase over-producer strain was used. Molasses from Mexico and Cuba were chemically analyzed (total and reducer sugars, nitrogen and phosphorous contents); the last one was selected based on chemical composition. Fermentations were performed using virgin and hydrolyzate bagasse (treatment with concentrated sulfuric acid). Results indicated that, the enzymatic yield (5231 U/L) is higher than those reported by other A. niger strains under solid state fermentation, using hydrolyzate bagasse. The acid hydrolysis promotes availability of fermentable sugars. In addition, maximum invertase activity was detected at 24 h using low substrate concentration, which may reduce production costs. This study presents an alternative method for invertase production using a xerophilic fungus isolated from Mexican semi-desert and inexpensive substrates (molasses and sugarcane bagasse). PMID:25242918

Extracellular invertase is involved in the regulation of clubroot disease in Arabidopsis thaliana.

PubMed

Siemens, Johannes; González, Maria-Cruz; Wolf, Sebastian; Hofmann, Christina; Greiner, Steffen; DU, Yejie; Rausch, Thomas; Roitsch, Thomas; Ludwig-Müller, Jutta

2011-04-01

Clubroot disease of Brassicaceae is caused by an obligate biotrophic protist, Plasmodiophora brassicae. During root gall development, a strong sink for assimilates is developed. Among other genes involved in sucrose and starch synthesis and degradation, the increased expression of invertases has been observed in a microarray experiment, and invertase and invertase inhibitor expression was confirmed using promoter::GUS lines of Arabidopsis thaliana. A functional approach demonstrates that invertases are important for gall development. Different transgenic lines expressing an invertase inhibitor under the control of two root-specific promoters, Pyk10 and CrypticT80, which results in the reduction of invertase activity, showed clearly reduced clubroot symptoms in root tissue with highest promoter expression, whereas hypocotyl galls developed normally. These results present the first evidence that invertases are important factors during gall development, most probably in supplying sugars to the pathogen. In addition, root-specific repression of invertase activity could be used as a tool to reduce clubroot symptoms. © 2010 The Authors. Molecular Plant Pathology © 2010 BSPP and Blackwell Publishing Ltd.

Cytoplasmic expression of a thermostable invertase from Thermotoga maritima in Lactococcus lactis.

PubMed

Pek, Han Bin; Lim, Pei Yu; Liu, Chengcheng; Lee, Dong-Yup; Bi, Xuezhi; Wong, Fong Tian; Ow, Dave Siak-Wei

2017-05-01

To evaluate the secretory and cytoplasmic expression of a thermostable Thermogata maritima invertase in Lactococcus lactis. The thermostable invertase from T. maritima was cloned with and without the USP45 secretory peptide into the pNZ8148 vector for nisin-inducible expression in L. lactis. The introduction of an USP45 secretion peptide at the N-terminal of the enzyme led to a loss of protein solubility. Computational homology modeling and hydrophobicity studies indicated that the USP45 peptide exposes a stretch of hydrophobic amino acids on the protein surface resulting in lower solubility. Removal of the USP45 secretion peptide allowed a soluble and functional invertase to be expressed intracellularly in L. lactis. Immobilized metal affinity chromatography purification of the cell lysate with nickel-NTA gave a single protein band on SDS-PAGE, while E. coli-expressed invertase consistently co-purified with an additional band. The yields of the purified invertase from E. coli and L. lactis were 14.1 and 6.3 mg/l respectively. Invertase can be expressed in L. lactis and purified in a functional form. L. lactis is a suitable host for the production of food-grade invertase for use in the food and biotechnology industries.

Altered invertase activities of symptomatic tissues on Beet severe curly top virus (BSCTV) infected Arabidopsis thaliana.

PubMed

Park, Jungan; Kim, Soyeon; Choi, Eunseok; Auh, Chung-Kyun; Park, Jong-Bum; Kim, Dong-Giun; Chung, Young-Jae; Lee, Taek-Kyun; Lee, Sukchan

2013-09-01

Arabidopsis thaliana infected with Beet severe curly top virus (BSCTV) exhibits systemic symptoms such as stunting of plant growth, callus induction on shoot tips, and curling of leaves and shoot tips. The regulation of sucrose metabolism is essential for obtaining the energy required for viral replication and the development of symptoms in BSCTV-infected A. thaliana. We evaluated the changed transcript level and enzyme activity of invertases in the inflorescence stems of BSCTV-infected A. thaliana. These results were consistent with the increased pattern of ribulose-1,5-bisphosphate carboxylase/oxygenase activity and photosynthetic pigment concentration in virus-infected plants to supply more energy for BSCTV multiplication. The altered gene expression of invertases during symptom development was functionally correlated with the differential expression patterns of D-type cyclins, E2F isoforms, and invertase-related genes. Taken together, our results indicate that sucrose sensing by BSCTV infection may regulate the expression of sucrose metabolism and result in the subsequent development of viral symptoms in relation with activation of cell cycle regulation.

[Effects of elevated ozone concentrations on enzyme activities and organic acids content in wheat rhizospheric soil.

PubMed

Yin, Wei Qin; Jing, Hao Qi; Wang, Ya Bo; Wei, Si Yu; Sun, Yue; Wang, Sheng Sen; Wang, Xuai Zhi

2018-02-01

The elevated concentration of tropospheric ozone (O 3 ) is an important global climate change driver, with adverse impacts on soil ecological environment and crop growth. In this study, a pot experiment was carried out in an open top chamber (OTC), to investigate the effects of elevated ozone concentration on soil enzyme activities (catalase, polyphenol oxidase, dehydrogenase and invertase), organic acids contents (oxalic acid, citric acid and malic acid) at different growth stages (tillering, jointing, heading and ripening stages) of wheat, and combined with the rhizospheric soil physicochemical properties and plant root characteristics to analyze the underlying reasons. The results showed that, elevated ozone concentration increased soil catalase, polyphenol oxidase, dehydrogenase and invertase activities at wheat ripening period to different degrees, with the effects on the activities of catalase and polyphenol oxidase being statistically significant. At the heading stage, activities of dehydrogenase and invertase were significantly increased by up to 76.7%. At the ripening stage, elevated ozone concentration significantly increased the content of citric acid and malic acid and redox potential (Eh) in rhizospheric soil, but reduced soil pH, electrical conductivity, total carbon and nitrogen. For root characteristics, elevated ozone concentrations significantly reduced the wheat root biomass, total root length and root surface area but increased the average root diameter.

The roles of call wall invertase inhibitor in regulating chilling tolerance in tomato.

PubMed

Xu, Xiao-Xia; Hu, Qin; Yang, Wan-Nian; Jin, Ye

2017-11-09

Hexoses are important metabolic signals that respond to abiotic and biotic stresses. Cold stress adversely affects plant growth and development, limiting productivity. The mechanism by which sugars regulate plant cold tolerance remains elusive. We examined the function of INVINH1, a cell wall invertase inhibitor, in tomato chilling tolerance. Cold stress suppressed the transcription of INVINH1 and increased that of cell wall invertase genes, Lin6 and Lin8 in tomato seedlings. Silencing INVINH1 expression in tomato increased cell wall invertase activity and enhanced chilling tolerance. Conversely, transgenic tomatoes over-expressing INVINH1 showed reduced cell wall invertase activity and were more sensitive to cold stress. Chilling stress increased glucose and fructose levels, and the hexoses content increased or decreased by silencing or overexpression INVINH1. Glucose applied in vitro masked the differences in chilling tolerance of tomato caused by the different expressions of INVINH1. The repression of INVINH1 or glucose applied in vitro regulated the expression of C-repeat binding factors (CBFs) genes. Transcript levels of NCED1, which encodes 9-cisepoxycarotenoid dioxygenase (NCED), a key enzyme in the biosynthesis of abscisic acid, were suppressed by INVINH1 after exposure to chilling stress. Meanwhile, application of ABA protected plant from chilling damage caused by the different expression of INVINH1. In tomato, INVINH1 plays an important role in chilling tolerance by adjusting the content of glucose and expression of CBFs.

Enhancement of invertase production by Aspergillus niger OZ-3 using low-intensity static magnetic fields.

PubMed

Taskin, Mesut; Esim, Nevzat; Genisel, Mucip; Ortucu, Serkan; Hasenekoglu, Ismet; Canli, Ozden; Erdal, Serkan

2013-01-01

The aim of this study is to investigate the effect of low-intensity static magnetic fields (SMFs) on invertase activity and growth on different newly identified molds. The most positive effect of SMFs on invertase activity and growth was observed for Aspergillus niger OZ-3. The submerged production of invertase was performed with the spores obtained at the different exposure times (120, 144, 168, and 196 hr) and magnetic field intensities (0.45, 3, 5, 7, and 9 mT). The normal magnetic field of the laboratory was assayed as 0.45 mT (control). Optimization of magnetic field intensity and exposure time significantly increased biomass production and invertase activity compared to 0.45 mT. The maximum invertase activity (51.14 U/mL) and biomass concentration (4.36 g/L) were achieved with the spores obtained at the 144 hr exposure time and 5 mT magnetic field intensity. The effect of low-intensity static magnetic fields (SMFs) on invertase activities of molds was investigated for the first time in the present study. As an additional contribution, a new hyper-invertase-producing mold strain was isolated.

Sulla carnosa modulates root invertase activity in response to the inhibition of long-distance sucrose transport under magnesium deficiency.

PubMed

Farhat, N; Smaoui, A; Maurousset, L; Porcheron, B; Lemoine, R; Abdelly, C; Rabhi, M

2016-11-01

Being the principal product of photosynthesis, sucrose is involved in many metabolic processes in plants. As magnesium (Mg) is phloem mobile, an inverse relationship between Mg shortage and sugar accumulation in leaves is often observed. Mg deficiency effects on carbohydrate contents and invertase activities were determined in Sulla carnosa Desf. Plants were grown hydroponically at different Mg concentrations (0.00, 0.01, 0.05 and 1.50 mM Mg) for one month. Mineral analysis showed that Mg contents were drastically diminished in shoots and roots mainly at 0.01 and 0.00 mM Mg. This decline was adversely associated with a significant increase of sucrose, fructose and mainly glucose in shoots of plants exposed to severe deficiency. By contrast, sugar contents were severely reduced in roots of these plants indicating an alteration of carbohydrate partitioning between shoots and roots of Mg-deficient plants. Cell wall invertase activity was highly enhanced in roots of Mg-deficient plants, while the vacuolar invertase activity was reduced at 0.00 mM Mg. This decrease of vacuolar invertase activity may indicate the sensibility of roots to Mg starvation resulting from sucrose transport inhibition. 14 CO 2 labeling experiments were in accordance with these findings showing an inhibition of sucrose transport from source leaves to sink tissues (roots) under Mg depletion. The obtained results confirm previous findings about Mg involvement in photosynthate loading into phloem and add new insights into mechanisms evolved by S. carnosa to cope with Mg shortage in particular the increase of the activity of cell wall invertase. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Cloning, 3D modeling and expression analysis of three vacuolar invertase genes from cassava (Manihot Esculenta Crantz).

PubMed

Yao, Yuan; Wu, Xiao-Hui; Geng, Meng-Ting; Li, Rui-Mei; Liu, Jiao; Hu, Xin-Wen; Guo, Jian-Chun

2014-05-15

Vacuolar invertase is one of the key enzymes in sucrose metabolism that irreversibly catalyzes the hydrolysis of sucrose to glucose and fructose in plants. In this research, three vacuolar invertase genes, named MeVINV1-3, and with 653, 660 and 639 amino acids, respectively, were cloned from cassava. The motifs of NDPNG (β-fructosidase motif), RDP and WECVD, which are conserved and essential for catalytic activity in the vacuolar invertase family, were found in MeVINV1 and MeVINV2. Meanwhile, in MeVINV3, instead of NDPNG we found the motif NGPDG, in which the three amino acids GPD are different from those in other vacuolar invertases (DPN) that might result in MeVINV3 being an inactivated protein. The N-terminal leader sequence of MeVINVs contains a signal anchor, which is associated with the sorting of vacuolar invertase to vacuole. The overall predicted 3D structure of the MeVINVs consists of a five bladed β-propeller module at N-terminus domain, and forms a β-sandwich module at the C-terminus domain. The active site of the protein is situated in the β-propeller module. MeVINVs are classified in two subfamilies, α and β groups, in which α group members of MeVINV1 and 2 are highly expressed in reproductive organs and tuber roots (considered as sink organs), while β group members of MeVINV3 are highly expressed in leaves (source organs). All MeVINVs are highly expressed in leaves, while only MeVINV1 and 2 are highly expressed in tubers at cassava tuber maturity stage. Thus, MeVINV1 and 2 play an important role in sucrose unloading and starch accumulation, as well in buffering the pools of sucrose, hexoses and sugar phosphates in leaves, specifically at later stages of plant development.

Simple Practical Investigations Using Invertase.

ERIC Educational Resources Information Center

Asare-Brown, Emma; Bullock, Clive

1988-01-01

Describes three activities, substrate inhibition, product inhibition by fructose and glucose, and gel immobilization of invertase for use with undergraduate biochemistry classes. Discusses materials, methods, and results. Stresses the advantages of practical exercises in undergraduate classes. (CW)

Highly efficient method towards in situ immobilization of invertase using cryogelation.

PubMed

Olcer, Zehra; Ozmen, Mehmet Murat; Sahin, Zeynep M; Yilmaz, Faruk; Tanriseven, Aziz

2013-12-01

A novel method was developed for the immobilization of Saccharomyces cerevisiae invertase within supermacroporous polyacrylamide cryogel and was used to produce invert sugar. First, the cross-linking of invertase with soluble polyglutaraldehyde (PGA) was carried out prior to immobilization in order to increase the bulkiness of invertase and thus preventing the leakage of the cross-linked enzyme after immobilization by entrapment. And then, in situ immobilization of PGA cross-linked invertase within cryogel synthesis was achieved by free radical polymerization in semi-frozen state. The method resulted in 100 % immobilization and 74 % activity yields. The immobilized invertase retained all the initial activity for 30 days and 30 batch reactions. Immobilization had no effect on optimum temperature and it was 60 °C for both free and immobilized enzyme. However, optimum pH was affected upon immobilization. Optimum pH values for free and immobilized enzyme were 4.5 and 5.0, respectively. The immobilized enzyme was more stable than the free enzyme at high pH and temperatures. The kinetic parameters for free and immobilized invertase were also determined. The newly developed method is simple yet effective and could be used for the immobilization of some other enzymes and microorganisms.

Immobilization of invertase on chitosan and its application to honey treatment

NASA Astrophysics Data System (ADS)

Nam, Nguyen Xuan; Nghia, Ho Trung Trong; Vy, Le Thi Tuong; Oanh, Huynh Ngoc; Hien, Phan Phuoc

2017-09-01

The optimal conditions for immobilized enzyme invertase on chitosan were studied. Beside that, the aim of the present work was to find out if the processing with chitosan - invertase can affect some of the main honey quality paramenters - reductive sugar (RS), colour and antioxidant activity. RS content were analyzed by DNS method, colour parameters (L*, a*, b*) were established in the CIE system and antioxidant activity were analyzed by DPPH method. The results showed that the immobilized conditions were as follows: ratio chitosan/invertase 7/1 (w/w), invertase 0.8%, glutaraldehyde 4%, 50°C at 60 minutes, pH 4.5. After the treatments, there was significant (P<0.05) difference on RS (58.38% for melaleuca honey, 15.11% for dimocarpus longan honey) and colour (ΔE=3.84 for melaleuca honey and ΔE=2.76 for dimocarpus longan honey). Moreover, there was no significant (P<0.05) difference on antioxidant activity.

Three-dimensional Structure of Saccharomyces Invertase

PubMed Central

Sainz-Polo, M. Angela; Ramírez-Escudero, Mercedes; Lafraya, Alvaro; González, Beatriz; Marín-Navarro, Julia; Polaina, Julio; Sanz-Aparicio, Julia

2013-01-01

Invertase is an enzyme that is widely distributed among plants and microorganisms and that catalyzes the hydrolysis of the disaccharide sucrose into glucose and fructose. Despite the important physiological role of Saccharomyces invertase (SInv) and the historical relevance of this enzyme as a model in early biochemical studies, its structure had not yet been solved. We report here the crystal structure of recombinant SInv at 3.3 Å resolution showing that the enzyme folds into the catalytic β-propeller and β-sandwich domains characteristic of GH32 enzymes. However, SInv displays an unusual quaternary structure. Monomers associate in two different kinds of dimers, which are in turn assembled into an octamer, best described as a tetramer of dimers. Dimerization plays a determinant role in substrate specificity because this assembly sets steric constraints that limit the access to the active site of oligosaccharides of more than four units. Comparative analysis of GH32 enzymes showed that formation of the SInv octamer occurs through a β-sheet extension that seems unique to this enzyme. Interaction between dimers is determined by a short amino acid sequence at the beginning of the β-sandwich domain. Our results highlight the role of the non-catalytic domain in fine-tuning substrate specificity and thus supplement our knowledge of the activity of this important family of enzymes. In turn, this gives a deeper insight into the structural features that rule modularity and protein-carbohydrate recognition. PMID:23430743

Characterization of the alkaline/neutral invertase gene in Dendrobium officinale and its relationship with polysaccharide accumulation.

PubMed

Gao, F; Cao, X F; Si, J P; Chen, Z Y; Duan, C L

2016-05-06

Dendrobium officinale is one of the most well-known traditional Chinese medicines, and polysaccharide is its main active ingredient. Many studies have investigated the synthesis and accumulation mechanisms of polysaccharide, but until recently, little was known about the molecular mechanism of how polysaccharide is synthesized because no related genes have been cloned. In this study, we cloned an alkaline/neutral invertase gene from D. officinale (DoNI) by the rapid amplification of cDNA ends (RACE) method. DoNI was 2231 bp long and contained an open reading frame that predicted a 62.8-kDa polypeptide with 554-amino acid residues. An alkaline/neutral invertase conserved domain was predicted from this deduced amino acid sequence, and DoNI had a similar deduced amino acid sequence to Setaria italica and Oryza brachyantha. We also found that DoNI expression in different tissues was closely related to DoNI activity, and more importantly, polysaccharide level. Our results indicate that DoNI is associated with polysaccharide accumulation in D. officinale.

Detection of mercury compounds using invertase-glucose oxidase-based biosensor

NASA Astrophysics Data System (ADS)

Amine, A.; Cremisini, C.; Palleschi, G.

1995-10-01

Mercury compounds have been determined with an electrochemical biosensor based on invertase inhibition. When invertase is in the presence of mercury its activity decreases; this causes a decrease of glucose production which is monitored by the glucose sensor and correlated to the concentration of mercury in solution. Parameters as pH, enzyme concentration, substrate concentration, and reaction and incubation time were optimized. Mercury compounds determination using soluble or immobilized invertase were reported. Results show that the inhibition was competitive and reversible. Mercury compounds can be detected directly in aqueous solution in the range 2 - 10 ppb.

Characterization of the co-purified invertase and β-glucosidase of a multifunctional extract from Aspergillus terreus.

PubMed

Giraldo, Marielle Aleixo; Gonçalves, Heloísa Bressan; Furriel, Rosa Dos Prazeres Melo; Jorge, João Atílio; Guimarães, Luis Henrique Souza

2014-05-01

The filamentous fungus Aspergillus terreus secretes both invertase and β-glucosidase when grown under submerged fermentation containing rye flour as the carbon source. The aim of this study was to characterize the co-purified fraction, especially the invertase activity. An invertase and a β-glucosidase were co-purified by two chromatographic steps, and the isolated enzymatic fraction was 139-fold enriched in invertase activity. SDS-PAGE analysis of the co-purified enzymes suggests that the protein fraction with invertase activity was heterodimeric, with subunits of 47 and 27 kDa. Maximal invertase activity, which was determined by response surface methodology, occurred in pH and temperature ranges of 4.0-6.0 and 55-65 °C, respectively. The invertase in co-purified enzymes was stable for 1 h at pH 3.0-10.0 and maintained full activity for up to 1 h at 55 °C when diluted in water. Invertase activity was stimulated by 1 mM concentrations of Mn²⁺ (161 %), Co²⁺ (68 %) and Mg²⁺ (61 %) and was inhibited by Al³⁺, Ag⁺, Fe²⁺ and Fe³⁺. In addition to sucrose, the co-purified enzymes hydrolyzed cellobiose, inulin and raffinose, and the apparent affinities for sucrose and cellobiose were quite similar (K(M) = 22 mM). However, in the presence of Mn²⁺, the apparent affinity and V(max) for sucrose hydrolysis increased approximately 2- and 2.9-fold, respectively, while for cellobiose, a 2.6-fold increase in V(max) was observed, but the apparent affinity decreased 5.5-fold. Thus, it is possible to propose an application of this multifunctional extract containing both invertase and β-glucosidase to degrade plant biomass, thus increasing the concentration of monosaccharides obtained from sucrose and cellobiose.

High invertase activity in tomato reproductive organs correlates with enhanced sucrose import into, and heat tolerance of, young fruit.

PubMed

Li, Zhimiao; Palmer, William M; Martin, Antony P; Wang, Rongqing; Rainsford, Frederick; Jin, Ye; Patrick, John W; Yang, Yuejian; Ruan, Yong-Ling

2012-02-01

Heat stress can cause severe crop yield losses by impairing reproductive development. However, the underlying mechanisms are poorly understood. We examined patterns of carbon allocation and activities of sucrose cleavage enzymes in heat-tolerant (HT) and -sensitive (HS) tomato (Solanum lycopersicum L.) lines subjected to normal (control) and heat stress temperatures. At the control temperature of 25/20 °C (day/night) the HT line exhibited higher cell wall invertase (CWIN) activity in flowers and young fruits and partitioned more sucrose to fruits but less to vegetative tissues as compared to the HS line, independent of leaf photosynthetic capacity. Upon 2-, 4-, or 24-h exposure to day or night temperatures of 5 °C or more above 25/20 °C, cell wall (CWIN) and vacuolar invertases (VIN), but not sucrose synthase (SuSy), activities in young fruit of the HT line were significantly higher than those of the HS line. The HT line had a higher level of transcript of a CWIN gene, Lin7, in 5-day fruit than the HS line under control and heat stress temperatures. Interestingly, heat induced transcription of an invertase inhibitor gene, INVINH1, but reduced its protein abundance. Transcript levels of LePLDa1, encoding phospholipase D, which degrades cell membranes, was less in the HT line than in the HS line after exposure to heat stress. The data indicate that high invertase activity of, and increased sucrose import into, young tomato fruit could contribute to their heat tolerance through increasing sink strength and sugar signalling activities, possibly regulating a programmed cell death pathway.

Comparative study of stability of soluble and cell wall invertase from Saccharomyces cerevisiae.

PubMed

Margetić, Aleksandra; Vujčić, Zoran

2017-03-16

Yeast Saccharomyces cerevisiae is the most significant source of enzyme invertase. It is mainly used in the food industry as a soluble or immobilized enzyme. The greatest amount of invertase is located in the periplasmic space in yeast. In this work, it was isolated into two forms of enzyme from yeast S. cerevisiae cell, soluble and cell wall invertase (CWI). Both forms of enzyme showed same temperature optimum (60°C), similar pH optimum, and kinetic parameters. The significant difference between these biocatalysts was observed in their thermal stability, stability in urea and methanol solution. At 60°C, CWI had 1.7 times longer half-life than soluble enzyme, while at 70°C CWI showed 8.7 times longer half-life than soluble enzyme. After 2-hr of incubation in 8 M urea solution, soluble invertase and CWI retained 10 and 60% of its initial activity, respectively. During 22 hr of incubation of both enzymes in 30 and 40% methanol, soluble invertase was completely inactivated, while CWI changed its activity within the experimental error. Therefore, soluble invertase and CWI have not shown any substantial difference, but CWI showed better thermal stability and stability in some of the typical protein-denaturing agents.

High invertase activity in tomato reproductive organs correlates with enhanced sucrose import into, and heat tolerance of, young fruit

PubMed Central

Li, Zhimiao; Palmer, William M.; Martin, Antony P.; Wang, Rongqing; Rainsford, Frederick; Jin, Ye; Patrick, John W.; Yang, Yuejian; Ruan, Yong-Ling

2012-01-01

Heat stress can cause severe crop yield losses by impairing reproductive development. However, the underlying mechanisms are poorly understood. We examined patterns of carbon allocation and activities of sucrose cleavage enzymes in heat-tolerant (HT) and -sensitive (HS) tomato (Solanum lycopersicum L.) lines subjected to normal (control) and heat stress temperatures. At the control temperature of 25/20 °C (day/night) the HT line exhibited higher cell wall invertase (CWIN) activity in flowers and young fruits and partitioned more sucrose to fruits but less to vegetative tissues as compared to the HS line, independent of leaf photosynthetic capacity. Upon 2-, 4-, or 24-h exposure to day or night temperatures of 5 °C or more above 25/20 °C, cell wall (CWIN) and vacuolar invertases (VIN), but not sucrose synthase (SuSy), activities in young fruit of the HT line were significantly higher than those of the HS line. The HT line had a higher level of transcript of a CWIN gene, Lin7, in 5-day fruit than the HS line under control and heat stress temperatures. Interestingly, heat induced transcription of an invertase inhibitor gene, INVINH1, but reduced its protein abundance. Transcript levels of LePLDa1, encoding phospholipase D, which degrades cell membranes, was less in the HT line than in the HS line after exposure to heat stress. The data indicate that high invertase activity of, and increased sucrose import into, young tomato fruit could contribute to their heat tolerance through increasing sink strength and sugar signalling activities, possibly regulating a programmed cell death pathway. PMID:22105847

A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania

PubMed Central

Lyda, Todd A.; Joshi, Manju B.; Andersen, John F.; Kelada, Andrew Y.; Owings, Joshua P.; Bates, Paul A.; Dwyer, Dennis M.

2015-01-01

Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts. PMID:25763714

A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania.

PubMed

Lyda, Todd A; Joshi, Manju B; Andersen, John F; Kelada, Andrew Y; Owings, Joshua P; Bates, Paul A; Dwyer, Dennis M

2015-06-01

Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts.

Optimized invertase expression and secretion cassette for improving Yarrowia lipolytica growth on sucrose for industrial applications.

PubMed

Lazar, Zbigniew; Rossignol, Tristan; Verbeke, Jonathan; Crutz-Le Coq, Anne-Marie; Nicaud, Jean-Marc; Robak, Małgorzata

2013-11-01

Yarrowia lipolytica requires the expression of a heterologous invertase to grow on a sucrose-based substrate. This work reports the construction of an optimized invertase expression cassette composed of Saccharomyces cerevisiae Suc2p secretion signal sequence followed by the SUC2 sequence and under the control of the strong Y. lipolytica pTEF promoter. This new construction allows a fast and optimal cleavage of sucrose into glucose and fructose and allows cells to reach the maximum growth rate. Contrary to pre-existing constructions, the expression of SUC2 is not sensitive to medium composition in this context. The strain JMY2593, expressing this new cassette with an optimized secretion signal sequence and a strong promoter, produces 4,519 U/l of extracellular invertase in bioreactor experiments compared to 597 U/l in a strain expressing the former invertase construction. The expression of this cassette strongly improved production of invertase and is suitable for simultaneously high production level of citric acid from sucrose-based media.

Aqueous two-phase (PEG4000/Na2SO4) extraction and characterization of an acid invertase from potato tuber (Solanum tuberosum).

PubMed

Yuzugullu, Yonca; Duman, Yonca Avcı

2015-01-01

Invertases are key metabolic enzymes that catalyze irreversible hydrolysis of sucrose into fructose and glucose. Plant invertases have essential roles in carbohydrate metabolism, plant development, and stress responses. To study their isolation and purification from potato, an attractive system useful for the separation of biological molecules, an aqueous two-phase system, was used. The influence of various system parameters such as type of phase-forming salts, polyethylene glycol (PEG) molecular mass, salt, and polymer concentration was investigated to obtain the highest recovery of enzyme. The PEG4000 (12.5%, w/w)/Na2SO4(15%, w/w) system was found to be ideal for partitioning invertase into the bottom salt-rich phase. The addition of 3% MnSO4 (w/w) at pH 5.0 increased the purity by 5.11-fold with the recovered activity of 197%. The Km and Vmax on sucrose were 3.95 mM and 0.143 U mL(-1) min(-1), respectively. Our data confirmed that the PEG4000/Na2SO4 aqueous two-phase system combined with the presence of MnSO4 offers a low-cost purification of invertase from readily available potato tuber in a single step. The biochemical characteristics of temperature and pH stability for potato invertase prepared from an ATPS make the enzyme a good candidate for its potential use in many research and industrial applications.

Cloning and sequence analysis of the invertase gene INV 1 from the yeast Pichia anomala.

PubMed

Pérez, J A; Rodríguez, J; Rodríguez, L; Ruiz, T

1996-02-01

A genomic library from the yeast Pichia anomala has been constructed and employed to clone the gene encoding the sucrose-hydrolysing enzyme invertase by complementation of a sucrose non-fermenting mutant of Saccharomyces cerevisiae. The cloned gene, INV1, was sequenced and found to encode a polypeptide of 550 amino acids which contained a 22 amino-acid signal sequence and ten potential glycosylation sites. The amino-acid sequence shows significant identity with other yeast invertases and also with Kluyveromyces marxianus inulinase, a yeast beta-fructofuranosidase which has a different substrate specificity. The nucleotide sequences of the 5' and 3' non-coding regions were found to contain several consensus motifs probably involved in the initiation and termination of gene transcription.

[Dynamics of aquic brown soil enzyme activities under no-tillage].

PubMed

Liu, Xiumei; Li, Qi; Liang, Wenju; Jiang, Yong; Wen, Dazhong

2006-12-01

This paper studied the effects of no-tillage on the dynamics of invertase, urease and acid phosphatase activities in an aquic brown soil during maize growing season. The results showed that in 0 - 10 cm soil layer, the invertase activity at jointing, trumpet-shaped and ripening stages, urease activity at jointing and booting stages, and acid phosphatase activity at booting and ripening stages were significantly higher under no-tillage (NT) than under conventional tillage (CT). In 10 - 20 cm soil layer, the invertase activity at seedling, jointing and trumpet-shaped stages was significantly different between NT and CT, and the urease activity during whole growing season except at booting stage was significantly higher under NT than under CT. In 20 - 30 cm soil layer, the invertase activity during maize growing season was significantly lower under NT than under CT, and urease activity at seedling stage and acid phosphate activity at ripening stage were significantly different between these two treatments. Under NT, there was a decreasing trend of soil enzyme activities with increasing soil depth; while under CT, soil invertase and acid phosphatase activities increased, but urease activity decreased with increasing soil depth.

Engineering Yarrowia lipolytica to express secretory invertase with strong FBA1IN promoter.

PubMed

Hong, Seung-Pyo; Seip, John; Walters-Pollak, Dana; Rupert, Ross; Jackson, Raymond; Xue, Zhixiong; Zhu, Quinn

2012-02-01

Oleaginous yeast Yarrowia lipolytica is an important host for the production of lipid-derived compounds or heterologous proteins. Selection of strong promoters and effective expression systems is critical for heterologous protein secretion. To search for a strong promoter in Y. lipolytica, activities of FBA1, TDH1 and GPM1 promoters were compared to that of TEF1 promoter by constructing GUS reporter fusions. The FBA1 promoter activity was 2.2 and 5.5 times stronger than the TDH1 and GPM1 promoters, respectively. The FBA1IN promoter (FBA1 sequence of -826 to +169) containing an intron (+64 to +165) showed five-fold higher expression than the FBA1 promoter (-831 to -1). The transcriptional enhancement by the 5'-region within the FBA1 gene was confirmed by GPM1::FBA1 chimeric promoter construction. Using the strong FBA1IN promoter, four different S. cerevisiae SUC2 expression cassettes were tested for the SUC+ phenotype in Y. lipolytica. Functional invertase secretion was facilitated by the Xpr2 prepro-region with an additional 13 amino acids of mature Xpr2, or by the native Suc2 signal sequence. However, these two secretory signals in tandem, or the mature Suc2 with no secretory signal, did not direct secretion of functional invertase. Unlike previously reported Y. lipolytica SUC+ strains, our engineered stains secreted most of invertase into the medium. Copyright © 2011 John Wiley & Sons, Ltd.

Tris-sucrose buffer system: a new specially designed medium for extracellular invertase production by immobilized cells of isolated yeast Cryptococcus laurentii MT-61.

PubMed

Aydogan, Mehmet Nuri; Taskin, Mesut; Canli, Ozden; Arslan, Nazli Pinar; Ortucu, Serkan

2014-01-01

The aims of the present study were to isolate new yeasts with high extracellular (exo) invertase activity and to investigate the usability of buffer systems as invertase production media by immobilized yeast cells. Among 70 yeast isolates, Cryptococcus laurentii MT-61 had the highest exo-invertase activity. Immobilization of yeast cells was performed using sodium alginate. Higher exo-invertase activity for immobilized cells was achieved in tris-sucrose buffer system (TSBS) compared to sodium acetate buffer system and potassium phosphate buffer system. TSBS was prepared by dissolving 30 g of sucrose in 1 L of tris buffer solution. The optimum pH, temperature, and incubation time for invertase production with immobilized cells were determined as 8.0, 35 °C and 36 h in TSBS, respectively. Under optimized conditions, maximum exo-invertase activity was found to be 28.4 U/mL in sterile and nonsterile TSBS. Immobilized cells could be reused in 14 and 12 successive cycles in sterile and nonsterile TSBS without any loss in the maximum invertase activity, respectively. This is the first report which showed that immobilized microbial cells could be used as a biocatalyst for exo-invertase production in buffer system. As an additional contribution, a new yeast strain with high invertase activity was isolated.

Natural diversity of potato (Solanum tuberosum) invertases

PubMed Central

2010-01-01

Background Invertases are ubiquitous enzymes that irreversibly cleave sucrose into fructose and glucose. Plant invertases play important roles in carbohydrate metabolism, plant development, and biotic and abiotic stress responses. In potato (Solanum tuberosum), invertases are involved in 'cold-induced sweetening' of tubers, an adaptive response to cold stress, which negatively affects the quality of potato chips and French fries. Linkage and association studies have identified quantitative trait loci (QTL) for tuber sugar content and chip quality that colocalize with three independent potato invertase loci, which together encode five invertase genes. The role of natural allelic variation of these genes in controlling the variation of tuber sugar content in different genotypes is unknown. Results For functional studies on natural variants of five potato invertase genes we cloned and sequenced 193 full-length cDNAs from six heterozygous individuals (three tetraploid and three diploid). Eleven, thirteen, ten, twelve and nine different cDNA alleles were obtained for the genes Pain-1, InvGE, InvGF, InvCD141 and InvCD111, respectively. Allelic cDNA sequences differed from each other by 4 to 9%, and most were genotype specific. Additional variation was identified by single nucleotide polymorphism (SNP) analysis in an association-mapping population of 219 tetraploid individuals. Haplotype modeling revealed two to three major haplotypes besides a larger number of minor frequency haplotypes. cDNA alleles associated with chip quality, tuber starch content and starch yield were identified. Conclusions Very high natural allelic variation was uncovered in a set of five potato invertase genes. This variability is a consequence of the cultivated potato's reproductive biology. Some of the structural variation found might underlie functional variation that influences important agronomic traits such as tuber sugar content. The associations found between specific invertase alleles and

Production optimization of invertase by Lactobacillus brevis Mm-6 and its immobilization on alginate beads.

PubMed

Awad, Ghada E A; Amer, Hassan; El-Gammal, Eman W; Helmy, Wafaa A; Esawy, Mona A; Elnashar, Magdy M M

2013-04-02

A sequential optimization strategy, based on statistical experimental designs, was employed to enhance the production of invertase by Lactobacillus brevis Mm-6 isolated from breast milk. First, a 2-level Plackett-Burman design was applied to screen the bioprocess parameters that significantly influence the invertase production. The second optimization step was performed using fractional factorial design in order to optimize the amounts of variables have the highest positive significant effect on the invertase production. A maximal enzyme activity of 1399U/ml was more than five folds the activity obtained using the basal medium. Invertase was immobilized onto grafted alginate beads to improve the enzyme's stability. Immobilization process increased the operational temperature from 30 to 60°C compared to the free enzyme. The reusability test proved the durability of the grafted alginate beads for 15 cycles with retention of 100% of the immobilized enzyme activity to be more convenient for industrial uses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functional characterization of an invertase inhibitor gene involved in sucrose metabolism in tomato fruit.

PubMed

Zhang, Ning; Jiang, Jing; Yang, Yan-li; Wang, Zhi-he

2015-10-01

In this study, we produced tomato plants overexpressing an invertase inhibitor gene (Sly-INH) from tomato, using a simple and efficient transient transformation system. Compared with control plants, the expression of Sly-INH was highly upregulated in Sly-INH overexpressing plants, as indicated by real-time polymerase chain reaction (PCR). Physiological analysis revealed that Sly-INH inhibited the activity of cell wall invertase (CWIN), which increased sugar accumulation in tomato fruit. Furthermore, Sly-INH mediated sucrose metabolism by regulating CWIN activity. Our results suggest that invertase activity is potentially regulated by the Sly-INH inhibitor at the post-translational level, and they demonstrate that the transient transformation system is an effective method for determining the functions of genes in tomato.

Kinetics and bioreactor studies of immobilized invertase on polyurethane rigid adhesive foam.

PubMed

Cadena, Pabyton G; Wiggers, Frank N; Silva, Roberto A; Lima Filho, José L; Pimentel, Maria C B

2011-01-01

A new support, polyurethane rigid adhesive foam (PRAF), which can be used to cover internal surface of metallic tubes, was used to immobilize invertase for application in an enzymatic bioreactor. The kinetic parameters were: Km--46.5±1.9 mM (PRAF-invertase) and 61.2±0.1 mM (free enzyme) and Vmax 42.0±4.3 U/mg protein/min (PRAF-invertase) and 445.3±24.0 U/mg protein/min (free invertase). The PRAF-invertase derivative maintained 50.1% of initial activity (69.17 U/g support) for 8 months (4°C) and was not observed microbial contamination. The bioreactor showed the best production of inverted sugar syrup using up-flow rate (0.48 L/h) with average conversion of 10.64±1.5% h(-1) at feeding rate (D) of 104 h(-1). The operational inactivation rate constant (kopi) and half-life were 1.92×10(-4) min(-1) and 60 h (continue use). The PRAF spray support looks promising as a new alternative to produce immobilized derivatives on reactor surfaces. Copyright © 2010 Elsevier Ltd. All rights reserved.

Gravity-stimulated changes in auxin and invertase gene expression in maize pulvinal cells

NASA Technical Reports Server (NTRS)

Long, Joanne C.; Zhao, Wei; Rashotte, Aaron M.; Muday, Gloria K.; Huber, Steven C.; Brown, C. S. (Principal Investigator)

2002-01-01

Maize (Zea mays) stem gravitropism involves differential elongation of cells within a highly specialized region, the stem internodal pulvinus. In the present study, we investigated factors that control gravitropic responses in this system. In the graviresponding pulvinus, hexose sugars (D-Glc and D-Fru) accumulated asymmetrically across the pulvinus. This correlated well with an asymmetric increase in acid invertase activity across the pulvinus. Northern analyses revealed asymmetric induction of one maize acid invertase gene, Ivr2, consistent with transcriptional regulation by gravistimulation. Several lines of evidence indicated that auxin redistribution, as a result of polar auxin transport, is necessary for gravity-stimulated Ivr2 transcript accumulation and differential cell elongation across the maize pulvinus. First, the auxin transport inhibitor, N-1-naphthylphthalamic acid, inhibited gravistimulated curvature and Ivr2 transcript accumulation. Second, a transient gradient of free indole-3-acetic acid (IAA) across the pulvinus was apparent shortly after initiation of gravistimulation. This temporarily free IAA gradient appears to be important for differential cell elongation and Ivr2 transcript accumulation. This is based on the observation that N-1-naphthylphthalamic acid will not inhibit gravitropic responses when applied to pulvinus tissue after the free IAA gradient peak has occurred. Third, IAA alone can stimulate Ivr2 transcript accumulation in non-gravistimulated pulvini. The gravity- and IAA-stimulated increase in Ivr2 transcripts was sensitive to the protein synthesis inhibitor, cycloheximide. Based on these results, a two-phase model describing possible relationships between gravitropic curvature, IAA redistribution, and Ivr2 expression is presented.

Sugar metabolism, chip color, invertase activity, and gene expression during long-term cold storage of potato (Solanum tuberosum) tubers from wild-type and vacuolar invertase silencing lines of Katahdin.

PubMed

Wiberley-Bradford, Amy E; Busse, James S; Jiang, Jiming; Bethke, Paul C

2014-11-16

Storing potato tubers at low temperatures minimizes sprouting and disease but can cause an accumulation of reducing sugars in a process called cold-induced sweetening. Tubers with increased amounts of reducing sugars produce dark-colored, bitter-tasting fried products with elevated amounts of acrylamide, a possible carcinogen. Vacuolar invertase (VInv), which converts sucrose produced by starch breakdown to glucose and fructose, is the key determinant of reducing sugar accumulation during cold-induced sweetening. In this study, wild-type tubers and tubers in which VInv expression was reduced by RNA interference were used to investigate time- and temperature-dependent changes in sugar contents, chip color, and expression of VInv and other genes involved in starch metabolism in tubers during long-term cold storage. VInv activities and tuber reducing sugar contents were much lower, and tuber sucrose contents were much higher, in transgenic than in wild-type tubers stored at 3-9°C for up to eight months. Large differences in VInv mRNA accumulation were not observed at later times in storage, especially at temperatures below 9°C, so differences in invertase activity were likely established early in the storage period and maintained by stability of the invertase protein. Sugar contents, chip color, and expression of several of the studied genes, including AGPase and GBSS, were affected by storage temperature in both wild-type and transgenic tubers. Though transcript accumulation for other sugar-metabolism genes was affected by storage temperature and duration, it was essentially unaffected by invertase silencing and altered sugar contents. Differences in stem- and bud-end sugar contents in wild-type and transgenic tubers suggested different compartmentalization of sucrose at the two ends of stored tubers. VInv silencing significantly reduced cold-induced sweetening in stored potato tubers, likely by means of differential VInv expression early in storage. Transgenic

Ectopic overexpression of the cell wall invertase gene CIN1 leads to dehydration avoidance in tomato.

PubMed

Albacete, Alfonso; Cantero-Navarro, Elena; Großkinsky, Dominik K; Arias, Cintia L; Balibrea, María Encarnación; Bru, Roque; Fragner, Lena; Ghanem, Michel E; González, María de la Cruz; Hernández, Jose A; Martínez-Andújar, Cristina; van der Graaff, Eric; Weckwerth, Wolfram; Zellnig, Günther; Pérez-Alfocea, Francisco; Roitsch, Thomas

2015-02-01

Drought stress conditions modify source-sink relations, thereby influencing plant growth, adaptive responses, and consequently crop yield. Invertases are key metabolic enzymes regulating sink activity through the hydrolytic cleavage of sucrose into hexose monomers, thus playing a crucial role in plant growth and development. However, the physiological role of invertases during adaptation to abiotic stress conditions is not yet fully understood. Here it is shown that plant adaptation to drought stress can be markedly improved in tomato (Solanum lycopersicum L.) by overexpression of the cell wall invertase (cwInv) gene CIN1 from Chenopodium rubrum. CIN1 overexpression limited stomatal conductance under normal watering regimes, leading to reduced water consumption during the drought period, while photosynthetic activity was maintained. This caused a strong increase in water use efficiency (up to 50%), markedly improving water stress adaptation through an efficient physiological strategy of dehydration avoidance. Drought stress strongly reduced cwInv activity and induced its proteinaceous inhibitor in the leaves of the wild-type plants. However, the CIN1-overexpressing plants registered 3- to 6-fold higher cwInv activity in all analysed conditions. Surprisingly, the enhanced invertase activity did not result in increased hexose concentrations due to the activation of the metabolic carbohydrate fluxes, as reflected by the maintenance of the activity of key enzymes of primary metabolism and increased levels of sugar-phosphate intermediates under water deprivation. The induced sink metabolism in the leaves explained the maintenance of photosynthetic activity, delayed senescence, and increased source activity under drought stress. Moreover, CIN1 plants also presented a better control of production of reactive oxygen species and sustained membrane protection. Those metabolic changes conferred by CIN1 overexpression were accompanied by increases in the concentrations of the

A unique invertase is important for sugar absorption of an obligate biotrophic pathogen during infection.

PubMed

Chang, Qing; Liu, Jie; Lin, Xiaohong; Hu, Shoujun; Yang, Yang; Li, Dan; Chen, Liyang; Huai, Baoyu; Huang, Lili; Voegele, Ralf T; Kang, Zhensheng

2017-09-01

An increased invertase activity in infected plant tissue has been observed in many plant-pathogen interactions. However, the origin of this increased invertase activity (plant and/or pathogen) is still under debate. In addition, the role of pathogen invertases in the infection process is also unclear. We identified and cloned a gene with homology to invertases from Puccinia striiformis f. sp. tritici (Pst). Transcript levels of PsINV were analyzed by quantitative reverse transcription PCR in both compatible and incompatible Pst-wheat interactions . Function of the gene product was confirmed by heterologous expression, and its function in Pst infection was analyzed by host-induced gene silencing (HIGS). Pst abundantly secretes invertase during its invasion attempts whether in a compatible or incompatible interaction with wheat. Further research into the different domains of this protein indicated that the rust-specific sequence contributes to a higher efficiency of sucrose hydrolysis. With PsINV silenced by HIGS during the infection process, growth of Pst is inhibited and conidial fructification incomplete. Finally, pathogenicity of Pst is impaired and spore yield significantly reduced. Our results clearly demonstrate that this Pst invertase plays a pivotal role in this plant-pathogen interaction probably by boosting sucrose hydrolysis to secure the pathogen's sugar absorption. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Effect of hypokinesia on invertase activity of the mucosa of the small intestine

NASA Technical Reports Server (NTRS)

Abdusattarov, A.

1980-01-01

The effect of prolonged hypokinesia on the enzyme activity of the middle portion of the small intestine was investigated. Eighty-four mongrel white male rats weighing 170-180 g were divided into two equal groups. The experimental group were maintained in single cages under 30 days of hypokinetic conditions and the control animals were maintained under ordinary laboratory conditions. It is concluded that rates of invertase formation and its inclusion in the composition if the cellular membrane, if judged by the enzyme activity studied in sections of the small intestine, are subject to phase changes in the course of prolonged hypokinesia.

Immobilized Sclerotinia sclerotiorum invertase to produce invert sugar syrup from industrial beet molasses by-product.

PubMed

Mouelhi, Refka; Abidi, Ferid; Galai, Said; Marzouki, M Nejib

2014-03-01

The fungus Sclerotinia sclerotiorum produces invertase activity during cultivation on many agroindustrial residues. The molasses induced invertase was purified by DEAE-cellulose chromatography. The molecular mass of the purified enzyme was estimated at 48 kDa. Optimal temperature was determined at 60 °C and thermal stability up to 65 °C. The enzyme was stable between pH 2.0 and 8.0; optimum pH was about 5.5. Apparent K(m) and V(max) for sucrose were estimated to be respectively 5.8 mM and 0.11 μmol/min. The invertase was activated by β-mercaptoethanol. Free enzyme exhibited 80 % of its original activity after two month's storage at 4 °C and 50 % after 1 week at 25 °C. In order to investigate an industrial application, the enzyme was immobilized on alginate and examined for invert sugar production by molasses hydrolysis in a continuous bioreactor. The yield of immobilized invertase was about 78 % and the activity yield was 59 %. Interestingly the immobilized enzyme hydrolyzed beet molasses consuming nearly all sucrose. It retained all of its initial activity after being used for 4 cycles and about 65 % at the sixth cycle. Regarding productivity; 20 g/l of molasses by-product gave the best invert sugar production 46.21 g/day/100 g substrate related to optimal sucrose conversion of 41.6 %.

Molecular cloning and expression in Saccharomyces cerevisiae and Neurospora crassa of the invertase gene from Neurospora crassa.

PubMed

Carú, M; Cifuentes, V; Pincheira, G; Jiménez, A

1989-10-01

A plasmid (named pCN2) carrying a 7.6 kb BamHI DNA insert was isolated from a Neurospora crassa genomic library raised in the yeast vector YRp7. Saccharomyces cerevisiae suco and N. crassa inv strains transformed with pNC2 were able to grow on sucrose-based media and expressed invertase activity. Saccharomyces cerevisiae suco (pNC2) expressed a product which immunoreacted with antibody raised against purified invertase from wild type N. crassa, although S. cerevisiae suc+ did not. The cloned DNA hybridized with a 7.6 kb DNA fragment from BamHI-restricted wild type N. crassa DNA. Plasmid pNC2 transformed N. crassa Inv- to Inv+ by integration either near to the endogenous inv locus (40% events) or at other genomic sites (60% events). It appears therefore that the cloned DNA piece encodes the N. crassa invertase enzyme. A 3.8 kb XhoI DNA fragment, derived from pNC2, inserted in YRp7, in both orientation, was able to express invertase activity in yeast, suggesting that it contains an intact invertase gene which is not expressed from a vector promoter.

A higher sink competitiveness of the rooting zone and invertases are involved in dark stimulation of adventitious root formation in Petunia hybrida cuttings.

PubMed

Klopotek, Yvonne; Franken, Philipp; Klaering, Hans-Peter; Fischer, Kerstin; Hause, Bettina; Hajirezaei, Mohammad-Reza; Druege, Uwe

2016-02-01

The contribution of carbon assimilation and allocation and of invertases to the stimulation of adventitious root formation in response to a dark pre-exposure of petunia cuttings was investigated, considering the rooting zone (stem base) and the shoot apex as competing sinks. Dark exposure had no effect on photosynthesis and dark respiration during the subsequent light period, but promoted dry matter partitioning to the roots. Under darkness, higher activities of cytosolic and vacuolar invertases were maintained in both tissues when compared to cuttings under light. This was partially associated with higher RNA levels of respective genes. However, activity of cell wall invertases and transcript levels of one cell wall invertase isogene increased specifically in the stem base during the first two days after cutting excision under both light and darkness. During five days after excision, RNA accumulation of four invertase genes indicated preferential expression in the stem base compared to the apex. Darkness shifted the balance of expression of one cytosolic and two vacuolar invertase genes towards the stem base. The results indicate that dark exposure before planting enhances the carbon sink competitiveness of the rooting zone and that expression and activity of invertases contribute to the shift in carbon allocation. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Invertase proteinaceous inhibitor of Cyphomandra betacea Sendt fruits.

PubMed

Ordóñez, R M; Isla, M I; Vattuone, M A; Sampietro, A R

2000-01-01

This work describes a new invertase proteinaceous inhibitor from Cyphomandra betacea Sendt. (tomate de arbol) fruits. The proteinaceous inhibitor was isolated and purified from a cell wall preparation. The pH stability, kinetics of the inhibition of the C. betacea invertase, inhibition of several higher plant invertases and lectin nature of the inhibitor were studied. The inhibitor structure involves a single polypeptide (Mr = 19000), as shown by gel filtration and SDS-PAGE determinations. N-terminal aminoacid sequence was determined. The properties and some structural features of the inhibitor are compared with the proteinaceous inhibitors from several plant species (Beta vulgaris L., Ipomoea batatas L. and Lycopersicon esculentum Mill.). All these inhibitors share lectinic properties, some common epitopes, some aminoacid sequences and a certain lack of specificity towards invertases of different species, genera and even plant family. In consequence, the inhibitors appear to belong to the same lectin family. It is now known that some lectins are part of the defence mechanism of higher plants against fungi and bacteria and this is a probable role of the proteinaceous inhibitors.

Involvement of Abscisic Acid in the Coordinated Regulation of a Stress-Inducible Hexose Transporter (VvHT5) and a Cell Wall Invertase in Grapevine in Response to Biotrophic Fungal Infection[W

PubMed Central

Hayes, Matthew A.; Feechan, Angela; Dry, Ian B.

2010-01-01

Biotrophic fungal and oomycete pathogens alter carbohydrate metabolism in infected host tissues. Symptoms such as elevated soluble carbohydrate concentrations and increased invertase activity suggest that a pathogen-induced carbohydrate sink is established. To identify pathogen-induced regulators of carbohydrate sink strength, quantitative real-time polymerase chain reaction was used to measure transcript levels of invertase and hexose transporter genes in biotrophic pathogen-infected grapevine (Vitis vinifera) leaves. The hexose transporter VvHT5 was highly induced in coordination with the cell wall invertase gene VvcwINV by powdery and downy mildew infection. However, similar responses were also observed in response to wounding, suggesting that this is a generalized response to stress. Analysis of the VvHT5 promoter region indicated the presence of multiple abscisic acid (ABA) response elements, suggesting a role for ABA in the transition from source to sink under stress conditions. ABA treatment of grape leaves was found to reproduce the same gene-specific transcriptional changes as observed under biotic and abiotic stress conditions. Furthermore, the key regulatory ABA biosynthetic gene, VvNCED1, was activated under these same stress conditions. VvHT5 promoter::β-glucuronidase-directed expression in transgenic Arabidopsis (Arabidopsis thaliana) was activated by infection with powdery mildew and by ABA treatment, and the expression was closely associated with vascular tissue adjacent to infected regions. Unlike VvHT1 and VvHT3, which appear to be predominantly involved in hexose transport in developing leaves and berries, VvHT5 appears to have a specific role in enhancing sink strength under stress conditions, and this is controlled through ABA. Our data suggest a central role for ABA in the regulation of VvcwINV and VvHT5 expression during the transition from source to sink in response to infection by biotrophic pathogens. PMID:20348211

Purification of alpha-glucosidae and invertase from bakers' yeast on modified polymeric supports.

PubMed

Lothe, R R; Purohit, S S; Shaikh, S S; Malshe, V C; Pandit, A B

1999-01-01

In the present work Amberlite XAD-16 and Indion NPA-1, Polystyrene Divinylbenzene macroreticular spherical resins, have been evaluated quantitatively as supports for the adsorption and isolation of the yeast proteins and the enzymes, invertase and alpha-glucosidase. Modification of these supports has been carried out by surface grafting using acrylate polymers to reduce the hydrophobicity and nonspecific adsorption of proteins. Good grafting efficiency, in excess of 90%, has been obtained using ultrasonic irradiation for the surface activation of polystyrene resins. XAD-16 has higher adsorption capacities for the total yeast proteins as well as for both the enzymes, alpha-glucosidase and invertase, than NPA-1 in its respective native and grafted form. Adsorption capacities of XAD-16 and NPA-1 in their respective native and grafted forms for alpha-glucosidase are higher than the capacities for invertase. Nonspecific adsorption of total proteins has been reduced considerably after the grafting of acrylate polymers on hydrophobic supports. At the same time selectivity for the adsorption of both the enzymes has been enhanced on grafted supports. The overall solid-liquid adsorption mass transfer coefficient values (Kla) estimated for adsorption of invertase on XAD are lower than those for alpha-glucosidase. Native and grafted resins could be regenerated and reused for adsorption of alpha-glucosidase for two regeneration cycles studied. Storage stability of invertase and alpha-glucosidase is the same on native and grafted form of XAD-16 and is more than the enzymes in the free form.

Transgene silencing of sucrose synthase in alfalfa (Medicago sativa L.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis.

PubMed

Samac, Deborah A; Bucciarelli, Bruna; Miller, Susan S; Yang, S Samuel; O'Rourke, Jamie A; Shin, Sanghyun; Vance, Carroll P

2015-12-01

Alfalfa (Medicago sativa L.) is a widely adapted perennial forage crop that has high biomass production potential. Enhanced cellulose content in alfalfa stems would increase the value of the crop as a bioenergy feedstock. We examined if increased expression of sucrose synthase (SUS; EC 2.4.1.13) would increase cellulose in stem cell walls. Alfalfa plants were transformed with a truncated alfalfa phosphoenolpyruvate carboxylase gene promoter (PEPC7-P4) fused to an alfalfa nodule-enhanced SUS cDNA (MsSUS1) or the β-glucuronidase (GUS) gene. Strong GUS expression was detected in xylem and phloem indicating that the PEPC7-P4 promoter was active in stem vascular tissue. In contrast to expectations, MsSUS1 transcript accumulation was reduced 75-90 % in alfalfa plants containing the PEPC7-P4::MsSUS1 transgene compared to controls. Enzyme assays indicated that SUS activity in stems of selected down-regulated transformants was reduced by greater than 95 % compared to the controls. Although SUS activity was detected in xylem and phloem of control plants by in situ enzyme assays, plants with the PEPC7-P4::MsSUS1 transgene lacked detectable SUS activity in post-elongation stem (PES) internodes and had very low SUS activity in elongating stem (ES) internodes. Loss of SUS protein in PES internodes of down-regulated lines was confirmed by immunoblots. Down-regulation of SUS expression and activity in stem tissue resulted in no obvious phenotype or significant change in cell wall sugar composition. However, alkaline/neutral (A/N) invertase activity increased in SUS down-regulated lines and high levels of acid invertase activity were observed. In situ enzyme assays of stem tissue showed localization of neutral invertase in vascular tissues of ES and PES internodes. These results suggest that invertases play a primary role in providing glucose for cellulose biosynthesis or compensate for the loss of SUS1 activity in stem vascular tissue.

Constitutive expression of cell wall invertase genes increases grain yield and starch content in maize.

PubMed

Li, Bei; Liu, Hua; Zhang, Yue; Kang, Tao; Zhang, Li; Tong, Jianhua; Xiao, Langtao; Zhang, Hongxia

2013-12-01

Grain size, number and starch content are important determinants of grain yield and quality. One of the most important biological processes that determine these components is the carbon partitioning during the early grain filling, which requires the function of cell wall invertase. Here, we showed the constitutive expression of cell wall invertase-encoding gene from Arabidopsis, rice (Oryza sativa) or maize (Zea mays), driven by the cauliflower mosaic virus (CaMV) 35S promoter, all increased cell wall invertase activities in different tissues and organs, including leaves and developing seeds, and substantially improved grain yield up to 145.3% in transgenic maize plants as compared to the wild-type plants, an effect that was reproduced in our 2-year field trials at different locations. The dramatically increased grain yield is due to the enlarged ears with both enhanced grain size and grain number. Constitutive expression of the invertase-encoding gene also increased total starch content up to 20% in the transgenic kernels. Our results suggest that cell wall invertase gene can be genetically engineered to improve both grain yield and grain quality in crop plants. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Covalent immobilization of invertase on PAMAM-dendrimer modified superparamagnetic iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Uzun, K.; Çevik, E.; Şenel, M.; Sözeri, H.; Baykal, A.; Abasıyanık, M. F.; Toprak, M. S.

2010-10-01

In this study, polyamidoamine (PAMAM) dendrimer was synthesized on the surface of superparamagnetite nanoparticles to enhance invertase immobilization. The amount of immobilized enzyme on the surface-hyperbranched magnetite nanoparticle was up to 2.5 times (i.e., 250%) as much as that of magnetite nanoparticle modified with only amino silane. Maximum reaction rate ( V max) and Michaelis-Menten constant ( K m) were determined for the free and immobilized enzymes. Various characteristics of immobilized invertase such as; the temperature activity, thermal stability, operational stability, and storage stability were evaluated and results revealed that stability of the enzyme is improved upon immobilization.

Investigation of yeast invertase immobilization onto cupric ion-chelated, porous, and biocompatible poly(hydroxyethyl methacrylate-n-vinyl imidazole) microspheres.

PubMed

Sari, Müfrettin Murat

2011-04-01

Cupric ion-chelated poly(hydroxyethyl methacrylate-n-vinyl imidazole) (poly(HEMA-VIM)) microspheres prepared by suspension polymerization were investigated as a specific adsorbent for immobilization of yeast invertase in a batch system. They were characterized by scanning electron microscopy, surface area, and pore size measurements. They have spherical shape and porous structure. The specific surface area of the p(HEMA-VIM) spheres was found to be 81.2 m²/g with a size range of 70-120 μm in diameter, and the swelling ratio was 86.9%. Then, Cu(II) ion chelated on the microspheres (546 μmol Cu(II)/g), and they were used in the invertase adsorption. Maximum invertase adsorption was 51.2 mg/g at pH 4.5. Cu(II) chelation increases the tendency from Freundlich-type to Langmuir-type adsorption model. The optimum activity for both free and adsorbed invertase was observed at pH 4.5. The optimum temperature for the poly(HEMA-VIM)/Cu(II)-invertase system was found to be at 55 °C, 10 °C higher than that of the free enzyme at 45 °C. V(max) values were determined as 342 and 304 U/mg enzyme, for free and adsorbed invertase, respectively. K(m) values were found to be same for free and adsorbed invertase (20 mM). Thermal and pH stability and reusability of invertase increased with immobilization.

Structural Analysis of the Catalytic Mechanism and Substrate Specificity of Anabaena Alkaline Invertase InvA Reveals a Novel Glucosidase*

PubMed Central

Xie, Jin; Cai, Kun; Hu, Hai-Xi; Jiang, Yong-Liang; Yang, Feng; Hu, Peng-Fei; Cao, Dong-Dong; Li, Wei-Fang; Chen, Yuxing; Zhou, Cong-Zhao

2016-01-01

Invertases catalyze the hydrolysis of sucrose to glucose and fructose, thereby playing a key role in primary metabolism and plant development. According to the optimum pH, invertases are classified into acid invertases (Ac-Invs) and alkaline/neutral invertases (A/N-Invs), which share no sequence homology. Compared with Ac-Invs that have been extensively studied, the structure and catalytic mechanism of A/N-Invs remain unknown. Here we report the crystal structures of Anabaena alkaline invertase InvA, which was proposed to be the ancestor of modern plant A/N-Invs. These structures are the first in the GH100 family. InvA exists as a hexamer in both crystal and solution. Each subunit consists of an (α/α)6 barrel core structure in addition to an insertion of three helices. A couple of structures in complex with the substrate or products enabled us to assign the subsites −1 and +1 specifically binding glucose and fructose, respectively. Structural comparison combined with enzymatic assays indicated that Asp-188 and Glu-414 are putative catalytic residues. Further analysis of the substrate binding pocket demonstrated that InvA possesses a stringent substrate specificity toward the α1,2-glycosidic bond of sucrose. Together, we suggest that InvA and homologs represent a novel family of glucosidases. PMID:27777307

Structural Analysis of the Catalytic Mechanism and Substrate Specificity of Anabaena Alkaline Invertase InvA Reveals a Novel Glucosidase.

PubMed

Xie, Jin; Cai, Kun; Hu, Hai-Xi; Jiang, Yong-Liang; Yang, Feng; Hu, Peng-Fei; Cao, Dong-Dong; Li, Wei-Fang; Chen, Yuxing; Zhou, Cong-Zhao

2016-12-02

Invertases catalyze the hydrolysis of sucrose to glucose and fructose, thereby playing a key role in primary metabolism and plant development. According to the optimum pH, invertases are classified into acid invertases (Ac-Invs) and alkaline/neutral invertases (A/N-Invs), which share no sequence homology. Compared with Ac-Invs that have been extensively studied, the structure and catalytic mechanism of A/N-Invs remain unknown. Here we report the crystal structures of Anabaena alkaline invertase InvA, which was proposed to be the ancestor of modern plant A/N-Invs. These structures are the first in the GH100 family. InvA exists as a hexamer in both crystal and solution. Each subunit consists of an (α/α) 6 barrel core structure in addition to an insertion of three helices. A couple of structures in complex with the substrate or products enabled us to assign the subsites -1 and +1 specifically binding glucose and fructose, respectively. Structural comparison combined with enzymatic assays indicated that Asp-188 and Glu-414 are putative catalytic residues. Further analysis of the substrate binding pocket demonstrated that InvA possesses a stringent substrate specificity toward the α1,2-glycosidic bond of sucrose. Together, we suggest that InvA and homologs represent a novel family of glucosidases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Targeting the AtCWIN1 Gene to Explore the Role of Invertases in Sucrose Transport in Roots and during Botrytis cinerea Infection

PubMed Central

Veillet, Florian; Gaillard, Cécile; Coutos-Thévenot, Pierre; La Camera, Sylvain

2016-01-01

Cell wall invertases (CWIN) cleave sucrose into glucose and fructose in the apoplast. CWINs are key regulators of carbon partitioning and source/sink relationships during growth, development and under biotic stresses. In this report, we monitored the expression/activity of Arabidopsis cell wall invertases in organs behaving as source, sink, or subjected to a source/sink transition after infection with the necrotrophic fungus Botrytis cinerea. We showed that organs with different source/sink status displayed differential CWIN activities, depending on carbohydrate needs or availabilities in the surrounding environment, through a transcriptional and posttranslational regulation. Loss-of-function mutation of the Arabidopsis cell wall invertase 1 gene, AtCWIN1, showed that the corresponding protein was the main contributor to the apoplastic sucrose cleaving activity in both leaves and roots. The CWIN-deficient mutant cwin1-1 exhibited a reduced capacity to actively take up external sucrose in roots, indicating that this process is mainly dependent on the sucrolytic activity of AtCWIN1. Using T-DNA and CRISPR/Cas9 mutants impaired in hexose transport, we demonstrated that external sucrose is actively absorbed in the form of hexoses by a sugar/H+ symport system involving the coordinated activity of AtCWIN1 with several Sugar Transporter Proteins (STP) of the plasma membrane, i.e., STP1 and STP13. Part of external sucrose was imported without apoplastic cleavage into cwin1-1 seedling roots, highlighting an alternative AtCWIN1-independent pathway for the assimilation of external sucrose. Accordingly, we showed that several genes encoding sucrose transporters of the plasma membrane were expressed. We also detected transcript accumulation of vacuolar invertase (VIN)-encoding genes and high VIN activities. Upon infection, AtCWIN1 was responsible for all the Botrytis-induced apoplastic invertase activity. We detected a transcriptional activation of several AtSUC and AtVIN genes

Mathematical modeling of the central carbohydrate metabolism in Arabidopsis reveals a substantial regulatory influence of vacuolar invertase on whole plant carbon metabolism.

PubMed

Nägele, Thomas; Henkel, Sebastian; Hörmiller, Imke; Sauter, Thomas; Sawodny, Oliver; Ederer, Michael; Heyer, Arnd G

2010-05-01

A mathematical model representing metabolite interconversions in the central carbohydrate metabolism of Arabidopsis (Arabidopsis thaliana) was developed to simulate the diurnal dynamics of primary carbon metabolism in a photosynthetically active plant leaf. The model groups enzymatic steps of central carbohydrate metabolism into blocks of interconverting reactions that link easily measurable quantities like CO(2) exchange and quasi-steady-state levels of soluble sugars and starch. When metabolite levels that fluctuate over diurnal cycles are used as a basic condition for simulation, turnover rates for the interconverting reactions can be calculated that approximate measured metabolite dynamics and yield kinetic parameters of interconverting reactions. We used experimental data for Arabidopsis wild-type plants, accession Columbia, and a mutant defective in vacuolar invertase, AtbetaFruct4, as input data. Reducing invertase activity to mutant levels in the wild-type model led to a correct prediction of increased sucrose levels. However, additional changes were needed to correctly simulate levels of hexoses and sugar phosphates, indicating that invertase knockout causes subsequent changes in other enzymatic parameters. Reduction of invertase activity caused a decline in photosynthesis and export of reduced carbon to associated metabolic pathways and sink organs (e.g. roots), which is in agreement with the reported contribution of vacuolar invertase to sink strength. According to model parameters, there is a role for invertase in leaves, where futile cycling of sucrose appears to have a buffering effect on the pools of sucrose, hexoses, and sugar phosphates. Our data demonstrate that modeling complex metabolic pathways is a useful tool to study the significance of single enzyme activities in complex, nonintuitive networks.

[Characteristics of extracellular invertase of Saccharomyces cerevisiae in Heterologous expression of the suc2 gene in Solarium Tuberosum plants].

PubMed

Deriabin, A N; Berdichevets, I N; Burakhanova, E A; Trunova, T I

2014-01-01

Some properties and activity of extracellular invertase in the Saccharomyces cerevisiae yeasts encoded by the suc2 gene in heterologous expression were described. It was shown that the target suc2 gene is actively expressed in the genome of the transformed potato plants and S. cerevisiae invertase synthesized by this gene is transported into the apoplast due to the signal peptide of the proteinase II inhibitor. This enzyme is present in the apoplast in a soluble form and absorbed into the cell wall.

Promoter regions of potato vacuolar invertase gene in response to sugars and hormones.

PubMed

Ou, Yongbin; Song, Botao; Liu, Xun; Xie, Conghua; Li, Meng; Lin, Yuan; Zhang, Huiling; Liu, Jun

2013-08-01

Potato vacuolar acid invertase (StvacINV1) (β-fructofuranosidase; EC 3.2.1.26) has been confirmed to play an important role in cold-induced sweetening of potato tubers. However, the transcriptional regulation mechanisms of StvacINV1 are largely unknown. In this study, the 5'-flanking sequence of StvacINV1 was cloned and the cis-acting elements were predicted. Histochemical assay showed that the StvacINV1 promoter governed β-glucuronidase (GUS) expression in potato leaves, stems, roots and tubers. Quantitative analysis of GUS expression suggested that the activity of StvacINV1 promoter was suppressed by sucrose, glucose, fructose, and cold, while enhanced by indole-3-acetic acid (IAA), and gibberellic acid (GA3). Further deletion analysis clarified that the promoter regions from -118 to -551, -551 to -1021, and -1021 to -1521 were required for responding to sucrose/glucose, GA3, and IAA, respectively. These findings provide essential information regarding transcriptional regulation mechanisms of StvacINV1. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Fungal invertase as an aid for fermentation of cane molasses into ethanol

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

Park, Y.K.; Sato, H.H.

1982-10-01

Comparative studies of the fermentation of cane molasses into ethanol by Saccharomyces cerevisiae in the presence or absence of fungal invertase were performed. When cane molasses was fermented by the yeast at 30 degrees Centigrade and pH 5.0, the presence of the enzyme had no effect on ethanol production. At pH 3.4, ethanol production was increased by the addition of invertase. At 40 degrees C, the addition of invertase increased ethanol production by 5.5% at pH 5.0 and by 20.9% at pH 3.5. (Refs. 8).

Reassessment of an Arabidopsis cell wall invertase inhibitor AtCIF1 reveals its role in seed germination and early seedling growth.

PubMed

Su, Tao; Wolf, Sebastian; Han, Mei; Zhao, Hongbo; Wei, Hongbin; Greiner, Steffen; Rausch, Thomas

2016-01-01

In higher plants, cell wall invertase (CWI) and vacuolar invertase (VI) are recognized as essential players in sugar metabolism and sugar signaling, thereby affecting source-sink interactions, plant development and responses to environmental cues. CWI and VI expression levels are transcriptionally controlled; however, both enzymes are also subject to posttranslational control by invertase inhibitor proteins. The physiological significances of inhibitor proteins during seed germination and early seedling development are not yet fully understood. Here, we demonstrate that the inhibitor isoform AtCIF1 impacted on seed germination and early seedling growth in Arabidopsis. The primary target of AtCIF1 was shown to be localized to the apoplast after expressing an AtCIF1 YFP-fusion construct in tobacco epidermis and transgenic Arabidopsis root. The analysis of expression patterns showed that AtCWI1 was co-expressed spatiotemporally with AtCIF1 within the early germinating seeds. Seed germination was observed to be accelerated independently of exogenous abscisic acid (ABA) in the AtCIF1 loss-of-function mutant cif1-1. This effect coincided with a drastic increase of CWI activity in cif1-1 mutant seeds by 24 h after the onset of germination, both in vitro and in planta. Accordingly, quantification of sugar content showed that hexose levels were significantly boosted in germinating seeds of the cif1-1 mutant. Further investigation of AtCIF1 overexpressors in Arabidopsis revealed a markedly suppressed CWI activity as well as delayed seed germination. Thus, we conclude that the posttranslational modulation of CWI activity by AtCIF1 helps to orchestrate seed germination and early seedling growth via fine-tuning sucrose hydrolysis and, possibly, sugar signaling.

Rapid stalk elongation in tulip (Tulipa gesneriana L. cv. Apeldoorn) and the combined action of cold-induced invertase and the water-channel protein gammaTIP.

PubMed

Balk, P A; de Boer, A D

1999-09-01

Many bulbous plants need a low-temperature treatment for flowering. Cold, for example, affects the elongation of the stalk, thereby influencing the quality of the cut flower. How the elongation of the stalk is promoted by cold and which physiological and biochemical mechanisms are involved have remained obscure. As invertase has been shown to be involved in the cold-induced elongation of the flower stalks of tulips (Lambrechts et al., 1994, Plant Physiol 104: 515-520), we further characterized this enzyme by cloning the cDNA and analysing its expression in various tissues of the tulip (Tulipa gesneriana L. cv. Apeldoorn) stalk. In addition, the role of sucrose synthase was investigated. Since turgor pressure is an important force driving cell elongation, the role of a water-channel protein (gammaTIP) was studied in relation to these two enzymes. The mRNA level of the invertase found was substantially up-regulated as a result of cold treatment. Analysis of the amino acid sequence of this invertase revealed the presence of a vacuolar targeting signal. Two different forms of sucrose synthase were found, the expression of one of them appeared to be restricted to the vascular tissue while the other form was present in the surrounding tissue. Both sucrose synthases were present in the stalk during the entire period of bulb storage and after planting, but their activities declined during stalk elongation. The expression of the gammaTIP gene was restricted mainly to the vascular tissue and its expression profile was identical to that of invertase. Simultaneous expression of invertase and gammaTIP possibly leads to an increase in osmotic potential and vacuolar water uptake, thus providing a driving force for stretching the stalk cells.

Identification, biochemical characterization, and in-vivo expression of the intracellular invertase BfrA from the pathogenic parasite Leishmania major.

PubMed

Belaz, Sorya; Rattier, Thibault; Lafite, Pierre; Moreau, Philippe; Routier, Françoise H; Robert-Gangneux, Florence; Gangneux, Jean-Pierre; Daniellou, Richard

2015-10-13

The parasitic life cycle of Leishmania includes an extracellular promastigote stage that occurs in the gut of the insect vector. During that period, the sucrose metabolism and more specifically the first glycosidase of this pathway are essential for growth and survival of the parasite. We investigated the expression of the invertase BfrA in the promastigote and amastigote stages of three parasite species representative of the three various clinical forms and of various geographical areas, namely Leishmania major, L. donovani and L. braziliensis. Thereafter, we cloned, overexpressed and biochemically characterized this invertase BfrA from L. major, heterologously expressed in both Escherichia coli and L. tarentolae. For all species, expression levels of BfrA mRNA were correlated to the time of the culture and the parasitic stage (promastigotes > amastigotes). BfrA exhibited no activity when expressed as a glycoprotein in L. tarentolae but proved to be an invertase when not glycosylated, yet owing low sequence homology with other invertases from the same family. Our data suggest that BfrA is an original invertase that is located inside the parasite. It is expressed in both parasitic stages, though to a higher extent in promastigotes. This work provides new insight into the parasite sucrose metabolism. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Invertase Overproduction May Provide for Inulin Fermentation by Selection Strains of Saccharomyces cerevisiae].

PubMed

Naumov, G I; Naumova, E S

2015-01-01

In some recent publications, the ability of selection strains of Saccharomyces cerevisiae to ferment inulin was attributed to inulinase activity. The review summarizes the literature data indicating that overproduction of invertase, an enzyme common to S. cerevisiae, may be responsible for this phenomenon.

Identification of the invertase gene family (INVs) in tea plant and their expression analysis under abiotic stress.

PubMed

Qian, Wenjun; Yue, Chuan; Wang, Yuchun; Cao, Hongli; Li, Nana; Wang, Lu; Hao, Xinyuan; Wang, Xinchao; Xiao, Bin; Yang, Yajun

2016-11-01

Fourteen invertase genes were identified in the tea plant, all of which were shown to participate in regulating growth and development, as well as in responding to various abiotic stresses. Invertase (INV) can hydrolyze sucrose into glucose and fructose, which plays a principal role in regulating plant growth and development as well as the plants response to various abiotic and biotic stresses. However, currently, there is a lack of reported information, regarding the roles of INVs in either tea plant development or in the tea plants response to various stresses. In this study, 14 INV genes were identified from the transcriptome data of the tea plant (Camellia sinensis (L.) O. Kuntze), and named CsINV1-5 and CsINV7-15. Based on the results of a Blastx search and phylogenetic analysis, the CsINV genes could be clustered into 6 acid invertase (AI) genes and 8 alkaline/neutral invertase (A/N-Inv) genes. The results of tissue-specific expression analysis showed that the transcripts of all the identified CsINV genes are detectable in various tissues. Under various abiotic stress conditions, the expression patterns of the 14 CsINV genes were diverse in both the leaves and roots, and some of them were shown to be significantly expressed. Overall, we hypothesize that the identified CsINV genes all participate in regulating growth and development in the tea plant, and most likely through different signaling pathways that regulate the carbohydrate allocation and the ratio of hexose and sucrose for improving the resistance of the leaves and the roots of the tea plant to various abiotic stresses.

[Export of an invertase by yeast cells (Candida utilis)].

PubMed

Alekseeva, O V; Sabirzianova, T A; Celiakh, I O; Kalebina, T S; Kulaev, I S

2014-01-01

Export and accumulation of various forms of invertase (EC 3.2.1.26) in the cell wall and culture liquid of the yeast Candida utilis was investigated. It was found that the high-molecular-weight CW-form of invertase is present in the cell wall. This form is not exported into the culture liquid, and it is by a third more glycosylated than the previously described exported S-form. It was shown that one of the two liquid forms of invertase exported into the culture-the glycosylated S-form--is retained in the cell wall, while the other one--the nonglycosylated F-form--was not detected in the cell wall. Based on these results, as well as data on the distribution dynamics of the enzyme in the culture liquid and in the cell wall during different growth stages of a yeast culture, we suggested that the nonglycosylated form was exported into the culture liquid via the zone of abnormal cell wall permeability and the glycosylated forms of this enzyme (both exported and nonexported) did not use this pathway (the degree of N-glycosylation is an important factor determining the final localization of the enzyme).

Alkaline β-fructofuranosidases of tuberous roots: Possible physiological function.

PubMed

Ricardo, C P

1974-12-01

Alkaline invertase of roots of carrot (Daucus carota L.) did not hydrolyze raffinose while the acid invertase from the same tissue showed with this sugar ca. 60% of the activity found with sucrose. The activity of the two invertases was inhibited by fructose to a different extent, the K i value being ca. 4×10(-2) M and 3×10(-1)M, respectively, for the alkaline and the acid invertases from the roots of both carrot and turnip (Brassica rapa L.). It is proposed that fructose inhibition of acid invertase is of no physiological significance but that, in contrast, hexoses might regulate the activity of alkaline invertase.Comparing several species and cultivars, it was found that the content of reducing sugars and the activity of alkaline invertase of mature tuberous roots showed a positive correlation. This indicates that alkaline invertase may participate in the regulation of the hexose level of the cell, as was previously suggested for sugar-cane. A scheme is presented which proposes a way of participation of alkaline invertase in such a regulation, assuming that this enzyme is located in the cytoplasm and acid invertase is membrane-bound and mainly located at the cell surface.

Effect of simulated acid rain on the litter decomposition of Quercus acutissima and Pinus massoniana in forest soil microcosms and the relationship with soil enzyme activities.

PubMed

Wang, Congyan; Guo, Peng; Han, Guomin; Feng, Xiaoguang; Zhang, Peng; Tian, Xingjun

2010-06-01

With the continuing increase in human activities, ecologists are increasingly interested in understanding the effects of acid rain on litter decomposition. Two dominant litters were chosen from Zijin Mountain in China: Quercus acutissima from a broad-leaved forest and Pinus massoniana from a coniferous forest. The litters were incubated in microcosms and treated with simulated acid rain (gradient pH levels). During a six-month incubation, changes in chemical composition (i.e., lignin, total carbohydrate, and nitrogen), litter mass losses, soil pH values, and activities of degradative enzymes were determined. Results showed that litter mass losses were depressed after exposure to acid rain and the effects of acid rain on the litter decomposition rates of needles were higher than on those of leaves. Results also revealed that simulated acid rain restrained the activities of cellulase, invertase, nitrate reductase, acid phosphatase, alkaline phosphatase, polyphenol oxidase, and urease, while it enhanced the activities of catalase in most cases during the six-month decomposition process. Catalase and polyphenol oxidase were primarily responsible for litter decomposition in the broad-leaved forest, while invertase, nitrate reductase, and urease were primarily responsible for litter decomposition in the coniferous forest. The results suggest acid rain-restrained litter decomposition may be due to the depressed enzymatic activities. According to the results of this study, soil carbon in subtropical forests would accumulate as a long-term consequence of continued acid rain. This may presumably alter the balance of ecosystem carbon flux, nutrient cycling, and humus formation, which may, in turn, have multiple effects on forest ecosystems. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

PubMed Central

Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

2012-01-01

Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

Sucrose and invertases, a part of the plant defense response to the biotic stresses

PubMed Central

Tauzin, Alexandra S.; Giardina, Thierry

2014-01-01

Sucrose is the main form of assimilated carbon which is produced during photosynthesis and then transported from source to sink tissues via the phloem. This disaccharide is known to have important roles as signaling molecule and it is involved in many metabolic processes in plants. Essential for plant growth and development, sucrose is engaged in plant defense by activating plant immune responses against pathogens. During infection, pathogens reallocate the plant sugars for their own needs forcing the plants to modify their sugar content and triggering their defense responses. Among enzymes that hydrolyze sucrose and alter carbohydrate partitioning, invertases have been reported to be affected during plant-pathogen interactions. Recent highlights on the role of invertases in the establishment of plant defense responses suggest a more complex regulation of sugar signaling in plant-pathogen interaction. PMID:25002866

Some Immunochemical Properties of Dextransucrase and Invertase from Streptococcus mutans

PubMed Central

Fukui, Kazuhiro; Fukui, Yoshio; Moriyama, Takafumi

1974-01-01

Dextransucrase and invertase of some strains of Streptococcus mutans were examined by immunodiffusion with antisera against enzymes purified from strain HS-6 (Bratthall's serotype a). Both antisera cross-reacted with crude enzyme preparations from the other serotype a (strains HS-1 and AHT) and d organisms (strains KIR, OMZ176, and OMZ65) but not with those from serotype b (strains FA-1 and BHT) or c organisms (strains GS-5, Ingbritt, and NCTC 10449). Based upon the antiserum used, the orders of antigenic similarity of the cross-reacting enzymes to the HS-6 enzymes were HS-6 > HS-1 > AHT = KIR = OMZ176 = OMZ65 for dextransucrase and HS-6 = HS-1 > AHT = KIR = OMZ176 = OMZ65 for invertase. It was found that the enzymes from serotype a organisms were not always antigenically homogeneous, as seen between strains HS-6, HS-1, or AHT for dextransucrase, and between the HS group and strain AHT for invertase. Antiserum against the HS-6 dextransucrase markedly inhibited the heterologous dextransucrases of serotype a organisms with the exception of strain HS-1 and d organisms, with or without the addition of dextran. Images PMID:16558114

Functional characterization of a vacuolar invertase from Solanum lycopersicum: post-translational regulation by N-glycosylation and a proteinaceous inhibitor.

PubMed

Tauzin, Alexandra S; Sulzenbacher, Gerlind; Lafond, Mickael; Desseaux, Véronique; Reca, Ida Barbara; Perrier, Josette; Bellincampi, Daniela; Fourquet, Patrick; Lévêque, Christian; Giardina, Thierry

2014-06-01

Plant vacuolar invertases, which belong to family 32 of glycoside hydrolases (GH32), are key enzymes in sugar metabolism. They hydrolyse sucrose into glucose and fructose. The cDNA encoding a vacuolar invertase from Solanum lycopersicum (TIV-1) was cloned and heterologously expressed in Pichia pastoris. The functional role of four N-glycosylation sites in TIV-1 has been investigated by site-directed mutagenesis. Single mutations to Asp of residues Asn52, Asn119 and Asn184, as well as the triple mutant (Asn52, Asn119 and Asn184), lead to enzymes with reduced specific invertase activity and thermostability. Expression of the N516D mutant, as well as of the quadruple mutant (N52D, N119D, N184D and N516D) could not be detected, indicating that these mutations dramatically affected the folding of the protein. Our data indicate that N-glycosylation is important for TIV-1 activity and that glycosylation of N516 is crucial for recombinant enzyme stability. Using a functional genomics approach a new vacuolar invertase inhibitor of S. lycopersicum (SolyVIF) has been identified. SolyVIF cDNA was cloned and heterologously expressed in Escherichia coli. Specific interactions between SolyVIF and TIV-1 were investigated by an enzymatic approach and surface plasmon resonance (SPR). Finally, qRT-PCR analysis of TIV-1 and SolyVIF transcript levels showed a specific tissue and developmental expression. TIV-1 was mainly expressed in flowers and both genes were expressed in senescent leaves. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Intensified fractionation of brewery yeast waste for the recovery of invertase using aqueous two-phase systems.

PubMed

De León-González, Grecia; González-Valdez, José; Mayolo-Deloisa, Karla; Rito-Palomares, Marco

2016-11-01

The potential recovery of high-value products from brewery yeast waste confers value to this industrial residue. Aqueous two-phase systems (ATPS) have demonstrated to be an attractive alternative for the primary recovery of biological products and are therefore suitable for the recovery of invertase from this residue. Sixteen different polyethylene glycol (PEG)-potassium phosphate ATPS were tested to evaluate the effects of PEG molecular weight (MW) and tie-line length (TLL) upon the partition behavior of invertase. Concentrations of crude extract from brewery yeast waste were then varied in the systems that presented the best behaviors to intensify the potential recovery of the enzyme. Results show that the use of a PEG MW 400 g mol -1 system with a TLL of 45.0% (w/w) resulted in an invertase bottom phase recovery with a purification factor of 29.5 and a recovery yield of up to 66.2% after scaling the system to a total weight of 15.0 g. This represents 15.1 mg of invertase per mL of processed bottom phase. With these results, a single-stage ATPS process for the recovery of invertase is proposed. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Purification and some properties of rose (Fructus cynosbati) hips invertase.

PubMed

Sacan, Ozlem; Yanardag, Refiye

2012-04-01

Invertase was purified from rose (Fructus cynosbati) hips by ammonium sulfate fractionation and hydroxyapatite column chromatography. The enzyme was obtained with a yield of 4.25% and about 10.48-fold purification and had a specific activity of 8.59 U/mg protein. The molecular mass of invertase was estimated to be 66.51 kDa by PAGE and 34 kDa by SDS-PAGE, indicating that the native enzyme was a homodimer. The enzyme was a glycoprotein and contained 5.86% carbohydrate. The K(m) for sucrose was 14.55 mM and the optimum pH and temperature of the enzyme were 4.5 and 40 degrees C, respectively. Sucrose was the most preferred substrate of the enzyme. The enzyme also hydrolyzed D(+) raffinose, D(+) trehalose and inulin (activity 39.88, 8.12 and 4.94%, respectively of that of sucrose), while D(+) lactose, cellobiose and D(+) maltose showed no effect on the enzyme. The substrate specificity was consistent with that for a beta-fructofuranoside, which is the most popular type in the higher plants. The enzyme was completely inhibited by HgCl2, MnCl2, MnSO4, FeCl3, Pb(NO3)2, ammonium heptamolybdate, iodoacetamide and pyridoxine hydrochloride. It was also inhibited by Ba(NO3)2 (86.32%), NH4Cl (84.91%), MgCl2 (74.45%), urea (71.63%), I2 (69.64%), LiCl (64.99%), BaCl2 (50.30%), Mg(NO3)2 (49.90%), CrCl3 (31.90%) and CuSO4 (21.45%) and but was activated by Tris (73.99%) and methionine (12.47%).

Genome-wide identification, 3D modeling, expression and enzymatic activity analysis of cell wall invertase gene family from cassava (Manihot esculenta Crantz).

PubMed

Yao, Yuan; Geng, Meng-Ting; Wu, Xiao-Hui; Liu, Jiao; Li, Rui-Mei; Hu, Xin-Wen; Guo, Jian-Chun

2014-04-28

The cell wall invertases play a crucial role on the sucrose metabolism in plant source and sink organs. In this research, six cell wall invertase genes (MeCWINV1-6) were cloned from cassava. All the MeCWINVs contain a putative signal peptide with a predicted extracellular location. The overall predicted structures of the MeCWINV1-6 are similar to AtcwINV1. Their N-terminus domain forms a β-propeller module and three conserved sequence domains (NDPNG, RDP and WECP(V)D), in which the catalytic residues are situated in these domains; while the C-terminus domain consists of a β-sandwich module. The predicted structure of Pro residue from the WECPD (MeCWINV1, 2, 5, and 6), and Val residue from the WECVD (MeCWINV3 and 4) are different. The activity of MeCWINV1 and 3 were higher than other MeCWINVs in leaves and tubers, which suggested that sucrose was mainly catalyzed by the MeCWINV1 and 3 in the apoplastic space of cassava source and sink organs. The transcriptional levels of all the MeCWINVs and their enzymatic activity were lower in tubers than in leaves at all the stages during the cassava tuber development. It suggested that the major role of the MeCWINVs was on the regulation of carbon exportation from source leaves, and the ratio of sucrose to hexose in the apoplasts; the role of these enzymes on the sucrose unloading to tuber was weaker.

Delayed ripening of banana fruit by salicylic acid.

PubMed

Srivastava; Dwivedi

2000-09-08

Salicylic acid treatment has been found to delay the ripening of banana fruits (Musa acuminata). Fruit softening, pulp:peel ratio, reducing sugar content, invertase and respiration rate have been found to decrease in salicylic acid treated fruits as compared with control ones. The activities of major cell wall degrading enzymes, viz. cellulase, polygalacturonase and xylanase were found to be decreased in presence of salicylic acid. The major enzymatic antioxidants namely, catalase and peroxidase, were also found to be decreased in presence of salicylic acid during banana fruit ripening.

Sucrose dependent mineral phosphate solubilization in Enterobacter asburiae PSI3 by heterologous overexpression of periplasmic invertases.

PubMed

Kumar, Chanchal; Wagh, Jitendra; Archana, G; Naresh Kumar, G

2016-12-01

Enterobacter asburiae PSI3 solubilizes mineral phosphates in the presence of glucose by the secretion of gluconic acid generated by the action of a periplasmic pyrroloquinoline quinone dependent glucose dehydrogenase. In order to achieve mineral phosphate solubilization phenotype in the presence of sucrose, plasmids pCNK4 and pCNK5 containing genes encoding the invertase enzyme of Zymomonas mobilis (invB) and of Saccharomyces cerevisiae (suc2) under constitutive promoters were constructed with malE signal sequence (in case of invB alone as the suc2 is secreted natively). When introduced into E. asburiae PSI3, E. a. (pCNK4) and E. a. (pCNK5) transformants secreted 21.65 ± 0.94 and 22 ± 1.3 mM gluconic acid, respectively, in the presence of 75 mM sucrose and they also solubilized 180 ± 4.3 and 438 ± 7.3 µM P from the rock phosphate. In the presence of a mixture of 50 mM sucrose and 25 mM glucose, E. a. (pCNK5) secreted 34 ± 2.3 mM gluconic acid and released 479 ± 8.1 µM P. Moreover, in the presence of a mixture of eight sugars (10 mM each) in the medium, E. a. (pCNK5) released 414 ± 5.3 µM P in the buffered medium. Thus, this study demonstrates incorporation of periplasmic invertase imparted P solubilization ability to E. asburiae PSI3 in the presence of sucrose and mixture of sugars.

Cytosolic invertase contributes to the supply of substrate for cellulose biosynthesis in developing wood.

PubMed

Rende, Umut; Wang, Wei; Gandla, Madhavi Latha; Jönsson, Leif J; Niittylä, Totte

2017-04-01

Carbon for cellulose biosynthesis is derived from sucrose. Cellulose is synthesized from uridine 5'-diphosphoglucose (UDP-glucose), but the enzyme(s) responsible for the initial sucrose cleavage and the source of UDP-glucose for cellulose biosynthesis in developing wood have not been defined. We investigated the role of CYTOSOLIC INVERTASEs (CINs) during wood formation in hybrid aspen (Populus tremula × tremuloides) and characterized transgenic lines with reduced CIN activity during secondary cell wall biosynthesis. Suppression of CIN activity by 38-55% led to a 9-13% reduction in crystalline cellulose. The changes in cellulose were reflected in reduced diameter of acid-insoluble cellulose microfibrils and increased glucose release from wood upon enzymatic digestion of cellulose. Reduced CIN activity decreased the amount of the cellulose biosynthesis precursor UDP-glucose in developing wood, pointing to the likely cause of the cellulose phenotype. The findings suggest that CIN activity has an important role in the cellulose biosynthesis of trees, and indicate that cellulose biosynthesis in wood relies on a quantifiable UDP-glucose pool. The results also introduce a concept of altering cellulose microfibril properties by modifying substrate supply to cellulose biosynthesis. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Purification and characterization of soluble (cytosolic) and bound (cell wall) isoforms of invertases in barley (Hordeum vulgare) elongating stem tissue

NASA Technical Reports Server (NTRS)

Karuppiah, N.; Vadlamudi, B.; Kaufman, P. B.

1989-01-01

Three different isoforms of invertases have been detected in the developing internodes of barley (Hordeum vulgare). Based on substrate specificities, the isoforms have been identified to be invertases (beta-fructosidases EC 3.2.1.26). The soluble (cytosolic) invertase isoform can be purified to apparent homogeneity by diethylaminoethyl cellulose, Concanavalin-A Sepharose, organo-mercurial Sepharose, and Sephacryl S-300 chromatography. A bound (cell wall) invertase isoform can be released by 1 molar salt and purified further by the same procedures as above except omitting the organo-mercurial Sepharose affinity chromatography step. A third isoform of invertase, which is apparently tightly associated with the cell wall, cannot be isolated yet. The soluble and bound invertase isoforms were purified by factors of 60- and 7-fold, respectively. The native enzymes have an apparent molecular weight of 120 kilodaltons as estimated by gel filtration. They have been identified to be dimers under denaturing and nondenaturing conditions. The soluble enzyme has a pH optimum of 5.5, Km of 12 millimolar, and a Vmax of 80 micromole per minute per milligram of protein compared with cell wall isozyme which has a pH optimum of 4.5, Km of millimolar, and a Vmax of 9 micromole per minute per milligram of protein.

Gln3p and Nil1p regulation of invertase activity and SUC2 expression in Saccharomyces cerevisiae.

PubMed

Oliveira, Edna Maria Morais; Mansure, José João; Bon, Elba Pinto da Silva

2005-04-01

In Saccharomyces cerevisiae, sensing and signalling pathways regulate gene expression in response to quality of carbon and nitrogen sources. One such system, the target of rapamycin (Tor) proteins, senses nutrients and uses the GATA activators Gln3p and Nil1p to regulate translation in response to low-quality carbon and nitrogen. The signal transduction, triggered in response to nitrogen nutrition that is sensed by the Tor proteins, operates via a regulatory pathway involving the cytoplasmic factor Ure2p. When carbon and nitrogen are abundant, the phosphorylated Ure2p anchors the also phosphorylated Gln3p and Nil1p in the cytoplasm. Upon a shift from high- to low-quality nitrogen or treatment with rapamycin all three proteins are dephosphorylated, causing Gln3p and Nil1p to enter the nucleus and promote transcription. The genes that code for yeast periplasmic enzymes with nutritional roles would be obvious targets for regulation by the sensing and signalling pathways that respond to quality of carbon and nitrogen sources. Indeed, previous results from our laboratory had shown that the GATA factors Gln3p, Nil1p, Dal80p, Nil2p and also the protein Ure2 regulate the expression of asparaginase II, coded by ASP3. We also had observed that the activity levels of the also periplasmic invertase, coded by SUC2, were 6-fold lower in ure2 mutant cells in comparison to wild-type cells collected at stationary phase. These results suggested similarities between the signalling pathways regulating the expression of ASP3 and SUC2. In the present work we showed that invertase levels displayed by the single nil1 and gln3 and by the double gln3nil1 mutant cells, cultivated in a sucrose-ammonium medium and collected at the exponential phase, were 6-, 10- and 60-fold higher, respectively, in comparison to their wild-type counterparts. RT-PCR data of SUC2 expression in the double-mutant cells indicated a 10-fold increase in the mRNA(SUC2) levels.

Genome-Wide Identification, 3D Modeling, Expression and Enzymatic Activity Analysis of Cell Wall Invertase Gene Family from Cassava (Manihot esculenta Crantz)

PubMed Central

Yao, Yuan; Geng, Meng-Ting; Wu, Xiao-Hui; Liu, Jiao; Li, Rui-Mei; Hu, Xin-Wen; Guo, Jian-Chun

2014-01-01

The cell wall invertases play a crucial role on the sucrose metabolism in plant source and sink organs. In this research, six cell wall invertase genes (MeCWINV1-6) were cloned from cassava. All the MeCWINVs contain a putative signal peptide with a predicted extracellular location. The overall predicted structures of the MeCWINV1-6 are similar to AtcwINV1. Their N-terminus domain forms a β-propeller module and three conserved sequence domains (NDPNG, RDP and WECP(V)D), in which the catalytic residues are situated in these domains; while the C-terminus domain consists of a β-sandwich module. The predicted structure of Pro residue from the WECPD (MeCWINV1, 2, 5, and 6), and Val residue from the WECVD (MeCWINV3 and 4) are different. The activity of MeCWINV1 and 3 were higher than other MeCWINVs in leaves and tubers, which suggested that sucrose was mainly catalyzed by the MeCWINV1 and 3 in the apoplastic space of cassava source and sink organs. The transcriptional levels of all the MeCWINVs and their enzymatic activity were lower in tubers than in leaves at all the stages during the cassava tuber development. It suggested that the major role of the MeCWINVs was on the regulation of carbon exportation from source leaves, and the ratio of sucrose to hexose in the apoplasts; the role of these enzymes on the sucrose unloading to tuber was weaker. PMID:24786092

Purification and characterization of acid trehalase from the yeast suc2 mutant.

PubMed

Mittenbühler, K; Holzer, H

1988-06-15

Acid trehalase was purified from the yeast suc2 deletion mutant. After hydrophobic interaction chromatography, the enzyme could be purified to a single band or peak by a further step of either polyacrylamide gel electrophoresis, gel filtration, or isoelectric focusing. An apparent molecular mass of 218,000 Da was calculated from gel filtration. Polyacrylamide gel electrophoresis of the purified enzyme in the presence of sodium dodecyl sulfate suggested a molecular mass of 216,000 Da. Endoglycosidase H digestion of the purified enzyme resulted after sodium dodecyl sulfate gel electrophoresis in one distinct band at 41,000 Da, representing the mannose-free protein moiety of acid trehalase. The carbohydrate content of the enzyme was 86%. Amino acid analysis indicated 354 residues/molecule of enzyme including 9 cysteine moieties and only 1 methionine. The isoelectric point of the enzyme was estimated by gel electrofocusing to be approximately 4.7. The catalytic activity showed a maximum at pH 4.5. The activity of the enzyme was not inhibited by 10 mM each of HgCl2, EDTA, iodoacetic acid, phenanthrolinium chloride or phenylmethylsulfonyl fluoride. There was no activation by divalent metal ions. The acid trehalase exhibited an apparent Km for trehalose of 4.7 +/- 0.1 mM and a Vmax of 99 mumol of trehalose min-1 X mg-1 at 37 degrees C and pH 4.5. The acid trehalase is located in the vacuoles. The rabbit antiserum raised against acid trehalase exhibited strong cross-reaction with purified invertase. These cross-reactions were removed by affinity chromatography using invertase coupled to CNBr-activated Sepharose 4B. Precipitation of acid trehalase activity was observed with the purified antiserum.

Tentacle-type immobilized metal affinity cryogel for invertase purification from Saccharomyces cerevisiae.

PubMed

Çetin, Kemal; Perçin, Işık; Denizli, Fatma; Denizli, Adil

2017-11-01

The aim of this study is to investigate the usability of cryogel columns for the purification of invertase from Saccharomyces cerevisiae. Poly(2-hydroxyethyl methacrylate) monolithic columns were produced via cryogelation. Ester groups of the poly(2-hydroxyethyl methacrylate) structure were then converted to imine groups by the reaction with poly(ethylene imine) in the presence of NaHCO 3 . Transition metal ions, Cu(II), Co(II), and Ni(II), were chelated on the PEI-modified cryogel columns. Purification of invertase from natural source namely S. cerevisiae was also studied, and the purification fold values were obtained as 41.350, 44.714, and 30.302 for Cu(II)-chelated, Co(II)-chelated, and Ni(II)-chelated PHEMA/PEI columns, respectively.

Effect of repeated applications of buprofezin and acephate on soil cellulases, amylase, and invertase.

PubMed

Raju, M Naga; Venkateswarlu, K

2014-10-01

The impact of repeated applications of buprofezin and acephate, at concentrations ranging from 0.25 to 1.0 kg ha(-1), on activities of cellulases, amylase, and invertase in unamended and nitrogen, phosphorous, and potassium (NPK) fertilizer-amended soil planted with cotton was studied. The nontarget effect of selected insecticides, when applied once, twice, or thrice on soil enzyme activities, was dose-dependent; the activities decreased with increasing concentrations of insecticides. However, there was a rapid decline in activities of enzymes after three repeated applications of insecticides in unamended or NPK-amended soil. Our data clearly suggest that insecticides must be applied judiciously in pest management in order to protect the enzymes largely implicated in soil fertility.

Activities of sucrose and sorbitol metabolizing enzymes in vegetative sinks of peach and correlation with sink growth rate

Treesearch

Riccardo Lo Bianco; Mark Rieger; Shi-Jean S. Sung

1999-01-01

Terminal portions of 'Flordaguard' peach roots (Prunus persica ((L.) Batsch) were divided into six segments and the activities of NAD+-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), soluble acid invertase (AI),...

Effect of temperature on soluble invertase activity, and glucose, fructose and sucrose status of onion bulbs (Allium cepa) in store.

PubMed

Benkeblia, Noureddine; Onodera, Shuichi; Yoshihira, Taiki; Kosaka, Shinichi; Shiomi, Norio

2004-06-01

The activity of soluble invertase, and the variation in glucose, fructose and sucrose contents in onion bulbs (Allium cepa) during long-term storage at 10 degrees C and 20 degrees C were investigated. Invertase activity increased progressively after 8 weeks to 0.084 and 0.092 nkat/g fresh weight (FW), then sharply to 0.29 and 0.35 nkat/g FW at 20 degrees C and 10 degrees C, respectively, and remained high during 5 weeks. Then, activity decreased abruptly to 0.039 and 0.041 nkat/g, and remained low during the last 8 weeks and close to that observed initially. Glucose increased to 17.73 and 14.62 mg/g FW after 4 weeks at 20 degrees C and 10 degrees C, respectively, then decreased sharply between week 5 and week 7 to 4.13 and 4.91 mg/g FW, respectively, and remained rather stable ranging from 9 and 10 mg/g FW at both temperatures. Fructose showed a similar pattern and was 14.8 and 21.68 mg/g FW at 20 degrees C and 10 degrees C, respectively. Between week 10 and week 24, fructose ranged from 5 and 6 mg/g FW, and from 6 and 7 mg/g FW at 20 degrees C and 10 degrees C, respectively. Sucrose increased to 19.63 and 14.43 mg/g FW at 20 degrees C and 10 degrees C, respectively, decreased during 3 weeks, and then increased randomly from 5.69 to 9.42 mg/g FW at 20 degrees C, but remained in a steady state at 10 degrees C ranging 5.03 +/- 0.78 mg/g FW. During the last 6 weeks, the sucrose content was higher at 20 degrees C than at 10 degrees C. The fructose-glucose ratio varied during the first 8 weeks but remained at a steady level during the last 16 weeks. The (glucose+fructose)/sucrose ratio increased randomly at 10 degrees C, whereas at 20 degrees C the ratio increased during 10 weeks then decreased progressively during the final 14 weeks.

Production of thermostable invertases by Aspergillus caespitosus under submerged or solid state fermentation using agroindustrial residues as carbon source

PubMed Central

Alegre, Ana Cláudia Paiva; de Lourdes Teixeira de Moraes Polizeli, Maria; Terenzi, Héctor Francisco; Jorge, João Atílio; Guimarães, Luis Henrique Souza

2009-01-01

The filamentous fungus Aspergillus caespitosus was a good producer of intracellular and extracellular invertases under submerged (SbmF) or solid-state fermentation (SSF), using agroindustrial residues, such as wheat bran, as carbon source. The production of extracellular enzyme under SSF at 30°C, for 72h, was enhanced using SR salt solution (1:1, w/v) to humidify the substrate. The extracellular activity under SSF using wheat bran was around 5.5-fold higher than that obtained in SbmF (Khanna medium) with the same carbon source. However, the production of enzyme with wheat bran plus oat meal was 2.2-fold higher than wheat bran isolated. The enzymatic production was affected by supplementation with nitrogen and phosphate sources. The addition of glucose in SbmF and SSF promoted the decreasing of extracellular activity, but the intracellular form obtained in SbmF was enhanced 3-5-fold. The invertase produced in SSF exhibited optimum temperature at 50°C while the extra- and intracellular enzymes produced in SbmF exhibited maximal activities at 60°C. All enzymatic forms exhibited maximal activities at pH 4.0-6.0 and were stable up to 1 hour at 50°C. PMID:24031406

Composition and antioxidant activity of Trigona carbonaria honey from Australia.

PubMed

Oddo, Livia Persano; Heard, Tim A; Rodríguez-Malaver, Antonio; Pérez, Rosa Ana; Fernández-Muiño, Miguel; Sancho, María Teresa; Sesta, Giulio; Lusco, Lorenzo; Vit, Patricia

2008-12-01

Stingless bees (Tribe Meliponini) are a diverse group of highly eusocial bees distributed throughout the tropics and subtropics. Trigona carbonaria honey, from Australia, was characterized by traditional physicochemical parameters (acidity, sugars, diastase, electrical conductivity, hydroxymethylfurfural, invertase, nitrogen, and water content) and other compositional factors (flavonoids, polyphenols, organic acids, and water activity), as well as total antioxidant capacity and radical scavenging activity. For the Australian T. carbonaria, the traditional analytical parameters were similar to those previously reported for neotropical stingless bee honey and confirm that honeys produced by Meliponini bees possess several physicochemical properties that are distinctly different from Apis mellifera honey, with higher values of moisture (26.5 +/- 0.8 g of water/100 g of honey), water activity (0.74 +/- 0.01), electrical conductivity (1.64 +/- 0.12 mS/cm), and free acidity (124.2 +/- 22.9 mEq/kg of honey) and a very low diastase activity (0.4 +/- 0.5 diastase number) and invertase activity (5.7 +/- 1.5 invertase number). The sugar spectrum was quite different from that of A. mellifera honey, with 20.3 +/- 2.9 g of maltose/100 g of honey. The values of pH (4.0 +/- 0.1), lactonic acidity (4.7 +/- 0.8 mEq/kg of honey), sucrose (1.8 +/- 0.4 g/100 g of honey), and fructose/glucose ratio (1.42 +/- 0.13) fell in the same ranges as those of A. mellifera honey. Citric (0.23 +/- 0.09) and malic (0.12 +/- 0.03) acid concentrations (in g/kg of honey) of T. carbonaria honeys were in the range described for A. mellifera honey. D-Gluconic was more concentrated (9.9 +/- 1.3 g/kg of honey), in the range of Italian Castanea, Thymus, Arbutus, and honeydew honeys. Flavonoid content was 10.02 +/- 1.59 mg of quercetin equivalents/100 g of honey, and polyphenol contents were 55.74 +/- 6.11 mg of gallic acid equivalents/100 g of honey. The antioxidant activity, expressed as percentage of 2

StInvInh2 as an inhibitor of StvacINV1 regulates the cold-induced sweetening of potato tubers by specifically capping vacuolar invertase activity.

PubMed

Liu, Xun; Lin, Yuan; Liu, Jun; Song, Botao; Ou, Yongbin; Zhang, Huiling; Li, Meng; Xie, Conghua

2013-06-01

Reducing sugar (RS) accumulation in cold-stored potato tubers, known as cold-induced sweetening (CIS), is a crucial factor causing unacceptable colour changes and acrylamide formation of fried products. The activity of vacuolar invertase (StvacINV1) is proved important for the CIS process, and invertase inhibitors are speculated to play roles in the post-translational regulation of StvacINV1 activity. In our previous research, two putative inhibitors (StInvInh2A and StInvInh2B) of StvacINV1 were implied to be involved in potato CIS. Here, we further reported that StInvInh2A and StInvInh2B had similar function that specifically inhibited StvacINV1 activity in potatoes. The genetic transformation of these inhibitor genes in potatoes by overexpression in CIS-sensitive and RNAi-silenced in CIS-resistant genotypes showed that StvacINV1 activity was strongly regulated by alteration of the transcripts of the inhibitors without impacting on the expression of StvacINV1. A negative power relationship was found between the transcripts of the inhibitors and StvacINV1 activity, suggesting 1) a transcriptional determination of the inhibitory capacity of StInvInh2A and StInvInh2B and 2) a significant inhibitory role of these inhibitors in post-translational modulation of StvacINV1. The results also demonstrated that depression of StvacINV1 activity through overexpression of StInvInh2A and StInvInh2B weakened accumulation of RS and acrylamide in cold-stored tubers and consequently improved the chip quality. The present research strongly suggest that both StInvInh2A and StInvInh2B function as inhibitors of StvacINV1 and play similar roles in regulating potato CIS by capping StvacINV1 activity. These inhibitors could be novel genetic resources applicable for improving quality of potato processing products. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Changes in Labile Organic Carbon Fractions and Soil Enzyme Activities after Marshland Reclamation and Restoration in the Sanjiang Plain in Northeast China

NASA Astrophysics Data System (ADS)

Song, Yanyu; Song, Changchun; Yang, Guisheng; Miao, Yuqing; Wang, Jiaoyue; Guo, Yuedong

2012-09-01

The extensive reclamation of marshland into cropland has tremendously impacted the ecological environment of the Sanjiang Plain in northeast China. To understand the impacts of marshland reclamation and restoration on soil properties, we investigated the labile organic carbon fractions and the soil enzyme activities in an undisturbed marshland, a cultivated marshland and three marshlands that had been restored for 3, 6 and 12 years. Soil samples collected from the different management systems at a depth of 0-20 cm in July 2009 were analyzed for soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC) and easily degradable organic carbon. In addition, the activities of the invertase, β-glucosidase, urease and acid phosphatase were determined. These enzymes are involved in C, N and P cycling, respectively. Long-term cultivation resulted in decreased SOC, DOC, MBC, microbial quotient and C (invertase, β-glucosidase) and N-transforming (urease) enzyme activities compared with undisturbed marshland. After marshland restoration, the MBC and DOC concentrations and the soil invertase, β-glucosidase and urease activities increased. Soil DOC and MBC concentrations are probably the main factors responsible for the different invertase, β-glucosidase and urease activities. In addition, marshland restoration caused a significant increase in the microbial quotient, which reflects enhanced efficiency of organic substrate use by microbial biomass. Our observations demonstrated that soil quality recovered following marshland restoration. DOC, MBC and invertase, β-glucosidase and urease activities were sensitive for discriminating soil ecosystems under the different types of land use. Thus, these parameters should be considered to be indicators for detecting changes in soil quality and environmental impacts in marshlands.

In-depth glycoproteomic characterisation of grape berry vacuolar invertase using a combination of mass spectrometry-based approaches.

PubMed

Hovasse, Agnès; Alayi, Tchilabalo Dilezitoko; Van Dorsselaer, Alain; Marchal, Richard; Jégou, Sandrine; Schaeffer-Reiss, Christine

2016-06-01

Vacuolar invertase is a key enzyme of sugar metabolism in grape berries. A full characterisation of this highly N-glycosylated protein is required to help understand its biological and biochemical significance in grapes. We have developed a mass spectrometry (MS)-based glycoproteomic approach wherein deglycosylated peptides are analysed by LC-MS/MS, while intact glycopeptides are characterised using a dedicated MS method to determine the attachment sites and micro-heterogeneity. For grape invertase, in parallel with deglycosylated peptides analysis, different enzymatic digestions were performed and glycopeptide detection was improved by enrichment method, nanoLC-MS and oxonium glycan ions. This MS-based glycoproteomic approach demonstrates that vacuolar invertase is glycosylated at all twelve potential N-glycosylation sites. Glycosylation is heterogeneous, with twelve glycoforms identified at six of the sites. The identification of several types of N-glycans is a major result to correlate with the surface and foaming properties of wine, the solubility, allergenicity, and protease resistance of wine proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validation of a thin-layer chromatography/densitometry method for the characterization of invertase activity.

PubMed

Ferey, Justine; Da Silva, David; Bravo-Veyrat, Sophie; Lafite, Pierre; Daniellou, Richard; Maunit, Benoît

2016-12-16

This paper presents a kinetic study of invertase, a specific fructofuranosidase cloned from the Leishmania major genome. The kinetic parameters of the β-d-fructofuranosidase from Leishmania major (BfrA) were determined using Thin-Layer Chromatography (TLC) and UV-densitometry (TLC@UV) specifically developed for the separation and detection of three carbohydrates namely sucrose, glucose and fructose. Separation was performed on TLC silica gel 60 F254 plates impregnated with sodium bisulphate and citrate and heated prior to development. This fast and easy separation was performed with two successive developments using ACN/H 2 O 80/20 (v/v) as mobile phase. Sensitive and repeatable derivatization of sugars was achieved by dipping the plates in a solution of 4-aminobenzoic acid. Quantification was performed by UV-detection. The method was validated according to ICH guidelines Q2(R1) in terms of specificity, limits of detection and quantification, precision and robustness (with n=3 replicates and CV ≤10%). The characterization of BfrA reaction kinetic was performed by monitoring the accumulation of either glucose or fructose detected by TLC@UV. Hydrolysis of sucrose was described by the Michaelis-Menten kinetic parameters (K M ; V max ) respectively equal to 63.09±7.590mM; 0.037±0.00094mM/min using glucose production and 83.01±14.39mM; 0.031±0.0021mM/min monitoring fructose. Hydrolyses of three alternative substrates, raffinose, stachyose and inulin, were also compared and the regiospecificity of the reaction was characterized. This TLC@UV method is shown to be suitable for the refined kinetic analysis of different reactions related to the hydrolysis of sugars. Copyright © 2016. Published by Elsevier B.V.

Biotransformation of pineapple juice sugars into dietetic derivatives by using a cell free oxidoreductase from Zymomonas mobilis together with commercial invertase.

PubMed

Aziz, M G; Michlmayr, H; Kulbe, K D; Del Hierro, A M

2011-01-05

An easy procedure for cell free biotransformation of pineapple juice sugars into dietetic derivatives was accomplished using a commercial invertase and an oxidoreductase from Zymomonas mobilis. First, pineapple juice sucrose was quantitatively converted into glucose and fructose by invertase, thus increasing the concentration of each monosaccharide in the original juice to almost twice. In a second step, glucose-fructose oxidoreductase (GFOR) transformed glucose into gluconolactone, and fructose into the low calorie sweetener sorbitol. The advantage of using GFOR is simultaneous reduction of fructose and oxidation of glucose, allowing the continuous regeneration of the essential coenzyme NADP(H), that is tightly bound to the enzyme. The yield of GFOR catalyzed sugar conversion depends on initial pH and control of pH during the reaction. At optimal conditions (pH control at 6.2) a maximum of 80% (w/v) sugar conversion was obtained. Without pH control, GFOR is inactivated rapidly due to gluconic acid formation. Therefore, conversion yields are relatively low at the natural pH of pineapple juice. The application of this process might be more advantageous on juices of other tropical fruits (papaya, jackfruit, mango) due to their naturally given higher pH. Copyright © 2010 Elsevier Inc. All rights reserved.

Genetic Engineering of Maize (Zea mays L.) with Improved Grain Nutrients.

PubMed

Guo, Xiaotong; Duan, Xiaoguang; Wu, Yongzhen; Cheng, Jieshan; Zhang, Juan; Zhang, Hongxia; Li, Bei

2018-02-21

Cell-wall invertase plays important roles in the grain filling of crop plants. However, its functions in the improvement of grain nutrients have not been investigated. In this work, the stable expression of cell-wall-invertase-encoding genes from different plant species and the contents of total starch, protein, amino acid, nitrogen, lipid, and phosphorus were examined in transgenic maize plants. High expressions of the cell-wall-invertase gene conferred enhanced invertase activity and sugar content in transgenic plants, leading to increased grain yield and improved grain nutrients. Transgenic plants with high expressions of the transgene produced more total starch, protein, nitrogen, and essential amino acids in the seeds. Overall, the results indicate that the cell-wall-invertase gene can be used as a potential candidate for the genetic breeding of grain crops with both improved grain yield and quality.

Exploring codon context bias for synthetic gene design of a thermostable invertase in Escherichia coli.

PubMed

Pek, Han Bin; Klement, Maximilian; Ang, Kok Siong; Chung, Bevan Kai-Sheng; Ow, Dave Siak-Wei; Lee, Dong-Yup

2015-01-01

Various isoforms of invertases from prokaryotes, fungi, and higher plants has been expressed in Escherichia coli, and codon optimisation is a widely-adopted strategy for improvement of heterologous enzyme expression. Successful synthetic gene design for recombinant protein expression can be done by matching its translational elongation rate against heterologous host organisms via codon optimization. Amongst the various design parameters considered for the gene synthesis, codon context bias has been relatively overlooked compared to individual codon usage which is commonly adopted in most of codon optimization tools. In addition, matching the rates of transcription and translation based on secondary structure may lead to enhanced protein folding. In this study, we evaluated codon context fitness as design criterion for improving the expression of thermostable invertase from Thermotoga maritima in Escherichia coli and explored the relevance of secondary structure regions for folding and expression. We designed three coding sequences by using (1) a commercial vendor optimized gene algorithm, (2) codon context for the whole gene, and (3) codon context based on the secondary structure regions. Then, the codon optimized sequences were transformed and expressed in E. coli. From the resultant enzyme activities and protein yield data, codon context fitness proved to have the highest activity as compared to the wild-type control and other criteria while secondary structure-based strategy is comparable to the control. Codon context bias was shown to be a relevant parameter for enhancing enzyme production in Escherichia coli by codon optimization. Thus, we can effectively design synthetic genes within heterologous host organisms using this criterion. Copyright © 2015 Elsevier Inc. All rights reserved.

SUC1 gene of Saccharomyces: a structural gene for the large (glycoprotein) and small (carbohydrate-free) forms of invertase.

PubMed Central

Rodriguez, L; Lampen, J O; MacKay, V L

1981-01-01

Saccharomyces cerevisiae revertant strain D10-ER1 has been shown to contain thermosensitive forms of the large (glycoprotein) and small (carbohydrate-free) invertases and a very low level of the small enzyme, along with a wild-type level of the large form (T. Mizunaga et al., Mol. Cell. Biol. 1:460-468, 1981). These characteristics cosegregated in crosses of the revertant strain with wild-type sucrose-fermenting (SUC1) or nonfermenting (suc0) strains. In addition, there is tight linkage between sucrose and maltose fermentation in revertant D10-ER1 (characteristic of the SUC1 and MAL1 genes). From this we infer that a single reversion event is responsible for the several changes observed in D10-ER1, and that this mutation maps within or very close to the SUC1 gene present in the ancestor strain 4059-358D. The revertant SUC1 allele in D10-ER1 (termed SUC1-R1) was expressed independently of the wild-type SUC1 gene when both were present in diploid cells. Diploids carrying only the wild-type or the mutant genes synthesized invertases with the characteristics of the parental Suc+ haploids. The possibility that a modifier gene was responsible for the alterations in the invertases of revertant D10-ER1 was ruled out by appropriate crosses. We conclude that SUC1 is a structural gene that codes for both the large and the small forms of invertase and suggest that SUC2 through SUC5 are structural genes as well. PMID:6765604

Invertase SUC2 Is the key hydrolase for inulin degradation in Saccharomyces cerevisiae.

PubMed

Wang, Shi-An; Li, Fu-Li

2013-01-01

Specific Saccharomyces cerevisiae strains were recently found to be capable of efficiently utilizing inulin, but genetic mechanisms of inulin hydrolysis in yeast remain unknown. Here we report functional characteristics of invertase SUC2 from strain JZ1C and demonstrate that SUC2 is the key enzyme responsible for inulin metabolism in S. cerevisiae.

Carbohydrate metabolism of vegetative and reproductive sinks in the late-maturing peach cultivar 'Encore'

Treesearch

Riccardo Lo Bianco; Mark Rieger; Shi-Jean S. Sung

1999-01-01

Activities of NAD+-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) in ?Encore? peach (Prunus persica L.) fruits and developing shoot tips were assayed during the growing season to determine whether carbohydrate metabolizing enzymes could...

Changes in sugar content and related enzyme activities in table grape (Vitis vinifera L.) in response to foliar selenium fertilizer.

PubMed

Zhu, Shuaimeng; Liang, Yinli; An, Xiaojuan; Kong, Fanchao; Gao, Dekai; Yin, Hongfei

2017-09-01

Spraying selenium (Se) fertilizer is an effective method for Se-enriched fruit production. Sugar content in fruit is the major factor determining berry quality. However, changes in sugar metabolism in response to Se fertilizer are unclear. Hence, this study was conducted to identify the effects of Se fertilizer on sugar metabolism and related enzyme activities of grape berries. Additionally, production of leaves with and without Se fertilizer was also investigated. Acid invertase (AI) activity, total soluble sugar and Se content in berries, and photosynthetic rate in leaves produced under Se fertilizer treatments were higher than that of control. Glucose and fructose were the primary sugars in berries, with a trace of sucrose. In both berries and leaves, neutral invertase activity was lower than AI, there was no significant difference in neutral invertase, sucrose synthase and sucrose phosphate synthase between Se fertilizer-treated and control. In berries, AI showed a significant positive correlation with glucose and fructose; also Se content was significantly correlated with sugar content. AI played an important role in the process of sugar accumulation in berries; high AI activity in berries and photosynthetic rate in leaves could explain the mechanism by which Se fertilizer affected sugar accumulation in berries. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Cell wall invertase as a regulator in determining sequential development of endosperm and embryo through glucose signaling early in seed development.

PubMed

Wang, Lu; Liao, Shengjin; Ruan, Yong-Ling

2013-01-01

Seed development depends on coordination among embryo, endosperm and seed coat. Endosperm undergoes nuclear division soon after fertilization, whereas embryo remains quiescent for a while. Such a developmental sequence is of great importance for proper seed development. However, the underlying mechanism remains unclear. Recent results on the cellular domain- and stage-specific expression of invertase genes in cotton and Arabidopsis revealed that cell wall invertase may positively and specifically regulate nuclear division of endosperm after fertilization, thereby playing a role in determining the sequential development of endosperm and embryo, probably through glucose signaling.

Apoplastic sugars and cell-wall invertase are involved in formation of the tolerance of cold-resistant potato plants to hypothermia.

PubMed

Deryabin, A N; Burakhanova, E A; Trunova, T I

2015-01-01

We studied the involvement of apoplastic sugars (glucose, fructose, and sucrose) and the cell-wall invertase (CWI) in the formation of the tolerance of cold-resistant potato plants (Solanum tuberosum L., cv Désirée) to hypothermia. The activity of CW1 and the content in the cell and the apoplast substrate (sucrose) and the reaction products of this enzyme (glucose and fructose) have a significant influence on the formation of the tolerance of cold-resistant potato plants to hypothermia.

[Study on relationship between effective components and soil enzyme activity in different growth patterns of Panax ginseng].

PubMed

Yang, Yan-Wen; Jiang, Yuan-Tong

2016-08-01

Study on 5 effective components and 6 soil enzyme activities of 2 different growth patterns, analyse the dates with the canonical correlation analysis, In order to reveal the relations between the effective components and soil enzyme activities. The result showed that they had a great relation between the effective components and soil enzyme activities, the activity of the same enzyme in humus soil was higher than that in farmland soil. Growth pattern of farmland soil, if the invertase and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside, water-miscible total proteins and total amino acid; Growth pattern of humus soil, if the invertase, urease and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside and the total essential oils. Integral soil enzyme activity can be used as a index of soil quality, which, together with other growth factors. The appropriate enzyme activity can accelerate the circulation and transformation of all kinds of material in the soil, improve effectively components accumulation. Copyright© by the Chinese Pharmaceutical Association.

Vascular cambial sucrose metabolism and growth in loblolly pine (Pinus taeda L.) in relation to transplanting stress

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; C.C. Black

1993-01-01

Sucrose synthase (SS) was the dominant enzyme of sucrose metabolism in both stem and root vascular cambial zone tissues of nursery-grown loblolly pine (Pinus taeda L.) seedlings.Acid invertase (AI) and neutral invertase (NI) activties were generally less than 10% of the SS activity in both tissues.In both cambial tissues, seasonal patterns of SS activity in stem and...

Sucrose metabolism and growth in transplanted loblolly pine seedlings

Treesearch

Shi-Jean S. Sung; C.C. Black; Paul P. Kormanik

1993-01-01

Loblolly pine (Pinus taeda L.) seedling height, root collar diameter, and the specific activities of three sucrose metabolizing enzymes, namely, sucrose synthase (SS), acid invertase, and neutral invertase, were measured to assess seedling responses to transplant stress. It was concluded that i) SS was the dominant enzyme for sucrose metabolism in...

Movement of 14C-Labeled Assimilates into Kernels of Zea mays L

PubMed Central

Shannon, Jack C.; Dougherty, C. T.

1972-01-01

Invertases of the placento-chalazal and pedicel tissues are much more active than invertase from the pericarp of Zea mays L. kernels 12 to 40 days after pollination. Sucrose synthetase was not detected in the pedicel or placento-chalazal tissues. Sucrose content and percentage increased in the pedicel with advancing kernel age. Hexoses accounted for over half of the sugars extracted from the placento-chalazal tissues. These data are consistent with the hypothesis that sucrose translocated to the pedicel is hydrolyzed by acid invertase(s) prior to entry of sugar into the endosperm tissue. The placentochalazal tissue appears to be the primary site of sucrose inversion with the pedicel invertase contributing more or less to this process depending on kernel age. PMID:16657925

A sensitive biosensor using double-layer capillary based immunomagnetic separation and invertase-nanocluster based signal amplification for rapid detection of foodborne pathogen.

PubMed

Huang, Fengchun; Zhang, Huilin; Wang, Lei; Lai, Weihua; Lin, Jianhan

2018-02-15

Combining double-layer capillary based high gradient immunomagnetic separation, invertase-nanocluster based signal amplification and glucose meter based signal detection, a novel biosensor was developed for sensitive and rapid detection of E. coli O157:H7 in this study. The streptavidin modified magnetic nanobeads (MNBs) were conjugated with the biotinylated polyclonal antibodies against E. coli O157:H7 to form the immune MNBs, which were captured by the high gradient magnetic field in the double-layer capillary to specifically separate and efficiently concentrate the target bacteria. Calcium chloride was used with the monoclonal antibodies against E. coli O157:H7 and the invertase to form the immune invertase-nanoclusters (INCs), which were used to react with the target bacteria to form the MNB-bacteria-INC complexes in the capillary. The sucrose was then injected into the capillary and catalyzed by the invertase on the complexes into the glucose, which was detected using the glucose meter to obtain the concentration of the glucose for final determination of the E. coli O157:H7 cells in the sample. A linear relationship between the readout of the glucose meter and the concentration of the E. coli O157:H7 cells (from 10 2 to 10 7 CFU/mL) was found and the lower detection limit of this biosensor was 79 CFU/mL. This biosensor might be extended for the detection of other foodborne pathogens by changing the antibodies and has shown the potential for the detection of foodborne pathogens in a large volume of sample to further increase the sensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Metarhizium robertsii produces an extracellular invertase (MrINV) that plays a pivotal role in rhizospheric interactions and root colonization.

PubMed

Liao, Xinggang; Fang, Weiguo; Lin, Liangcai; Lu, Hsiao-Ling; St Leger, Raymond J

2013-01-01

As well as killing pest insects, the rhizosphere competent insect-pathogenic fungus Metarhizium robertsii also boosts plant growth by providing nitrogenous nutrients and increasing resistance to plant pathogens. Plant roots secrete abundant nutrients but little is known about their utilization by Metarhizium spp. and the mechanistic basis of Metarhizium-plant associations. We report here that M. robertsii produces an extracellular invertase (MrInv) on plant roots. Deletion of MrInv (ΔMrInv) reduced M. robertsii growth on sucrose and rhizospheric exudates but increased colonization of Panicum virgatum and Arabidopsis thaliana roots. This could be accounted for by a reduction in carbon catabolite repression in ΔMrInv increasing production of plant cell wall-degrading depolymerases. A non-rhizosphere competent scarab beetle specialist Metarhizium majus lacks invertase which suggests that rhizospheric competence may be related to the sugar metabolism of different Metarhizium species.

The Isolation of Invertase from Baker's Yeast: A Four-Part Exercise in Protein Purification and Characterization

ERIC Educational Resources Information Center

Timerman, Anthony P.; Fenrick, Angela M.; Zamis, Thomas M.

2009-01-01

A sequence of exercises for the isolation and characterization of invertase (E.C. 3.1.2.26) from baker's yeast obtained from a local grocery store is outlined. Because the enzyme is colorless, the use of colored markers and the sequence of purification steps are designed to "visualize" the process by which a colorless protein is selectively…

Nectar Sugar Modulation and Cell Wall Invertases in the Nectaries of Day- and Night- Flowering Nicotiana.

PubMed

Tiedge, Kira; Lohaus, Gertrud

2018-01-01

Nectar composition varies between species, depending on flowering time and pollinator type, among others. Various models of the biochemical and molecular mechanisms underlying nectar production and secretion have been proposed. To gain insights into these mechanisms, day- and night-flowering tobacco ( Nicotiana ) species with high or low proportions of hexoses in the nectar were analyzed. Nectar and nectaries were simultaneously collected, throughout the day and night. Soluble sugars and starch were determined and the activity and expression level of cell wall invertase (CW-INVs) were measured in nectaries. Nectaries and nectar of the five Nicotiana species contained different amounts of sucrose, glucose, and fructose. CW-INV activity was detected in the nectaries of all Nicotiana species and is probably involved in the hydrolysis of sucrose in the nectary tissue and during nectar secretion. The larger differences in the sucrose-to-hexose-ratio between nectaries and nectar in diurnal species compared to nocturnal species can be explained by higher sucrose cleavage within the nectaries in night-flowering species, and during secretion in day-flowering species. However, cell wall invertase alone cannot be responsible for the differences in sugar concentrations. Within the nectaries of the Nicotiana species, a portion of the sugars is transiently stored as starch. In general, night-flowering species showed higher starch contents in the nectaries compared to day-flowering species. Moreover, in night flowering species, the starch content decreased during the first half of the dark period, when nectar production peaks. The sucrose concentrations in the cytoplasm of nectarial cells were extrapolated from nectary sucrose contents. In day-flowering species, the sucrose concentration in the nectary cytoplasm was about twice as high as in nectar, whereas in night-flowering species the situation was the opposite, which implies different secretion mechanisms. The secreted nectar

Nectar Sugar Modulation and Cell Wall Invertases in the Nectaries of Day- and Night- Flowering Nicotiana

PubMed Central

Tiedge, Kira; Lohaus, Gertrud

2018-01-01

Nectar composition varies between species, depending on flowering time and pollinator type, among others. Various models of the biochemical and molecular mechanisms underlying nectar production and secretion have been proposed. To gain insights into these mechanisms, day- and night-flowering tobacco (Nicotiana) species with high or low proportions of hexoses in the nectar were analyzed. Nectar and nectaries were simultaneously collected, throughout the day and night. Soluble sugars and starch were determined and the activity and expression level of cell wall invertase (CW-INVs) were measured in nectaries. Nectaries and nectar of the five Nicotiana species contained different amounts of sucrose, glucose, and fructose. CW-INV activity was detected in the nectaries of all Nicotiana species and is probably involved in the hydrolysis of sucrose in the nectary tissue and during nectar secretion. The larger differences in the sucrose-to-hexose-ratio between nectaries and nectar in diurnal species compared to nocturnal species can be explained by higher sucrose cleavage within the nectaries in night-flowering species, and during secretion in day-flowering species. However, cell wall invertase alone cannot be responsible for the differences in sugar concentrations. Within the nectaries of the Nicotiana species, a portion of the sugars is transiently stored as starch. In general, night-flowering species showed higher starch contents in the nectaries compared to day-flowering species. Moreover, in night flowering species, the starch content decreased during the first half of the dark period, when nectar production peaks. The sucrose concentrations in the cytoplasm of nectarial cells were extrapolated from nectary sucrose contents. In day-flowering species, the sucrose concentration in the nectary cytoplasm was about twice as high as in nectar, whereas in night-flowering species the situation was the opposite, which implies different secretion mechanisms. The secreted nectar

[Soil basal respiration and enzyme activities in the root-layer soil of tea bushes in a red soil].

PubMed

Yu, Shen; He, Zhenli; Zhang, Rongguang; Chen, Guochao; Huang, Changyong

2003-02-01

Soil basal respiration potential, metabolic quotient (qCO2), and activities of urease, invertase and acid phosphomonoesterase were investigated in the root-layer of 10-, 40-, and 90-yr-old tea bushes grown on the same type of red soil. The soil daily basal respiration potential ranged from 36.23 to 58.52 mg.kg-1.d-1, and the potentials in the root-layer of 40- or 90-yr-old were greater than that of 10-yr old tea bushes. The daily qCO2, ranging from 0.30 to 0.68, was in the reverse trend. The activities of test three enzymes changed differently with tea bushes' age. Urease activity in the root-layer of all age tea bushes ranged from 41.48 to 47.72 mg.kg-1.h-1 and slightly decreased with tea bushes' age. Invertase activity was 189.29-363.40 mg.kg-1.h-1 and decreased with tea bushes' age, but its activity in the root-layer of 10-year old tea bushes was significantly greater than that in the root-layer soil of 40- or 90-year old tea bushes. Acid phosphomonoesterase activity (444.22-828.32 mg.kg-1.h-1) increased significantly with tea bushes' age. Soil basal respiration potential, qCO2 and activities of 3 soil enzymes were closely related to soil pH, soil organic carbon, total nitrogen and C/N ratio, total soluble phenol, and microbial biomass carbon, respectively.

Kernel Abortion in Maize 1

PubMed Central

Hanft, Jonathan M.; Jones, Robert J.

1986-01-01

Kernels cultured in vitro were induced to abort by high temperature (35°C) and by culturing six kernels/cob piece. Aborting kernels failed to enter a linear phase of dry mass accumulation and had a final mass that was less than 6% of nonaborting field-grown kernels. Kernels induced to abort by high temperature failed to synthesize starch in the endosperm and had elevated sucrose concentrations and low fructose and glucose concentrations in the pedicel during early growth compared to nonaborting kernels. Kernels induced to abort by high temperature also had much lower pedicel soluble acid invertase activities than did nonaborting kernels. These results suggest that high temperature during the lag phase of kernel growth may impair the process of sucrose unloading in the pedicel by indirectly inhibiting soluble acid invertase activity and prevent starch synthesis in the endosperm. Kernels induced to abort by culturing six kernels/cob piece had reduced pedicel fructose, glucose, and sucrose concentrations compared to kernels from field-grown ears. These aborting kernels also had a lower pedicel soluble acid invertase activity compared to nonaborting kernels from the same cob piece and from field-grown ears. The low invertase activity in pedicel tissue of the aborting kernels was probably caused by a lack of substrate (sucrose) for the invertase to cleave due to the intense competition for available assimilates. In contrast to kernels cultured at 35°C, aborting kernels from cob pieces containing all six kernels accumulated starch in a linear fashion. These results indicate that kernels cultured six/cob piece abort because of an inadequate supply of sugar and are similar to apical kernels from field-grown ears that often abort prior to the onset of linear growth. PMID:16664846

Optimizing culture conditions for production of intra and extracellular inulinase and invertase from Aspergillus niger ATCC 20611 by response surface methodology (RSM).

PubMed

Dinarvand, Mojdeh; Rezaee, Malahat; Foroughi, Majid

The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R 2 ) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30°C, 6% (v/v), inoculum size and 150rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Hormonal and metabolic regulation of tomato fruit sink activity and yield under salinity

PubMed Central

Albacete, Alfonso; Cantero-Navarro, Elena; Balibrea, María E.; Großkinsky, Dominik K.; de la Cruz González, María; Martínez-Andújar, Cristina; Smigocki, Ann C.; Roitsch, Thomas; Pérez-Alfocea, Francisco

2014-01-01

Salinization of water and soil has a negative impact on tomato (Solanum lycopersicum L.) productivity by reducing growth of sink organs and by inducing senescence in source leaves. It has been hypothesized that yield stability implies the maintenance or increase of sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves through changes in sucrolytic enzymes and their regulation by phytohormones. In this study, classical and functional physiological approaches have been integrated to study the influence of metabolic and hormonal factors on tomato fruit sink activity, growth, and yield: (i) exogenous hormones were applied to plants, and (ii) transgenic plants overexpressing the cell wall invertase (cwInv) gene CIN1 in the fruits and de novo cytokinin (CK) biosynthesis gene IPT in the roots were constructed. Although salinity reduces fruit growth, sink activity, and trans-zeatin (tZ) concentrations, it increases the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) during the actively growing period (25 days after anthesis). Indeed, exogenous application of the CK analogue kinetin to salinized actively growing fruits recovered sucrolytic activities (mainly cwInv and sucrose synthase), sink strength, and fruit weight, whereas the ethylene-releasing compound ethephon had a negative effect in equivalent non-stressed fruits. Fruit yield was increased by both the constitutive expression of CIN1 in the fruits (up to 4-fold) or IPT in the root (up to 30%), owing to an increase in the fruit number (lower flower abortion) and in fruit weight. This is possibly related to a recovery of sink activity in reproductive tissues due to both (i) increase in sucrolytic activities (cwInv, sucrose synthase, and vacuolar and cytoplasmic invertases) and tZ concentration, and (ii) a decrease in the ACC levels and the activity of the invertase inhibitor. This study provides new functional evidences about the role of

Student Collaboration in a Series of Integrated Experiments to Study Enzyme Reactor Modeling with Immobilized Cell-Based Invertase

ERIC Educational Resources Information Center

Taipa, M. A^ngela; Azevedo, Ana M.; Grilo, Anto´nio L.; Couto, Pedro T.; Ferreira, Filipe A. G.; Fortuna, Ana R. M.; Pinto, Ine^s F.; Santos, Rafael M.; Santos, Susana B.

2015-01-01

An integrative laboratory study addressing fundamentals of enzyme catalysis and their application to reactors operation and modeling is presented. Invertase, a ß-fructofuranosidase that catalyses the hydrolysis of sucrose, is used as the model enzyme at optimal conditions (pH 4.5 and 45 °C). The experimental work involves 3 h of laboratory time…

Cloning of Sucrose:Sucrose 1-Fructosyltransferase from Onion and Synthesis of Structurally Defined Fructan Molecules from Sucrose1

PubMed Central

Vijn, Irma; van Dijken, Anja; Lüscher, Marcel; Bos, Antoine; Smeets, Edward; Weisbeek, Peter; Wiemken, Andres; Smeekens, Sjef

1998-01-01

Sucrose (Suc):Suc 1-fructosyltransferase (1-SST) is the key enzyme in plant fructan biosynthesis, since it catalyzes de novo fructan synthesis from Suc. We have cloned 1-SST from onion (Allium cepa) by screening a cDNA library using acid invertase from tulip (Tulipa gesneriana) as a probe. Expression assays in tobacco (Nicotiana plumbaginifolia) protoplasts showed the formation of 1-kestose from Suc. In addition, an onion acid invertase clone was isolated from the same cDNA library. Protein extracts of tobacco protoplasts transformed with this clone showed extensive Suc-hydrolyzing activity. Conditions that induced fructan accumulation in onion leaves also induced 1-SST mRNA accumulation, whereas the acid invertase mRNA level decreased. Structurally different fructan molecules could be produced from Suc by a combined incubation of protein extract of protoplasts transformed with 1-SST and protein extract of protoplasts transformed with either the onion fructan:fructan 6G-fructosyltransferase or the barley Suc:fructan 6-fructosyltransferase. PMID:9701606

Regulation of maize kernel weight and carbohydrate metabolism by abscisic acid applied at the early and middle post-pollination stages in vitro.

PubMed

Zhang, Li; Li, Xu-Hui; Gao, Zhen; Shen, Si; Liang, Xiao-Gui; Zhao, Xue; Lin, Shan; Zhou, Shun-Li

2017-09-01

Abscisic acid (ABA) accumulates in plants under drought stress, but views on the role of ABA in kernel formation and abortion are not unified. The response of the developing maize kernel to exogenous ABA was investigated by excising kernels from cob sections at four days after pollination and culturing in vitro with different concentrations of ABA (0, 5, 10, 100μM). When ABA was applied at the early post-pollination stage (EPPS), significant weight loss was observed at high ABA concentration (100μM), which could be attributed to jointly affected sink capacity and activity. Endosperm cells and starch granules were decreased significantly with high concentration, and ABA inhibited the activities of soluble acid invertase and acid cell wall invertase, together with earlier attainment of peak values. When ABA was applied at the middle post-pollination stage (MPPS), kernel weight was observably reduced with high concentration and mildly increased with low concentration, which was regulated due to sink activity. The inhibitory effect of high concentration and the mild stimulatory effect of low concentration on sucrose synthase and starch synthase activities were noted, but a peak level of ADP-glucose pyrophosphorylase (AGPase) was stimulated in all ABA treatments. Interestingly, AGPase peak values were advanced by low concentration and postponed by high concentration. In addition, compared with the control, the weight of low ABA concentration treatments were not statistically significant at the two stages, whereas weight loss from high concentration applied at EPPS was considerably obvious compared with that of the MPPS, but neither led to kernel abortion. The temporal- and dose-dependent impacts of ABA reveal a complex process of maize kernel growth and development. Copyright © 2017 Elsevier GmbH. All rights reserved.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds.

PubMed

Gorim, Linda; Asch, Folkard

2017-05-24

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds

PubMed Central

Gorim, Linda; Asch, Folkard

2017-01-01

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition. PMID:28538658

[Effects of altitudes on soil microbial biomass and enzyme activity in alpine-gorge regions.

PubMed

Cao, Rui; Wu, Fu Zhong; Yang, Wan Qin; Xu, Zhen Feng; Tani, Bo; Wang, Bin; Li, Jun; Chang, Chen Hui

2016-04-22

In order to understand the variations of soil microbial biomass and soil enzyme activities with the change of altitude, a field incubation was conducted in dry valley, ecotone between dry valley and mountain forest, subalpine coniferous forest, alpine forest and alpine meadow from 1563 m to 3994 m of altitude in the alpine-gorge region of western Sichuan. The microbial biomass carbon and nitrogen, and the activities of invertase, urease and acid phosphorus were measured in both soil organic layer and mineral soil layer. Both the soil microbial biomass and soil enzyme activities showed the similar tendency in soil organic layer. They increased from 2158 m to 3028 m, then decreased to the lowest value at 3593 m, and thereafter increased until 3994 m in the alpine-gorge region. In contrast, the soil microbial biomass and soil enzyme activities in mineral soil layer showed the trends as, the subalpine forest at 3028 m > alpine meadow at 3994 m > montane forest ecotone at 2158 m > alpine forest at 3593 m > dry valley at 1563 m. Regardless of altitudes, soil microbial biomass and soil enzyme activities were significantly higher in soil organic layer than in mineral soil layer. The soil microbial biomass was significantly positively correlated with the activities of the measured soil enzymes. Moreover, both the soil microbial biomass and soil enzyme activities were significantly positively correlated with soil water content, organic carbon, and total nitrogen. The activity of soil invertase was significantly positively correlated with soil phosphorus content, and the soil acid phosphatase was so with soil phosphorus content and soil temperature. In brief, changes in vegetation and other environmental factors resulting from altitude change might have strong effects on soil biochemical properties in the alpine-gorge region.

Heat stress affects carbohydrate metabolism during cold-induced sweetening of potato (Solanum tuberosum L.).

PubMed

Herman, Derek J; Knowles, Lisa O; Knowles, N Richard

2017-03-01

Tolerance to heat stress for retention of low-temperature sweetening-resistant phenotype in potato is conferred by insensitivity of acid invertase activity to cold induction. Heat stress exacerbated cold sweetening (buildup of reducing sugars) of the LTS (low-temperature sweetening)-susceptible potato (Solanum tuberosum L.) cultivars, Ranger Russet and Russet Burbank, and completely abolished the resistance to cold sweetening in the LTS-resistant cultivars/clones, Sage Russet, GemStar Russet, POR06V12-3 and A02138-2. Payette Russet and EGA09702-2, however, demonstrated considerable tolerance to heat stress for retention of their LTS-resistant phenotype. Heat-primed Payette Russet and EGA09702-2 tubers accumulated fourfold more sucrose when subsequently stored at 4 °C, while reducing sugar concentrations also increased marginally but remained low relative to the non-heat-tolerant LTS-resistant clones, resulting in light-colored fries. By contrast, sucrose concentrations in heat-primed tubers of the non-heat-tolerant clones remained unchanged during LTS, but reducing sugars increased fivefold, resulting in darkening of processed fries. Acid invertase activity increased in the LTS-susceptible and non-heat-tolerant LTS-resistant cultivars/clones during cold storage. However, Payette Russet tubers maintained very low invertase activity regardless of heat stress and cold storage treatments, as was the case for Innate ® Russet Burbank (W8) tubers, where silenced invertase conferred robust tolerance to heat stress for retention of LTS-resistant phenotype. Importantly, heat-stressed tubers of Payette Russet, EGA09702-2 and Innate ® Russet Burbank (W8) demonstrated similar low reducing sugar and high sucrose-accumulating phenotypes when stored at 4 °C. Tolerance to heat stress for retention of LTS-resistant phenotype in Payette Russet and likely its maternal parent, EGA09702-2, is, therefore, conferred by the ability to maintain low invertase activity during cold

Carbohydrate Content and Enzyme Metabolism in Developing Canola Siliques.

PubMed Central

King, S. P.; Lunn, J. E.; Furbank, R. T.

1997-01-01

Little biochemical information is available on carbohydrate metabolism in developing canola (Brassica napus L.) silique (pod) wall and seed tissues. This research examines the carbohydrate contents and sucrose (Suc) metabolic enzyme activities in different aged silique wall and seed tissues during oil filling. The silique wall partitioned photosynthate into Suc over starch and predominantly accumulated hexose. The silique wall hexose content and soluble acid invertase activity rapidly fell as embryos progressed from the early- to late-cotyledon developmental stages. A similar trend was not evident for alkaline invertase, Suc synthase (SuSy), and Suc-phosphate synthase. Silique wall SuSy activities were much higher than source leaves at all times and may serve to supply the substrate for secondary cell wall thickening. In young seeds starch was the predominant accumulated carbohydrate over the sampled developmental range. Seed hexose levels dropped as embryos developed from the early- to midcotyledon stage. Hexose and starch were localized to the testa or liquid endosperm, whereas Suc was evenly distributed among seed components. With the switch to oil accumulation, seed SuSy activity increased by 3.6-fold and soluble acid invertase activity decreased by 76%. These data provide valuable baseline knowledge for the genetic manipulation of canola seed carbon partitioning. PMID:12223695

Carbohydrate Content and Enzyme Metabolism in Developing Canola Siliques.

PubMed

King, S. P.; Lunn, J. E.; Furbank, R. T.

1997-05-01

Little biochemical information is available on carbohydrate metabolism in developing canola (Brassica napus L.) silique (pod) wall and seed tissues. This research examines the carbohydrate contents and sucrose (Suc) metabolic enzyme activities in different aged silique wall and seed tissues during oil filling. The silique wall partitioned photosynthate into Suc over starch and predominantly accumulated hexose. The silique wall hexose content and soluble acid invertase activity rapidly fell as embryos progressed from the early- to late-cotyledon developmental stages. A similar trend was not evident for alkaline invertase, Suc synthase (SuSy), and Suc-phosphate synthase. Silique wall SuSy activities were much higher than source leaves at all times and may serve to supply the substrate for secondary cell wall thickening. In young seeds starch was the predominant accumulated carbohydrate over the sampled developmental range. Seed hexose levels dropped as embryos developed from the early- to midcotyledon stage. Hexose and starch were localized to the testa or liquid endosperm, whereas Suc was evenly distributed among seed components. With the switch to oil accumulation, seed SuSy activity increased by 3.6-fold and soluble acid invertase activity decreased by 76%. These data provide valuable baseline knowledge for the genetic manipulation of canola seed carbon partitioning.

Suppression of the vacuolar invertase gene delays senescent sweetening in chipping potatoes.

PubMed

Wiberley-Bradford, Amy E; Bethke, Paul C

2018-01-01

Potato chip processors require potato tubers that meet quality specifications for fried chip color, and color depends largely upon tuber sugar contents. At later times in storage, potatoes accumulate sucrose, glucose, and fructose. This developmental process, senescent sweetening, manifests as a blush of color near the center of the fried chip, becomes more severe with time, and limits the storage period. Vacuolar invertase (VInv) converts sucrose to glucose and fructose and is hypothesized to play a role in senescent sweetening. To test this hypothesis, senescent sweetening was quantified in multiple lines of potato with reduced VInv expression. Chip darkening from senescent sweetening was delayed by about 4 weeks for tubers with reduced VInv expression. A strong positive correlation between frequency of dark chips and tuber hexose content was observed. Tubers with reduced VInv expression had lower hexose to sucrose ratios than controls. VInv activity contributes to reducing sugar accumulation during senescent sweetening. Sucrose breakdown during frying may contribute to chip darkening. Suppressing VInv expression increases the storage period of the chipping potato crop, which is an important consideration, as potatoes with reduced VInv expression are entering commercial production in the USA. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Biochemical and Thermodynamical Characterization of Glucose Oxidase, Invertase, and Alkaline Phosphatase Secreted by Antarctic Yeasts.

PubMed

Yuivar, Yassef; Barahona, Salvador; Alcaíno, Jennifer; Cifuentes, Víctor; Baeza, Marcelo

2017-01-01

The use of enzymes in diverse industries has increased substantially over past decades, creating a well-established and growing global market. Currently, the use of enzymes that work better at ambient or lower temperatures in order to decrease the temperatures of production processes is desirable. There is thus a continuous search for enzymes in cold environments, especially from microbial sources, with amylases, proteases, lipases and, cellulases being the most studied. Other enzymes, such as glucose oxidase (GOD), invertase (Inv), and alkaline phosphatase (ALP), also have a high potential for application, but have been much less studied in microorganisms living in cold-environments. In this work, secretion of these three enzymes by Antarctic yeast species was analyzed, and five, three, and five species were found to produce extracellular GOD, Inv, and ALP, respectively. The major producers of GOD, Inv, and ALP were Goffeauzyma gastrica, Wickerhamomyces anomalus , and Dioszegia sp., respectively, from which the enzymes were purified and characterized. Contrary to what was expected, the highest GOD and Inv activities were found at 64°C and 60°C, respectively, and at 47°C for ALP. However, the three enzymes maintained a significant percentage of activity at lower temperatures, especially ALP that kept a 67 and 43% of activity at 10°C and 4°C, respectively.

Biochemical and Thermodynamical Characterization of Glucose Oxidase, Invertase, and Alkaline Phosphatase Secreted by Antarctic Yeasts

PubMed Central

Yuivar, Yassef; Barahona, Salvador; Alcaíno, Jennifer; Cifuentes, Víctor; Baeza, Marcelo

2017-01-01

The use of enzymes in diverse industries has increased substantially over past decades, creating a well-established and growing global market. Currently, the use of enzymes that work better at ambient or lower temperatures in order to decrease the temperatures of production processes is desirable. There is thus a continuous search for enzymes in cold environments, especially from microbial sources, with amylases, proteases, lipases and, cellulases being the most studied. Other enzymes, such as glucose oxidase (GOD), invertase (Inv), and alkaline phosphatase (ALP), also have a high potential for application, but have been much less studied in microorganisms living in cold-environments. In this work, secretion of these three enzymes by Antarctic yeast species was analyzed, and five, three, and five species were found to produce extracellular GOD, Inv, and ALP, respectively. The major producers of GOD, Inv, and ALP were Goffeauzyma gastrica, Wickerhamomyces anomalus, and Dioszegia sp., respectively, from which the enzymes were purified and characterized. Contrary to what was expected, the highest GOD and Inv activities were found at 64°C and 60°C, respectively, and at 47°C for ALP. However, the three enzymes maintained a significant percentage of activity at lower temperatures, especially ALP that kept a 67 and 43% of activity at 10°C and 4°C, respectively. PMID:29312954

Grape hexokinases are involved in the expression regulation of sucrose synthase- and cell wall invertase-encoding genes by glucose and ABA.

PubMed

Wang, Xiu-Qin; Zheng, Li-Li; Lin, Hao; Yu, Fei; Sun, Li-Hui; Li, Li-Mei

2017-05-01

Hexokinase (HXK, EC 2.7.1.1) is a multifunctional protein that both is involved in catalyzing the first step of glycolysis and plays an important role in sugar signaling. However, the supporting genetic evidence on hexokinases (CsHXKs) from grape (Vitis vinifera L. cv. Cabernet Sauvignon) berries has been lacking. Here, to investigate the role of CsHXK isoforms as glucose (Glc) and abscisic acid (ABA) sensors, we cloned two hexokinase isozymes, CsHXK1 and CsHXK2 with highly conserved genomic structure of nine exons and eight introns. We also found adenosine phosphate binding, substrate recognition and connection sites in their putative proteins. During grape berry development, the expression profiles of two CsHXK isoforms, sucrose synthases (SuSys) and cell wall invertase (CWINV) genes increased concomitantly with high levels of endogenous Glc and ABA. Furthermore, we showed that in wild type grape berry calli (WT), glucose repressed the expression levels of sucrose synthase (SuSy) and cell wall invertase (CWINV) genes, while ABA increased their expression levels. ABA could not only effectively improve the expression levels of SuSy and CWINV, but also block the repression induced by glucose on the expression of both genes. However, after silencing CsHXK1 or CsHXK2 in grape calli, SuSy and CWINV expression were enhanced, and the expressions of the two genes are insensitive in response to Glc treatment. Interestingly, exogenous ABA alone could not or less increase SuSy and CWINV expression in silencing CsHXK1 or CsHXK2 grape calli compared to WT. Meantime, ABA could not block the repression induced by glucose on the expression of SuSy and CWINV in CsHXK1 or CsHXK2 mutants. Therefore, Glc signal transduction depends on the regulation of CsHXK1 or CsHXK2. ABA signal was also disturbed by CsHXK1 or CsHXK2 silencing. The present results provide new insights into the regulatory role of Glc and ABA on the enzymes related to sugar metabolism in grape berry.

Down-regulation of a wheat alkaline/neutral invertase correlates with reduced host susceptibility to wheat stripe rust caused by Puccinia striiformis.

PubMed

Liu, Jie; Han, Lina; Huai, Baoyu; Zheng, Peijing; Chang, Qing; Guan, Tao; Li, Dan; Huang, Lili; Kang, Zhensheng

2015-12-01

Numerous studies have found that sucrose (Suc) metabolism plays a crucial role in the environmental stress response of many plant species. The majority of Suc metabolism-associated reports refer to acid invertases (Ac-Invs). However, alkaline/neutral Invs (A/N-Invs) have been poorly studied. In this study, a wheat A/N-Inv gene, Ta-A/N-Inv1, with three copies located on chromosomes 4A, 4B, and 4D, was cloned from a wheat-Puccinia striiformis f. sp. tritici (Pst) interaction cDNA library. Transcripts of the three Ta-A/N-Inv1 copies were up-regulated in wheat leaves that were infected by Pst or had experienced certain abiotic treatments. Furthermore, the expression of Ta-A/N-Inv1 was decreased by treatment with exogenous hormones. Heterologous mutant complementation and subcellular localization revealed that Ta-A/N-Inv1 is a cytoplasmic invertase. Knocking down all three copies of Ta-A/N-Inv1 using the barley stripe mosaic virus-induced gene silencing system reduced the susceptibility of wheat to the Pst virulent pathotype CYR31, which is associated with pathogen-induced H2O2 accumulation and enhanced necrosis. Interestingly, 48h dark treatment of the Ta-A/N-Inv1-knockdown plants immediately after inoculation abrogated their enhanced resistance, suggesting that H2O2 production and its associated cell death and resistance in the Ta-A/N-Inv1-silenced plants require light. Consistent with this observation, photosynthesis and reactive oxygen species (ROS)-related genes were significantly up-regulated in the Ta-A/N-Inv1-knockdown plants infected by CYR31 under light exposure. These results suggest that Ta-A/N-Inv1 might act as a negative regulator in wheat disease resistance to Pst by increasing cytoplasmic hexose accumulation and downregulating photosynthesis of the leaves to avoid cell death due to excessive ROS production. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions

Cell wall-bound invertase limits sucrose export and is involved in symptom development and inhibition of photosynthesis during compatible interaction between tomato and Xanthomonas campestris pv vesicatoria.

PubMed

Kocal, Nurcan; Sonnewald, Uwe; Sonnewald, Sophia

2008-11-01

Cell wall-bound invertase (cw-Inv) plays an important role in carbohydrate partitioning and regulation of sink-source interaction. There is increasing evidence that pathogens interfere with sink-source interaction, and induction of cw-Inv activity has frequently been shown in response to pathogen infection. To investigate the role of cw-Inv, transgenic tomato (Solanum lycopersicum) plants silenced for the major leaf cw-Inv isoforms were generated and analyzed during normal growth and during the compatible interaction with Xanthomonas campestris pv vesicatoria. Under normal growth conditions, activities of sucrolytic enzymes as well as photosynthesis and respiration were unaltered in the transgenic plants compared with wild-type plants. However, starch levels of source leaves were strongly reduced, which was most likely caused by an enhanced sucrose exudation rate. Following X. campestris pv vesicatoria infection, cw-Inv-silenced plants showed an increased sucrose to hexose ratio in the apoplast of leaves. Symptom development, inhibition of photosynthesis, and expression of photosynthetic genes were clearly delayed in transgenic plants compared with wild-type plants. In addition, induction of senescence-associated and pathogenesis-related genes observed in infected wild-type plants was abolished in cw-Inv-silenced tomato lines. These changes were not associated with decreased bacterial growth. In conclusion, cw-Inv restricts carbon export from source leaves and regulates the sucrose to hexose ratio in the apoplast. Furthermore, an increased apoplastic hexose to sucrose ratio can be linked to inhibition of photosynthesis and induction of pathogenesis-related gene expression but does not significantly influence bacterial growth. Indirectly, bacteria may benefit from low invertase activity, since the longevity of host cells is raised and basal defense might be dampened.

Temporal dynamics of the compositions and activities of soil microbial communities post-application of the insecticide chlorantraniliprole in paddy soils.

PubMed

Wu, Meng; Liu, Jia; Li, Weitao; Liu, Ming; Jiang, Chunyu; Li, Zhongpei

2017-10-01

Chlorantraniliprole (CAP) is a newly developed insecticide widely used in rice fields in China. There has been few studies evaluating the toxicological effects of CAP on soil-associated microbes. An 85-day microcosm experiment was performed to reveal the dissipation dynamics of CAP in three types of paddy soils in subtropical China. The effects of CAP on microbial activities (microbial biomass carbon-MBC, basal soil respiration-BSR, microbial metabolic quotient-qCO 2 , acid phosphatase and sucrose invertase activities) in the soils were periodically evaluated. Microbial phospholipid fatty acid (PLFA) analysis was used to evaluate the change of soil microbial community composition on day 14 and 50 of the experiment. CAP residues were extracted using the quick, easy, cheap, effective, rugged, and safe (QuChERS) method and quantification was measured by high performance liquid chromatography (HPLC). The half-lives (DT 50 ) of CAP were in the range of 41.0-53.0 days in the three soils. The results showed that CAP did not impart negative effects on MBC during the incubation. CAP inhibited BSR, qCO 2 , acid phosphatase and sucrose invertase activities in the first 14 days of incubation in all the soils. After day 14, the soil microbial parameters of CAP-treated soils became statistically at par with their controls. Principal component analysis (PCA) determining abundance of biomarker PLFAs indicated that the application of CAP significantly changed the compositions of microbial communities in all three paddy soils on day 14 but the compositions of soil microbial communities recovered by day 50. This study indicates that CAP does not ultimately impair microbial activities and microbial compositions of these three paddy soil types. Copyright © 2017 Elsevier Inc. All rights reserved.

Allelic differences in a vacuolar invertase affect Arabidopsis growth at early plant development.

PubMed

Leskow, Carla Coluccio; Kamenetzky, Laura; Dominguez, Pia Guadalupe; Díaz Zirpolo, José Antonio; Obata, Toshihiro; Costa, Hernán; Martí, Marcelo; Taboga, Oscar; Keurentjes, Joost; Sulpice, Ronan; Ishihara, Hirofumi; Stitt, Mark; Fernie, Alisdair Robert; Carrari, Fernando

2016-07-01

Improving carbon fixation in order to enhance crop yield is a major goal in plant sciences. By quantitative trait locus (QTL) mapping, it has been demonstrated that a vacuolar invertase (vac-Inv) plays a key role in determining the radical length in Arabidopsis. In this model, variation in vac-Inv activity was detected in a near isogenic line (NIL) population derived from a cross between two divergent accessions: Landsberg erecta (Ler) and Cape Verde Island (CVI), with the CVI allele conferring both higher Inv activity and longer radicles. The aim of the current work is to understand the mechanism(s) underlying this QTL by analyzing structural and functional differences of vac-Inv from both accessions. Relative transcript abundance analyzed by quantitative real-time PCR (qRT-PCR) showed similar expression patterns in both accessions; however, DNA sequence analyses revealed several polymorphisms that lead to changes in the corresponding protein sequence. Moreover, activity assays revealed higher vac-Inv activity in genotypes carrying the CVI allele than in those carrying the Ler allele. Analyses of purified recombinant proteins showed a similar K m for both alleles and a slightly higher V max for that of Ler. Treatment of plant extracts with foaming to release possible interacting Inv inhibitory protein(s) led to a large increase in activity for the Ler allele, but no changes for genotypes carrying the CVI allele. qRT-PCR analyses of two vac-Inv inhibitors in seedlings from parental and NIL genotypes revealed different expression patterns. Taken together, these results demonstrate that the vac-Inv QTL affects root biomass accumulation and also carbon partitioning through a differential regulation of vac-Inv inhibitors at the mRNA level. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Primary, Secondary Metabolites, Photosynthetic Capacity and Antioxidant Activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) Exposed to Potassium Fertilization under Greenhouse Conditions

PubMed Central

Ibrahim, Mohd Hafiz; Jaafar, Hawa Z. E.; Karimi, Ehsan; Ghasemzadeh, Ali

2012-01-01

A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (gs), intercellular CO2 (Ci), apparent quantum yield (ξ) and lower dark respiration rates (Rd), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant. PMID:23203128

Sucrose-Metabolizing Enzymes in Transport Tissues and Adjacent Sink Structures in Developing Citrus Fruit 1

PubMed Central

Lowell, Cadance A.; Tomlinson, Patricia T.; Koch, Karen E.

1989-01-01

Juice tissues of citrus lack phloem; therefore, photosynthates enroute to juice sacs exit the vascular system on the surface of each segment. Areas of extensive phloem unloading and transport (vascular bundles + segment epidermis) can thus be separated from those of assimilate storage (juice sacs) and adjacent tissues where both processes occur (peel). Sugar composition, dry weight accumulation, and activities of four sucrose-metabolizing enzymes (soluble and cell-wall-bound acid invertase, alkaline invertase, sucrose synthase, and sucrose phosphate synthase) were measured in these transport and sink tissues of grapefruit (Citrus paradisi Macf.) to determine more clearly whether a given enzyme appeared to be more directly associated with assimilate transport versus deposition or utilization. Results were compared at three developmental stages. Activity of sucrose (per gram fresh weight and per milligram protein) extracted from zones of extensive phloem unloading and transport was significantly greater than from adjacent sink tissues during the stages (II and III) when juice sacs grow most rapidly. In stage II fruit, activity of sucrose synthase also significantly surpassed that of all other sucrose-metabolizing enzymes in extracts from the transport tissues (vascular bundles + segment epidermis). In contrast, sucrose phosphate synthase and alkaline invertase at this stage of growth were the most active enzymes from adjacent, rapidly growing, phloem-free sink tissues (juice sacs). Activity of these two enzymes in extracts from juice sacs was significantly greater than that form the transport tissues (vascular bundles + segment epidermis). Soluble acid invertase was the most active enzyme in extracts from all tissues of very young fruit (stage I), including nonvascular regions, but nearly disappeared prior to the onset of juice sac sugar accumulation. The physiological function of high sucrose synthase activity in the transport tissues during rapid sucrose import

[Effects of long-term fertilization on enzyme activities in black soil of Northeast China].

PubMed

Wang, Shu-Qi; Han, Xiao-Zeng; Qiao, Yun-Fa; Wang, Shou-Yu

2008-03-01

In this paper, black soil samples at the depths of 0-20 cm and 20-40 cm were collected from the Hailun Agricultural Ecology Station of Chinese Academy of Sciences to study the effects of long-term fertilization on their urease, invertase, phosphatase and catalase activities and total C and N contents. The results showed that long-term application of chemical fertilizers and organic manure increased the activities of urease, invertase and phosphatase in 0-20 cm and 20-40 cm soil layers in different degree, and the combined application of them increased the activities of the three enzymes significantly, with an increment of 43.6%-113.2%, 25.9%-79.5% and 14.7%-134.4% in 0-20 cm soil layer and 56.1%-127.2%, 14.5%-113.8% and 16.2%-207.2% in 20-40 cm soil layer, respectively. However, long-term application of chemical fertilizers without organic manure had little effects on catalase activity. The activities of urease, invertase and phosphatase decreased with increasing soil depth. Long-term application of N fertilizer increased urease activity, and P fertilization had obvious positive effect on phosphatase activity. Long-term fertilization also had obvious effects on the soil total C and N contents and C/N ratio.

[Effects of intensive management on soil C and N pools and soil enzyme activities in Moso bamboo plantations.

PubMed

Yang, Meng; Li, Yong Fu; Li, Yong Chun; Xiao, Yong Heng; Yue, Tian; Jiang, Pei Kun; Zhou, Guo Mo; Liu, Juan

2016-11-18

In order to elucidate the effects of intensive management on soil carbon pool, nitrogen pool, enzyme activities in Moso bamboo (Phyllostachys pubescens) plantations, we collected soil samples from the soil surface (0-20 cm) and subsurface (20-40 cm) layers in the adjacent Moso bamboo plantations with extensive and intensive managements in Sankou Township, Lin'an City, Zhejiang Province. We determined different forms of C, N and soil invertase, urease, catalase and acid phosphatase activities. The results showed that long-term intensive management of Moso bamboo plantations significantly decreased the content and storage of soil organic carbon (SOC), with the SOC storage in the soil surface and subsurface layers decreased by 13.2% and 18.0%, respectively. After 15 years' intensive management of Masoo bamboo plantations, the contents of soil water soluble carbon (WSOC), hot water soluble carbon (HWSOC), microbial carbon (MBC) and readily oxidizable carbon (ROC) were significantly decreased in the soil surface and subsurface layers. The soil N storage in the soil surface and subsurface layers in intensively managed Moso bamboo plantations increased by 50.8% and 36.6%, respectively. Intensive management significantly increased the contents of nitrate-N (NO 3 - -N) and ammonium-N (NH 4 + -N), but decreased the contents of water-soluble nitrogen (WSON) and microbial biomass nitrogen (MBN). After 15 years' intensive management of Masoo bamboo plantations, the soil invertase, urease, catalase and acid phosphatase activities in the soil surface layer were significantly decreased, the soil acid phosphatase activity in the soil subsurface layer were significantly decreased, and other enzyme activities in the soil subsurface layer did not change. In conclusion, long-term intensive management led to a significant decline of soil organic carbon storage, soil labile carbon and microbial activity in Moso bamboo plantations. Therefore, we should consider the use of organic

Silencing leaf sorbitol synthesis alters long-distance partitioning and apple fruit quality

PubMed Central

Teo, Gianni; Suzuki, Yasuo; Uratsu, Sandie L.; Lampinen, Bruce; Ormonde, Nichole; Hu, William K.; DeJong, Ted M.; Dandekar, Abhaya M.

2006-01-01

Sorbitol and sucrose are major products of photosynthesis distributed in apple trees (Malus domestica Borkh. cv. “Greensleeves”) that affect quality in fruit. Transgenic apple plants were silenced or up-regulated for sorbitol-6-phosphate dehydrogenase by using the CaMV35S promoter to define the role of sorbitol distribution in fruit development. Transgenic plants with suppressed sorbitol-6-phosphate dehydrogenase compensated by accumulating sucrose and starch in leaves, and morning and midday net carbon assimilation rates were significantly lower. The sorbitol to sucrose ratio in leaves was reduced by ≈90% and in phloem exudates by ≈75%. The fruit accumulated more glucose and less fructose, starch, and malic acid, with no overall differences in weight and firmness. Sorbitol dehydrogenase activity was reduced in silenced fruit, but activities of neutral invertase, vacuolar invertase, cell wall-bound invertase, fructose kinase, and hexokinase were unaffected. Analyses of transcript levels and activity of enzymes involved in carbohydrate metabolism throughout fruit development revealed significant differences in pathways related to sorbitol transport and breakdown. Together, these results suggest that sorbitol distribution plays a key role in fruit carbon metabolism and affects quality attributes such as sugar–acid balance and starch accumulation. PMID:17132742

Cell Wall Invertase Promotes Fruit Set under Heat Stress by Suppressing ROS-Independent Cell Death.

PubMed

Liu, Yong-Hua; Offler, Christina E; Ruan, Yong-Ling

2016-09-01

Reduced cell wall invertase (CWIN) activity has been shown to be associated with poor seed and fruit set under abiotic stress. Here, we examined whether genetically increasing native CWIN activity would sustain fruit set under long-term moderate heat stress (LMHS), an important factor limiting crop production, by using transgenic tomato (Solanum lycopersicum) with its CWIN inhibitor gene silenced and focusing on ovaries and fruits at 2 d before and after pollination, respectively. We found that the increase of CWIN activity suppressed LMHS-induced programmed cell death in fruits. Surprisingly, measurement of the contents of H2O2 and malondialdehyde and the activities of a cohort of antioxidant enzymes revealed that the CWIN-mediated inhibition on programmed cell death is exerted in a reactive oxygen species-independent manner. Elevation of CWIN activity sustained Suc import into fruits and increased activities of hexokinase and fructokinase in the ovaries in response to LMHS Compared to the wild type, the CWIN-elevated transgenic plants exhibited higher transcript levels of heat shock protein genes Hsp90 and Hsp100 in ovaries and HspII17.6 in fruits under LMHS, which corresponded to a lower transcript level of a negative auxin responsive factor IAA9 but a higher expression of the auxin biosynthesis gene ToFZY6 in fruits at 2 d after pollination. Collectively, the data indicate that CWIN enhances fruit set under LMHS through suppression of programmed cell death in a reactive oxygen species-independent manner that could involve enhanced Suc import and catabolism, HSP expression, and auxin response and biosynthesis. © 2016 American Society of Plant Biologists. All rights reserved.

Short-term high temperature growth conditions during vegetative-to-reproductive phase transition irreversibly compromise cell wall invertase-mediated sucrose catalysis and microspore meiosis in grain sorghum

USDA-ARS?s Scientific Manuscript database

Grain sorghum (Sorghum bicolor L. Moench) crop yield is significantly compromised by high temperature stress-induced male sterility, and is attributed to reduced cell wall invertase (CWI)-mediated sucrose hydrolysis in microspores and anthers leading to altered carbohydrate metabolism and starch def...

Elevated temperature altered photosynthetic products in wheat seedlings and organic compounds and biological activity in rhizopshere soil under cadmium stress.

PubMed

Jia, Xia; Zhao, YongHua; Wang, WenKe; He, Yunhua

2015-09-23

The objective of this study was to investigate the effects of slightly elevated atmospheric temperature in the spring on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated temperature was associated with increased soluble sugars, reducing sugars, starch, and total sugars, and with decreased amino acids in wheat seedlings under Cd stress. Elevated temperature improved total soluble sugars, free amino acids, soluble phenolic acids, and organic acids in rhizosphere soil under Cd stress. The activity of amylase, phenol oxidase, invertase, β-glucosidase, and l-asparaginase in rhizosphere soil was significantly improved by elevated temperature under Cd stress; while cellulase, neutral phosphatase, and urease activity significantly decreased. Elevated temperature significantly improved bacteria, fungi, actinomycetes, and total microorganisms abundance and fluorescein diacetate activity under Cd stress. In conclusion, slightly elevated atmospheric temperature in the spring improved the carbohydrate levels in wheat seedlings and organic compounds and biological activity in rhizosphere soil under Cd stress in the short term. In addition, elevated atmospheric temperature in the spring stimulated available Cd by affecting pH, DOC, phenolic acids, and organic acids in rhizosphere soil, which resulted in the improvement of the Cd uptake by wheat seedlings.

Elevated temperature altered photosynthetic products in wheat seedlings and organic compounds and biological activity in rhizopshere soil under cadmium stress

PubMed Central

Jia, Xia; Zhao, YongHua; Wang, WenKe; He, Yunhua

2015-01-01

The objective of this study was to investigate the effects of slightly elevated atmospheric temperature in the spring on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated temperature was associated with increased soluble sugars, reducing sugars, starch, and total sugars, and with decreased amino acids in wheat seedlings under Cd stress. Elevated temperature improved total soluble sugars, free amino acids, soluble phenolic acids, and organic acids in rhizosphere soil under Cd stress. The activity of amylase, phenol oxidase, invertase, β-glucosidase, and l-asparaginase in rhizosphere soil was significantly improved by elevated temperature under Cd stress; while cellulase, neutral phosphatase, and urease activity significantly decreased. Elevated temperature significantly improved bacteria, fungi, actinomycetes, and total microorganisms abundance and fluorescein diacetate activity under Cd stress. In conclusion, slightly elevated atmospheric temperature in the spring improved the carbohydrate levels in wheat seedlings and organic compounds and biological activity in rhizosphere soil under Cd stress in the short term. In addition, elevated atmospheric temperature in the spring stimulated available Cd by affecting pH, DOC, phenolic acids, and organic acids in rhizosphere soil, which resulted in the improvement of the Cd uptake by wheat seedlings. PMID:26395070

Elevated temperature altered photosynthetic products in wheat seedlings and organic compounds and biological activity in rhizopshere soil under cadmium stress

NASA Astrophysics Data System (ADS)

Jia, Xia; Zhao, Yonghua; Wang, Wenke; He, Yunhua

2015-09-01

The objective of this study was to investigate the effects of slightly elevated atmospheric temperature in the spring on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated temperature was associated with increased soluble sugars, reducing sugars, starch, and total sugars, and with decreased amino acids in wheat seedlings under Cd stress. Elevated temperature improved total soluble sugars, free amino acids, soluble phenolic acids, and organic acids in rhizosphere soil under Cd stress. The activity of amylase, phenol oxidase, invertase, β-glucosidase, and L-asparaginase in rhizosphere soil was significantly improved by elevated temperature under Cd stress; while cellulase, neutral phosphatase, and urease activity significantly decreased. Elevated temperature significantly improved bacteria, fungi, actinomycetes, and total microorganisms abundance and fluorescein diacetate activity under Cd stress. In conclusion, slightly elevated atmospheric temperature in the spring improved the carbohydrate levels in wheat seedlings and organic compounds and biological activity in rhizosphere soil under Cd stress in the short term. In addition, elevated atmospheric temperature in the spring stimulated available Cd by affecting pH, DOC, phenolic acids, and organic acids in rhizosphere soil, which resulted in the improvement of the Cd uptake by wheat seedlings.

[Effects of bio-organic fertilizer on soil enzyme activities and microbial community in kiwifruit orchard.

PubMed

Sun, Jia Un; Fu, Qing Xia; Gu, Jie; Wang, Xiao Juan; Gao, Hua

2016-03-01

A field experiment was conducted to compare the effects of three fertilizer managements (bio-organic fertilizer, traditional organic fertilizer and chemical fertilizer) and a no-fertilizer control on soil enzyme activities and microbial community functional diversity in a kiwifruit orchard. The results showed that the soil invertase and FDA hydrolase activities in the bio-organic fertilizer treatment were 12.2%-129.4% and 18.8%-87.4% higher than those in the no-fertilizer control during kiwifruit growth period, respectively. The application of bio-organic fertilizer also increased soil urease and acid phosphatase activities at the expanding stage and maturity stage. The Biolog results suggested that bio-organic fertilizer treatment improved the average well color development (AWCD) and increased the species diversity, richness and evenness. The relative ratios of six groups of carbon sources by microbes were changed to some extent after the application of bio-organic fertilizer. Compared with the no-fertilizer control, bio-organic fertilizer application decreased the capacity of microbes in using amino acids, but enhanced the utilization of polyphenols and polyamines. The principal components analysis demonstrated that the differentiation of microbial community was mainly in utilization of carbohydrates, amino acids and carboxylic acids.

Modulation of organic acids and sugar content in tomato fruits by an abscisic acid-regulated transcription factor.

PubMed

Bastías, Adriana; López-Climent, María; Valcárcel, Mercedes; Rosello, Salvador; Gómez-Cadenas, Aurelio; Casaretto, José A

2011-03-01

Growing evidence suggests that the phytohormone abscisic acid (ABA) plays a role in fruit development. ABA signaling components of developmental programs and responses to stress conditions include the group of basic leucine zipper transcriptional activators known as ABA-response element binding factors (AREBs/ABFs). AREB transcription factors mediate ABA-regulated gene expression involved in desiccation tolerance and are expressed mainly in seeds and in vegetative tissues under stress; however, they are also expressed in some fruits such as tomato. In order to get an insight into the role of ABA signaling in fruit development, the expression of two AREB-like factors were investigated during different developmental stages. In addition, tomato transgenic lines that overexpress and downregulate one AREB-like transcription factor, SlAREB1, were used to determine its effect on the levels of some metabolites determining fruit quality. Higher levels of citric acid, malic acid, glutamic acid, glucose and fructose were observed in SlAREB1-overexpressing lines compared with those in antisense suppression lines in red mature fruit pericarp. The higher hexose concentration correlated with increased expression of genes encoding a vacuolar invertase (EC 3.2.1.26) and a sucrose synthase (EC 2.4.1.13). No significant changes were found in ethylene content which agrees with the normal ripening phenotype observed in transgenic fruits. These results suggest that an AREB-mediated ABA signal affects the metabolism of these compounds during the fruit developmental program. Copyright © Physiologia Plantarum 2010.

Cell Wall Invertase Promotes Fruit Set under Heat Stress by Suppressing ROS-Independent Cell Death1[OPEN

PubMed Central

2016-01-01

Reduced cell wall invertase (CWIN) activity has been shown to be associated with poor seed and fruit set under abiotic stress. Here, we examined whether genetically increasing native CWIN activity would sustain fruit set under long-term moderate heat stress (LMHS), an important factor limiting crop production, by using transgenic tomato (Solanum lycopersicum) with its CWIN inhibitor gene silenced and focusing on ovaries and fruits at 2 d before and after pollination, respectively. We found that the increase of CWIN activity suppressed LMHS-induced programmed cell death in fruits. Surprisingly, measurement of the contents of H2O2 and malondialdehyde and the activities of a cohort of antioxidant enzymes revealed that the CWIN-mediated inhibition on programmed cell death is exerted in a reactive oxygen species-independent manner. Elevation of CWIN activity sustained Suc import into fruits and increased activities of hexokinase and fructokinase in the ovaries in response to LMHS. Compared to the wild type, the CWIN-elevated transgenic plants exhibited higher transcript levels of heat shock protein genes Hsp90 and Hsp100 in ovaries and HspII17.6 in fruits under LMHS, which corresponded to a lower transcript level of a negative auxin responsive factor IAA9 but a higher expression of the auxin biosynthesis gene ToFZY6 in fruits at 2 d after pollination. Collectively, the data indicate that CWIN enhances fruit set under LMHS through suppression of programmed cell death in a reactive oxygen species-independent manner that could involve enhanced Suc import and catabolism, HSP expression, and auxin response and biosynthesis. PMID:27462084

Tomato ovary-to-fruit transition is characterized by a spatial shift of mRNAs for cell wall invertase and its inhibitor with the encoded proteins localized to sieve elements.

PubMed

Palmer, William M; Ru, Lei; Jin, Ye; Patrick, John W; Ruan, Yong-Ling

2015-02-01

Central to understanding fruit development is to elucidate the processes mediating a successful transition from pre-pollination ovaries to newly set fruit, a key step in establishing fruit yield potential. In tomato, cell wall invertase (CWIN) LIN5 and its inhibitor INH1 are essential for fruit growth. However, the molecular and cellular basis by which they exert their roles in ovary-to-fruit transition remains unknown. To address this issue, we conducted a study focusing on ovaries and fruitlets at 2 days before and 2 days after anthesis, respectively. In situ hybridization analyses revealed that LIN5 and INH1 exhibited a dispersed expression in ovaries compared with their phloem-specific expression in fruitlets. Remarkably, LIN5 and INH1 proteins were immunologically co-localized to cell walls of sieve elements (SEs) in ovaries immediately prior to anthesis and in young fruitlets, but were undetectable in provascular bundles of younger ovaries. A burst in CWIN activity occurred during ovary-to-fruit transition. Interestingly, the ovaries, but not the fruitlets, exhibited high expression of a defective invertase, SldeCWIN1, an ortholog of which is known to enhance inhibition of INH on CWIN activity in tobacco. Imaging of a fluorescent symplasmic tracer indicated an apoplasmic phloem unloading pathway operated in ovaries, contrary to the previously observed symplasmic unloading pathway in fruit pericarp. These new data indicate that (1) a phloem-specific patterning of the CWIN and INH mRNAs is induced during ovary-to-fruit transition, and (2) LIN5 protein functions specifically in walls of SEs and increases its activity during ovary-to-fruit transition, probably to facilitate phloem unloading and to generate a glucose signal positively regulating cell division, hence fruit set. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Enzyme activity as an indicator of soil-rehabilitation processes at a zinc and lead ore mining and processing area.

PubMed

Ciarkowska, Krystyna; Sołek-Podwika, Katarzyna; Wieczorek, Jerzy

2014-01-01

The activities of soil enzymes in relation to the changes occurring in the soil on a degraded area in southern Poland after zinc and lead mining were analyzed. An evaluation of the usefulness of urease and invertase activities for estimating the progress of the rehabilitation processes in degraded soil was performed. The data show that the soil samples differed significantly in organic carbon (0.68-104.0 g kg(-1)) and total nitrogen (0.03-8.64 g kg(-1)) content in their surface horizons. All of the soil samples (apart from one covered with forest) had very high total concentrations of zinc (4050-10,884 mg kg(-1)), lead (959-6661 mg kg(-1)) and cadmium (24.4-174.3 mg kg(-1)) in their surface horizons, and similar concentrations in their deeper horizons. Nevertheless, the amounts of the soluble forms of the above-mentioned heavy metals were quite low and they accounted for only a small percentage of the total concentrations: 1.4% for Zn, 0.01% for Pb and 2.6% for Cd. Urease activities were ranked as follows: soil from flotation settler (0.88-1.78 μg N-NH4(+) 2h(-1) g(-1))activity (2.14-5.73 μg N-NH4(+) 2h(-1) g(-1)). Invertase activities were similar in soil that was undisturbed by mining and in soil from old slag heaps, ranging from 20.5 to 77.1mg of the inverted sugar, but they were much lower in soil from the flotation settler (0.12-6.95 mg of the inverted sugar). The results demonstrated that heavy pollution with Zn, Pb and Cd slightly decreased the activities of urease and invertase. It is thought that it resulted from the enzyme reactions occurring in slightly acidic or alkaline soil conditions. Under such conditions, heavy metals occur mainly in insoluble forms. The activities of these enzymes are strongly dependent on the content and decomposition of organic matter in the soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sugar - hormone crosstalk in seed development: Two redundant pathways of IAA biosynthesis are regulated differentially in the invertase-deficient miniature1 (mn1) seed mutant in maize

USDA-ARS?s Scientific Manuscript database

The miniature1 (mn1) seed phenotype is a loss-of-function mutation at the Mn1 locus that encodes a cell wall invertase; its deficiency leads to pleiotropic changes including altered sugar levels and decreased levels of IAA throughout seed development. To understand the molecular details of such suga...

Altered sucrose synthase and invertase expression affects the local and systemic sugar metabolism of nematode-infected Arabidopsis thaliana plants

PubMed Central

Hofmann, Julia

2014-01-01

Sedentary endoparasitic nematodes of plants induce highly specific feeding cells in the root central cylinder. From these, the obligate parasites withdraw all required nutrients. The feeding cells were described as sink tissues in the plant’s circulation system that are supplied with phloem-derived solutes such as sugars. Currently, there are several publications describing mechanisms of sugar import into the feeding cells. However, sugar processing has not been studied so far. Thus, in the present work, the roles of the sucrose-cleaving enzymes sucrose synthases (SUS) and invertases (INV) in the development of Heterodera schachtii were studied. Gene expression analyses indicate that both enzymes are regulated transcriptionally. Nematode development was enhanced on multiple INV and SUS mutants. Syncytia of these mutants were characterized by altered enzyme activity and changing sugar pool sizes. Further, the analyses revealed systemically affected sugar levels and enzyme activities in the shoots of the tested mutants, suggesting changes in the source–sink relationship. Finally, the development of the root-knot nematode Meloidogyne javanica was studied in different INV and SUS mutants and wild-type Arabidopsis plants. Similar effects on the development of both sedentary endoparasitic nematode species (root-knot and cyst nematode) were observed, suggesting a more general role of sucrose-degrading enzymes during plant–nematode interactions. PMID:24187419

Altered sucrose synthase and invertase expression affects the local and systemic sugar metabolism of nematode-infected Arabidopsis thaliana plants.

PubMed

Cabello, Susana; Lorenz, Cindy; Crespo, Sara; Cabrera, Javier; Ludwig, Roland; Escobar, Carolina; Hofmann, Julia

2014-01-01

Sedentary endoparasitic nematodes of plants induce highly specific feeding cells in the root central cylinder. From these, the obligate parasites withdraw all required nutrients. The feeding cells were described as sink tissues in the plant's circulation system that are supplied with phloem-derived solutes such as sugars. Currently, there are several publications describing mechanisms of sugar import into the feeding cells. However, sugar processing has not been studied so far. Thus, in the present work, the roles of the sucrose-cleaving enzymes sucrose synthases (SUS) and invertases (INV) in the development of Heterodera schachtii were studied. Gene expression analyses indicate that both enzymes are regulated transcriptionally. Nematode development was enhanced on multiple INV and SUS mutants. Syncytia of these mutants were characterized by altered enzyme activity and changing sugar pool sizes. Further, the analyses revealed systemically affected sugar levels and enzyme activities in the shoots of the tested mutants, suggesting changes in the source-sink relationship. Finally, the development of the root-knot nematode Meloidogyne javanica was studied in different INV and SUS mutants and wild-type Arabidopsis plants. Similar effects on the development of both sedentary endoparasitic nematode species (root-knot and cyst nematode) were observed, suggesting a more general role of sucrose-degrading enzymes during plant-nematode interactions.

Synthesis and biological activity of amino acid conjugates of abscisic acid.

PubMed

Todoroki, Yasushi; Narita, Kenta; Muramatsu, Taku; Shimomura, Hajime; Ohnishi, Toshiyuki; Mizutani, Masaharu; Ueno, Kotomi; Hirai, Nobuhiro

2011-03-01

We prepared 19 amino acid conjugates of the plant hormone abscisic acid (ABA) and investigated their biological activity, enzymatic hydrolysis by a recombinant Arabidopsis amidohydrolases GST-ILR1 and GST-IAR3, and metabolic fate in rice seedlings. Different sets of ABA-amino acids induced ABA-like responses in different plants. Some ABA-amino acids, including some that were active in bioassays, were hydrolyzed by recombinant Arabidopsis GST-IAR3, although GST-ILR1 did not show hydrolysis activity for any of the ABA-amino acids. ABA-L-Ala, which was active in all the bioassays, an Arabidopsis seed germination, spinach seed germination, and rice seedling elongation assays, except in a lettuce seed germination assay and was hydrolyzed by GST-IAR3, was hydrolyzed to free ABA in rice seedlings. These findings suggest that some plant amidohydrolases hydrolyze some ABA-amino acid conjugates. Because our study indicates the possibility that different plants have hydrolyzing activity toward different ABA-amino acids, an ABA-amino acid may function as a species-selective pro-hormone of ABA. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of different deficit irrigation on sugar accumulation of pineapple during development

NASA Astrophysics Data System (ADS)

Feng, Haiyan; Du, Liqing; Liu, Shenghui; Zhang, Xiumei

2017-08-01

The potted pineapple cultivar ‘Comte de paris’ was used to study the influence of deficit irrigation on fruit sugar accumulation in greenhouse during the fruit enlargement period. The study included a control (normal irrigation) and two treatment groups, moderate deficit (50% of the control irrigation) and severe deficit (25% of the control irrigation). The results indicated that the deficit irrigation significantly decreased the sucrose accumulation. The sucrose content in the fruits of moderate deficit irrigation was the lowest. During the mature period, the deficit irrigation decreased the sucrose phosophate synthase activity(SPS) an increased the sucrose synthase (SS) and neutral invertase (NI). The moderate deficit irrigation significantly improved the acid invertase activity(AI). However, it was inhibited by the severe deficit irrigation. In general, the moderate treatment reduced the SPS activity and enhanced the NI and AI activities, while the severe treatment decreased the SPS and AI activities.

Fatty acids activate a chimera of the clofibric acid-activated receptor and the glucocorticoid receptor.

PubMed Central

Göttlicher, M; Widmark, E; Li, Q; Gustafsson, J A

1992-01-01

Peroxisome proliferators such as clofibric acid, nafenopin, and WY-14,643 have been shown to activate PPAR (peroxisome proliferator-activated receptor), a member of the steroid nuclear receptor superfamily. We have cloned the cDNA from the rat that is homologous to that from the mouse [Issemann, I. & Green, S. (1990) Nature (London) 347, 645-650], which encodes a 97% similar protein with a particularly well-conserved putative ligand-binding domain. To search for physiologically occurring activators, we established a transcriptional transactivation assay by stably expressing in CHO cells a chimera of rat PPAR and the human glucocorticoid receptor that activates expression of the placental alkaline phosphatase reporter gene under the control of the mouse mammary tumor virus promoter. Testing of compounds related to lipid metabolism or peroxisomal proliferation revealed that 150 microM concentrations of arachidonic or linoleic acid but not of dehydroepiandrosterone, cholesterol, or 25-hydroxy-cholesterol, activate the receptor chimera. In addition, saturated fatty acids induce the reporter gene. Shortening the chain length to n = 6 or introduction of an omega-terminal carboxylic group abolished the activation potential of the fatty acid. In conclusion, the present results indicate that fatty acids can regulate gene expression mediated by a member of the steroid nuclear receptor superfamily. Images PMID:1316614

Three acidic residues are at the active site of a beta-propeller architecture in glycoside hydrolase families 32, 43, 62, and 68.

PubMed

Pons, Tirso; Naumoff, Daniil G; Martínez-Fleites, Carlos; Hernández, Lázaro

2004-02-15

Multiple-sequence alignment of glycoside hydrolase (GH) families 32, 43, 62, and 68 revealed three conserved blocks, each containing an acidic residue at an equivalent position in all the enzymes. A detailed analysis of the site-directed mutations so far performed on invertases (GH32), arabinanases (GH43), and bacterial fructosyltransferases (GH68) indicated a direct implication of the conserved residues Asp/Glu (block I), Asp (block II), and Glu (block III) in substrate binding and hydrolysis. These residues are close in space in the 5-bladed beta-propeller fold determined for Cellvibrio japonicus alpha-L-arabinanase Arb43A [Nurizzo et al., Nat Struct Biol 2002;9:665-668] and Bacillus subtilis endo-1,5-alpha-L-arabinanase. A sequence-structure compatibility search using 3D-PSSM, mGenTHREADER, INBGU, and SAM-T02 programs predicted indistinctly the 5-bladed beta-propeller fold of Arb43A and the 6-bladed beta-propeller fold of sialidase/neuraminidase (GH33, GH34, and GH83) as the most reliable topologies for GH families 32, 62, and 68. We conclude that the identified acidic residues are located at the active site of a beta-propeller architecture in GH32, GH43, GH62, and GH68, operating with a canonical reaction mechanism of either inversion (GH43 and likely GH62) or retention (GH32 and GH68) of the anomeric configuration. Also, we propose that the beta-propeller architecture accommodates distinct binding sites for the acceptor saccharide in glycosyl transfer reaction. Copyright 2003 Wiley-Liss, Inc.

Acid Rain: Activities for Science Teachers.

ERIC Educational Resources Information Center

Johnson, Eric; And Others

1983-01-01

Seven complete secondary/college level acid rain activities are provided. Activities include overview; background information and societal implications; major concepts; student objectives; vocabulary/material lists; procedures; instructional strategies; and questions/discussion and extension suggestions. Activities consider effects of acid rain on…

Antioxidant and antimicrobial activities of cinnamic acid derivatives.

PubMed

Sova, M

2012-07-01

Cinnamic acid is an organic acid occurring naturally in plants that has low toxicity and a broad spectrum of biological activities. In the search for novel pharmacologically active compounds, cinnamic acid derivatives are important and promising compounds with high potential for development into drugs. Many cinnamic acid derivatives, especially those with the phenolic hydroxyl group, are well-known antioxidants and are supposed to have several health benefits due to their strong free radical scavenging properties. It is also well known that cinnamic acid has antimicrobial activity. Cinnamic acid derivatives, both isolated from plant material and synthesized, have been reported to have antibacterial, antiviral and antifungal properties. Acids, esters, amides, hydrazides and related derivatives of cinnamic acid with such activities are here reviewed.

Interplay of sugar, light and gibberellins in expression of Rosa hybrida vacuolar invertase 1 regulation.

PubMed

Rabot, Amélie; Portemer, Virginie; Péron, Thomas; Mortreau, Eric; Leduc, Nathalie; Hamama, Latifa; Coutos-Thévenot, Pierre; Atanassova, Rossitza; Sakr, Soulaiman; Le Gourrierec, José

2014-10-01

Our previous findings showed that the expression of the Rosa hybrida vacuolar invertase 1 gene (RhVI1) was tightly correlated with the ability of buds to grow out and was under sugar, gibberellin and light control. Here, we aimed to provide an insight into the mechanistic basis of this regulation. In situ hybridization showed that RhVI1 expression was localized in epidermal cells of young leaves of bursting buds. We then isolated a 895 bp fragment of the promoter of RhVI1. In silico analysis identified putative cis-elements involved in the response to sugars, light and gibberellins on its proximal part (595 bp). To carry out functional analysis of the RhVI1 promoter in a homologous system, we developed a direct method for stable transformation of rose cells. 5' deletions of the proximal promoter fused to the uidA reporter gene were inserted into the rose cell genome to study the cell's response to exogenous and endogenous stimuli. Deletion analysis revealed that the 468 bp promoter fragment is sufficient to trigger reporter gene activity in response to light, sugars and gibberellins. This region confers sucrose- and fructose-, but not glucose-, responsive activation in the dark. Inversely, the -595 to -468 bp region that carries the sugar-repressive element (SRE) is required to down-regulate the RhVI1 promoter in response to sucrose and fructose in the dark. We also demonstrate that sugar/light and gibberellin/light act synergistically to up-regulate β-glucuronidase (GUS) activity sharply under the control of the 595 bp pRhVI1 region. These results reveal that the 127 bp promoter fragment located between -595 and -468 bp is critical for light and sugar and light and gibberellins to act synergistically. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Effects of clofibric acid on the activity and activity state of the hepatic branched-chain 2-oxo acid dehydrogenase complex.

PubMed Central

Zhao, Y; Jaskiewicz, J; Harris, R A

1992-01-01

Feeding clofibric acid to rats caused little or no change in total activity of the liver branched-chain 2-oxo acid dehydrogenase complex (BCODC). No change in mass of liver BCODC was detected by immunoblot analysis in response to dietary clofibric acid. No changes in abundance of mRNAs for the BCODC E1 alpha, E1 beta and E2 subunits were detected by Northern-blot analysis. Likewise, dietary clofibric acid had no effect on the activity state of liver BCODC (percentage of enzyme in the dephosphorylated, active, form) of rats fed on a chow diet. However, dietary clofibric acid greatly increased the activity state of liver BCODC of rats fed on a diet deficient in protein. No stable change in liver BCODC kinase activity was found in response to clofibric acid in either chow-fed or low-protein-fed rats. Clofibric acid had a biphasic effect on flux through BCODC in hepatocytes prepared from low-protein-fed rats. Stimulation of BCODC flux at low concentrations was due to clofibric acid inhibition of BCODC kinase, which in turn allowed activation of BCODC by BCODC phosphatase. Inhibition of BCODC flux at high concentrations was due to direct inhibition of BCODC by clofibric acid. The results suggest that the effects of clofibric acid in vivo on branched-chain amino acid metabolism can be explained by the inhibitory effects of this drug on BCODC kinase. Images Fig. 2. Fig. 3. PMID:1637295

Pollution in the urban soils of Lianyungang, China, evaluated using a pollution index, mobility of heavy metals, and enzymatic activities.

PubMed

Li, Yu; Li, Hong-Guan; Liu, Fu-Cheng

2017-01-01

Soil samples from 16 urban sites in Lianyungang, China were collected and analyzed. A pollution index was used to assess the potential ecological risk of heavy metals and a sequential extraction procedure was used to evaluate the relative distribution of Cu, Zn, Pb, Cd, Cr, and As in exchangeable, carbonate, Fe/Mn oxide, organic/sulfide, and residual fractions. The mobility of heavy metals and urease (URE) activity, alkaline phosphatase (ALP) activity, and invertase (INV) activity of soils was determined. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and As in Lianyungang soils were much higher than those in the coastal city soil background values of Jiangsu and China. Among the five studied regions (utilities, commercial, industrial, tourism, and roadside), the industrial region had the highest metal concentrations demonstrating that land use had a significant impact on the accumulation of heavy metals in Lianyungang soils. Compared to the other metals, Cd showed the highest ecological risk. According to chemical partitioning, Cu was associated with the organic/sulfides and Pb and Zn were mainly in the carbonate and the Fe/Mn oxide phase. The greatest amounts of Cd were found in exchangeable and carbonate fractions, while Cr and As were mainly in the residual fraction. Cd had the highest mobility of all metals, and the order of mobility (highest to lowest) of heavy metals in Lianyungang soils was Cd > Zn > Pb > Cu > As > Cr. Soil urease activity, alkaline phosphatase activity, and invertase activity varied considerably in different pollution degree sites. Soil enzyme activities had the lowest levels in roadside and industrial regions. Across all the soil data in the five regions, the total Cu, Zn, Pb, Cd, Cr, and As level was negatively correlated with urease activity, alkaline phosphatase activity, and invertase activity, but the relationship was not significant. In the industrial region, alkaline phosphatase activity had

"JCE" Classroom Activity #109: My Acid Can Beat Up Your Acid!

ERIC Educational Resources Information Center

Putti, Alice

2011-01-01

In this guided-inquiry activity, students investigate the ionization of strong and weak acids. Bead models are used to study acid ionization on a particulate level. Students analyze seven strong and weak acid models and make generalizations about the relationship between acid strength and dissociation. (Contains 1 table and 2 figures.)

Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon

PubMed Central

Gao, Lei; Zhao, Shengjie; Lu, Xuqiang; He, Nan; Zhu, Hongju; Dou, Junling

2018-01-01

Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus) fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar ‘203Z’ and its near-isogenic line (NIL) ‘SW’ (in the ‘203Z’ background) were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs) related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy), sucrose-phosphate synthase (SPSs), insoluble acid invertases (IAI), NAD-dependent malate dehydrogenase (NAD-cyt MDH), aluminum-activated malate transporter (ALMT), and citrate synthase (CS). This is the first report addressing comparative transcriptome analysis via NILs materials in watermelon fruit. These findings provide an important basis for understanding the molecular mechanism that leads to soluble sugar and organic acid accumulation and metabolism during watermelon fruit development and ripening. PMID:29324867

Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon.

PubMed

Gao, Lei; Zhao, Shengjie; Lu, Xuqiang; He, Nan; Zhu, Hongju; Dou, Junling; Liu, Wenge

2018-01-01

Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus) fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar '203Z' and its near-isogenic line (NIL) 'SW' (in the '203Z' background) were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs) related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy), sucrose-phosphate synthase (SPSs), insoluble acid invertases (IAI), NAD-dependent malate dehydrogenase (NAD-cyt MDH), aluminum-activated malate transporter (ALMT), and citrate synthase (CS). This is the first report addressing comparative transcriptome analysis via NILs materials in watermelon fruit. These findings provide an important basis for understanding the molecular mechanism that leads to soluble sugar and organic acid accumulation and metabolism during watermelon fruit development and ripening.

10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

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

Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp; Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University; Kim, Young-Il

2015-04-17

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increasedmore » adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.« less

Synthesis of novel lipoamino acid conjugates of sapienic acid and evaluation of their cytotoxicity activities.

PubMed

Gopal, Sanganamoni Chinna; Kaki, Shiva Shanker; Rao, Bhamidipati V S K; Poornachandra, Yedla; Kumar, Chityal Ganesh; Narayana Prasad, Rachapudi Badari

2014-01-01

Novel lipoamino acids were prepared with the coupling of sapienic acid [(Z)-6-hexadecenoic acid] with α - amino group of amino acids and the resulting N-sapienoyl amino acids were tested for their cytotoxicity activities against four cancer based cell lines. Initially, sapienic acid was synthesized by the Wittig coupling of triphenylphosphonium bromide salt of 6-bromohexanoic acid and decanal with a Z specific reagent. The prepared sapienic acid was subsequently converted to its acid chloride which was further coupled with amino acids by the Schotten-Baumann reaction to form N-sapienoyl amino acid conjugates. Structural characterization of the prepared N-sapienoyl amino acid derivatives was done by spectral data (IR, mass spectra and NMR). These lipoamino acid derivatives were screened for in vitro cytotoxicity evaluation. Cytotoxicity evaluation against four cancer cell lines showed that N-sapienoyl isoleucine was active against three cell lines whereas other derivatives either showed activity against only one or two cell lines with very moderate activity and two derivatives were observed to be inactive against the tested cell lines.

Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity

PubMed Central

Woo, Ji-Min; Kim, Ji-Won; Song, Ji-Won; Blank, Lars M.; Park, Jin-Byung

2016-01-01

The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass. PMID:27681369

Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity.

PubMed

Woo, Ji-Min; Kim, Ji-Won; Song, Ji-Won; Blank, Lars M; Park, Jin-Byung

The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass.

Soil enzyme activities in Pinus tabuliformis (Carriere) plantations in northern China

Treesearch

Weiwei Wang; Deborah Page-Dumroese; Ruiheng Lv; Chen Xiao; Guolei Li; Yong Liu

2016-01-01

Changes in forest stand structure may alter the activity of invertase, urease, catalase and phenol oxidase after thinning Pinus tabuliformis (Carriére) plantations in Yanqing County of Beijing, China. We examined changes in these soil enzymes as influenced by time since thinning (24, 32, and 40 years since thinning) for 3 seasons (spring, summer and autumn)...

Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611

PubMed Central

Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B.

2013-01-01

The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R 2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

[Characteristics of soil microbes and enzyme activities in different degraded alpine meadows].

PubMed

Yin, Ya Li; Wang, Yu Qin; Bao, Gen Sheng; Wang, Hong Sheng; Li, Shi Xiong; Song, Mei Ling; Shao, Bao Lian; Wen, Yu Cun

2017-12-01

Soil microbial biomass C and N, microbial diversities and enzyme activity in 0-10 cm and 10-20 cm soil layers of different degraded grasslands (non-degradation, ND; light degradation, LD; moderate degradation, MD; sever degradation, SD; and black soil beach, ED) were measured by Biolog and other methods. The results showed that: 1) There were significant diffe-rences between 0-10 cm and 10-20 cm soil layers in soil microbial biomass, diversities and inver-tase activities in all grasslands. 2) The ratio of soil microbial biomass C to N decreased significantly with the grassland degradation. In the 0-10 cm soil layer, microbial biomass C and N in ND and LD were significantly higher than that in MD, SD and ED. Among the latter three kinds of grasslands, there was no difference for microbial biomass C, but microbial biomass N was lower in MD than in the other grasslands. The average color change rate (AWCD) and McIntosh Index (U) also decreased with grassland degradation, but only the reduction from ND to MD was significant. There were no differences among all grasslands for Shannon index (H) and Simpson Index (D). The urease activity was highest in MD and SD, and the activity of phosphatase and invertase was lowest in ED. In the 10-20 cm soil layer, microbial biomass C in ND and LD were significantly higher than that in the other grasslands. Microbial biomass N in LD and ED were significantly higher than that in the other grasslands. Carbon metabolism index in MD was significantly lower than that in LD and SD. AWCD and U index in ND and LD were significantly higher than that in ED. H index and D index showed no difference among different grasslands. The urease activity in ND and MD was significantly higher than that in the other grasslands. The phosphatase activity was highest in MD, and the invertase activity was lowest in MD. 3) The belowground biomass was significantly positively correlated with microbial biomass, carbon metabolic index and phosphatase activity

Strong activation of bile acid-sensitive ion channel (BASIC) by ursodeoxycholic acid

PubMed Central

Wiemuth, Dominik; Sahin, Hacer; Lefèvre, Cathérine M.T.; Wasmuth, Hermann E.; Gründer, Stefan

2013-01-01

Bile acid-sensitive ion channel (BASIC) is a member of the DEG/ENaC gene family of unknown function. Rat BASIC (rBASIC) is inactive at rest. We have recently shown that cholangiocytes, the epithelial cells lining the bile ducts, are the main site of BASIC expression in the liver and identified bile acids, in particular hyo- and chenodeoxycholic acid, as agonists of rBASIC. Moreover, it seems that extracellular divalent cations stabilize the resting state of rBASIC, because removal of extracellular divalent cations opens the channel. In this addendum, we demonstrate that removal of extracellular divalent cations potentiates the activation of rBASIC by bile acids, suggesting an allosteric mechanism. Furthermore, we show that rBASIC is strongly activated by the anticholestatic bile acid ursodeoxycholic acid (UDCA), suggesting that BASIC might mediate part of the therapeutic effects of UDCA. PMID:23064163

Comparative evaluation of extracellular β-D-fructofuranosidase in submerged and solid-state fermentation produced by newly identified Bacillus subtilis strain.

PubMed

Lincoln, Lynette; More, Sunil S

2018-04-17

To screen and identify a potential extracellular β-D-fructofuranosidase or invertase producing bacterium from soil, and comparatively evaluate the enzyme biosynthesis under submerged and solid-state fermentation. Extracellular invertase producing bacteria were screened from soil. Identification of the potent bacterium was performed based on microscopic examinations and 16S rDNA molecular sequencing. Bacillus subtilis LYN12 invertase secretion was surplus with wheat bran humidified with molasses medium (70%), with elevated activity at 48 h and 37 °C under solid-state fermentation, whereas under submerged conditions increased activity was observed at 24 h and 45 °C in the molasses medium. The study revealed a simple fermentative medium for elevated production of extracellular invertase from a fast growing Bacillus strain. Bacterial invertases are scarce and limited reports are available. By far, this is the first report on the comparative analysis of optimization of extracellular invertase synthesis from Bacillus subtilis strain by submerged and solid-state fermentation. The use of agricultural residues increased yields resulting in development of a cost-effective and stable approach. Bacillus subtilis LYN12 invertase possesses excellent fermenting capability to utilize agro-industrial residues under submerged and solid-state conditions. This could be a beneficial candidate in food and beverage processing industries. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

HbNIN2, a cytosolic alkaline/neutral-invertase, is responsible for sucrose catabolism in rubber-producing laticifers of Hevea brasiliensis (para rubber tree).

PubMed

Liu, Shujin; Lan, Jixian; Zhou, Binhui; Qin, Yunxia; Zhou, Yihua; Xiao, Xiaohu; Yang, Jianghua; Gou, Jiqing; Qi, Jiyan; Huang, Yacheng; Tang, Chaorong

2015-04-01

In Hevea brasiliensis, an alkaline/neutral invertase (A/N-Inv) is responsible for sucrose catabolism in latex (essentially the cytoplasm of rubber-producing laticifers, the source of natural rubber) and implicated in rubber yield. However, neither the gene encoding this enzyme nor its molecular and biochemical properties have been well documented. Three Hevea A/N-Inv genes, namely HbNIN1, 2 and 3, were first cloned and characterized in planta and in Escherichia coli. Cellular localizations of HbNIN2 mRNA and protein were probed. From latex, active A/N-Inv proteins were purified, identified, and explored for enzymatic properties. HbNIN2 was identified as the major A/N-Inv gene functioning in latex based on its functionality in E. coli, its latex-predominant expression, the conspicuous localization of its mRNA and protein in the laticifers, and its expressional correlation with rubber yield. An active A/N-Inv protein was partially purified from latex, and determined as HbNIN2. The enhancement of HbNIN2 enzymatic activity by pyridoxal is peculiar to A/N-Invs in other plants. We conclude that HbNIN2, a cytosolic A/N-Inv, is responsible for sucrose catabolism in rubber laticifers. The results contribute to the studies of sucrose catabolism in plants as a whole and natural rubber synthesis in particular. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Bactericidal Activity of Usnic Acid-Loaded Electrospun Fibers.

PubMed

Araújo, Evando S; Pereira, Eugênia C; da Costa, Mateus M; da Silva, Nicácio H; de Oliveira, Helinando P

2016-01-01

Usnic acid has been progressively reported in the literature as one of the most important lichen metabolites characterized by a rich diversity of applications such as antifungal, antimicrobial, antiprotozoal and antiviral agent. Particularly, antimicrobial activity of usnic acid can be improved by encapsulation of active molecules in enteric electrospun fibers, allowing the controlled release of active molecule at specific pH. Few relevant patents to the topic have been reviewed and cited. Bactericidal activity of usnic acid-loaded electrospun fibers of Eudragit L-100 and polyvinylpyrrolidone was examined against Staphylococcus aureus using inhibition hales methodology. The controlled release of active material at high pH is established after 10 minutes of interaction with media and results in reasonable activity against S. aureus, as detected by inhibition hales. The strong biological activity of usnic acid-loaded electrospun fibers provides a promising application for corresponding material as a bactericidal agent for wound healing treatment.

Characterization and antioxidant activity of gallic acid derivative

NASA Astrophysics Data System (ADS)

Malinda, Krissan; Sutanto, Hery; Darmawan, Akhmad

2017-11-01

Peroxidase enzyme was used to catalyze the dimerization process of gallic acid. The structure of the dimerization product was characterized by 1H NMR and LC-MS-MS. The mechanism of gallic acid dimerization was also discussed. It was proposed that ellagic acid was formed through an oxidative coupling mechanism that lead to the formation of a C-C bond and followed by an intramolecular Fischer esterification mechanism that lead to the formation of two C-O bonds. Moreover, the antioxidant activity of gallic acid and ellagic acid were also studied. Gallic acid and ellagic acid exhibited the DPPH radical scavenging activity with IC50 values of 13.2 μM and 15.9 μM, respectively.

Soil properties and enzyme activities as affected by biogas slurry irrigation in the Three Gorges Reservoir areas of China.

PubMed

Chen, Shiling; Yu, Weiwei; Zhang, Zhi; Luo, Surong

2015-03-01

Biogas slurry, as a quality organic fertilizer, is widely used on large scale livestock farmland in Southwest China. In the present study, slurry collected from anaerobic tank of dairy farm was used to irrigate farmland having typical purple soil in Chongquing, China. The study revealed that irrigation with biogasslurry increased soil ammonium nitrogen and soil nitrate by 47.8 and 19% respectively as compared to control check. The average soil available phosphorus and soil phosphorus absorption co-efficient changed slightly. Relative enzyme activities of N and P transformation were indicated by catalase, urease, invertase and phosphatase activity. Irrigation period and irrigation quantity were selected as variable factor Catalase, invertase and urease activity was highest when irrigation period and irrigation quantitiy was 4 days and 500 ml; whereas highest phosphatase activity increased significantly in purple irrigated by biogas slurry. The result of the present study is helpful in finding optimum irrigation conditions required for enzyme activity within defined range. It further reveals that biogas slurry enriches soil with various nutrients by enhancing N, P content and enzyme activities as well as it also deals with large number of biogas slurry for protecting the environment.

[Study on anti-bacterium activity of ginkgolic acids and their momomers].

PubMed

Yang, Xiaoming; Zhu, Wei; Chen, Jun; Qian, Zhiyu; Xie, Jimin

2004-09-01

Ginkgolic acids and their three monomers were separated from ginkgo sarcotestas. The anti-bacterium activity of ginkgolic acids were tested. The relation between the anti-bacterium activity and side chain of ginkgolic acid were studied. The MIC of ginkgolic acids and their three monomers and salicylic acid were tested. Ginkgolic acid has strong inhibitive effect on G+-bacterium. Salicylic acid has no side chain, so no anti-bacterial activity. When the length of gingkolic acid side chain is C13:0, it has the strongest anti-bacterial activity in three monomers. The side chain of ginkgolic acid is the key functional group that possessed anti-bacterial activity. The length of Ginkgolic acid was the main effective factor of anti-bacterial activity.

The role of hexokinases from grape berries (Vitis vinifera L.) in regulating the expression of cell wall invertase and sucrose synthase genes.

PubMed

Wang, X Q; Li, L M; Yang, P P; Gong, C L

2014-02-01

In plants, hexokinase (HXK, EC 2.7.1.1) involved in hexose phosphorylation, plays an important role in sugar sensing and signaling. In this study, we found that at Phase I of grape berry development, lower hexose (glucose or fructose) levels were concomitant with higher HXK activities and protein levels. After the onset of ripening, we demonstrated a drastic reduction in HXK activity and protein levels accompanied by a rising hexose level. Therefore, our results revealed that HXK activity and protein levels had an inverse relationship with the endogenous glucose or fructose levels during grape berry development. A 51 kDa HXK protein band was detected throughout grape berry development. In addition, HXK located in the vacuoles, cytoplasm, nucleus, proplastid, chloroplast, and mitochondrion of the berry flesh cells. During grape berry development, HXK transcriptional level changed slightly, while cell wall invertase (CWINV) and sucrose synthase (SuSy) expression was enhanced after véraison stage. Intriguingly, when sliced grape berries were incubated in different glucose solutions, CWINV and SuSy expression was repressed by glucose, and the intensity of repression depended on glucose concentration and incubation time. After sliced, grape berries were treated with different glucose analogs, CWINV and SuSy expression analyses revealed that phosphorylation of hexoses by hexokinase was an essential component in the glucose-dependent CWINV and SuSy expression. In the meantime, mannoheptulose, a specific inhibitor of hexokinase, blocked the repression induced by glucose on CWINV and SuSy expression. It suggested that HXK played a major role in regulating CWINV and SuSy expression during grape berry development.

Gastric acid secretion: activation and inhibition.

PubMed Central

Sachs, G.; Prinz, C.; Loo, D.; Bamberg, K.; Besancon, M.; Shin, J. M.

1994-01-01

Peripheral regulation of gastric acid secretion is initiated by the release of gastrin from the G cell. Gastrin then stimulates the cholecystokinin-B receptor on the enterochromaffin-like cell beginning a calcium signaling cascade. An exocytotic release of histamine follows with concomitant activation of a C1- current. The released histamine begins the H2-receptor mediated sequence of events in the parietal cell, which results in activation of the gastric H+/K+ - ATPase. This enzyme is the final common pathway of acid secretion. The H+/K+ - ATPase is composed of two subunits: the larger alpha-subunit couples ion transport to hydrolysis of ATP, the smaller beta-subunit is required for appropriate assembly of the holoenzyme. Both the membrane and extracytoplasmic domain contain the ion transport pathway, and therefore, this region is the target for the antisecretory drugs of the post-H2 era. The 100 kDa alpha-subunit has probably 10 membrane spanning segments with, therefore, five extracytoplasmic loops. The 35 kDA beta-subunit has a single membrane spanning segment, and most of this protein is extracytoplasmic with the six or seven N glycosylation consensus sequences occupied. Omeprazole is an acid-accumulated, acid-activated, prodrug that binds covalently to two cysteine residues at positions 813 (or 822) and 892, accessible from the acidic face of the pump. Lansoprazole binds to cys321, 813 (or 822) and 892; pantoprazole binds to cys813 and 822. The common binding site for these drugs (cys813 or 822) is responsible for the inhibition of acid transport. Covalent inhibition of the acid pump improves control of acid secretion, but since the effective half life of the inhibition in man is about 48 hr, full inhibition of acid secretion, perhaps necessary for eradication of Helicobacter pylori in combination with a single antibiotic, will require prolongation of the effect of this class of drug. PMID:7502535

Uric acid disrupts hypochlorous acid production and the bactericidal activity of HL-60 cells.

PubMed

Carvalho, Larissa A C; Lopes, João P P B; Kaihami, Gilberto H; Silva, Railmara P; Bruni-Cardoso, Alexandre; Baldini, Regina L; Meotti, Flavia C

2018-06-01

Uric acid is the end product of purine metabolism in humans and is an alternative physiological substrate for myeloperoxidase. Oxidation of uric acid by this enzyme generates uric acid free radical and urate hydroperoxide, a strong oxidant and potentially bactericide agent. In this study, we investigated whether the oxidation of uric acid and production of urate hydroperoxide would affect the killing activity of HL-60 cells differentiated into neutrophil-like cells (dHL-60) against a highly virulent strain (PA14) of the opportunistic pathogen Pseudomonas aeruginosa. While bacterial cell counts decrease due to dHL-60 killing, incubation with uric acid inhibits this activity, also decreasing the release of the inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF- α). In a myeloperoxidase/Cl - /H 2 O 2 cell-free system, uric acid inhibited the production of HOCl and bacterial killing. Fluorescence microscopy showed that uric acid also decreased the levels of HOCl produced by dHL-60 cells, while significantly increased superoxide production. Uric acid did not alter the overall oxidative status of dHL-60 cells as measured by the ratio of reduced (GSH) and oxidized (GSSG) glutathione. Our data show that uric acid impairs the killing activity of dHL-60 cells likely by competing with chloride by myeloperoxidase catalysis, decreasing HOCl production. Despite diminishing HOCl, uric acid probably stimulates the formation of other oxidants, maintaining the overall oxidative status of the cells. Altogether, our results demonstrated that HOCl is, indeed, the main relevant oxidant against bacteria and deviation of myeloperoxidase activity to produce other oxidants hampers dHL-60 killing activity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Activated carbon from peach stones using phosphoric acid activation at medium temperatures.

PubMed

Kim, Dong-Su

2004-01-01

In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one.

Structure-Activity Correlations with Compounds Related to Abscisic Acid 1

PubMed Central

Sondheimer, Ernest; Walton, Daniel C.

1970-01-01

Inhibition of cell expansion of excised embryonic axes of Phaseolus vulgaris was used to evaluate the growth-inhibiting activity of abscisic acid and related compounds. None of the 13 compounds tested was as active as abscisic acid. 4-Hydroxyisophorone, a substance representative of the abscisic acid ring system was essentially inactive; cis, trans-3-methylsorbic acid, a compound resembling the side chain of abscisic acid, had low activity; and cis, trans-β-ionylideneacetic acid was one-sixth as active. Loss of the ring double bond results in a drastic decrease in biological activity. Comparison of our results with those reported previously leads to the suggestion that the double bond of the cyclohexyl moiety may have an important function in determining the degree of activity of cis, trans-ionylideneacetic acids. Two modes of action are discussed. It seems possible that the ring double bond is involved in covalent bonding in binding of the abscisic acid analogue to macromolecules. This may require formation of an intermediate epoxide. It can also be argued that stereochemical differences between cyclohexane derivatives are important factors in determining the degree of biological activity. PMID:5423465

Risk assessment of petroleum-contaminated soil using soil enzyme activities and genotoxicity to Vicia faba.

PubMed

Ma, Jun; Shen, Jinglong; Liu, Qingxing; Fang, Fang; Cai, Hongsheng; Guo, Changhong

2014-05-01

Pollution caused by petroleum is one of the most serious problems worldwide. To better understand the toxic effects of petroleum-contaminated soil on the microflora and phytocommunity, we conducted a comprehensive field study on toxic effects of petroleum contaminated soil collected from the city of Daqing, an oil producing region of China. Urease, protease, invertase, and dehydrogenase activity were significantly reduced in microflora exposed to contaminated soils compared to the controls, whereas polyphenol oxidase activity was significantly increased (P < 0.05). Soil pH, electrical conductivity, and organic matter content were correlated with total petroleum hydrocarbons (TPHs) and a correlation (P < 0.01) existed between the C/N ratio and TPHs. Protease, invertase and catalase were correlated with TPHs. The Vicia faba micronucleus (MN) test, chromosome aberrant (CA) analyses, and the mitotic index (MI) were used to detect genotoxicity of water extracts of the soil. Petroleum-contaminated samples indicated serious genotoxicity to plants, including decreased index level of MI, increased frequency of MN and CA. The combination of enzyme activities and genotoxicity test via Vicia faba can be used as an important indicator for assessing the impact of TPH on soil ecosystem.

Spectroscopic studies on the antioxidant activity of p-coumaric acid

NASA Astrophysics Data System (ADS)

Kiliç, Ismail; Yeşiloğlu, Yeşim

2013-11-01

p-coumaric acid (4-hydroxycinnamic acid), a phenolic acid, is a hydroxyl derivative of cinnamic acid. It decreases low density lipoprotein (LDL) peroxidation and reduces the risk of stomach cancer. In vitro radical scavenging and antioxidant capacity of p-coumaric acid were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2‧-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. p-Coumaric acid inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and ascorbic acid displayed 66.8%, 69.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, p-coumaric acid had an effective DPPHrad scavenging, ABTSrad + scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that p-coumaric acid can be used in the pharmacological and food industry because of these properties.

Seasonal Dynamics of Soil Labile Organic Carbon and Enzyme Activities in Relation to Vegetation Types in Hangzhou Bay Tidal Flat Wetland

PubMed Central

Shao, Xuexin; Yang, Wenying; Wu, Ming

2015-01-01

Soil labile organic carbon and soil enzymes play important roles in the carbon cycle of coastal wetlands that have high organic carbon accumulation rates. Soils under three vegetations (Phragmites australis, Spartina alterniflora, and Scirpusm mariqueter) as well as bare mudflat in Hangzhou Bay wetland of China were collected seasonally. Seasonal dynamics and correlations of soil labile organic carbon fractions and soil enzyme activities were analyzed. The results showed that there were significant differences among vegetation types in the contents of soil organic carbon (SOC) and dissolved organic carbon (DOC), excepting for that of microbial biomass carbon (MBC). The P. australis soil was with the highest content of both SOC (7.86 g kg-1) and DOC (306 mg kg-1), while the S. mariqueter soil was with the lowest content of SOC (6.83 g kg-1), and the bare mudflat was with the lowest content of DOC (270 mg kg-1). Soil enzyme activities were significantly different among vegetation types except for urease. The P. australis had the highest annual average activity of alkaline phosphomonoesterase (21.4 mg kg-1 h-1), and the S. alterniflora had the highest annual average activities of β-glycosidase (4.10 mg kg-1 h-1) and invertase (9.81mg g-1 24h-1); however, the bare mudflat had the lowest activities of alkaline phosphomonoesterase (16.2 mg kg-1 h-1), β-glycosidase (2.87 mg kg-1 h-1), and invertase (8.02 mg g-1 24h-1). Analysis also showed that the soil labile organic carbon fractions and soil enzyme activities had distinct seasonal dynamics. In addition, the soil MBC content was significantly correlated with the activities of urease and β-glucosidase. The DOC content was significantly correlated with the activities of urease, alkaline phosphomonoesterase, and invertase. The results indicated that vegetation type is an important factor influencing the spatial-temporal variation of soil enzyme activities and labile organic carbon in coastal wetlands. PMID:26560310

Eicosapentaenoic Acid Modulates Trichomonas vaginalis Activity.

PubMed

Korosh, Travis; Jordan, Kelsey D; Wu, Ja-Shin; Yarlett, Nigel; Upmacis, Rita K

2016-01-01

Trichomonas vaginalis is a sexually transmitted parasite and, while it is often asymptomatic in males, the parasite is associated with disease in both sexes. Metronidazole is an effective treatment for trichomoniasis, but resistant strains have evolved and, thus, it has become necessary to investigate other possible therapies. In this study, we examined the effects of native and oxidized forms of the sodium salts of eicosapentaenoic, docosahexaenoic, and arachidonic acids on T. vaginalis activity. Eicosapentaenoic acid was the most toxic with 190 and 380 μM causing approximately 90% cell death in Casu2 and ATCC 50142 strains, respectively. In contrast, oxidized eicosapentaenoic acid was the least toxic, requiring > 3 mM to inhibit activity, while low levels (10 μM) were associated with increased parasite density. Mass spectrometric analysis of oxidized eicosapentaenoic acid revealed C20 products containing one to six additional oxygen atoms and various degrees of bond saturation. These results indicate that eicosapentaenoic acid has different effects on T. vaginalis survival, depending on whether it is present in the native or oxidized form. A better understanding of lipid metabolism in T. vaginalis may facilitate the design of synthetic fatty acids that are effective for the treatment of metronidazole-resistant T. vaginalis. © 2015 The Author(s) Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

Spectroscopic studies on the antioxidant activity of p-coumaric acid.

PubMed

Kiliç, Ismail; Yeşiloğlu, Yeşim

2013-11-01

p-coumaric acid (4-hydroxycinnamic acid), a phenolic acid, is a hydroxyl derivative of cinnamic acid. It decreases low density lipoprotein (LDL) peroxidation and reduces the risk of stomach cancer. In vitro radical scavenging and antioxidant capacity of p-coumaric acid were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe(2+)) chelating activity and ferric ions (Fe(3+)) reducing ability. p-Coumaric acid inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45μg/mL concentration. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and ascorbic acid displayed 66.8%, 69.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, p-coumaric acid had an effective DPPH scavenging, ABTS(+) scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe(3+)) reducing power and ferrous ions (Fe(2+)) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that p-coumaric acid can be used in the pharmacological and food industry because of these properties. Copyright © 2013 Elsevier B.V. All rights reserved.

Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

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

Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi

2011-04-22

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a humanmore » adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The

Vascularization, high-volume solution flow, and localized roles for enzymes of sucrose metabolism during tumorigenesis by Agrobacterium tumefaciens.

PubMed

Wächter, Rebecca; Langhans, Markus; Aloni, Roni; Götz, Simone; Weilmünster, Anke; Koops, Ariane; Temguia, Leopoldine; Mistrik, Igor; Pavlovkin, Jan; Rascher, Uwe; Schwalm, Katja; Koch, Karen E; Ullrich, Cornelia I

2003-11-01

Vascular differentiation and epidermal disruption are associated with establishment of tumors induced by Agrobacterium tumefaciens. Here, we address the relationship of these processes to the redirection of nutrient-bearing water flow and carbohydrate delivery for tumor growth within the castor bean (Ricinus communis) host. Treatment with aminoethoxyvinyl-glycine showed that vascular differentiation and epidermal disruption were central to ethylene-dependent tumor establishment. CO2 release paralleled tumor growth, but water flow increased dramatically during the first 3 weeks. However, tumor water loss contributed little to water flow to host shoots. Tumor water loss was followed by accumulation of the osmoprotectants, sucrose (Suc) and proline, in the tumor periphery, shifting hexose-to-Suc balance in favor of sugar signals for maturation and desiccation tolerance. Concurrent activities and sites of action for enzymes of Suc metabolism changed: Vacuolar invertase predominated during initial import of Suc into the symplastic continuum, corresponding to hexose concentrations in expanding tumors. Later, Suc synthase (SuSy) and cell wall invertase rose in the tumor periphery to modulate both Suc accumulation and descending turgor for import by metabolization. Sites of abscisic acid immunolocalization correlated with both central vacuolar invertase and peripheral cell wall invertase. Vascular roles were indicated by SuSy immunolocalization in xylem parenchyma for inorganic nutrient uptake and in phloem, where resolution allowed SuSy identification in sieve elements and companion cells, which has widespread implications for SuSy function in transport. Together, data indicate key roles for ethylene-dependent vascularization and cuticular disruption in the redirection of water flow and carbohydrate transport for successful tumor establishment.

Vascularization, High-Volume Solution Flow, and Localized Roles for Enzymes of Sucrose Metabolism during Tumorigenesis by Agrobacterium tumefaciens1

PubMed Central

Wächter, Rebecca; Langhans, Markus; Aloni, Roni; Götz, Simone; Weilmünster, Anke; Koops, Ariane; Temguia, Leopoldine; Mistrik, Igor; Pavlovkin, Jan; Rascher, Uwe; Schwalm, Katja; Koch, Karen E.; Ullrich, Cornelia I.

2003-01-01

Vascular differentiation and epidermal disruption are associated with establishment of tumors induced by Agrobacterium tumefaciens. Here, we address the relationship of these processes to the redirection of nutrient-bearing water flow and carbohydrate delivery for tumor growth within the castor bean (Ricinus communis) host. Treatment with aminoethoxyvinyl-glycine showed that vascular differentiation and epidermal disruption were central to ethylene-dependent tumor establishment. CO2 release paralleled tumor growth, but water flow increased dramatically during the first 3 weeks. However, tumor water loss contributed little to water flow to host shoots. Tumor water loss was followed by accumulation of the osmoprotectants, sucrose (Suc) and proline, in the tumor periphery, shifting hexose-to-Suc balance in favor of sugar signals for maturation and desiccation tolerance. Concurrent activities and sites of action for enzymes of Suc metabolism changed: Vacuolar invertase predominated during initial import of Suc into the symplastic continuum, corresponding to hexose concentrations in expanding tumors. Later, Suc synthase (SuSy) and cell wall invertase rose in the tumor periphery to modulate both Suc accumulation and descending turgor for import by metabolization. Sites of abscisic acid immunolocalization correlated with both central vacuolar invertase and peripheral cell wall invertase. Vascular roles were indicated by SuSy immunolocalization in xylem parenchyma for inorganic nutrient uptake and in phloem, where resolution allowed SuSy identification in sieve elements and companion cells, which has widespread implications for SuSy function in transport. Together, data indicate key roles for ethylene-dependent vascularization and cuticular disruption in the redirection of water flow and carbohydrate transport for successful tumor establishment. PMID:14526106

Catalytic Ethanol Dehydration over Different Acid-activated Montmorillonite Clays.

PubMed

Krutpijit, Chadaporn; Jongsomjit, Bunjerd

2016-01-01

In the present study, the catalytic dehydration of ethanol to obtain ethylene over montmorillonite clays (MMT) with mineral acid activation including H2SO4 (SA-MMT), HCl (HA-MMT) and HNO3 (NA-MMT) was investigated at temperature range of 200 to 400°C. It revealed that HA-MMT exhibited the highest catalytic activity. Ethanol conversion and ethylene selectivity were found to increase with increased reaction temperature. At 400°C, the HA-MMT yielded 82% of ethanol conversion having 78% of ethylene yield. At lower temperature (i.e. 200 to 300°C), diethyl ether (DEE) was a major product. The highest activity obtained from HA-MMT can be attributed to an increase of weak acid sites and acid density by the activation of MMT with HCl. It can be also proven by various characterization techniques that in most case, the main structure of MMT did not alter by acid activation (excepted for NA-MMT). Upon the stability test for 72 h during the reaction, the MMT and HA-MMT showed only slight deactivation due to carbon deposition. Hence, the acid activation of MMT by HCl is promising to enhance the catalytic dehydration of ethanol.

Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants.

PubMed

Wang, Lu; Ruan, Yong-Ling

2016-05-01

Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. © 2016 American Society of Plant Biologists. All Rights Reserved.

Activation of olefins via asymmetric Bronsted acid catalysis

DOE PAGES

Tsuji, Nobuya; Kennemur, Jennifer L.; Buyck, Thomas; ...

2018-03-30

The activation of olefins for asymmetric chemical synthesis traditionally relies on transition metal catalysts. In contrast, biological enzymes with Bronsted acidic sites of appropriate strength can protonate olefins and thereby generate carbocations that ultimately react to form natural products. Although chemists have recently designed chiral Bronsted acid catalysts to activate imines and carbonyl compounds, mimicking these enzymes to protonate simple olefins that then engage in asymmetric catalytic reactions has remained a substantial synthetic challenge. Here, we show that a class of confined and strong chiral Bronsted acids enables the catalytic asymmetric intramolecular hydroalkoxylation of unbiased olefins. In conclusion, the methodologymore » gives rapid access to biologically active 1,1-disubstituted tetrahydrofurans, including (–)-Boivinianin A.« less

Activation of olefins via asymmetric Bronsted acid catalysis

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

Tsuji, Nobuya; Kennemur, Jennifer L.; Buyck, Thomas

The activation of olefins for asymmetric chemical synthesis traditionally relies on transition metal catalysts. In contrast, biological enzymes with Bronsted acidic sites of appropriate strength can protonate olefins and thereby generate carbocations that ultimately react to form natural products. Although chemists have recently designed chiral Bronsted acid catalysts to activate imines and carbonyl compounds, mimicking these enzymes to protonate simple olefins that then engage in asymmetric catalytic reactions has remained a substantial synthetic challenge. Here, we show that a class of confined and strong chiral Bronsted acids enables the catalytic asymmetric intramolecular hydroalkoxylation of unbiased olefins. In conclusion, the methodologymore » gives rapid access to biologically active 1,1-disubstituted tetrahydrofurans, including (–)-Boivinianin A.« less

Chlorogenic Acid Inhibits Human Platelet Activation and Thrombus Formation

PubMed Central

Fuentes, Eduardo; Caballero, Julio; Alarcón, Marcelo; Rojas, Armando; Palomo, Iván

2014-01-01

Background Chlorogenic acid is a potent phenolic antioxidant. However, its effect on platelet aggregation, a critical factor in arterial thrombosis, remains unclear. Consequently, chlorogenic acid-action mechanisms in preventing platelet activation and thrombus formation were examined. Methods and Results Chlorogenic acid in a dose-dependent manner (0.1 to 1 mmol/L) inhibited platelet secretion and aggregation induced by ADP, collagen, arachidonic acid and TRAP-6, and diminished platelet firm adhesion/aggregation and platelet-leukocyte interactions under flow conditions. At these concentrations chlorogenic acid significantly decreased platelet inflammatory mediators (sP-selectin, sCD40L, CCL5 and IL-1β) and increased intraplatelet cAMP levels/PKA activation. Interestingly, SQ22536 (an adenylate cyclase inhibitor) and ZM241385 (a potent A2A receptor antagonist) attenuated the antiplatelet effect of chlorogenic acid. Chlorogenic acid is compatible to the active site of the adenosine A2A receptor as revealed through molecular modeling. In addition, chlorogenic acid had a significantly lower effect on mouse bleeding time when compared to the same dose of aspirin. Conclusions Antiplatelet and antithrombotic effects of chlorogenic acid are associated with the A2A receptor/adenylate cyclase/cAMP/PKA signaling pathway. PMID:24598787

Chitosan-caffeic acid-genipin films presenting enhanced antioxidant activity and stability in acidic media.

PubMed

Nunes, Cláudia; Maricato, Élia; Cunha, Ângela; Nunes, Alexandra; da Silva, José A Lopes; Coimbra, Manuel A

2013-01-02

The use of chitosan films has been limited due to their high degradability in aqueous acidic media. In order to produce chitosan films with high antioxidant activity and insoluble in acid solutions caffeic acid was grafted to chitosan by a radical mechanism using ammonium cerium (IV) nitrate (60 mM). Genipin was used as cross-linker. This methodology originated films with 80% higher antioxidant activity than the pristine film. Also, these films only lost 11% of their mass upon seven days immersion into an aqueous solution at pH 3.5 under stirring. The films surface wettability (contact angle 105°), mechanical properties (68 MPa of tensile strength and 4% of elongation at break), and thermal stability for temperatures lower than 300 °C were not significantly influenced by the covalent linkage of caffeic acid and genipin to chitosan. Due to their characteristics, mainly higher antioxidant activity and lower solubility, these are promising materials to be used as active films. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis and biological activity of alkynoic acids derivatives against mycobacteria

PubMed Central

Vilchèze, Catherine; Leung, Lawrence W.; Bittman, Robert; Jacobs, William R.

2015-01-01

2-alkynoic acids have bactericidal activity against Mycobacterium smegmatis but their activity fall sharply as the length of the carbon chain increased. In this study, derivatives of 2- alkynoic acids were synthesized and tested against fast- and slow-growing mycobacteria. Their activity was first evaluated in M. smegmatis against their parental 2-alkynoic acids, as well as isoniazid, a first-line antituberculosis drug. The introduction of additional unsaturation or heteroatoms into the carbon chain enhanced the antimycobacterial activity of longer chain alkynoic acids (more than 19 carbons long). In contrast, although the modification of the carboxylic group did not improve the antimycobacterial activity, it significantly reduced the toxicity of the compounds against eukaryotic cells. Importantly, 4-(alkylthio)but-2-ynoic acids, had better bactericidal activity than the parental 2-alkynoic acids and on a par with isoniazid against the slow-grower Mycobacterium bovis BCG. These compounds had also low toxicity against eukaryotic cells, suggesting that they could be potential therapeutic agents against other types of topical mycobacterial infections causing skin diseases including Mycobacterium abscessus, Mycobacterium ulcerans, and Mycobacterium leprae. Moreover, they provide a possible scaffold for future drug development. PMID:26256431

Effects of Soil Salinity on Sucrose Metabolism in Cotton Fiber

PubMed Central

Liu, Jingran; Luo, Junyu; Zhao, Xinhua; Dong, Helin; Ma, Yan; Sui, Ning; Zhou, Zhiguo; Meng, Yali

2016-01-01

Cotton (Gosspium hirsutum L.) is classified as a salt tolerant crop. However, its yield and fiber quality are negatively affected by soil salinity. Studies on the enzymatic differences in sucrose metabolism under different soil salinity levels are lacking. Therefore, field experiments, using two cotton cultivars, CCRI-79 (salt-tolerant) and Simian 3 (salt-sensitive), were conducted in 2013 and 2014 at three different salinity levels (1.15 dS m-1 [low soil salinity], 6.00 dS m-1 [medium soil salinity], and 11.46 dS m-1 [high soil salinity]). The objective was to elucidate the effects of soil salinity on sucrose content and the activity of key enzymes that are related to sucrose metabolism in cotton fiber. Results showed that as the soil salinity increased, cellulose content, sucrose content, and sucrose transformation rate declined; the decreases in cellulose content and sucrose transformation rate caused by the increase in soil salinity were more in Simian 3 than those in CCRI-79. With increase in soil salinity, activities of sucrose metabolism enzymes sucrose phophate synthase (SPS), acidic invertase, and alkaline invertase were decreased, whereas sucrose synthase (SuSy) activity increased. However, the changes displayed in the SuSy and SPS activities in response to increase in soil salinity were different and the differences were large between the two cotton cultivars. These results illustrated that suppressed cellulose synthesis and sucrose metabolism under high soil salinity were mainly due to the change in SPS, SuSy, and invertase activities, and the difference in cellulose synthesis and sucrose metabolism in fiber for the two cotton cultivars in response to soil salinity was determined mainly by both SuSy and SPS activities. PMID:27227773

A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

PubMed

Paudyal, Ranju; Barnes, Ruth H; Karatzas, Kimon Andreas G

2018-02-01

Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Leaf carbohydrate metabolism during defense

PubMed Central

Essmann, Jutta; Bones, Philipp; Weis, Engelbert

2008-01-01

The significance of cell wall invertase (cwINV) for plant defense was investigated by comparing wild type (wt) tobacco Nicotiana tabacum L. Samsun NN (SNN) with plants with RNA interference-mediated repression of cwINV (SNN::cwINV) during the interaction with the oomycetic phytopathogen Phytophthora nicotianae. We have previously shown that the transgenic plants developed normally under standard growth conditions, but exhibited weaker defense reactions in infected source leaves and were less tolerant to the pathogen. Here, we show that repression of cwINV was not accompanied by any compensatory activities of intracellular sucrose-cleaving enzymes such as vacuolar and alkaline/neutral invertases or sucrose synthase (SUSY), neither in uninfected controls nor during infection. In wt source leaves vacuolar invertase did not respond to infection, and the activity of alkaline/neutral invertases increased only slightly. SUSY however, was distinctly stimulated, in parallel to enhanced cwINV. In SNN::cwINV SUSY-activation was largely repressed upon infection. SUSY may serve to allocate sucrose into callose deposition and other carbohydrate-consuming defense reactions. Its activity, however, seems to be directly affected by cwINV and the related reflux of carbohydrates from the apoplast into the mesophyll cells. PMID:19704530

PMAA-stabilized ferrofluid/chitosan/yeast composite for bioapplications

NASA Astrophysics Data System (ADS)

Baldikova, Eva; Prochazkova, Jitka; Stepanek, Miroslav; Hajduova, Jana; Pospiskova, Kristyna; Safarikova, Mirka; Safarik, Ivo

2017-04-01

A simple, one-pot process for the preparation of magnetically responsive yeast-based biocatalysts was developed. Saccharomyces cerevisiae, Candida utilis and Kluyveromyces lactis cells were successfully incorporated into chitosan gel magnetically modified with poly(methacrylic acid)-stabilized magnetic fluid (PMAA-FF) during its formation. Magnetic PMAA-FF/chitosan/yeast composites were efficiently employed for invert sugar production. The dependence of invertase activity on used yeast, amount of magnetic biocatalyst, agitation time and after reuse was studied in detail. The tested magnetic biocatalysts retained at least 69% of their initial activity after 8 reuse cycles.

Establishing the relative importance of damaged starch and fructan as sources of fermentable sugars in wheat flour and whole meal bread dough fermentations.

PubMed

Struyf, Nore; Laurent, Jitka; Lefevere, Bianca; Verspreet, Joran; Verstrepen, Kevin J; Courtin, Christophe M

2017-03-01

It is generally believed that maltose drives yeast-mediated bread dough fermentation. The relative importance of fructose and glucose, released from wheat fructan and sucrose by invertase, compared to maltose is, however, not documented. This is surprising given the preference of yeast for glucose and fructose over maltose. This study revealed that, after 2h fermentation of wheat flour dough, about 44% of the sugars consumed were generated by invertase-mediated degradation of fructan, raffinose and sucrose. The other 56% were generated by amylases. In whole meal dough, 70% of the sugars consumed were released by invertase activity. Invertase-mediated sugar release seems to be crucial during the first hour of fermentation, while amylase-mediated sugar release was predominant in the later stages of fermentation, which explains why higher amylolytic activity prolonged the productive fermentation time only. These results illustrate the importance of wheat fructan and sucrose content and their degradation for dough fermentations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Natural cinnamic acids, synthetic derivatives and hybrids with antimicrobial activity.

PubMed

Guzman, Juan David

2014-11-25

Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC) of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships.

In vivo analgesic and anti-inflammatory activities of ursolic acid and oleanoic acid from Miconia albicans (Melastomataceae).

PubMed

Vasconcelos, Maria Anita L; Royo, Vanessa A; Ferreira, Daniele S; Crotti, Antonio E Miller; Andrade e Silva, Márcio L; Carvalho, José Carlos T; Bastos, Jairo Kenupp; Cunha, Wilson R

2006-01-01

The aim of this work was to use in vivo models to evaluate the analgesic and anti-inflammatory activities of ursolic acid (UA) and oleanoic acid (OA), the major compounds isolated as an isomeric mixture from the crude methylene chloride extract of Miconia albicans aerial parts in an attempt to clarify if these compounds are responsible for the analgesic properties displayed by this plant. Ursolic acid inhibited abdominal constriction in a dose-dependent manner, and the result obtained at a content of 40 mg kg(-1) was similar to that produced by administration of acetylsalicylic acid at a content of 100 mg kg(-1). Both acids reduced the number of paw licks in the second phase of the formalin test, and both of them displayed a significant anti-inflammatory effect at a content of 40 mg kg(-1). It is noteworthy that the administration of the isolated mixture, containing 65% ursolic acid/35% oleanolic acid, did not display significant analgesic and anti-inflammatory activities. On the basis of the obtained results, considering that the mixture of UA and OA was poorly active, it is suggested that other compounds, rather than UA and OA, should be responsible for the evaluated activities in the crude extract, since the crude extract samples displayed good activities.

Label-free shotgun proteomics and metabolite analysis reveal a significant metabolic shift during citrus fruit development

PubMed Central

Katz, Ehud; Boo, Kyung Hwan; Kim, Ho Youn; Eigenheer, Richard A.; Phinney, Brett S.; Shulaev, Vladimir; Negre-Zakharov, Florence; Sadka, Avi; Blumwald, Eduardo

2011-01-01

Label-free LC-MS/MS-based shot-gun proteomics was used to quantify the differential protein synthesis and metabolite profiling in order to assess metabolic changes during the development of citrus fruits. Our results suggested the occurrence of a metabolic change during citrus fruit maturation, where the organic acid and amino acid accumulation seen during the early stages of development shifted into sugar synthesis during the later stage of citrus fruit development. The expression of invertases remained unchanged, while an invertase inhibitor was up-regulated towards maturation. The increased expression of sucrose-phosphate synthase and sucrose-6-phosphate phosphatase and the rapid sugar accumulation suggest that sucrose is also being synthesized in citrus juice sac cells during the later stage of fruit development. PMID:21841177

Anti-Helicobacter pylori activity of anacardic acids from Amphipterygium adstringens.

PubMed

Castillo-Juárez, Israel; Rivero-Cruz, Fausto; Celis, Heliodoro; Romero, Irma

2007-10-08

Amphipterygium adstringens (Schltdl.) Standl. (Anacardiaceae) is widely used in traditional Mexican medicine for the treatment of gastritis and ulcers. In this work, we studied the anti-Helicobacter pylori activity of its bark, this Gram-negative bacterium is considered the major etiological agent of chronic active gastritis and peptic ulcer disease, and it is linked to gastric carcinoma. From a bio-guided assay of the fractions obtained form a continuous Soxhlet extraction of the bark, we identified that petroleum ether fraction had significant antimicrobial activity against Helicobacter pylori. From this fraction, we isolated an anacardic acids mixture and three known triterpenes: masticadienonic acid; 3alpha-hydroxymasticadienonic acid; 3-epi-oleanolic; as well as the sterol beta-sitosterol. Only the anacardic acids mixture exhibits a potent dose-dependent antibacterial activity (MIC=10 microg/ml in broth cultures). It is enriched in saturated alkyl phenolic acids (C15:0, C16:0, C17:0 C19:0) which represents a novel source of these compounds with potent anti-Helicobacter pylori activity. The promising use of anacardic acids and Amphipterygium adstringens bark in the development of an integral treatment of Helicobacter pylori diseases is discussed.

Spectroscopic studies on the antioxidant activity of ellagic acid

NASA Astrophysics Data System (ADS)

Kilic, Ismail; Yeşiloğlu, Yeşim; Bayrak, Yüksel

2014-09-01

Ellagic acid (EA, C14H6O8) is a natural dietary polyphenol whose benefits in a variety of diseases shown in epidemiological and experimental studies involve anti-inflammation, anti-proliferation, anti-angiogenesis, anticarcinogenesis and anti-oxidation properties. In vitro radical scavenging and antioxidant capacity of EA were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2‧-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. EA inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-tocopherol and ascorbic acid displayed 69.8%, 66.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, EA had an effective DPPH• scavenging, ABTSrad + scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that EA can be used in the pharmacological, food industry and medicine because of these properties.

Microbial biomass carbon and enzyme activities of urban soils in Beijing.

PubMed

Wang, Meie; Markert, Bernd; Shen, Wenming; Chen, Weiping; Peng, Chi; Ouyang, Zhiyun

2011-07-01

To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing. Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon. The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p < 0.01. It was shown that the older and the biologically more stable part of city exhibited higher microbial activity levels than the more recently developed part of the city and the road areas of heavy traffic. It was concluded that the land use patterns in Beijing urban soils influenced the nature and activities of the microbial communities.

[Effects of exogenous glucose and starch on soil carbon metabolism of root zone and root function in potted sweet cherry].

PubMed

Zhou, Wen-jie; Zhang, Peng; Qin, Si-jun; Lyu, De-guo

2015-11-01

One-year-old potted sweet cheery trees were treated with 4 g · kg(-1) exogenous glucose or starch and with non-addition of exogenous carbon as the control for up to 60 days. Soil of root zone was sampled to analyze soil microbial biomass carbon, activities of invertase and amylase and microbial community functional diversity during the 60-day treatment, and roots were sampled for analysis of root respiratory rate, respiratory pathways and root viability after treatment for 30 days. Results showed that the invertase activity and the microbial biomass carbon initially increased and decreased subsequently, with the maxima which were 14.0% and 13.1% higher in the glucose treatment than in the control treatment appeared after 15 and 7 days of treatments, respectively. Soil organic matter content increased first then decreased and finally moderately increased again. Amylase activity was 7.5-fold higher in the starch treatment than in the control treatment after 15-day treatment. Soil microbial biomass carbon was higher in the starch treatment than in the control treatment except after 7-day treatment. Soil organic matter content initially increased and then decreased, but it was still 19.8% higher than in the control after 60-day treatment. BIOLOG results showed that the maximum average well color development (AWCD) value and microbial activity appeared after 15-day treatment in the following order: starch>glucose>control. After 30-day treatment, glucose treatment resulted in a significant increase in the soil microbial utilization of carbohydrates, carboxylic acid, amino acids, phenolic acids and amines, and starch treatment significantly increased the soil microbial utilization of carbohydrates, carboxylic acid, polymers and phenolic acids. After 30-day treatment, the total root respiratory rate and root viability were 21.4%, 19.4% and 65.5%, 37.0% higher in glucose treatment than in the control and starch treatments, respectively. These results indicated exogenous

[Correlation Between Functional Groups and Radical Scavenging Activities of Acidic Polysaccharides from Dendrobium].

PubMed

Liao, Ying; Yuan, Wen-yu; Zheng, Wen-ke; Luo, Ao-xue; Fan, Yi-jun

2015-11-01

To compare the radical scavenging activity of five different acidic polysaccharides, and to find the correlation with the functional groups. Alkali extraction method and Stepwise ethanol precipitation method were used to extract and concentrate the five Dendrobium polysaccharides, and to determine the contents of sulfuric acid and uronic acid of each kind of acidic polysaccharides, and the scavenging activity to ABTS+ radical and hydroxyl radical. Functional group structures were examined by FTIR Spectrometer. Five kinds of Dendrobium polysaccharides had different ability of scavenging ABTS+ free radical and hydroxyl free radical. Moreover, the study had shown that five kinds of antioxidant activity of acidic polysaccharides had obvious correlation withuronic acid and sulfuric acid. The antioxidant activity of each sample was positively correlated with the content of uronic acid, and negatively correlated with the content of sulfuric acid. Sulfuric acid can inhibit the antioxidant activity of acidic polysaccharide but uronic acid can enhance the free radical scavenging activity. By analyzing the structure characteristics of five acidic polysaccharides, all samples have similar structures, however, Dendrobium denneanum, Dendrobium devonianum and Dendrobium officinale which had β configuration have higher antioxidant activity than Dendrobium nobile and Dendrobium fimbriatum which had a configuration.

Antimicrobial and Efflux Inhibitor Activity of Usnic Acid Against Mycobacterium abscessus.

PubMed

Ramis, Ivy B; Vianna, Júlia S; Reis, Ana Júlia; von Groll, Andrea; Ramos, Daniela F; Viveiros, Miguel; da Silva, Pedro E Almeida

2018-06-18

New drugs are needed to treat infections with antimicrobial-resistant Mycobacterium abscessus ; therefore, we evaluated usnic acid as an antimicrobial agent and efflux inhibitor (EI) against M. abscessus . Usnic acid showed antimicrobial activity, and synergistically, the EI verapamil increased this activity. In addition, when we evaluated the interaction of antimicrobials with usnic acid, the increase of their activity was observed. Finally, usnic acid showed an efflux inhibitory effect between the classical EIs verapamil and carbonyl cyanide m-chlorophenylhydrazine. In conclusion, usnic acid showed both antimicrobial and EI activity, indicating that this natural compound may be a promising scaffold for new drugs against this difficult-to-treat microorganism. Georg Thieme Verlag KG Stuttgart · New York.

Antidiabetic Activity from Gallic Acid Encapsulated Nanochitosan

NASA Astrophysics Data System (ADS)

Purbowatiningrum; Ngadiwiyana; Ismiyarto; Fachriyah, E.; Eviana, I.; Eldiana, O.; Amaliyah, N.; Sektianingrum, A. N.

2017-02-01

Diabetes mellitus (DM) has become a health problem in the world because it causes death. One of the phenolic compounds that have antidiabetic activity is gallic acid. However, the use of this compound still provides unsatisfactory results due to its degradation during the absorption process. The solution offered to solve the problem is by encapsulated it within chitosan nanoparticles that serve to protect the bioactive compound from degradation, increases of solubility and delivery of a bioactive compound to the target site by using freeze-drying technique. The result of chitosan nanoparticle’s Scanning Electron Microscopy (SEM) showed that chitosan nanoparticle’s size is uniform and it is smaller than chitosan. The value of encapsulation efficiency (EE) of gallic acid which encapsulated within chitosan nanoparticles is about 50.76%. Inhibition test result showed that gallic acid-chitosan nanoparticles at 50 ppm could inhibite α-glucosidase activity in 28.87% with 54.94 in IC50. So it can be concluded that gallic acid can be encapsulated in nanoparticles of chitosan and proved that it could inhibit α-glucosidase.

Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants1[OPEN

PubMed Central

2016-01-01

Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. PMID:26969720

Structure-activity relationship investigation of tertiary amine derivatives of cinnamic acid as acetylcholinesterase and butyrylcholinesterase inhibitors: compared with that of phenylpropionic acid, sorbic acid and hexanoic acid.

PubMed

Gao, Xiaohui; Tang, Jingjing; Liu, Haoran; Liu, Linbo; Kang, Lu; Chen, Wen

2018-12-01

In the present investigation, 48 new tertiary amine derivatives of cinnamic acid, phenylpropionic acid, sorbic acid and hexanoic acid (4d-6g, 10d-12g, 16d-18g and 22d-24g) were designed, synthesized and evaluated for the effect on AChE and BChE in vitro. The results revealed that the alteration of aminoalkyl types and substituted positions markedly influences the effects in inhibiting AChE. Almost of all cinnamic acid derivatives had the most potent inhibitory activity than that of other acid derivatives with the same aminoalkyl side chain. Unsaturated bond and benzene ring in cinnamic acid scaffold seems important for the inhibitory activity against AChE. Among them, compound 6g revealed the most potent AChE inhibitory activity (IC 50 value: 3.64 µmol/L) and highest selectivity over BChE (ratio: 28.6). Enzyme kinetic study showed that it present a mixed-type inhibition against AChE. The molecular docking study suggested that it can bind with the catalytic site and peripheral site of AChE.

Nonsteroidal anti-inflammatory drug flufenamic acid is a potent activator of AMP-activated protein kinase.

PubMed

Chi, Yuan; Li, Kai; Yan, Qiaojing; Koizumi, Schuichi; Shi, Liye; Takahashi, Shuhei; Zhu, Ying; Matsue, Hiroyuki; Takeda, Masayuki; Kitamura, Masanori; Yao, Jian

2011-10-01

Flufenamic acid (FFA) is a nonsteroidal anti-inflammatory drug (NSAID). It has anti-inflammatory and antipyretic properties. In addition, it modulates multiple channel activities. The mechanisms underlying the pharmacological actions of FFA are presently unclear. Given that AMP-activated protein kinase (AMPK) has both anti-inflammatory and channel-regulating functions, we examined whether FFA induces AMPK activation. 1) Exposure of several different types of cells to FFA resulted in an elevation of AMPKα phosphorylation at Thr172. This effect of FFA was reproduced by functionally and structurally similar mefenamic acid, tolfenamic acid, niflumic acid, and meclofenamic acid. 2) FFA-induced activation of AMPK was largely abolished by the treatment of cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester) (an intracellular Ca(2+) chelator) or depletion of extracellular Ca(2+), whereas it was mimicked by stimulation of cells with the Ca(2+) ionophore 5-(methylamino)-2-({(2R,3R,6S,8S,9R,11R)-3,9,11-trimethyl-8-[(1S)-1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl]-1,7-dioxaspiro[5.5]undec-2-yl}methyl)-1,3-benzoxazole-4-carboxylic acid (A23187) or ionomycin. 3) FFA triggered a rise in intracellular Ca(2+), which was abolished by cyclosporine, a blocker of mitochondrial permeability transition pore. Cyclosporine also abolished FFA-induced activation of AMPK. 4) Inhibition of Ca(2+)/calmodulin-dependent kinase kinase β (CaMKKβ) with 7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid acetate (STO-609) or down-regulation of CaMKKβ with short interfering RNA largely abrogated FFA-induced activation of AMPK. 5) FFA significantly suppressed nuclear factor-κB activity and inducible nitric-oxide synthase expression triggered by interleukin-1β and tumor necrosis factor α. This suppression was also largely abrogated by STO-609. Taken together, we conclude that FFA induces AMPK activation through the Ca(2+)-CaMKKβ pathway

Antibacterial activity of triterpene acids and semi-synthetic derivatives against oral pathogens

PubMed

Scalon Cunha, Luis C; Andrade e Silva, Márcio L; Cardoso Furtado, Niege A J; Vinhólis, Adriana H C; Martins, Carlos H; da Silva Filho, Ademar A; Cunha, Wilson R

2007-01-01

Triterpene acids (ursolic, oleanoic, gypsogenic, and sumaresinolic acids) isolated from Miconia species, along with a mixture of ursolic and oleanolic acids and a mixture of maslinic and 2-a-hydroxyursolic acids, as well as ursolic acid derivatives were evaluated against the following microorganisms: Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis, which are potentially responsible for the formation of dental caries in humans. The microdilution method was used for the determination of the minimum inhibitory concentration (MIC) during the evaluation of the antibacterial activity. All the isolated compounds, mixtures, and semi-synthetic derivatives displayed activity against all the tested bacteria, showing that they are promising antiplaque and anticaries agents. Ursolic and oleanolic acids displayed the most intense antibacterial effect, with MIC values ranging from 30 microg/mL to 80 microg/mL. The MIC values of ursolic acid derivatives, as well as those obtained for the mixture of ursolic and oleanolic acids showed that these compounds do not have higher antibacterial activity when compared with the activity observed with either ursolic acid or oleanolic acid alone. With regard to the structure-activity relationship of triterpene acids and derivatives, it is suggested that both hydroxy and carboxy groups present in the triterpenes are important for their antibacterial activity against oral pathogens.

Biological Activities of Oleanolic Acid Derivatives from Calendula officinalis Seeds.

PubMed

Zaki, Ahmed; Ashour, Ahmed; Mira, Amira; Kishikawa, Asuka; Nakagawa, Toshinori; Zhu, Qinchang; Shimizu, Kuniyoshi

2016-05-01

Phytochemical examination of butanol fraction of Calendula officinalis seeds led to the isolation of two compounds identified as 28-O-β-D-glucopyranosyl-oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS1) and oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS2). Biological evaluation was carried out for these two compounds such as melanin biosynthesis inhibitory, hyaluronic acid production activities, anti obesity using lipase inhibition and adipocyte differentiation as well as evaluation of the protective effect against hydrogen peroxide induced neurotoxicity in neuro-2A cells. The results showed that, compound CS2 has a melanin biosynthesis stimulatory activity; however, compound CS1 has a potent stimulatory effect for the production of hyaluronic acid on normal human dermal fibroblast from adult (NHDF-Ad). Both compounds did not show any inhibitory effect on both lipase and adipocyte differentiation. Compound CS2 could protect neuro-2A cells and increased cell viability against H2 O2 . These activities (melanin biosynthesis stimulatory and protective effect against H2 O2 of CS2 and hyaluronic acid productive activities of these triterpene derivatives) have been reported for the first time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Fatty acid synthase inhibition activates AMP-activated protein kinase in SKOV3 human ovarian cancer cells.

PubMed

Zhou, Weibo; Han, Wan Fang; Landree, Leslie E; Thupari, Jagan N; Pinn, Michael L; Bililign, Tsion; Kim, Eun Kyoung; Vadlamudi, Aravinda; Medghalchi, Susan M; El Meskini, Rajaa; Ronnett, Gabriele V; Townsend, Craig A; Kuhajda, Francis P

2007-04-01

Fatty acid synthase (FAS), the enzyme responsible for the de novo synthesis of fatty acids, is highly expressed in ovarian cancers and most common human carcinomas. Inhibition of FAS and activation of AMP-activated protein kinase (AMPK) have been shown to be cytotoxic to human cancer cells in vitro and in vivo. In this report, we explore the cytotoxic mechanism of action of FAS inhibition and show that C93, a synthetic FAS inhibitor, increases the AMP/ATP ratio, activating AMPK in SKOV3 human ovarian cancer cells, which leads to cytotoxicity. As a physiologic consequence of AMPK activation, acetyl-CoA carboxylase (ACC), the rate-limiting enzyme of fatty acid synthesis, was phosphorylated and inhibited whereas glucose oxidation was increased. Despite these attempts to conserve energy, the AMP/ATP ratio increased with worsening cellular redox status. Pretreatment of SKOV3 cells with compound C, an AMPK inhibitor, substantially rescued the cells from C93 cytotoxicity, indicating its dependence on AMPK activation. 5-(Tetradecyloxy)-2-furoic acid, an ACC inhibitor, did not activate AMPK despite inhibiting fatty acid synthesis pathway activity and was not significantly cytotoxic to SKOV3 cells. This indicates that substrate accumulation from FAS inhibition triggering AMPK activation, not end-product depletion of fatty acids, is likely responsible for AMPK activation. C93 also exhibited significant antitumor activity and apoptosis against SKOV3 xenografts in athymic mice without significant weight loss or cytotoxicity to proliferating cellular compartments such as bone marrow, gastrointestinal tract, or skin. Thus, pharmacologic FAS inhibition selectively activates AMPK in ovarian cancer cells, inducing cytotoxicity while sparing most normal human tissues from the pleiotropic effects of AMPK activation.

The History of Maltose-active Disaccharidases.

PubMed

Lentze, Michael J

2018-06-01

The history of maltose-active disaccharidases is closely related to the history of the sugar and starch industry. It began in the 19th century, when a shortage of cane sugar occurred in continental Europe, because Napoleon Bonaparte decreed that no goods could be imported from England to the countries he occupied. Other sugar sources had to be found, and it led to the identification of sugar beets as alternative source of sugar by Marggraf in 1774, to the detection of starch hydrolysis by diluted sulfuric acid by Kirchhoff in 1812, and to the starch digestion enzyme, α-amylase, by Payen in 1833. In the 20th century, Borkström's group in Sweden investigated the absorption of nutrients in human adults by transintubation techniques and found that the luminal concentration of invertase was small compared to that of α-amylase. They speculated that the major locus of this enzyme activity must be in the intestinal cells. Borkström's coworker, Dahlqvist, investigated the maltose-active enzymes in pig intestine, and a second group around Semenza studied the maltase-active enzymes in rabbit intestine. After the first descriptions of congenital sucrase-isomaltase deficiency in 1960 and 1961, the research on disaccharidases increased. Dahlqvist published the first quantitative method to measure these enzymes. Consecutive research led to the discovery of 4 maltases, which were later identified as 2 complex enzymes: the sucrase-isomaltase complex and the maltase-glucoamylase complex. The homology of the 2 enzyme complexes was later determined when the cDNA sequences of the 2 complexes in human intestine were identified.

Formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations - A review.

PubMed

Zhao, Cindy J; Schieber, Andreas; Gänzle, Michael G

2016-11-01

Fermented foods are valued for their rich and complex odour and taste. The metabolic activity of food-fermenting microorganisms determines food quality and generates odour and taste compounds. This communication reviews the formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations. Pathways of the generation of taste compounds are presented for soy sauce, cheese, fermented meats, and bread. Proteolysis or autolysis during food fermentations generates taste-active amino acids and peptides; peptides derived from proteolysis particularly impart umami taste (e.g. α-glutamyl peptides) or bitter taste (e.g. hydrophobic peptides containing proline). Taste active peptide derivatives include pyroglutamyl peptides, γ-glutamyl peptides, and succinyl- or lactoyl amino acids. The influence of fermentation microbiota on proteolysis, and peptide hydrolysis, and the metabolism of glutamate and arginine is well understood, however, the understanding of microbial metabolic activities related to the formation of taste-active peptide derivatives is incomplete. Improved knowledge of the interactions between taste-active compounds will enable the development of novel fermentation strategies to develop tastier, less bitter, and low-salt food products, and may provide novel and "clean label" ingredients to improve the taste of other food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of starch with antioxidative activity by baking starch with organic acids.

PubMed

Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

2011-01-01

A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

Mechanisms for the activation of Toll-like receptor 2/4 by saturated fatty acids and inhibition by docosahexaenoic acid.

PubMed

Hwang, Daniel H; Kim, Jeong-A; Lee, Joo Young

2016-08-15

Saturated fatty acids can activate Toll-like receptor 2 (TLR2) and TLR4 but polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA) inhibit the activation. Lipopolysaccharides (LPS) and lipopetides, ligands for TLR4 and TLR2, respectively, are acylated by saturated fatty acids. Removal of these fatty acids results in loss of their ligand activity suggesting that the saturated fatty acyl moieties are required for the receptor activation. X-ray crystallographic studies revealed that these saturated fatty acyl groups of the ligands directly occupy hydrophobic lipid binding domains of the receptors (or co-receptor) and induce the dimerization which is prerequisite for the receptor activation. Saturated fatty acids also induce the dimerization and translocation of TLR4 and TLR2 into lipid rafts in plasma membrane and this process is inhibited by DHA. Whether saturated fatty acids induce the dimerization of the receptors by interacting with these lipid binding domains is not known. Many experimental results suggest that saturated fatty acids promote the formation of lipid rafts and recruitment of TLRs into lipid rafts leading to ligand independent dimerization of the receptors. Such a mode of ligand independent receptor activation defies the conventional concept of ligand induced receptor activation; however, this may enable diverse non-microbial molecules with endogenous and dietary origins to modulate TLR-mediated immune responses. Emerging experimental evidence reveals that TLRs play a key role in bridging diet-induced endocrine and metabolic changes to immune responses. Published by Elsevier B.V.

Evaluation of the antibacterial activity of the methylene chloride extract of Miconia ligustroides, isolated triterpene acids, and ursolic acid derivatives.

PubMed

Cunha, Wilson R; de Matos, Geilton X; Souza, Maria Goreti M; Tozatti, Marcos G; Andrade e Silva, Márcio L; Martins, Carlos H G; da Silva, Rosangela; Da Silva Filho, Ademar A

2010-02-01

The methylene chloride extract of Miconia ligustroides (DC.) Naudin (Melastomataceae), the isolated compounds ursolic and oleanolic acids and a mixture of these acids, and ursolic acid derivatives were evaluated against the following microorganisms: Bacillus cereus (ATCC 14579), Vibrio cholerae (ATCC 9458), Salmonella choleraesuis (ATCC 10708), Klebsiella pneumoniae (ATCC 10031), and Streptococcus pneumoniae (ATCC 6305). The microdilution method was used for determination of the minimum inhibitory concentration (MIC) during evaluation of the antibacterial activity. The methylene chloride extract showed no activity against the selected microorganisms. Ursolic acid was active against B. cereus, showing a MIC value of 20 microg/mL. Oleanolic acid was effective against B. cereus and S. pneumoniae with a MIC of 80 microg/mL in both cases. The mixture of triterpenes, ursolic and oleanolic acids, did not enhance the antimicrobial activity. However, the acetyl and methyl ester derivatives, prepared from ursolic acid, increased the inhibitory activity for S. pneumoniae.

EMF radiations (1800 MHz)-inhibited early seedling growth of maize (Zea mays) involves alterations in starch and sucrose metabolism.

PubMed

Kumar, Arvind; Singh, Harminder Pal; Batish, Daizy R; Kaur, Shalinder; Kohli, Ravinder Kumar

2016-07-01

The present study investigated the impact of 1800-MHz electromagnetic field radiations (EMF-r), widely used in mobile communication, on the growth and activity of starch-, sucrose-, and phosphate-hydrolyzing enzymes in Zea mays seedlings. We exposed Z. mays to modulated continuous wave homogenous EMF-r at specific absorption rate (SAR) of 1.69±0.0 × 10(-1) W kg(-1) for ½, 1, 2, and 4 h. The analysis of seedlings after 7 days revealed that short-term exposure did not induce any significant change, while longer exposure of 4 h caused significant growth and biochemical alterations. There was a reduction in the root and coleoptile length with more pronounced effect on coleoptile growth (23 % reduction on 4-h exposure). The contents of photosynthetic pigments and total carbohydrates declined by 13 and 18 %, respectively, in 4-h exposure treatments compared to unexposed control. The activity of starch-hydrolyzing enzymes-α- and β-amylases-increased by ∼92 and 94 %, respectively, at an exposure duration of 4 h, over that in the control. In response to 4-h exposure treatment, the activity of sucrolytic enzymes-acid invertases and alkaline invertases-was increased by 88 and 266 %, whereas the specific activities of phosphohydrolytic enzymes (acid phosphatases and alkaline phosphatases) showed initial increase up to ≤2 h duration and then declined at >2 h exposure duration. The study concludes that EMF-r-inhibited seedling growth of Z. mays involves interference with starch and sucrose metabolism.

Synthesis and Anti-microbial Activity of Novel Phosphatidylethanolamine-N-amino Acid Derivatives.

PubMed

Vijeetha, Tadla; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Surya Koppeswara Rao, Bhamidipati Venkata; Prasad, Rachapudi Badari Narayana; Kumar, Koochana Pranay; Surya Narayana Murthy, Upadyaula

2015-01-01

The study involved synthesis of five novel amino acid derivatives of phosphatidylethanolamine isolated from egg yolk lecithin employing a three step procedure i) N-protection of L-amino acids with BOC anhydride in alkaline medium ii) condensation of - CO2H group of N-protected amino acid with free -NH2 of PE by a peptide linkage and iii) deprotection of N-protected group of amino acids to obtain phosphatidylethanolamine-N-amino acid derivatives in 60-75% yield. The five L-amino acids used were L glycine, L-valine, L-leucine, L-isoleucine and L-phenylalanine. The amino acid derivatives were screened for anti-baterial activity against B. subtilis, S. aureus, P. aeroginosa and E. coli taking Streptomycin as reference compound and anti-fungal activity against C. albicans, S. cervisiae, A. niger taking AmphotericinB as reference compound. All the amino acid derivatives exhibited extraordinary anti-bacterial activities about 3 folds or comparable to Streptomycin and moderate or no anti-fungal activity against Amphotericin-B.

Fatty acid-amino acid conjugates are essential for systemic activation of salicylic acid-induced protein kinase and accumulation of jasmonic acid in Nicotiana attenuata.

PubMed

Hettenhausen, Christian; Heinrich, Maria; Baldwin, Ian T; Wu, Jianqiang

2014-11-28

Herbivory induces the activation of mitogen-activated protein kinases (MAPKs), the accumulation of jasmonates and defensive metabolites in damaged leaves and in distal undamaged leaves. Previous studies mainly focused on individual responses and a limited number of systemic leaves, and more research is needed for a better understanding of how different plant parts respond to herbivory. In the wild tobacco Nicotiana attenuata, FACs (fatty acid-amino acid conjugates) in Manduca sexta oral secretions (OS) are the major elicitors that induce herbivory-specific signaling but their role in systemic signaling is largely unknown. Here, we show that simulated herbivory (adding M. sexta OS to fresh wounds) dramatically increased SIPK (salicylic acid-induced protein kinase) activity and jasmonic acid (JA) levels in damaged leaves and in certain (but not all) undamaged systemic leaves, whereas wounding alone had no detectable systemic effects; importantly, FACs and wounding are both required for activating these systemic responses. In contrast to the activation of SIPK and elevation of JA in specific systemic leaves, increases in the activity of an important anti-herbivore defense, trypsin proteinase inhibitor (TPI), were observed in all systemic leaves after simulated herbivory, suggesting that systemic TPI induction does not require SIPK activation and JA increases. Leaf ablation experiments demonstrated that within 10 minutes after simulated herbivory, a signal (or signals) was produced and transported out of the treated leaves, and subsequently activated systemic responses. Our results reveal that N. attenuata specifically recognizes herbivore-derived FACs in damaged leaves and rapidly send out a long-distance signal to phylotactically connected leaves to activate MAPK and JA signaling, and we propose that FACs that penetrated into wounds rapidly induce the production of another long-distance signal(s) which travels to all systemic leaves and activates TPI defense.

A gain-of-function mutation of plastidic invertase alters nuclear gene expression with sucrose treatment partially via GENOMES UNCOUPLED1-mediated signaling.

PubMed

Maruta, Takanori; Miyazaki, Nozomi; Nosaka, Ryota; Tanaka, Hiroyuki; Padilla-Chacon, Daniel; Otori, Kumi; Kimura, Ayako; Tanabe, Noriaki; Yoshimura, Kazuya; Tamoi, Masahiro; Shigeoka, Shigeru

2015-05-01

Plastid gene expression (PGE) is one of the signals that regulate the expression of photosynthesis-associated nuclear genes (PhANGs) via GENOMES UNCOUPLED1 (GUN1)-dependent retrograde signaling. We recently isolated Arabidopsis sugar-inducible cotyledon yellow-192 (sicy-192), a gain-of-function mutant of plastidic invertase, and showed that following the treatment of this mutant with sucrose, the expression of PhANGs as well as PGE decreased, suggesting that the sicy-192 mutation activates a PGE-evoked and GUN1-mediated retrograde pathway. To clarify the relationship between the sicy-192 mutation, PGE, and GUN1-mediated pathway, plastid and nuclear gene expression in a double mutant of sicy-192 and gun1-101, a null mutant of GUN1 was studied. Plastid-encoded RNA polymerase (PEP)-dependent PGE was markedly suppressed in the sicy-192 mutant by the sucrose treatment, but the suppression as well as cotyledon yellow phenotype was not mitigated by GUN1 disruption. Microarray analysis revealed that the altered expression of nuclear genes such as PhANG in the sucrose-treated sicy-192 mutant was largely dependent on GUN1. The present findings demonstrated that the sicy-192 mutation alters nuclear gene expression with sucrose treatment via GUN1, which is possibly followed by inhibiting PEP-dependent PGE, providing a new insight into the role of plastid sugar metabolism in nuclear gene expression. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

One-step production of a biologically active novel furan fatty acid from 7,10-dihydroxy-8(E)-octadecenoic acid

USDA-ARS?s Scientific Manuscript database

Furan fatty acids (F-acids) gain special attentions since they are known to play important roles in biological systems including humans. Specifically F-acids are known to have strong antioxidant activity like radical scavenging activity. Although widely distributed in most biological systems, F-ac...

Allspice and Clove As Source of Triterpene Acids Activating the G Protein-Coupled Bile Acid Receptor TGR5

PubMed Central

Ladurner, Angela; Zehl, Martin; Grienke, Ulrike; Hofstadler, Christoph; Faur, Nadina; Pereira, Fátima C.; Berry, David; Dirsch, Verena M.; Rollinger, Judith M.

2017-01-01

Worldwide, metabolic diseases such as obesity and type 2 diabetes have reached epidemic proportions. A major regulator of metabolic processes that gained interest in recent years is the bile acid receptor TGR5 (Takeda G protein-coupled receptor 5). This G protein-coupled membrane receptor can be found predominantly in the intestine, where it is mainly responsible for the secretion of the incretins glucagon-like peptide 1 (GLP-1) and peptide YY (PYY). The aim of this study was (i) to identify plant extracts with TGR5-activating potential, (ii) to narrow down their activity to the responsible constituents, and (iii) to assess whether the intestinal microbiota produces transformed metabolites with a different activity profile. Chenodeoxycholic acid (CDCA) served as positive control for both, the applied cell-based luciferase reporter gene assay for TGR5 activity and the biotransformation assay using mouse fecal slurry. The suitability of the workflow was demonstrated by the biotransformation of CDCA to lithocholic acid resulting in a distinct increase in TGR5 activity. Based on a traditional Tibetan formula, 19 plant extracts were selected and investigated for TGR5 activation. Extracts from the commonly used spices Syzygium aromaticum (SaroE, clove), Pimenta dioica (PdioE, allspice), and Kaempferia galanga (KgalE, aromatic ginger) significantly increased TGR5 activity. After biotransformation, only KgalE showed significant differences in its metabolite profile, which, however, did not alter its TGR5 activity compared to non-transformed KgalE. UHPLC-HRMS (high-resolution mass spectrometry) analysis revealed triterpene acids (TTAs) as the main constituents of the extracts SaroE and PdioE. Identification and quantification of TTAs in these two extracts as well as comparison of their TGR5 activity with reconstituted TTA mixtures allowed the attribution of the TGR5 activity to TTAs. EC50s were determined for the main TTAs, i.e., oleanolic acid (2.2 ± 1.6 μM), ursolic

Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

NASA Astrophysics Data System (ADS)

Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

2016-02-01

Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

Development of Activity-based Cost Functions for Cellulase, Invertase, and Other Enzymes

NASA Astrophysics Data System (ADS)

Stowers, Chris C.; Ferguson, Elizabeth M.; Tanner, Robert D.

As enzyme chemistry plays an increasingly important role in the chemical industry, cost analysis of these enzymes becomes a necessity. In this paper, we examine the aspects that affect the cost of enzymes based upon enzyme activity. The basis for this study stems from a previously developed objective function that quantifies the tradeoffs in enzyme purification via the foam fractionation process (Cherry et al., Braz J Chem Eng 17:233-238, 2000). A generalized cost function is developed from our results that could be used to aid in both industrial and lab scale chemical processing. The generalized cost function shows several nonobvious results that could lead to significant savings. Additionally, the parameters involved in the operation and scaling up of enzyme processing could be optimized to minimize costs. We show that there are typically three regimes in the enzyme cost analysis function: the low activity prelinear region, the moderate activity linear region, and high activity power-law region. The overall form of the cost analysis function appears to robustly fit the power law form.

Identification of the fatty acid activation site on human ClC-2.

PubMed

Cuppoletti, John; Tewari, Kirti P; Chakrabarti, Jayati; Malinowska, Danuta H

2017-06-01

Fatty acids (including lubiprostone and cobiprostone) are human ClC-2 (hClC-2) Cl - channel activators. Molecular and cellular mechanisms underlying this activation were examined. Role of a four-amino acid PKA activation site, RGET 691 , of hClC-2 was investigated using wild-type (WT) and mutant (AGET, RGEA, and AGAA) hClC-2 expressed in 293EBNA cells as well as involvement of PKA, intracellular cAMP concentration ([cAMP] i ), EP 2 , or EP 4 receptor agonist activity. All fatty acids [lubiprostone, cobiprostone, eicosatetraynoic acid (ETYA), oleic acid, and elaidic acid] caused significant rightward shifts in concentration-dependent Cl - current activation (increasing EC 50 s) with mutant compared with WT hClC-2 channels, without changing time and voltage dependence, current-voltage rectification, or methadone inhibition of the channel. As with lubiprostone, cobiprostone activation of hClC-2 occurred with PKA inhibitor (myristoylated protein kinase inhibitor) present or when using double PKA activation site (RRAA 655 /RGEA 691 ) mutant. Cobiprostone did not activate human CFTR. Fatty acids did not increase [cAMP] i in hClC-2/293EBNA or T84 cells. Using T84 CFTR knockdown cells, cobiprostone increased hClC-2 Cl - currents without increasing [cAMP] i, while PGE 2 and forskolin-IBMX increased both. Fatty acids were not agonists of EP 2 or EP 4 receptors. L-161,982, a supposed EP 4 -selective inhibitor, had no effect on lubiprostone-activated hClC-2 Cl - currents but significantly decreased T84 cell barrier function measured by transepithelial resistance and fluorescent dextran transepithelial movement. The present findings show that RGET 691 of hClC-2 (possible binding site) plays an important functional role in fatty acid activation of hClC-2. PKA, [cAMP] i , and EP 2 or EP 4 receptors are not involved. These studies provide the molecular basis for fatty acid regulation of hClC-2. Copyright © 2017 the American Physiological Society.

PtrA/NINV, an alkaline/neutral invertase gene of Poncirus trifoliata, confers enhanced tolerance to multiple abiotic stresses by modulating ROS levels and maintaining photosynthetic efficiency.

PubMed

Dahro, Bachar; Wang, Fei; Peng, Ting; Liu, Ji-Hong

2016-03-29

Alkaline/neutral invertase (A/N-INV), an enzyme that hydrolyzes sucrose irreversibly into glucose and fructose, is essential for normal plant growth,development, and stress tolerance. However, the physiological and/or molecular mechanism underpinning the role of A/N-INV in abiotic stress tolerance is poorly understood. In this report, an A/N-INV gene (PtrA/NINV) was isolated from Poncirus trifoliata, a cold-hardy relative of citrus, and functionally characterized. PtrA/NINV expression levels were induced by cold, salt, dehydration, sucrose, and ABA, but decreased by glucose. PtrA/NINV was found to localize in both chloroplasts and mitochondria. Overexpression of PtrA/NINV conferred enhanced tolerance to multiple stresses, including cold, high salinity, and drought, as supported by lower levels of reactive oxygen species (ROS), reduced oxidative damages, decreased water loss rate, and increased photosynthesis efficiency, relative to wild-type (WT). The transgenic plants exhibited higher A/N-INV activity and greater reducing sugar content under normal and stress conditions. PtrA/NINV is an important gene implicated in sucrose decomposition, and plays a positive role in abiotic stress tolerance by promoting osmotic adjustment, ROS detoxification and photosynthesis efficiency. Thus, PtrA/NINV has great potential to be used in transgenic breeding for improvement of stress tolerance.

Sugar homeostasis mediated by cell wall invertase GRAIN INCOMPLETE FILLING 1 (GIF1) plays a role in pre-existing and induced defence in rice.

PubMed

Sun, Li; Yang, Dong-lei; Kong, Yu; Chen, Ying; Li, Xiao-Zun; Zeng, Long-Jun; Li, Qun; Wang, Er-Tao; He, Zu-Hua

2014-02-01

Sugar metabolism and sugar signalling are not only critical for plant growth and development, but are also important for stress responses. However, how sugar homeostasis is involved in plant defence against pathogen attack in the model crop rice remains largely unknown. In this study, we observed that the grains of gif1, a loss-of-function mutant of the cell wall invertase gene GRAIN INCOMPLETE FILLING 1 (GIF1), were hypersusceptible to postharvest fungal pathogens, with decreased levels of sugars and a thinner glume cell wall in comparison with the wild-type. Interestingly, constitutive expression of GIF1 enhanced resistance to both the rice bacterial pathogen Xanthomonas oryzae pv. oryzae and the fungal pathogen Magnaporthe oryzae. The GIF1-overexpressing (GIF1-OE) plants accumulated higher levels of glucose, fructose and sucrose compared with the wild-type plants. More importantly, higher levels of callose were deposited in GIF1-OE plants during pathogen infection. Moreover, the cell wall was much thicker in the infection sites of the GIF1-OE plants when compared with the wild-type plants. We also found that defence-related genes were constitutively activated in the GIF1-OE plants. Taken together, our study reveals that sugar homeostasis mediated by GIF1 plays an important role in constitutive and induced physical and chemical defence. © 2013 BSPP AND JOHN WILEY & SONS LTD.

The HIV-1 transcriptional activator Tat has potent nucleic acid chaperoning activities in vitro.

PubMed

Kuciak, Monika; Gabus, Caroline; Ivanyi-Nagy, Roland; Semrad, Katharina; Storchak, Roman; Chaloin, Olivier; Muller, Sylviane; Mély, Yves; Darlix, Jean-Luc

2008-06-01

The human immunodeficiency virus type 1 (HIV-1) is a primate lentivirus that causes the acquired immunodeficiency syndrome (AIDS). In addition to the virion structural proteins and enzyme precursors, that are Gag, Env and Pol, HIV-1 encodes several regulatory proteins, notably a small nuclear transcriptional activator named Tat. The Tat protein is absolutely required for virus replication since it controls proviral DNA transcription to generate the full-length viral mRNA. Tat can also regulate mRNA capping and splicing and was recently found to interfere with the cellular mi- and siRNA machinery. Because of its extensive interplay with nucleic acids, and its basic and disordered nature we speculated that Tat had nucleic acid-chaperoning properties. This prompted us to examine in vitro the nucleic acid-chaperoning activities of Tat and Tat peptides made by chemical synthesis. Here we report that Tat has potent nucleic acid-chaperoning activities according to the standard DNA annealing, DNA and RNA strand exchange, RNA ribozyme cleavage and trans-splicing assays. The active Tat(44-61) peptide identified here corresponds to the smallest known sequence with DNA/RNA chaperoning properties.

The HIV-1 transcriptional activator Tat has potent nucleic acid chaperoning activities in vitro

PubMed Central

Kuciak, Monika; Gabus, Caroline; Ivanyi-Nagy, Roland; Semrad, Katharina; Storchak, Roman; Chaloin, Olivier; Muller, Sylviane; Mély, Yves; Darlix, Jean-Luc

2008-01-01

The human immunodeficiency virus type 1 (HIV-1) is a primate lentivirus that causes the acquired immunodeficiency syndrome (AIDS). In addition to the virion structural proteins and enzyme precursors, that are Gag, Env and Pol, HIV-1 encodes several regulatory proteins, notably a small nuclear transcriptional activator named Tat. The Tat protein is absolutely required for virus replication since it controls proviral DNA transcription to generate the full-length viral mRNA. Tat can also regulate mRNA capping and splicing and was recently found to interfere with the cellular mi- and siRNA machinery. Because of its extensive interplay with nucleic acids, and its basic and disordered nature we speculated that Tat had nucleic acid-chaperoning properties. This prompted us to examine in vitro the nucleic acid-chaperoning activities of Tat and Tat peptides made by chemical synthesis. Here we report that Tat has potent nucleic acid-chaperoning activities according to the standard DNA annealing, DNA and RNA strand exchange, RNA ribozyme cleavage and trans-splicing assays. The active Tat(44–61) peptide identified here corresponds to the smallest known sequence with DNA/RNA chaperoning properties. PMID:18442994

Antiviral Activity of Polyacrylic and Polymethacrylic Acids

PubMed Central

De Somer, P.; De Clercq, E.; Billiau, A.; Schonne, E.; Claesen, M.

1968-01-01

Polyacrylic acid (PAA) and polymethacrylic acid (PMAA) were investigated for their antiviral properties in tissue culture. Compared to other related polyanions, as dextran sulfate, polystyrene sulfonate, polyvinyl sulfate, and polyphloroglucinol phosphate, PAA and PMAA were found to be significantly more antivirally active and less cytotoxic. PMAA added 24 hr prior to virus inoculation inhibited viral growth most efficiently but it was still effective when added 3 hr after infection. Neither a direct irreversible action on the virus nor inhibition of virus penetration into the cell could explain the antiviral activity of PMAA. PMAA inhibited the adsorption of the virus to the host cell and suppressed the one-cycle viral synthesis in tissue cultures inoculated with infectious RNA. PMID:4302187

Tapping natural variation at functional level reveals allele specific molecular characteristics of potato invertase Pain-1.

PubMed

Draffehn, Astrid M; Durek, Pawel; Nunes-Nesi, Adriano; Stich, Benjamin; Fernie, Alisdair R; Gebhardt, Christiane

2012-12-01

Biochemical, molecular and genetic studies emphasize the role of the potato vacuolar invertase Pain-1 in the accumulation of reducing sugars in potato tubers upon cold storage, and thereby its influence on the quality of potato chips and French fries. Previous studies showed that natural Pain-1 cDNA alleles were associated with better chip quality and higher tuber starch content. In this study, we focused on the functional characterization of these alleles. A genotype-dependent transient increase of total Pain-1 transcript levels in cold-stored tubers of six different genotypes as well as allele-specific expression patterns were detected. 3D modelling revealed putative structural differences between allelic Pain-1 proteins at the molecule's surface and at the substrate binding site. Furthermore, the yeast SUC2 mutant was complemented with Pain-1 cDNA alleles and enzymatic parameters of the heterologous expressed proteins were measured at 30 and 4 °C. Significant differences between the alleles were detected. The observed functional differences between Pain-1 alleles did not permit final conclusions on the mechanism of their association with tuber quality traits. Our results show that natural allelic variation at the functional level is present in potato, and that the heterozygous genetic background influences the manifestation of this variation. © 2012 Blackwell Publishing Ltd.

Vacuolar status and water relations in embryonic axes of recalcitrant Aesculus hippocastanum seeds during stratification and early germination.

PubMed

Obroucheva, Natalie V; Lityagina, Snezhana V; Novikova, Galina V; Sin'kevich, Irina A

2012-01-01

In tropical recalcitrant seeds, their rapid transition from shedding to germination at high hydration level is of physiological interest but difficult to study because of the time constraint. In recalcitrant horse chestnut seeds produced in central Russia, this transition is much longer and extends through dormancy and dormancy release. This extended time period permits studies of the water relations in embryonic axes during the long recalcitrant period in terms of vacuolar status and water transport. Horse chestnut (Aesculus hippocastanum) seeds sampled in Moscow were stratified in cold wet sand for 4 months. Vacuole presence and development in embryonic axes were examined by vital staining, light and electron microscopy. Aquaporins and vacuolar H(+)-ATPase were identified immunochemically. Water channel operation was tested by water inflow rate. Vacuolar acid invertase was estimated in terms of activity and electrophoretic properties. Throughout the long recalcitrant period after seed shedding, cells of embryonic axes maintained active vacuoles and a high water content. Preservation of enzyme machinery in vacuoles was evident from retention of invertase activity, substrate specificity, molecular mass and subunit composition. Plasmalemma and tonoplast aquaporins and the E subunit of vacuolar H(+)-ATPase were also present. In non-dormant seeds prior to growth initiation, vacuoles enlarged at first in hypocotyls, and then in radicles, with their biogenesis being similar. Vacuolation was accompanied by increasing invertase activity, leading to sugar accumulation and active osmotic functioning. After growth initiation, vacuole enlargement was favoured by enhanced water inflow through water channels formed by aquaporins. Maintenance of high water content and desiccation sensitivity, as well as preservation of active vacuoles in embryonic axes after shedding, can be considered a specific feature of recalcitrant seeds, overlooked when studying tropical recalcitrants due

Vacuolar status and water relations in embryonic axes of recalcitrant Aesculus hippocastanum seeds during stratification and early germination

PubMed Central

Obroucheva, Natalie V.; Lityagina, Snezhana V.; Novikova, Galina V.; Sin'kevich, Irina A.

2012-01-01

Backgrounds and aims In tropical recalcitrant seeds, their rapid transition from shedding to germination at high hydration level is of physiological interest but difficult to study because of the time constraint. In recalcitrant horse chestnut seeds produced in central Russia, this transition is much longer and extends through dormancy and dormancy release. This extended time period permits studies of the water relations in embryonic axes during the long recalcitrant period in terms of vacuolar status and water transport. Methodology Horse chestnut (Aesculus hippocastanum) seeds sampled in Moscow were stratified in cold wet sand for 4 months. Vacuole presence and development in embryonic axes were examined by vital staining, light and electron microscopy. Aquaporins and vacuolar H+-ATPase were identified immunochemically. Water channel operation was tested by water inflow rate. Vacuolar acid invertase was estimated in terms of activity and electrophoretic properties. Principal results Throughout the long recalcitrant period after seed shedding, cells of embryonic axes maintained active vacuoles and a high water content. Preservation of enzyme machinery in vacuoles was evident from retention of invertase activity, substrate specificity, molecular mass and subunit composition. Plasmalemma and tonoplast aquaporins and the E subunit of vacuolar H+-ATPase were also present. In non-dormant seeds prior to growth initiation, vacuoles enlarged at first in hypocotyls, and then in radicles, with their biogenesis being similar. Vacuolation was accompanied by increasing invertase activity, leading to sugar accumulation and active osmotic functioning. After growth initiation, vacuole enlargement was favoured by enhanced water inflow through water channels formed by aquaporins. Conclusions Maintenance of high water content and desiccation sensitivity, as well as preservation of active vacuoles in embryonic axes after shedding, can be considered a specific feature of recalcitrant

Triboelectrification of active pharmaceutical ingredients: week acids and their salts.

PubMed

Fujinuma, Kenta; Ishii, Yuji; Yashihashi, Yasuo; Yonemochi, Estuo; Sugano, Kiyohiko; Tarada, Katsuhide

2015-09-30

The effect of salt formulation on the electrostatic property of active pharmaceutical ingredients was investigated. The electrostatic property of weak acids (carboxylic acids and amide-enole type acid) and their sodium salts was evaluated by a suction-type Faraday cage meter. Free carboxylic acids showed negative chargeability, whereas their sodium salts showed more positive chargeability than the free acids. However, no such trend was observed for amide-enole type acids. Copyright © 2015 Elsevier B.V. All rights reserved.

Saturated fatty acids activate TLR-mediated pro-inflammatory signaling pathways

USDA-ARS?s Scientific Manuscript database

Toll-like receptor 4 (TLR4) and TLR2 were shown to be activated by saturated fatty acids (SFAs) but inhibited by docosahexaenoic acid (DHA). However, one report (ATVB 11:1944, 2009) suggested that SFA-induced TLR activation in cell culture systems is due to contaminants in BSA used for conjugating f...

Structural Requirements of Alkylglyceryl-l-Ascorbic Acid Derivatives for Melanogenesis Inhibitory Activity.

PubMed

Taira, Norihisa; Katsuyama, Yushi; Yoshioka, Masato; Muraoka, Osamu; Morikawa, Toshio

2018-04-10

l-Ascorbic acid has multifunctional benefits on skin aesthetics, including inhibition of melanin production, and is widely used in cosmetics. It, however, has low stability and poor skin penetration. We hypothesize that alkylglyceryl-l-ascorbic acid derivatives, highly stable vitamin C-alkylglycerol conjugates, would have similar anti-melanogenic activity with better stability and penetration. We test 28 alkylglyceryl-l-ascorbic acid derivatives ( 1 - 28 ) on theophylline-stimulated B16 melanoma 4A5 cells to determine if they inhibit melanogenesis and establish any structure-function relationships. Although not the most potent inhibitors, 3- O -(2,3-dihydroxypropyl)-2- O -hexyl-l-ascorbic acid ( 6 , IC 50 = 81.4 µM) and 2- O -(2,3-dihydroxypropyl)-3- O -hexyl-l-ascorbic acid ( 20 , IC 50 = 117 µM) are deemed the best candidate derivatives based on their inhibitory activities and low toxicities. These derivatives are also found to be more stable than l-ascorbic acid and to have favorable characteristics for skin penetration. The following structural requirements for inhibitory activity of alkylglyceryl-l-ascorbic acid derivatives are also determined: (i) alkylation of glyceryl-l-ascorbic acid is essential for inhibitory activity; (ii) the 3- O -alkyl-derivatives ( 2 - 14 ) exhibit stronger inhibitory activity than the corresponding 2- O -alkyl-derivatives ( 16 - 28 ); and (iii) derivatives with longer alkyl chains have stronger inhibitory activities. Mechanistically, our studies suggest that l-ascorbic acid derivatives exert their effects by suppressing the mRNA expression of tyrosinase and tyrosine-related protein-1.

Antimicrobial activity of fatty acid methyl esters of some members of Chenopodiaceae.

PubMed

Chandrasekaran, Manivachagam; Kannathasan, Krishnan; Venkatesalu, Venugopalan

2008-01-01

Fatty acid methyl ester (FAME) extracts of four halophytic plants, viz. Arthrocnemum indicum, Salicornia brachiata, Suaeda maritima and Suaeda monoica belonging to the family Chenopodiaceae, were prepared and their composition was analyzed by GC-MS. The FAME extracts were also screened for antibacterial and antifungal activities. The GC-MS analysis revealed the presence of more saturated fatty acids than unsaturated fatty acids. Among the fatty acids analyzed, the relative percentage of lauric acid was high in S. brachiata (61.85%). The FAME extract of S. brachiata showed the highest antibacterial and antifungal activities among the extracts tested. The other three extracts showed potent antibacterial and moderate anticandidal activities.

Key mediators of intracellular amino acids signaling to mTORC1 activation.

PubMed

Duan, Yehui; Li, Fengna; Tan, Kunrong; Liu, Hongnan; Li, Yinghui; Liu, Yingying; Kong, Xiangfeng; Tang, Yulong; Wu, Guoyao; Yin, Yulong

2015-05-01

Mammalian target of rapamycin complex 1 (mTORC1) is activated by amino acids to promote cell growth via protein synthesis. Specifically, Ras-related guanosine triphosphatases (Rag GTPases) are activated by amino acids, and then translocate mTORC1 to the surface of late endosomes and lysosomes. Ras homolog enriched in brain (Rheb) resides on this surface and directly activates mTORC1. Apart from the presence of intracellular amino acids, Rag GTPases and Rheb, other mediators involved in intracellular amino acid signaling to mTORC1 activation include human vacuolar sorting protein-34 (hVps34) and mitogen-activating protein kinase kinase kinase kinase-3 (MAP4K3). Those molecular links between mTORC1 and its mediators form a complicate signaling network that controls cellular growth, proliferation, and metabolism. Moreover, it is speculated that amino acid signaling to mTORC1 may start from the lysosomal lumen. In this review, we discussed the function of these mediators in mTORC1 pathway and how these mediators are regulated by amino acids in details.

Efficient synthesis of anacardic acid analogues and their antibacterial activities.

PubMed

Mamidyala, Sreeman K; Ramu, Soumya; Huang, Johnny X; Robertson, Avril A B; Cooper, Matthew A

2013-03-15

Anacardic acid derivatives exhibit a broad range of biological activities. In this report, an efficient method for the synthesis of anacardic acid derivatives was explored, and a small set of salicylic acid variants synthesised retaining a constant hydrophobic element (a naphthyl tail). The naphthyl side chain was introduced via Wittig reaction and the aldehyde installed using directed ortho-metalation reaction of the substituted o-anisic acids. The failure of ortho-metalation using unprotected carboxylic acid group compelled us to use directed ortho-metalation in which a tertiary amide was used as a strong ortho-directing group. In the initial route, tertiary amide cleavage during final step was challenging, but cleaving the tertiary amide before Wittig reaction was beneficial. The Wittig reaction with protected carboxylic group (methyl ester) resulted in side-products whereas using sodium salt resulted in higher yields. The novel compounds were screened for antibacterial activity and cytotoxicity. Although substitution on the salicylic head group enhanced antibacterial activities they also enhanced cytotoxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

The role of mitochondria in carbon catabolite repression in yeast.

PubMed

Haussmann, P; Zimmermann, F K

1976-10-18

The role of mitochondria in carbon catabolite repression in Saccharomyces cerevisiae was investigated by comparing normal, respiratory competent (RHO) strains with their mitochondrially inherited, respiratory deficient mutant derivatives (rho). Formation of maltase and invertase was used as an indicator system for the effect of carbon catabolite repression on carbon catabolic reactions. Fermentation rates for glucose, maltose and sucrose were the same in RHO and rho strains. Specific activities of maltase and invertase were usually higher in the rho-mutants. A very pronounced difference in invertase levels was observed when cells were grown on maltose; rho-mutants had around 30 times more invertase than their RHO parent strains. The fact that rho-mutants were much less sensitive to carbon catabolite repression of invertase synthesis than their RHO parents was used to search for the mitochondrial factor(s) or function(s) involved in carbon catabolite repression. A possible metabolic influence of mitochondria on this system of regulation was tested after growth of RHO strains under anaerobic conditions (no respiration nor oxidative phosphorylation), in the presence of KCN (respiration inhibited), dinitrophenol (uncoupling of oxidative phosphorylation) and of both inhibitors anaerobic conditions and dinitrophenol had no effect on the extent of invertase repression. KCN reduced the degree of repression but not to the level found in rho-mutants. A combination of both inhibitors gave the same results as with KCN alone. Erythromycin and chloramphenicol were used as specific inhibitors of mitochondrial protein synthesis. Erythromycin prevented the formation of mitochondrial respiratory systems but did not induce rho-mutants under the conditions used. However, repression of invertase was as strong as in the absence of the inhibitor. Chloramphenicol led only to a slight reduction of the respiratory systems and did not affect invertase levels. A combination of both

Effect of fatty acids on Staphylococcus aureus delta-toxin hemolytic activity.

PubMed

Kapral, F A

1976-01-01

The lysis of human erythrocytes by Staphylococcus aureus delta-toxin proceeded without a lag and was directly proportional to toxin concentration and temperature of incubation. Lysis was complete within 8 min. Addition of saturated, straight-chain fatty acids of 13 to 19 carbons increased the activity of delta-toxin, whereas those with 21 to 23 carbons were inhibitory. Palmitic acid was the fatty acid most active in augmenting delta-toxin, but its effect could be abolished by the simultaneous addition of either tricosanoic acid or egg lecithin.

High and low molecular weight hyaluronic acid differentially influence macrophage activation

PubMed Central

Rayahin, Jamie E.; Buhrman, Jason S.; Zhang, Yu; Koh, Timothy J.; Gemeinhart, Richard A.

2015-01-01

Macrophages exhibit phenotypic diversity permitting wide-ranging roles in maintaining physiologic homeostasis. Hyaluronic acid, a major glycosaminoglycan of the extracellular matrix, has been shown to have differential signaling based on its molecular weight. With this in mind, the main objective of this study was to elucidate the role of hyaluronic acid molecular weight on macrophage activation and reprogramming. Changes in macrophage activation were assessed by activation state selective marker measurement, specifically quantitative real time polymerase chain reaction, and cytokine enzyme-linked immunoassays, after macrophage treatment with differing molecular weights of hyaluronic acid under four conditions: the resting state, concurrent with classical activation, and following inflammation involving either classically or alternatively activated macrophages. Regardless of initial polarization state, low molecular weight hyaluronic acid induced a classically activated-like state, confirmed by up-regulation of pro-inflammatory genes, including nos2, tnf, il12b, and cd80, and enhanced secretion of nitric oxide and TNF-α. High molecular weight hyaluronic acid promoted an alternatively activated-like state, confirmed by up regulation of pro-resolving gene transcription, including arg1, il10, and mrc1, and enhanced arginase activity. Overall, our observations suggest that macrophages undergo phenotypic changes dependent on molecular weight of hyaluronan that correspond to either (1) pro-inflammatory response for low molecular weight HA or (2) pro-resolving response for high molecular weight HA. These observations bring significant further understanding of the influence of extracellular matrix polymers, hyaluronic acid in particular, on regulating the inflammatory response of macrophages. This knowledge can be used to guide the design of HA-containing biomaterials to better utilize the natural response to HAs. PMID:26280020

Cloning and expression of Saccharomyces cerevisiae SUC2 gene in yeast platform and characterization of recombinant enzyme biochemical properties.

PubMed

Mohandesi, Nooshin; Siadat, Seyed Omid Ranaei; Haghbeen, Kamahldin; Hesampour, Ardeshir

2016-12-01

Invertase (EC.3.2.1.26) catalyzes the hydrolysis of sucrose to an equimolar mixture of D-glucose and D-fructose which is of interest for various industrial applications. In this research, Saccharomyces cerevisiae invertase gene (SUC2) was optimized based on Pichia pastoris codon preference. The synthetic gene was introduced into the methylotrophic yeast Pichia pastoris under the control of the inducible AOX1 promoter. High level of the extracellular recombinant invertase (R-inv) production was achieved via methanol induction for 4 days and purified by His-Tag affinity chromatography which appeared to be a mixture of glycosylated proteins with various sizes of 85-95 kDa on SDS-PAGE. Deglycosylation of the proteins by Endo-H resulted in the proteins with average molecular weight of 60 kDa. The purified recombinant invertase biochemical properties and kinetic parameters determined a pH and temperature optimum at 4.8 and 60 °C, respectively, which in comparison with native S. cerevisiae invertase, thermal stability of recombinant invertase is highly increased in different heating treatment experiments. The purification of recombinant invertase resulted in an enzyme with specific activity of 178.56 U/mg with 3.83-fold of purification and the kinetic constants for enzyme were Km value of 19 mM and Vmax value of 300 μmol min -1  mg -1 With kinetic efficiency (Kcat/Km) of 13.15 s -1  mmol -1 it can be concluded that recombinant P. pastoris invertase can be more effective for industrial quality criteria. We conclude that recombinant P. pastoris enzyme with broad pH stability, substrate specificity and proper thermal stability can fulfil a series of predefined industrial quality criteria to be used in food, pharmaceutical and bio ethanol production industries.

Synthesizing Pt nanoparticles in the presence of methylamine: Impact of acetic acid treatment in the electrocatalytic activity of formic acid oxidation

NASA Astrophysics Data System (ADS)

Ooi, M. D. Johan; Aziz, A. Abdul

2017-05-01

Surfactant removal from the surface of platinum nanoparticles prepared by solution based method is a prerequisite process to accomplish a high catalytic activity for electrochemical reactions. Here, we report a possible approach of combining acid acetic with thermal treatment for improving catalytic performance of formic acid oxidation. This strategy involves conversion of amine to amide in acetic acid followed by surfactant removal via subsequent thermal treatment at 85 °C. This combined activation technique produced monodisperse nanoparticle with the size of 3 to 5 nm with enhanced formic acid oxidation activity, particularly in perchloric acid solution. Pt treated in 1 h of acetic acid and heat treatment of 9 h shows high electrochemical surface area value (27.6 m2/g) compares to Pt without activation (16.6 m2/g). The treated samples also exhibit high current stability of 0.3 mA/cm2 compares to the as-prepared mA/cm2). Shorter duration of acid wash and longer duration of heating process result in high electrocatalytic activity. This work demonstrates a possible technique in improving catalytic activity of platinum nanoparticles synthesized using methylamine as surfactant.

Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA) in Groundwater under Acidic Conditions

PubMed Central

Yin, Penghua; Hu, Zhihao; Song, Xin; Liu, Jianguo; Lin, Na

2016-01-01

Perfluorooctanoic acid (PFOA) is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C–50 °C), persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO4−• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO4−•, followed by a HF elimination process aided by •OH, which produces one-CF2-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn−1F2n−1COOH). The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs. PMID:27322298

Activity of earthworm in Latosol under simulated acid rain stress.

PubMed

Zhang, Jia-En; Yu, Jiayu; Ouyang, Ying

2015-01-01

Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period. Results showed that earthworms tended to escape from the soil and eventually died for the SAR at pH = 2.0 as a result of acid toxicity. The catalase activity in the earthworms decreased with the SAR pH levels, whereas the superoxide dismutases activity in the earthworms showed a fluctuate pattern: decreasing from pH 6.5 to 5.0 and increasing from pH 5.0 to 4.0. Results implied that the growth of earthworms was retarded at the SAR pH ≤ 3.0.

Nematicidal Activity of Kojic Acid Produced by Aspergillus oryzae against Meloidogyne incognita.

PubMed

Kim, Tae Yoon; Jang, Ja Yeong; Jeon, Sun Jeong; Lee, Hye Won; Bae, Chang-Hwan; Yeo, Joo Hong; Lee, Hyang Burm; Kim, In Seon; Park, Hae Woong; Kim, Jin-Cheol

2016-08-28

The fungal strain EML-DML3PNa1 isolated from leaf of white dogwood (Cornus alba L.) showed strong nematicidal activity with juvenile mortality of 87.6% at a concentration of 20% fermentation broth filtrate at 3 days after treatment. The active fungal strain was identified as Aspergillus oryzae, which belongs to section Flavi, based on the morphological characteristics and sequence analysis of the ITS rDNA, calmodulin (CaM), and β-tubulin (BenA) genes. The strain reduced the pH value to 5.62 after 7 days of incubation. Organic acid analysis revealed the presence of citric acid (515.0 mg/kg), malic acid (506.6 mg/kg), and fumaric acid (21.7 mg/kg). The three organic acids showed moderate nematicidal activities, but the mixture of citric acid, malic acid, and fumaric acid did not exhibit the full nematicidal activity of the culture filtrate of EML- DML3PNa1. Bioassay-guided fractionation coupled with (1)H- and (13)C-NMR and EI-MS analyses led to identification of kojic acid as the major nematicidal metabolite. Kojic acid exhibited dose-dependent mortality and inhibited the hatchability of M. incognita, showing EC50 values of 195.2 µg/ml and 238.3 µg/ml, respectively, at 72 h postexposure. These results suggest that A. oryzae EML-DML3PNa1 and kojic acid have potential as a biological control agent against M. incognita.

[Morphophysiological monitoring of winter wheat at spring in connection with problem of global climate change].

PubMed

Klimov, S V; Burakhanova, E A; Dubinina, I M; Alieva, G P; Sal'nikova, E B; Trunova, T I

2006-01-01

Data on morphophysiological monitoring of winter wheat (Triticum aestivum L.) cultivar Mironovskaya 808 grown in Hoagland and Arnon solution in a greenhouse and transferred to natural conditions in March-April 2004 with the mean daily temperature of 0.6 +/- 0.7 degrees C within the exposure period of 42 days are presented. Water content, dry weight of plants and their organs, frost hardiness of plants, degree of tissue damage by frost, CO2 metabolism (photosynthesis and respiration), concentrations of sugars in tissues and proportions between different sugar forms, and activities of soluble and insoluble acid and alkaline phosphatases were monitored. Monitoring was carried out for three experimental variants simulating different microclimatic conditions in spring: after snow melting (experiment I), under ice crust (experiment II), and under snow cover (experiment III). Plants in experiments III and II demonstrated a higher water content in tissues, lower frost hardiness, higher rates of biomass loss, lower concentration of sugars and lower di- to monosaccharide ratio in tissues, and higher total invertase activity, particularly, cell wall-associated acid invertase activity. The dark respiration rates at 0 degrees C did not significantly differ between experimental variants. The photosynthetic capacity at this measurement temperature was maintained in all experimental variants being most pronounced in experiment II with the most intense photoinhibition under natural conditions. Comparison of experiments III and II with experiment I is used to discuss the negative effect of changes in certain microclimatic variables associated with global warming and leading to plant extortion and death from frost in spring.

Phosphoric acid purification through different raw and activated clay materials (Southern Tunisia)

NASA Astrophysics Data System (ADS)

Trabelsi, Wafa; Tlili, Ali

2017-05-01

This study concerns the purification of Tunisian phosphoric acid produced by the Tunisian Chemical Group (TCG), using raw and activated clays materials from Southern Tunisia. The Gafsa basin clays samples (Jebel Hamadi (JHM); Jebel Stah (JS) and the El Hamma sample (Jebel Aïdoudi (JAD)) were activated with 3 M, HCl solution. Phosphoric acid purification was performed on raw and activated clays. Mineralogical characterisation was carried out using the X-ray powder diffraction method and infrared absorption spectroscopy. Textural changes between raw and activated clays were identified using SEM observations and specific surface analysis. Jebel Hamadi clays were almost dominated by smectite associated with kaolinite and illite traces, while Jebel Stah and Jebel Aïdoudi clays were composed of the association of smectite, illite and kaolinite. It is worth noting that the position of the smectite (001) reflection increased after the acidic activation in all studied samples, indicating the relaxation of the smectite structure along the c-axis. This was corroborated by the increasing specific surface area of the clay particles with the activation process. The specific surface area was close to 50 m2/g and 200 m2/g, for raw and activated materials, respectively. The maximum phosphoric acid purification was obtained by using activated clays with 3 N HCl for 4 h. This performance correlated with the maximum of the external specific surface area which generated strong acid sites. Furthermore, the best results of phosphoric acids purification from TCG were obtained at a specific consumption equivalent to 30 Kg of clay/ton of P2O5. These results showed that the best phosphoric acid purification was yielded by Jebel Aïdoudi clay. In all cases, the highest organic carbon reduction rates in the phosphoric acid after filtration were obtained at 90°C.

Fatty acid conjugation enhances the activities of antimicrobial peptides.

PubMed

Li, Zhining; Yuan, Penghui; Xing, Meng; He, Zhumei; Dong, Chuanfu; Cao, Yongchang; Liu, Qiuyun

2013-04-01

Antimicrobial peptides are small molecules that play a crucial role in innate immunity in multi-cellular organisms, and usually expressed and secreted constantly at basal levels to prevent infection, but local production can be augmented upon an infection. The clock is ticking as rising antibiotic abuse has led to the emergence of many drug resistance bacteria. Due to their broad spectrum antibiotic and antifungal activities as well as anti-viral and anti-tumor activities, efforts are being made to develop antimicrobial peptides into future microbial agents. This article describes some of the recent patents on antimicrobial peptides with fatty acid conjugation. Potency and selectivity of antimicrobial peptide can be modulated with fatty acid tails of variable length. Interaction between membranes and antimicrobial peptides was affected by fatty acid conjugation. At concentrations above the critical miscelle concentration (CMC), propensity of solution selfassembly hampered binding of the peptide to cell membranes. Overall, fatty acid conjugation has enhanced the activities of antimicrobial peptides, and occasionally it rendered inactive antimicrobial peptides to be bioactive. Antimicrobial peptides can not only be used as medicine but also as food additives.

Low-temperature effect on enzyme activities involved in sucrose-starch partitioning in salt-stressed and salt-acclimated cotyledons of quinoa (Chenopodium quinoa Willd.) seedlings.

PubMed

Rosa, Mariana; Hilal, Mirna; González, Juan A; Prado, Fernando E

2009-04-01

The effect of low temperature on growth, sucrose-starch partitioning and related enzymes in salt-stressed and salt-acclimated cotyledons of quinoa (Chenopodium quinoa Willd.) was studied. The growth of cotyledons and growing axes in seedlings grown at 25/20 degrees C (light/dark) and shifted to 5/5 degrees C was lower than in those only growing at 25/20 degrees C (unstressed). However, there were no significant differences between low-temperature control and salt-treated seedlings. The higher activities of sucrose phosphate synthase (SPS, EC 2.4.1.14) and soluble acid invertase (acid INV, EC 3.2.1.25) were observed in salt-stressed cotyledons; however, the highest acid INV activity was observed in unstressed cotyledons. ADP-glucose pyrophosphorylase (ADP-GPPase, EC 2.7.7.27) was higher in unstressed cotyledons than in stressed ones. However, between 0 and 4days the highest value was observed in salt-stressed cotyledons. The lowest value of ADP-GPPase was observed in salt-acclimated cotyledons. Low temperature also affected sucrose synthase (SuSy, EC 2.4.1.13) activity in salt-treated cotyledons. Sucrose and glucose were higher in salt-stressed cotyledons, but fructose was essentially higher in low-temperature control. Starch was higher in low-temperature control; however, the highest content was observed at 0day in salt-acclimated cotyledons. Results demonstrated that low temperature induces different responses on sucrose-starch partitioning in salt-stressed and salt-acclimated cotyledons. Data also suggest that in salt-treated cotyledons source-sink relations (SSR) are changed in order to supply soluble sugars and proline for the osmotic adjustment. Relationships between starch formation and SuSy activity are also discussed.

Synthesis and antiplasmodial activity of betulinic acid and ursolic acid analogues.

PubMed

Innocente, Adrine M; Silva, Gloria N S; Cruz, Laura Nogueira; Moraes, Miriam S; Nakabashi, Myna; Sonnet, Pascal; Gosmann, Grace; Garcia, Célia R S; Gnoatto, Simone C B

2012-10-12

More than 40% of the World population is at risk of contracting malaria, which affects primarily poor populations in tropical and subtropical areas. Antimalarial pharmacotherapy has utilised plant-derived products such as quinine and artemisinin as well as their derivatives. However, worldwide use of these antimalarials has caused the spread of resistant parasites, resulting in increased malaria morbidity and mortality. Considering that the literature has demonstrated the antimalarial potential of triterpenes, specially betulinic acid (1) and ursolic acid (2), this study investigated the antimalarial activity against P. falciparum chloroquine-sensitive 3D7 strain of some new derivatives of 1 and 2 with modifications at C-3 and C-28. The antiplasmodial study employed flow cytometry and spectrofluorimetric analyses using YOYO-1, dihydroethidium and Fluo4/AM for staining. Among the six analogues obtained, compounds 1c and 2c showed excellent activity (IC₅₀ = 220 and 175 nM, respectively) while 1a and b demonstrated good activity (IC₅₀ = 4 and 5 μM, respectively). After cytotoxicity evaluation against HEK293T cells, 1a was not toxic, while 1c and 2c showed IC₅₀ of 4 μM and a selectivity index (SI) value of 18 and 23, respectively. Moreover, compound 2c, which presents the best antiplasmodial activity, is involved in the calcium-regulated pathway(s).

Enhanced solubility and antioxidant activity of chlorogenic acid-chitosan conjugates due to the conjugation of chitosan with chlorogenic acid.

PubMed

Rui, Liyun; Xie, Minhao; Hu, Bing; Zhou, Li; Saeeduddin, Muhammad; Zeng, Xiaoxiong

2017-08-15

Chlorogenic acid-chitosan conjugate was synthesized by introducing of chlorogenic acid onto chitosan with the aid of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and hydroxybenzotriazole. The data of UV-vis, FT-IR and NMR for chlorogenic acid-chitosan conjugates demonstrated the successful conjugation of chlorogenic acid with chitosan. Compared to chitosan, chlorogenic acid-chitosan conjugates exhibited increased solubility in distilled water, 1% acetic acid solution (v/v) or 50% ethanol solution (v/v) containing 0.5% acetic acid. Moreover, chlorogenic acid-chitosan conjugates showed dramatic enhancements in metal ion chelating activity, total antioxidant capacity, scavenging activities on 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) and superoxide radicals, inhibitory effects on lipid peroxidation and β-carotene-linoleic acid bleaching, and protective effect on H 2 O 2 -induced oxidative injury of PC12 cells. Particularly, chlorogenic acid-chitosan conjugate exhibited higher inhibitory effects on lipid peroxidation and β-carotene-linoleic acid bleaching than chlorogenic acid. The results suggested that chlorogenic acid-chitosan conjugates could serve as food supplements to enhance the function of foods in future. Copyright © 2017 Elsevier Ltd. All rights reserved.

A potential plant-derived antifungal acetylenic acid mediates its activity by interfering with fatty acid homeostasis

USDA-ARS?s Scientific Manuscript database

6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses...

Physiological Aspects of Sugar Exchange between the Gametophyte and the Sporophyte of Polytrichum formosum

PubMed Central

Renault, Sylvie; Bonnemain, Jean Louis; Faye, Loïc; Gaudillere, Jean Pierre

1992-01-01

The sporophyte of bryophytes is dependent on the gametophyte for its carbon nutrition. This is especially true of the sporophytes of Polytrichum species, and it was generally thought that sucrose was the main form of sugar for long distance transport in the leptom. In Polytrichum formosum, sucrose was the main soluble sugar of the sporophyte and gametophyte tissues, and the highest concentration (about 230 mm) was found in the haustorium. In contrast, sugars collected from the vaginula apoplast were mainly hexoses, with traces of sucrose and trehalose. p-Chloromercuribenzene sulfonate, a nonpermeant inhibitor of the cell wall invertase, strongly reduced the hexose to sucrose ratio. The highest cell wall invertase activity (pH 4.5) was located in the vaginula, whereas the highest activity of a soluble invertase (pH 7.0) was found in both the vaginula and the haustorium. Glucose uptake was carrier-mediated but only weakly dependent on the external pH and the transmembrane electrical gradient, in contrast to amino acid uptake (S. Renault, C. Despeghel-Caussin, J.L. Bonnemain, S. Delrot [1989] Plant Physiol 90: 913-920). Furthermore, addition of 5 or 50 mm glucose to the incubation medium induced a marginal depolarization of the transmembrane potential difference of the transfer cells and had no effect on the pH of this medium. Glucose was converted to sucrose after its absorption into the haustorium. These results demonstrate the noncontinuity of sucrose at the gametophyte/sporophyte interface. They suggest that its conversion to glucose and fructose at this interface, and the subsequent reconversion to sucrose after hexose absorption by haustorium cells, mainly governs sugar accumulation in this latter organ. PMID:16653202

Site-specific incorporation of redox active amino acids into proteins

DOEpatents

Alfonta, Lital [San Diego, CA; Schultz, Peter G [La Jolla, CA; Zhang, Zhiwen [Austin, TX

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.

Site-specific incorporation of redox active amino acids into proteins

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

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

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.

Site-specific incorporation of redox active amino acids into proteins

DOEpatents

Alfonta, Lital [San Diego, CA; Schultz, Peter G [La Jolla, CA; Zhang, Zhiwen [San Diego, CA

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.

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.

Site-specific incorporation of redox active amino acids into proteins

DOEpatents

Alfonta, Lital [San Diego, CA; Schultz, Peter G [La Jolla, CA; Zhang, Zhiwen [San Diego, CA

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.

Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

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

Mondala, Andro; Hernandez, Rafael; French, Todd

2012-01-01

The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2%more » w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.« less

Nitrogen additions affect litter quality and soil biochemical properties in a peatland of Northeast China

USGS Publications Warehouse

Song, Yanyu; Song, Changchun; Meng, Henan; Swarzenski, Christopher M.; Wang, Xianwei; Tan, Wenwen

2017-01-01

Nitrogen (N) is a limiting nutrient in many peatland ecosystems. Enhanced N deposition, a major component of global climate change, affects ecosystem carbon (C) balance and alters soil C storage by changing plant and soil properties. However, the effects of enhanced N deposition on peatland ecosystems are poorly understood. We conducted a two-year N additions field experiment in a peatland dominated by Eriophorum vaginatum in the Da Xing’an Mountains, Northeast China. Four levels of N treatments were applied: (1) CK (no N added), (2) N1 (6 g N m−2 yr−1), (3) N2 (12 g N m−2 yr−1), and (4) N3 (24 g N m−2  yr−1). Plant and soil material was harvested at the end of the second growing season. N additions increased litter N and phosphorus (P) content, as well as β-glucosidase, invertase, and acid-phosphatase activity, but decreased litter C:N and C:P ratios. Litter carbon content remained unchanged. N additions increased available NH4+–N and NO3−–N as well as total Gram-positive (Gram+), Gram-negative (Gram−), and total bacterial phospholipid fatty acids (PLFA) in shallow soil (0–15 cm depth). An increase in these PLFAs was accompanied by a decrease in soil labile organic C (microbial biomass carbon and dissolved organic carbon), and appeared to accelerate decomposition and reduce the stability of the soil C pool. Invertase and urease activity in shallow soils and acid-phosphatase activity in deep soils (15–30 cm depth) was inhibited by N additions. Together, these findings suggest that an increase in N deposition in peatlands could accelerate litter decomposition and the loss of labile C, as well as alter microbial biomass and function.

DNA Inversion on Conjugative Plasmid pVT745

PubMed Central

Chen, Jinbiao; Leblanc, Donald J.; Galli, Dominique M.

2002-01-01

Plasmid pVT745 from Actinobacillus actinomycetemcomitans strain VT745 can be transferred to other A. actinomycetemcomitans strains at a frequency of 10−6. Screening of transconjugants revealed that the DNA of pDMG21A, a pVT745 derivative containing a kanamycin resistance gene, displayed a structural rearrangement after transfer. A 9-kb segment on the plasmid had switched orientation. The inversion was independent of RecA and required the activity of the pVT745-encoded site-specific recombinase. This recombinase, termed Inv, was highly homologous to invertases of the Din family. Two recombination sites of 22 bp, which are arranged in opposite orientation and which function as DNA crossover sequences, were identified on pVT745. One of the sites was located adjacent to the 5′ end of the invertase gene, inv. Inversion of the 9-kb segment on pVT745 derivatives has been observed in all A. actinomycetemcomitans strains tested except for the original host, VT745. This would suggest that a host factor that is either inactive or absent in VT745 is required for efficient recombination. Inactivation of the invertase in the donor strain resulted in a 1,000-fold increase in the number of transconjugants upon plasmid transfer. It is proposed that an activated invertase causes the immediate loss of the plasmid in most recipient cells after mating. No biological role has been associated with the invertase as of yet. PMID:12374826

Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

PubMed Central

Boshtam, Maryam; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

2013-01-01

Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health. PMID:24167374

Serum paraoxonase 1 activity is associated with fatty acid composition of high density lipoprotein.

PubMed

Boshtam, Maryam; Razavi, Amirnader Emami; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

2013-01-01

Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω 6 fatty acids of HDL. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.

Antioxidant activity of phenolic acids and their metabolites: synthesis and antioxidant properties of the sulfate derivatives of ferulic and caffeic acids and of the acyl glucuronide of ferulic acid.

PubMed

Piazzon, A; Vrhovsek, U; Masuero, D; Mattivi, F; Mandoj, F; Nardini, M

2012-12-19

The main metabolites of caffeic and ferulic acids (ferulic acid-4'-O-sulfate, caffeic acid-4'-O-sulfate, and caffeic acid-3'-O-sulfate), the most representative phenolic acids in fruits and vegetables, and the acyl glucuronide of ferulic acid were synthesized, purified, and tested for their antioxidant activity in comparison with those of their parent compounds and other related phenolics. Both the ferric reducing antioxidant power (FRAP) assay and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging method were used. Ferulic acid-4'-O-sulfate and ferulic acid-4'-O-glucuronide exhibited very low antioxidant activity, while the monosulfate derivatives of caffeic acid were 4-fold less efficient as the antioxidant than caffeic acid. The acyl glucuronide of ferulic acid showed strong antioxidant action. The antioxidant activity of caffeic acid-3'-O-glucuronide and caffeic acid-4'-O-glucuronide was also studied. Our results demonstrate that some of the products of phenolic acid metabolism still retain strong antioxidant properties. Moreover, we first demonstrate the ex vivo synthesis of the acyl glucuronide of ferulic acid by mouse liver microsomes, in addition to the phenyl glucuronide.

Protective Effect of Unsaturated Fatty Acids on Palmitic Acid-Induced Toxicity in Skeletal Muscle Cells is not Mediated by PPARδ Activation.

PubMed

Tumova, Jana; Malisova, Lucia; Andel, Michal; Trnka, Jan

2015-10-01

Unsaturated free fatty acids (FFA) are able to prevent deleterious effects of saturated FFA in skeletal muscle cells although the mechanisms involved are still not completely understood. FFA act as endogenous ligands of peroxisome proliferator-activated receptors (PPAR), transcription factors regulating the expression of genes involved in lipid metabolism. The aim of this study was to determine whether activation of PPARδ, the most common PPAR subtype in skeletal muscle, plays a role in mediating the protective effect of unsaturated FFA on saturated FFA-induced damage in skeletal muscle cells and to examine an impact on mitochondrial respiration. Mouse C2C12 myotubes were treated for 24 h with different concentrations of saturated FFA (palmitic acid), unsaturated FFA (oleic, linoleic and α-linolenic acid), and their combinations. PPARδ agonist GW501516 and antagonist GSK0660 were also used. Both mono- and polyunsaturated FFA, but not GW501516, prevented palmitic acid-induced cell death. Mono- and polyunsaturated FFA proved to be effective activators of PPARδ compared to saturated palmitic acid; however, in combination with palmitic acid their effect on PPARδ activation was blocked and stayed at the levels observed for palmitic acid alone. Unsaturated FFA at moderate physiological concentrations as well as GW501516, but not palmitic acid, mildly uncoupled mitochondrial respiration. Our results indicate that although unsaturated FFA are effective activators of PPARδ, their protective effect on palmitic acid-induced toxicity is not mediated by PPARδ activation and subsequent induction of lipid regulatory genes in skeletal muscle cells. Other mechanisms, such as mitochondrial uncoupling, may underlie their effect.

p-Coumaric acid and its conjugates: dietary sources, pharmacokinetic properties and biological activities.

PubMed

Pei, Kehan; Ou, Juanying; Huang, Junqing; Ou, Shiyi

2016-07-01

p-Coumaric acid (4-hydroxycinnamic acid) is a phenolic acid that has low toxicity in mice (LD50 = 2850 mg kg(-1) body weight), serves as a precursor of other phenolic compounds, and exists either in free or conjugated form in plants. Conjugates of p-coumaric acid have been extensively studied in recent years due to their bioactivities. In this review, the occurrence, bioavailability and bioaccessibility of p-coumaric acid and its conjugates with mono-, oligo- and polysaccharides, alkyl alcohols, organic acids, amine and lignin are discussed. Their biological activities, including antioxidant, anti-cancer, antimicrobial, antivirus, anti-inflammatory, antiplatelet aggregation, anxiolytic, antipyretic, analgesic, and anti-arthritis activities, and their mitigatory effects against diabetes, obesity, hyperlipaemia and gout are compared. Cumulative evidence from multiple studies indicates that conjugation of p-coumaric acid greatly strengthens its biological activities; however, the high biological activity but low absorption of its conjugates remains a puzzle. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Acidic Extracellular pH Promotes Activation of Integrin αvβ3

PubMed Central

Paradise, Ranjani K.; Lauffenburger, Douglas A.; Van Vliet, Krystyn J.

2011-01-01

Acidic extracellular pH is characteristic of the cell microenvironment in several important physiological and pathological contexts. Although it is well established that acidic extracellular pH can have profound effects on processes such as cell adhesion and migration, the underlying molecular mechanisms are largely unknown. Integrin receptors physically connect cells to the extracellular matrix, and are thus likely to modulate cell responses to extracellular conditions. Here, we examine the role of acidic extracellular pH in regulating activation of integrin αvβ3. Through computational molecular dynamics simulations, we find that acidic extracellular pH promotes opening of the αvβ3 headpiece, indicating that acidic pH can thereby facilitate integrin activation. This prediction is consistent with our flow cytometry and atomic force microscope-mediated force spectroscopy assays of integrin αvβ3 on live cells, which both demonstrate that acidic pH promotes activation at the intact cell surface. Finally, quantification of cell morphology and migration measurements shows that acidic extracellular pH affects cell behavior in a manner that is consistent with increased integrin activation. Taken together, these computational and experimental results suggest a new and complementary mechanism of integrin activation regulation, with associated implications for cell adhesion and migration in regions of altered pH that are relevant to wound healing and cancer. PMID:21283814

Short versus long term effects of cyanide on sugar metabolism and transport in dormant walnut kernels.

PubMed

Gerivani, Zahra; Vashaee, Elham; Sadeghipour, Hamid Reza; Aghdasi, Mahnaz; Shobbar, Zahra-Sadat; Azimmohseni, Majid

2016-11-01

Tree seed dormancy release by cold stratification accompanies with the embryo increased gluconeogenesis competence. Cyanide also breaks seed dormancy however, integrated information about its effects on carbon metabolism is lacking. Accordingly, the impacts of HCN on germination, lipid gluconeogenesis and sugar transport capacity of walnut (Juglans regia L.) kernels were investigated during 10-days period prior to radicle protrusion. HCN increased walnut kernel germination and within four days of kernel incubation, hastened the decline of starch, reducing and non-reducing sugars and led to greater activities of alkaline invertase and glucose-6-phosphate dehydrogenase. From four days of kernel incubation onwards, starch and non-reducing sugars accumulated only in the HCN treated axes. Cyanide also increased the activities of phosphoenolpyruvate carboxykinase and glyoxysomal succinate oxidase and led to greater acid invertase activity during the aforementioned period. The expressions of both sucrose transporter (JrSUT1) and H + -ATPase (JrAHA1) genes especially in cotyledons and H + -ATPase activity in kernels were significantly enhanced by exposure to cyanide. Thus in short-term HCN led to prevalence of carbohydrate catabolic events such as oxidative pentose phosphate pathway and possibly glycolysis in dormant walnut kernels. Long-term effects however, are increased gluconeogenesis and enhanced sugar transport capacity of kernels as a prerequisite for germination. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Function and Dynamics of Auxin and Carbohydrates during Earlywood/Latewood Transition in Scots Pine1

PubMed Central

Uggla, Claes; Magel, Elisabeth; Moritz, Thomas; Sundberg, Björn

2001-01-01

In temperate regions the annual pattern of wood development is characterized by the formation of radially narrow and thick walled latewood cells. This takes place at the later part of the growing season when cambial cell division declines. To gain new insight into the regulation of this process, micro-analytical techniques were used to visualize the distribution of indole-3-acetic acid (IAA), soluble carbohydrates, and activities of sucrose (Suc)-metabolizing enzymes across the cambial region tissues in Scots pine (Pinus sylvestris). The total amount of IAA in the cambial region did not change with latewood initiation. But its radial distribution pattern was altered, resulting in an increased concentration in the cambial meristem and its recent derivatives. Thus, initiation of latewood formation and cessation of cambial cell division is not a consequence of decreased IAA concentrations in dividing and expanding cells. Rather, IAA most likely has a role in defining the altered developmental pattern associated with latewood formation. Carbohydrates and enzyme activities showed distinctive radial distribution patterns. Suc peaked in the phloem and decreased sharply to low levels across the cambial zone, whereas fructose and glucose reached their highest levels in the maturing tracheids. Suc synthase was the dominating Suc cleaving enzyme with a peak in the secondary wall-forming tracheids and in the phloem. Soluble acid invertase peaked in dividing and expanding cells. Suc-phosphate synthase had its highest activities in the phloem. Activities of cell wall bound invertase were low. The absence of major seasonal variations indicates that carbohydrate availability is not a trigger for latewood initiation. However, steep concentration gradients of the sugars suggest a role for sugar signaling in vascular development. PMID:11299382

Function and dynamics of auxin and carbohydrates during earlywood/latewood transition in scots pine.

PubMed

Uggla, C; Magel, E; Moritz, T; Sundberg, B

2001-04-01

In temperate regions the annual pattern of wood development is characterized by the formation of radially narrow and thick walled latewood cells. This takes place at the later part of the growing season when cambial cell division declines. To gain new insight into the regulation of this process, micro-analytical techniques were used to visualize the distribution of indole-3-acetic acid (IAA), soluble carbohydrates, and activities of sucrose (Suc)-metabolizing enzymes across the cambial region tissues in Scots pine (Pinus sylvestris). The total amount of IAA in the cambial region did not change with latewood initiation. But its radial distribution pattern was altered, resulting in an increased concentration in the cambial meristem and its recent derivatives. Thus, initiation of latewood formation and cessation of cambial cell division is not a consequence of decreased IAA concentrations in dividing and expanding cells. Rather, IAA most likely has a role in defining the altered developmental pattern associated with latewood formation. Carbohydrates and enzyme activities showed distinctive radial distribution patterns. Suc peaked in the phloem and decreased sharply to low levels across the cambial zone, whereas fructose and glucose reached their highest levels in the maturing tracheids. Suc synthase was the dominating Suc cleaving enzyme with a peak in the secondary wall-forming tracheids and in the phloem. Soluble acid invertase peaked in dividing and expanding cells. Suc-phosphate synthase had its highest activities in the phloem. Activities of cell wall bound invertase were low. The absence of major seasonal variations indicates that carbohydrate availability is not a trigger for latewood initiation. However, steep concentration gradients of the sugars suggest a role for sugar signaling in vascular development.

Synthesis and biological evaluation of 2-heteroarylthioalkanoic acid analogues of clofibric acid as peroxisome proliferator-activated receptor alpha agonists.

PubMed

Giampietro, Letizia; Ammazzalorso, Alessandra; Giancristofaro, Antonella; Lannutti, Fabio; Bettoni, Giancarlo; De Filippis, Barbara; Fantacuzzi, Marialuigia; Maccallini, Cristina; Petruzzelli, Michele; Morgano, Annalisa; Moschetta, Antonio; Amoroso, Rosa

2009-10-22

A series of 2-heteroarylthioalkanoic acids were synthesized through systematic structural modifications of clofibric acid and evaluated for human peroxisome proliferator-activated receptor alpha (PPARalpha) transactivation activity, with the aim of obtaining new hypolipidemic compounds. Some thiophene and benzothiazole derivatives showing a good activation of the receptor alpha were screened for activity against the PPARgamma isoform. The gene induction of selected compounds was also investigated in the human hepatoma cell line.

Influence of different forms of acidities on soil microbiological properties and enzyme activities at an acid mine drainage contaminated site.

PubMed

Sahoo, Prafulla Kumar; Bhattacharyya, Pradip; Tripathy, Subhasish; Equeenuddin, Sk Md; Panigrahi, M K

2010-07-15

Assessment of microbial parameters, viz. microbial biomass, fluorescence diacetate, microbial respiration, acid phosphatase, beta-glucosidase and urease with respect to acidity helps in evaluating the quality of soils. This study was conducted to investigate the effects of different forms of acidities on soil microbial parameters in an acid mine drainage contaminated site around coal deposits in Jainta Hills of India. Total potential and exchangeable acidity, extractable and exchangeable aluminium were significantly higher in contaminated soil compared to the baseline (p<0.01). Different forms of acidity were significantly and positively correlated with each other (p<0.05). Further, all microbial properties were positively and significantly correlated with organic carbon and clay (p<0.05). The ratios of microbial parameters with organic carbon were negatively correlated with different forms of acidity. Principal component analysis and cluster analyses showed that the microbial activities are not directly influenced by the total potential acidity and extractable aluminium. Though acid mine drainage affected soils had higher microbial biomass and activities due to higher organic matter content than those of the baseline soils, the ratios of microbial parameters/organic carbon indicated suppression of microbial growth and activities due to acidity stress. 2010 Elsevier B.V. All rights reserved.

Activity of virgin coconut oil, lauric acid or monolaurin in combination with lactic acid against Staphylococcus aureus.

PubMed

Tangwatcharin, Pussadee; Khopaibool, Prapaporn

2012-07-01

The objective of this study was to investigate the in vitro activities of virgin coconut oil, lauric acid and monolaurin in combination with lactic acid against two strains of Staphylococcus aureus, ATCC 25923 and an isolate from a pig carcass, by determination of Fractional Bactericidal Concentration Index (FBCI), time-kill method, as well as scanning and transmission electron microscopy. Minimum bactericidal concentrations (MBC) of lauric acid, monolaurin and lactic acid were 3.2 mg/ml, 0.1 mg/ml and 0.4% (v/v), respectively. The effects of lauric acid + lactic acid and monolaurin + lactic acid combinations were synergistic against both strains, exhibiting FBCIs of 0.25 and 0.63, respectively. In time-kill studies, lauric acid and monolaurin + lactic acid combinations added at their minimum inhibitory concentrations produced a bactericidal effect. The induction of stress in non-stressed cells was dependent on the type and concentration of antimicrobial. This resulted in a loss and change of the cytoplasm and membrane in cells of the bacterium. In contrast, virgin coconut oil (10%) was not active against S. aureus. The bacterial counts found in pork loin treated with lauric acid and monolaurin alone were significantly higher (p <0.05) than those treated with both lipids in combination with lactic acid at sub-inhibitory concentrations. The color, odor and overall acceptability of the pork loins were adversely affected by treatment with the three lipids and lactic acid alone but when combinations of the agents were used the sensory quality was acceptable.

Pharmacologic activation of peroxisome proliferator-activating receptor-α accelerates hepatic fatty acid oxidation in neonatal pigs

PubMed Central

Shim, Kwanseob; Jacobi, Sheila; Odle, Jack; Lin, Xi

2018-01-01

Up-regulation of peroxisome proliferator-activating receptor-α (PPARα) and increasing fatty acid oxidation are important for reducing pre-weaning mortality of pigs. We examined the time-dependent regulatory effects of PPARα activation via oral postnatal clofibrate administration (75 mg/(kg-BW·d) for up to 7 days) on mitochondrial and peroxisomal fatty acid oxidation in pigs, a species with limited hepatic fatty acid oxidative capacity due to low ketogenesis. Hepatic oxidation was increased by 44-147% (depending on fatty acid chain-length) and was attained after only 4 days of clofibrate treatment. Acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase I (CPTI) activities accelerated in parallel. The increase in CPTI activity was accompanied by a rapid reduction in the sensitivity of CPTI to malonyl-CoA inhibition. The mRNA abundance of CPTI and ACO, as well as peroxisomal keto-acyl-CoA thiolase (KetoACoA) and mitochondrial malonyl-CoA decarboxylase (MCD), also were augmented greatly. However, the increase in ACO activity and MCD expression were different from CPTI, and significant interactions were observed between postnatal age and clofibrate administration. Furthermore, the expression of acetyl-CoA carboxylase β (ACCβ) decreased with postnatal age and clofibrate had no effect on its expression. Collectively these results demonstrate that the expression of PPARα target genes and the increase in fatty acid oxidation induced by clofibrate are time- and age-dependent in the liver of neonatal pigs. Although the induction patterns of CPTI, MCD, ACO, KetoACoA, and ACCβ are different during the early postnatal period, 4 days of exposure to clofibrate were sufficient to robustly accelerate fatty acid oxidation.

Activation mechanism of melB tyrosinase from Aspergillus oryzae by acidic treatment.

PubMed

Fujieda, Nobutaka; Murata, Michiaki; Yabuta, Shintaro; Ikeda, Takuya; Shimokawa, Chizu; Nakamura, Yukihiro; Hata, Yoji; Itoh, Shinobu

2013-01-01

The pro form of recombinant tyrosinase from Aspergillus oryzae (melB) shows no catalytic activity, but acid treatment (around pH 3.5) of protyrosinase activates it to induce tyrosinase activity. Circular dichroism spectra, gel filtration analysis, and colorimetric assay have indicated that acid treatment around pH 3.5 induced the disruption of the conformation of the C-terminal domain covering the enzyme active site. These structural changes induced by the acid treatment may open the entrance to the enzyme active site for substrate incorporation. To compare the mechanism of hydroxylation by the acid-treated tyrosinase with that by trypsin-treated tyrosinase, a detailed steady-state kinetic analysis of the phenolase activity was performed by monitoring the O(2)-consumption rate using a Clark-type oxygen electrode. The results clearly show that the phenolase activity (phenol hydroxylation) of the activated tyrosinase involves an electrophilic aromatic substitution mechanism as in the case of mushroom tyrosinase (Yamazaki and Itoh in J. Am. Chem. Soc. 125:13034-13035, 2003) and activated hemocyanin with urea (Morioka et al. in J. Am. Chem. Soc. 128:6788-6789, 2006).

Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

USGS Publications Warehouse

Bradley, Michael W.; Worland, Scott C.

2015-01-01

Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

Atomic determinants of BK channel activation by polyunsaturated fatty acids

PubMed Central

Tian, Yutao; Aursnes, Marius; Hansen, Trond Vidar; Tungen, Jørn Eivind; Galpin, Jason D.; Leisle, Lilia; Ahern, Christopher A.; Xu, Rong; Heinemann, Stefan H.; Hoshi, Toshinori

2016-01-01

Docosahexaenoic acid (DHA), a polyunsaturated ω-3 fatty acid enriched in oily fish, contributes to better health by affecting multiple targets. Large-conductance Ca2+- and voltage-gated Slo1 BK channels are directly activated by nanomolar levels of DHA. We investigated DHA–channel interaction by manipulating both the fatty acid structure and the channel composition through the site-directed incorporation of unnatural amino acids. Electrophysiological measurements show that the para-group of a Tyr residue near the ion conduction pathway has a critical role. To robustly activate the channel, ionization must occur readily by a fatty acid for a good efficacy, and a long nonpolar acyl tail with a Z double bond present at the halfway position for a high affinity. The results suggest that DHA and the channel form an ion–dipole bond to promote opening and demonstrate the channel druggability. DHA, a marine-derived nutraceutical, represents a promising lead compound for rational drug design and discovery. PMID:27849612

Synthesis and antituberculosis activity of new fatty acid amides.

PubMed

D'Oca, Caroline Da Ros Montes; Coelho, Tatiane; Marinho, Tamara Germani; Hack, Carolina Rosa Lopes; Duarte, Rodrigo da Costa; da Silva, Pedro Almeida; D'Oca, Marcelo Gonçalves Montes

2010-09-01

This work reports the synthesis of new fatty acid amides from C16:0, 18:0, 18:1, 18:1 (OH), and 18:2 fatty acids families with cyclic and acyclic amines and demonstrate for the first time the activity of these compounds as antituberculosis agents against Mycobacterium tuberculosis H(37)Rv, M. tuberculosis rifampicin resistance (ATCC 35338), and M. tuberculosis isoniazid resistance (ATCC 35822). The fatty acid amides derivate from ricinoleic acid were the most potent one among a series of tested compounds, with a MIC 6.25 microg/mL for resistance strains. Copyright 2010 Elsevier Ltd. All rights reserved.

Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage

USDA-ARS?s Scientific Manuscript database

Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose-phosphate synthase (SPS), soluble acid (SAI) and cell-wall invertase (CWI) are importan...

[The effect of niflumic acid on gamma aminobutyric acid activated current in DRG neurons].

PubMed

Li, Li; Li, Jing; Ma, Ke-Tao; Cheng, Hong-Ju; Zhao, Lei; Wang, Yang; Si, Jun-Qiang

2013-01-01

To explore the modulatory effect of niflumic acid (NFA) on gamma aminobutyric acid (GABA)-activated currents of dorsal root ganglion (DRG) neurons in rat. The whole-cell patch-clamp technique was used to record the NFA- and GABA-activated currents in neurons freshly dissociated from rat DRG neurons. Application of NFA(0.1 - 100 micromol/L) could induce concentration-dependent outward currents in some cells (21/48,43.75%), and GABA (0.1 - 100 micromol/L) could induce concentration-dependent inward currents in some cells(150/159,94.32%). NFA-(100 micromol/L) and GABA-(100 micromol/L) activated currents were (0.27 +/- 0.06) nA (n = 12) and (1.29 +/- 0.72) nA (n = 53) respectively. However, pre-application of NFA (0.1 - 100 micromol/L) could inhibit the GABA-activated inward current which was identified to be GABAA receptor-mediated current. The inhibitory effects of NFA were concentration-dependent. NFA could not alter the EC50 (about 30 micromol/L) and inverse potential (about -10 mV) of GABA-activated current (P > 0.05). Pre-application of NFA exerts a more strong inhibitory effect on the peak value of GABA-activated current.

Porous structure and surface chemistry of phosphoric acid activated carbon from corncob

NASA Astrophysics Data System (ADS)

Sych, N. V.; Trofymenko, S. I.; Poddubnaya, O. I.; Tsyba, M. M.; Sapsay, V. I.; Klymchuk, D. O.; Puziy, A. M.

2012-11-01

Active carbons have been prepared from corncob using chemical activation with phosphoric acid at 400 °C using varied ratio of impregnation (RI). Porous structure of carbons was characterized by nitrogen adsorption and scanning electron microscopy. Surface chemistry was studied by IR and potentiometric titration method. It has been shown that porosity development was peaked at RI = 1.0 (SBET = 2081 m2/g, Vtot = 1.1 cm3/g), while maximum amount of acid surface groups was observed at RI = 1.25. Acid surface groups of phosphoric acid activated carbons from corncob includes phosphate and strongly acidic carboxylic (pK = 2.0-2.6), weakly acidic carboxylic (pK = 4.7-5.0), enol/lactone (pK = 6.7-7.4; 8.8-9.4) and phenol (pK = 10.1-10.7). Corncob derived carbons showed high adsorption capacity to copper, especially at low pH. Maximum adsorption of methylene blue and iodine was observed for carbon with most developed porosity (RI = 1.0).

Influence of ethylenediamine-n,n’-disuccinic acid (EDDS) concentration on the bactericidal activity of fatty acids in vitro

USDA-ARS?s Scientific Manuscript database

The antibacterial activity of mixtures of ethylenediamine-N,N’-disuccinic acid (EDDS) and antibacterial fatty acids (FA) was examined using the agar diffusion assay. Solutions of caproic, caprylic, capric, and lauric acids dissolved in potassium hydroxide (KOH) were supplemented with 0, 5, or 10 mM ...

Antiproliferative activity of synthetic fatty acid amides from renewable resources.

PubMed

dos Santos, Daiane S; Piovesan, Luciana A; D'Oca, Caroline R Montes; Hack, Carolina R Lopes; Treptow, Tamara G M; Rodrigues, Marieli O; Vendramini-Costa, Débora B; Ruiz, Ana Lucia T G; de Carvalho, João Ernesto; D'Oca, Marcelo G Montes

2015-01-15

In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line-the most aggressive CNS cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acid Rain: A Teacher's Guide. Activities for Grades 4 to 12.

ERIC Educational Resources Information Center

National Wildlife Federation, Washington, DC.

This guide on acid rain for elementary and secondary students is divided into three study areas: (1) What Causes Acid Rain; (2) What Problems Acid Rain Has Created; (3) How You and Your Students Can Help Combat Acid Rain. Each section presents background information and a series of lessons pertaining to the section topic. Activities include…

Acid Rain. Activities for Grades 4 to 12. A Teacher's Guide.

ERIC Educational Resources Information Center

Wood, David; Bryant, Jeannette

This teacher's guide on acid rain is divided into three study areas to explain: (1) what causes acid rain; (2) what problems acid rain has created; and (3) what teachers and students can do to help combat acid rain. Instructions for activities within the study areas include suggested grade levels, objectives, materials needed, and directions for…

Activity of earthworm in Latosol under simulated acid rain stress

Treesearch

Jia-En Zhang; Jiayu Yu; Ying Ouyang

2015-01-01

Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period....

Antioxidant activities and fatty acid composition of wild grown myrtle (Myrtus communis L.) fruits

PubMed Central

Serce, Sedat; Ercisli, Sezai; Sengul, Memnune; Gunduz, Kazim; Orhan, Emine

2010-01-01

The fruits of eight myrtles, Myrtus communis L. accessions from the Mediterranean region of Turkey were evaluated for their antioxidant activities and fatty acid contents. The antioxidant activities of the fruit extracts were determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. The fatty acid contents of fruits were determined by using gas chromatography. The methanol extracts of fruits exhibited a high level of free radical scavenging activity. There was a wide range (74.51-91.65%) of antioxidant activity among the accessions in the β-carotene-linoleic acid assay. The amount of total phenolics (TP) was determined to be between 44.41-74.44 μg Gallic acid equivalent (GAE)/mg, on a dry weight basis. Oleic acid was the dominant fatty acid (67.07%), followed by palmitic (10.24%), and stearic acid (8.19%), respectively. These results suggest the future utilization of myrtle fruit extracts as food additives or in chemoprevention studies. PMID:20548930

Antioxidant activities and fatty acid composition of wild grown myrtle (Myrtus communis L.) fruits.

PubMed

Serce, Sedat; Ercisli, Sezai; Sengul, Memnune; Gunduz, Kazim; Orhan, Emine

2010-01-01

The fruits of eight myrtles, Myrtus communis L. accessions from the Mediterranean region of Turkey were evaluated for their antioxidant activities and fatty acid contents. The antioxidant activities of the fruit extracts were determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. The fatty acid contents of fruits were determined by using gas chromatography. The methanol extracts of fruits exhibited a high level of free radical scavenging activity. There was a wide range (74.51-91.65%) of antioxidant activity among the accessions in the beta-carotene-linoleic acid assay. The amount of total phenolics (TP) was determined to be between 44.41-74.44 mug Gallic acid equivalent (GAE)/mg, on a dry weight basis. Oleic acid was the dominant fatty acid (67.07%), followed by palmitic (10.24%), and stearic acid (8.19%), respectively. These results suggest the future utilization of myrtle fruit extracts as food additives or in chemoprevention studies.

Synthesis and antioxidant activity of polyhydroxylated trans-restricted 2-arylcinnamic acids.

PubMed

Miliovsky, Mitko; Svinyarov, Ivan; Prokopova, Elena; Batovska, Daniela; Stoyanov, Simeon; Bogdanov, Milen G

2015-02-02

A series of sixteen polyhydroxylated trans-restricted 2-arylcinnamic acid analogues 3a-p were synthesized through a one-pot reaction between homophthalic anhydrides and various aromatic aldehydes, followed by treatment with BBr3. The structure of the newly synthesized compounds was confirmed by spectroscopic methods and the configuration around the double bond was unequivocally estimated by means of gated decoupling 13C-NMR spectra. It was shown that the trans-cinnamic acid fragment incorporated into the target compounds' structure ensures the cis-configuration of the stilbene backbone and prevents further isomerization along the carbon-carbon double bond. The antioxidant activity of compounds 3a-p was measured against 1,1-diphenyl-2-picrylhydrazyl (DPPH●), hydroxyl (OH●) and superoxide (O2●▬) radicals. The results obtained showed that the tested compounds possess higher activities than natural antioxidants such as protocatechuic acid, caffeic acid and gallic acid. Moreover, it was shown that a combination of two different and independently acting fragments of well-known pharmacological profiles into one covalently bonded hybrid molecule evoke a synergistic effect resulting in higher than expected activity. To rationalize the apparent antioxidant activity and to establish the mechanism of action, a SAR analysis and DFT quantum chemical computations were also performed.

Oleic acid and linoleic acid from Tenebrio molitor larvae inhibit BACE1 activity in vitro: molecular docking studies.

PubMed

Youn, Kumju; Yun, Eun-Young; Lee, Jinhyuk; Kim, Ji-Young; Hwang, Jae-Sam; Jeong, Woo-Sik; Jun, Mira

2014-02-01

In our ongoing research to find therapeutic compounds for Alzheimer's disease (AD) from natural resources, the inhibitory activity of the BACE1 enzyme by Tenebrio molitor larvae and its major compounds were evaluated. The T. molitor larvae extract and its fractions exhibited strong BACE1 suppression. The major components of hexane fraction possessing both high yield and strong BACE1 inhibition were determined by thin layer chromatography, gas chromatography, and nuclear magnetic resonance analysis. A remarkable composition of unsaturated long chain fatty acids, including oleic acid and linoleic acid, were identified. Oleic acid, in particular, noncompetitively attenuated BACE1 activity with a half-maximal inhibitory concentration (IC₅₀) value of 61.31 μM and Ki value of 34.3 μM. Furthermore, the fatty acids were stably interacted with BACE1 at different allosteric sites of the enzyme bound with the OH of CYS319 and the NH₃ of TYR320 for oleic acid and with the C=O group of GLN304 for linoleic acid. Here, we first revealed novel pharmacophore features of oleic acids and linoleic acid to BACE1 by in silico docking studies. The present findings would clearly suggest potential guidelines for designing novel BACE1 selective inhibitors.

Butyric acid stimulates bovine neutrophil functions and potentiates the effect of platelet activating factor.

PubMed

Carretta, M D; Hidalgo, A I; Burgos, J; Opazo, L; Castro, L; Hidalgo, M A; Figueroa, C D; Taubert, A; Hermosilla, C; Burgos, R A

2016-08-01

Increased short-chain fatty acid (SCFA) production is associated with subacute ruminal acidosis (SARA) and activation of inflammatory processes. In humans and rodents, SCFAs modulate inflammatory responses in the gut via free fatty acid receptor 2 (FFA2). In bovines, butyric acid is one of the most potent FFA2 agonists. Its expression in bovine neutrophils has recently been demonstrated, suggesting a role in innate immune response in cattle. This study aimed to evaluate if butyric acid modulates oxidative and non-oxidative functions or if it can potentiate other inflammatory mediators in bovine neutrophils. Our results showed that butyric acid can activate bovine neutrophils, inducing calcium (Ca(2+)) influx and mitogen-activated protein kinase (MAPK) phosphorylation, two second messengers involved in FFA2 activation. Ca(2+) influx induced by butyric acid was dependent on the extracellular and intracellular Ca(2+) source and phospholipase C (PLC) activation. Butyric acid alone had no significant effect on reactive oxygen species (ROS) production and chemotaxis; however, a priming effect on platelet-activating factor (PAF), a potent inflammatory mediator, was observed. Butyric acid increased CD63 expression and induced the release of neutrophil granule markers matrix metalloproteinase-9 (MMP-9) and lactoferrin. Finally, we observed that butyric acid induced neutrophil extracellular trap (NET) formation without affecting cellular viability. These findings suggest that butyric acid, a component of the ruminal fermentative process, can modulate the innate immune response of ruminants. Copyright © 2016 Elsevier B.V. All rights reserved.

Pleiotropy and its dissection through a metabolic gene Miniature1 (Mn1) that encodes a cell wall invertase in developing seeds of maize.

PubMed

Chourey, Prem S; Li, Qin-Bao; Cevallos-Cevallos, Juan

2012-03-01

The Mn1-encoded endosperm-specific cell wall invertase is a major determinant of sink strength of developing seeds through its control of both sink size, cell number and cell size, and sink activity via sucrose hydrolysis and release of hexoses essential for energy and signaling functions. Consequently, loss-of-function mutations of the gene lead to the mn1 seed phenotype that shows ∼70% reduction in seed mass at maturity and several pleiotropic changes. A comparative analysis of endosperm and embryo mass in the Mn1 and mn1 genotypes showed here significant reductions of both tissues in the mn1 starting with early stages of development. Clearly, embryo development was endosperm-dependent. To gain a mechanistic understanding of the changes, sugar levels were measured in both endosperm and embryo samples. Changes in the levels of all sugars tested, glc, fru, suc, and sorbitol, were mainly observed in the endosperm. Greatly reduced fru levels in the mutant led to RNA level expression analyses by q-PCR of several genes that encode sucrose and fructose metabolizing enzymes. The mn1 endosperm showed reductions in gene expression, ranging from ∼70% to 99% of the Mn1 samples, for both suc-starch and suc--energy pathways, suggesting an in vivo metabolic coordinated regulation due to the hexose-deficiency. Together, these data provide evidence of the Mn1-dependent interconnected network of several pathways as a possible basis for pleiotropic changes in seed development. Published by Elsevier Ireland Ltd.

Molecular mechanisms behind the antimicrobial activity of hop iso-α-acids in Lactobacillus brevis.

PubMed

Schurr, Benjamin C; Hahne, Hannes; Kuster, Bernhard; Behr, Jürgen; Vogel, Rudi F

2015-04-01

The main bittering component in beer, hop iso-α-acids, have been characterised as weak acids, which act as ionophores impairing microbial cells' function under acidic conditions as present in beer. Besides medium pH, divalent cations play a central role regarding the efficacy of the antimicrobial effect. The iso-α-acids' non-bitter derivatives humulinic acids can be found in isomerised hop extracts and can be generated during hop storage. Therefore, they have been under investigation concerning their influence on beer sensory properties. This study sketches the molecular mechanism behind iso-α-acids' antimicrobial activity in Lactobacillus (L.) brevis regarding their ionophore activity versus the dependence of the inhibitory potential on manganese binding, and suggests humulinic acids as novel tasteless food preservatives. We designed and synthesised chemically modified iso-α-acids to enhance the basic understanding of the molecular mechanism of antimicrobial iso-α-acids. It could be observed that a manganese-binding dependent transmembrane redox reaction (oxidative stress) plays a crucial role in inhibition. Privation of an acidic hydroxyl group neither erased ionophore activity, nor did it entirely abolish antimicrobial activity. Humulinic acids proved to be highly inhibitory, even outperforming iso-α-acids. Copyright © 2014 Elsevier Ltd. All rights reserved.

THE ENHANCEMENT OF CHLOROFORM-INDUCED PLASMA PROTEOLYTIC ACTIVITY BY EPSILON AMINOCAPROIC ACID

PubMed Central

Donaldson, Virginia H.; Ratnoff, Oscar D.

1962-01-01

The proteolytic activity in chloroform-treated plasma euglobulins has been attributed to plasmin. Plasmin can digest both casein and fibrin. Epsilon aminocaproic acid, which inhibits the activation of plasminogen, the precursor of plasmin, by streptokinase, urokinase, and tissue activators enhanced the development of casein hydrolytic activity in a mixture of chloroform and plasma euglobulins. Fibrinolytic activity was also enhanced, but this was evident only if the epsilon aminocaproic acid was removed from the chloroform-treated euglobulins prior to assay. The reasons for the paradoxical enhancement of chloroform-induced casein hydrolysis by euglobulins containing epsilon aminocaproic acid are unclear. However, studies of optimal pH, heat stability, and the effect of ionic strength on the activation of the precursor of this proteolytic enzyme do not differentiate it from plasminogen. PMID:13887179

Acetylsalicylic Acid Produces Different Effects on the Production of Active Oxygen Species by Activated Platelets in Different Inflammatory Diseases.

PubMed

Gabbasov, Z A; Kogan-Yasny, V V; Lakhno, D A; Kagan, L G; Ryzhkova, E V; Vasilieva, E Yu; Shpektor, A V

2017-11-01

We studied the effect of acetylsalicylic acid on ROS generation by platelets in patients after surgical interventions and in patients with bronchial asthma was studied. Platelets stimulated with platelet-activating factor are characterized by weak luminol-enhanced chemiluminescence in healthy people and patients after operations with laparoscopic incisions. Addition of platelet activation factor to platelet samples from patients after open abdominal surgery caused intensive chemiluminescence that was suppressed after platelet incubation with acetylsalicylic acid. At the same time, platelets of patients with aspirin-sensitive asthma did not respond to addition of platelet activating factor, but after incubation with acetylsalicylic acid, an intensive burst of chemiluminescence was detected with a maximum in 5-10 sec after the addition of a platelet-activating factor. In patients with bronchial asthma tolerant to aspirin, platelet activation factor did not induce chemiluminescence irrespective of incubation with acetylsalicylic acid.

The bile acid-sensitive ion channel (BASIC) is activated by alterations of its membrane environment.

PubMed

Schmidt, Axel; Lenzig, Pia; Oslender-Bujotzek, Adrienne; Kusch, Jana; Lucas, Susana Dias; Gründer, Stefan; Wiemuth, Dominik

2014-01-01

The bile acid-sensitive ion channel (BASIC) is a member of the DEG/ENaC family of ion channels. Channels of this family are characterized by a common structure, their physiological functions and modes of activation, however, are diverse. Rat BASIC is expressed in brain, liver and intestinal tract and activated by bile acids. The physiological function of BASIC and its mechanism of bile acid activation remain a puzzle. Here we addressed the question whether amphiphilic bile acids activate BASIC by directly binding to the channel or indirectly by altering the properties of the surrounding membrane. We show that membrane-active substances other than bile acids also affect the activity of BASIC and that activation by bile acids and other membrane-active substances is non-additive, suggesting that BASIC is sensitive for changes in its membrane environment. Furthermore based on results from chimeras between BASIC and ASIC1a, we show that the extracellular and the transmembrane domains are important for membrane sensitivity.

Effects of rare sugar D-allulose on acid production and probiotic activities of dairy lactic acid bacteria.

PubMed

Kimoto-Nira, H; Moriya, N; Hayakawa, S; Kuramasu, K; Ohmori, H; Yamasaki, S; Ogawa, M

2017-07-01

It has recently been reported that the rare sugar d-allulose has beneficial effects, including the suppression of postprandial blood glucose elevation in humans, and can be substituted for sucrose as a low-calorie food ingredient. To examine the applications of d-allulose in the dairy industry, we investigated the effects of d-allulose on the acid production of 8 strains of yogurt starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and 4 strains of lactococci, including potential probiotic candidates derived from dairy products. Acid production by 2 L. delbrueckii ssp. bulgaricus yogurt starter strains in milk was suppressed by d-allulose, but this phenomenon was also observed in some strains with another sugar (xylose), a sugar alcohol (sorbitol), or both. In contrast, among the dairy probiotic candidates, Lactococcus lactis H61, which has beneficial effects for human skin when drunk as part of fermented milk, was the only strain that showed suppression of acid production in the presence of d-allulose. Strain H61 did not metabolize d-allulose. We did not observe suppression of acid production by strain H61 with the addition of xylose or sorbitol, and xylose and sorbitol were not metabolized by strain H61. The acid production of strain H61 after culture in a constituted medium (tryptone-yeast extract-glucose broth) was also suppressed with the addition of d-allulose, but growth efficiency and sugar fermentation style were not altered. Probiotic activities-such as the angiotensin-converting enzyme inhibitory activity of H61-fermented milk and the superoxide dismutase activity of H61 cells grown in tryptone-yeast extract-glucose broth-were not affected by d-allulose. d-Allulose may suppress acid production in certain lactic acid bacteria without altering their probiotic activity. It may be useful for developing new probiotic dairy products from probiotic strains such as Lactococcus lactis H61. Copyright © 2017 American Dairy Science

[Dynamic changes of soil microbial populations and enzyme activities in super-high yielding summer maize farmland soil].

PubMed

Hou, Peng; Wang, Yong-jun; Wang, Kong-jun; Yang, Jin-sheng; Li, Deng-hai; Dong, Shu-ting; Liu, Jing-guo

2008-08-01

To reveal the characteristics of the dynamic changes of soil microbial populations and enzyme activities in super-high yielding ( > 15,000 kg x hm(-2)) summer maize farmland soil, a comparative study was conducted in the experimental fields in National Maize Engineering Research Center (Shandong). On the fields with an annual yield of >15,000 kg x hm(-2) in continuous three years, a plot with the yield of 20 322 kg x hm(-2) (HF) was chosen to make comparison with the conventional farmland (CF) whose maize yield was 8920. 1 kg x hm(-2). The numbers of bacteria, fungi, and actinomycetes as well as the activities of urease and invertase in 0-20 cm soil layer were determined. The results showed that in the growth period of maize, the numbers of bacteria, fungi, and actinomycetes in the two farmland soils increased first and declined then. At the later growth stages of maize, the numbers of soil microbes, especially those of bacteria and actinomycetes, were lower in HF than those in CF. At harvest stage, the ratio of the number of soil bacteria to fungi (B/ F) in HF was 2.03 times higher than that at sowing stage, and 3.02 times higher than that in CF. The B/F in CF had less difference at harvest and sowing stages. The soil urease activity in HF was significantly lower than that in CF at jointing stage, and the invertase activity in HF decreased rapidly after blooming stage, being significantly lower than that in CF.

From N-triisopropylsilylpyrrole to an optically active C-4 substituted pyroglutamic acid: total synthesis of penmacric acid.

PubMed

Berini, Christophe; Pelloux-Léon, Nadia; Minassian, Frédéric; Denis, Jean-Noël

2009-11-07

The stereoselective synthesis of penmacric acid, an optically active C-4 substituted pyroglutamic acid, has been efficiently achieved through an unusual 11-step sequence starting from simple N-triisopropylsilylpyrrole. The key-steps are the initial addition of the pyrrole nucleus onto a chiral nitrone and the obtention of the pyroglutamic acid moiety by reductive hydrogenation of the pyrrole followed by oxidation of the corresponding pyrrolidine into pyrrolidinone.

Jasmonic acid and salicylic acid activate a common defense system in rice.

PubMed

Tamaoki, Daisuke; Seo, Shigemi; Yamada, Shoko; Kano, Akihito; Miyamoto, Ayumi; Shishido, Hodaka; Miyoshi, Seika; Taniguchi, Shiduku; Akimitsu, Kazuya; Gomi, Kenji

2013-06-01

Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice.

Immunomodulatory and cellular anti-oxidant activities of caffeic, ferulic, and p-coumaric phenolic acids: a structure-activity relationship study.

PubMed

Kilani-Jaziri, Soumaya; Mokdad-Bzeouich, Imen; Krifa, Mounira; Nasr, Nouha; Ghedira, Kamel; Chekir-Ghedira, Leila

2017-10-01

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses and to reduce damage to the human body. To determine whether phenolic compounds (caffeic, ferulic, and p-coumaric acids) have immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we evaluated their effect on splenocyte proliferation and lysosomal enzyme activity. We also investigated the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL). In addition, induction of the cellular antioxidant activity in splenocytes, macrophages, and red blood cells was determined by measuring the fluorescence of the DCF product. The study first results indicated that caffeic, ferulic, and p-coumaric acids significantly promote LPS-stimulated splenocyte proliferation, suggesting a potential activation of B cells, and enhanced humoral immune response in hosts treated by the tested natural products. Phenolic acids significantly enhanced the killing activity of isolated NK and CTL cells but had negligible effects on mitogen-induced proliferation of splenic T cells. We showed that caffeic acid enhances lysosomal enzyme activity in murine peritoneal macrophages, suggesting a potential role in activating such cells. Immunomodulatory activity was concomitant with the cellular antioxidant effect in macrophages and splenocytes of caffeic and ferulic acids. We conclude from this study that caffeic, ferulic, and p-coumaric acids exhibited an immunomodulatory effect which could be ascribed, in part, to their cytoprotective effect via their antioxidant capacity. Furthermore, these results suggest that these natural products could be potentially used to modulate immune cell functions in physiological and pathological conditions.

Measurement and correlation of the solubility of gossypol acetic acid and gossypol acetic acid of optical activity in different solvents

NASA Astrophysics Data System (ADS)

Zhang, B.; Tang, H.; Liu, X. Y.; Zhai, X.; Yao, X. C.

2018-01-01

The equilibrium method was used to measure the solubility of gossypol acetic acid and gossypol acetic acid of optical activity in isopropyl alcohol, ethanol, acetic acid and ethyl acetate at temperature from 288.15 to 315.15. The Empirical equation and the Apelblat equation model were adopted to correlate the experimental data. For gossypol acetic acid, the root-mean-square deviations (RMSD) were observed in the range of 0.023-4.979 and 0.0112-0.614 for the Empirical equation and the Apelblat equation, respectively. For gossypol acetic acid of optical activity, the RMSD were observed in the range of 0.021-2.211 and 0.021-2.243 for the Empirical equation and the Apelblat equation, individually. And the maximum relative average deviation was 7.5%. Both equations offered an accurate mathematical expression of the experimental results. The calculated solubility showed a good relationship with the experimental solubility for most of solvents. This study provided valuable datas not only for optimizing the process of purification of gossypol acetic acid of optical activity in industry but also for further theoretical studies.

Abscisic acid-dependent multisite phosphorylation regulates the activity of a transcription activator AREB1.

PubMed

Furihata, Takashi; Maruyama, Kyonoshin; Fujita, Yasunari; Umezawa, Taishi; Yoshida, Riichiro; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2006-02-07

bZIP-type transcription factors AREBs/ABFs bind an abscisic acid (ABA)-responsive cis-acting element named ABRE and transactivate downstream gene expression in Arabidopsis. Because AREB1 overexpression could not induce downstream gene expression, activation of AREB1 requires ABA-dependent posttranscriptional modification. We confirmed that ABA activated 42-kDa kinase activity, which, in turn, phosphorylated Ser/Thr residues of R-X-X-S/T sites in the conserved regions of AREB1. Amino acid substitutions of R-X-X-S/T sites to Ala suppressed transactivation activity, and multiple substitution of these sites resulted in almost complete suppression of transactivation activity in transient assays. In contrast, substitution of the Ser/Thr residues to Asp resulted in high transactivation activity without exogenous ABA application. A phosphorylated, transcriptionally active form was achieved by substitution of Ser/Thr in all conserved R-X-X-S/T sites to Asp. Transgenic plants overexpressing the phosphorylated active form of AREB1 expressed many ABA-inducible genes, such as RD29B, without ABA treatment. These results indicate that the ABA-dependent multisite phosphorylation of AREB1 regulates its own activation in plants.

Microbial activity in an acid resin deposit: biodegradation potential and ecotoxicology in an extremely acidic hydrocarbon contamination.

PubMed

Kloos, Karin; Schloter, Michael; Meyer, Ortwin

2006-11-01

Acid resins are residues produced in a recycling process for used oils that was in use in the forties and fifties of the last century. The resin-like material is highly contaminated with mineral oil hydrocarbons, extremely acidic and co-contaminated with substituted and aromatic hydrocarbons, and heavy metals. To determine the potential for microbial biodegradation the acid resin deposit and its surroundings were screened for microbial activity by soil respiration measurements. No microbial activity was found in the core deposit. However, biodegradation of hydrocarbons was possible in zones with a lower degree of contamination surrounding the deposit. An extreme acidophilic microbial community was detected close to the core deposit. With a simple ecotoxicological approach it could be shown that the pure acid resin that formed the major part of the core deposit, was toxic to the indigenous microflora due to its extremely low pH of 0-1.

Structural and functional properties of the N transcriptional activation domain of thyroid transcription factor-1: similarities with the acidic activation domains.

PubMed Central

Tell, G; Perrone, L; Fabbro, D; Pellizzari, L; Pucillo, C; De Felice, M; Acquaviva, R; Formisano, S; Damante, G

1998-01-01

The thyroid transcription factor 1 (TTF-1) is a tissue-specific transcription factor involved in the development of thyroid and lung. TTF-1 contains two transcriptional activation domains (N and C domain). The primary amino acid sequence of the N domain does not show any typical characteristic of known transcriptional activation domains. In aqueous solution the N domain exists in a random-coil conformation. The increase of the milieu hydrophobicity, by the addition of trifluoroethanol, induces a considerable gain of alpha-helical structure. Acidic transcriptional activation domains are largely unstructured in solution, but, under hydrophobic conditions, folding into alpha-helices or beta-strands can be induced. Therefore our data indicate that the inducibility of alpha-helix by hydrophobic conditions is a property not restricted to acidic domains. Co-transfections experiments indicate that the acidic domain of herpes simplex virus protein VP16 (VP16) and the TTF-1 N domain are interchangeable and that a chimaeric protein, which combines VP16 linked to the DNA-binding domain of TTF-1, undergoes the same regulatory constraints that operate for the wild-type TTF-1. In addition, we demonstrate that the TTF-1 N domain possesses two typical properties of acidic activation domains: TBP (TATA-binding protein) binding and ability to activate transcription in yeast. Accordingly, the TTF-1 N domain is able to squelch the activity of the p65 acidic domain. Altogether, these structural and functional data suggest that a non-acidic transcriptional activation domain (TTF-1 N domain) activates transcription by using molecular mechanisms similar to those used by acidic domains. TTF-1 N domain and acidic domains define a family of proteins whose common property is to activate transcription through the use of mechanisms largely conserved during evolutionary development. PMID:9425125

Kinetics and Quantitative Structure—Activity Relationship Study on the Degradation Reaction from Perfluorooctanoic Acid to Trifluoroacetic Acid

PubMed Central

Gong, Chen; Sun, Xiaomin; Zhang, Chenxi; Zhang, Xue; Niu, Junfeng

2014-01-01

Investigation of the degradation kinetics of perfluorooctanoic acid (PFOA) has been carried out to calculate rate constants of the main elementary reactions using the multichannel Rice-Ramsperger-Kassel-Marcus theory and canonical variational transition state theory with small-curvature tunneling correction over a temperature range of 200~500 K. The Arrhenius equations of rate constants of elementary reactions are fitted. The decarboxylation is role step in the degradation mechanism of PFOA. For the perfluorinated carboxylic acids from perfluorooctanoic acid to trifluoroacetic acid, the quantitative structure–activity relationship of the decarboxylation was analyzed with the genetic function approximation method and the structure–activity model was constructed. The main parameters governing rate constants of the decarboxylation reaction from the eight-carbon chain to the two-carbon chain were obtained. As the structure–activity model shows, the bond length and energy of C1–C2 (RC1–C2 and EC1–C2) are positively correlated to rate constants, while the volume (V), the energy difference between EHOMO and ELUMO (ΔE), and the net atomic charges on atom C2 (QC2) are negatively correlated. PMID:25196516

Chemical composition and antimicrobial activity of fatty acid methyl ester of Quercus leucotrichophora fruits.

PubMed

Sati, Ankita; Sati, Sushil Chandra; Sati, Nitin; Sati, O P

2017-03-01

Natural fats and dietary oils are chief source of fatty acids and are well known to have antimicrobial activities against various microbes. The chemical composition and antimicrobial activities of fatty acids from fruits of white Oak (Quercus leucotrichophora) are yet unexplored and therefore the present study for the first time determines the fatty acid composition, and the antibacterial and antifungal activities of fatty acid methyl esters (FAME) of the white Oak plant found along the Himalayan region of Uttarakhand, India. The GCMS analysis revealed the presence of higher amount of saturated fatty acids than unsaturated fatty acids. FAME extract of fruits of Q. leucotrichophora demonstrated better antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. The present studies clearly establish the potential of the fruits of Q. leucotrichophora for use in soap, cosmetics and pharmaceutical industries.

Changes in Dehydrodiferulic Acids and Peroxidase Activity against Ferulic Acid Associated with Cell Walls during Growth of Pinus pinaster Hypocotyl.

PubMed Central

Sanchez, M.; Pena, M. J.; Revilla, G.; Zarra, I.

1996-01-01

Hydroxycinnamic acids associated with hypocotyl cell walls of dark-grown seedlings of Pinus pinaster Aiton were extracted with 1 N NaOH and identified by gas chromatography-mass spectrometry. The main hydroxycinnamic acid found was ferulic acid. Diferulic acid dehydrodimers were also found, with the 8,8-coupled isomer (compound 11) being the dehydrodiferulate present in the highest amount. However, the 5,5-coupled isomer, commonly referred to referred to as diferulic acid, was not detected. Two truxillic acids, 4-4[prime]-dihydroxy-3-3[prime]-dimethoxy-[alpha]-truxillic acids I and II, were tentatively identified. The 8,8-coupled dehydrodiferulic acid (compound 11) was the phenolic acid that showed the most conspicuous changes with hypocotyl age as well as along the hypocotyl axis. Peroxidase activity against ferulic acid was found in the apoplastic fluid as well as being ionically and covalently bound to the cell walls. The peroxidase activity increased with hypocotyl age as well as from the subapical toward the basal region of the hypocotyls. A key role in the cell-wall stiffening of 8,8 but not 5,5 dimerization of ferulic acid catalyzed by cell-wall peroxidases is proposed. PMID:12226339

A mitochondrial alkaline/neutral invertase isoform (A/N-InvC) functions in developmental energy-demanding processes in Arabidopsis.

PubMed

Martín, Mariana L; Lechner, Leandra; Zabaleta, Eduardo J; Salerno, Graciela L

2013-03-01

Recent findings demonstrate that alkaline/neutral invertases (A/N-Invs), enzymes that catalyze the breakdown of sucrose into glucose and fructose, are essential proteins in plant life. The fact that different isoforms are present in multiple locations makes them candidates for the coordination of metabolic processes. In the present study, we functionally characterized the encoding gene of a novel A/N-Inv (named A/N-InvC) from Arabidopsis, which localizes in mitochondria. A/N-InvC is expressed in roots, in aerial parts (shoots and leaves) and flowers. A detailed phenotypic analysis of knockout mutant plants (invc) reveals an impaired growth phenotype. Shoot growth was severely reduced, but root development was not affected as reported for A/N-InvA mutant (inva) plants. Remarkably, germination and flowering, two energy demanding processes, were the most affected stages. The effect of exogenous growth regulators led us to suggest that A/N-InvC may be modulating hormone balance in relation to the radicle emergence. We also show that oxygen consumption is reduced in inva and invc in comparison with wild-type plants, indicating that both organelle isoenzymes may play a fundamental role in mitochondrion functionality. Taken together, our results emphasize the involvement of mitochondrial A/N-Invs in developmental processes and uncover the possibility of playing different roles for the two isoforms located in the organelle.

Purifying capability, enzyme activity, and nitrification potentials in December in integrated vertical flow constructed wetland with earthworms and different substrates.

PubMed

Xu, Defu; Gu, Jiaru; Li, Yingxue; Zhang, Yu; Howard, Alan; Guan, Yidong; Li, Jiuhai; Xu, Hui

2016-01-01

The response of purifying capability, enzyme activity, nitrification potentials, and total number of bacteria in the rhizosphere in December to wetland plants, substrates, and earthworms was investigated in integrated vertical flow constructed wetlands (IVFCW). The removal efficiency of total nitrogen (TN), NH4-N, chemical oxygen demand (COD), and total phosphorus (TP) was increased when earthworms were added into IVFCW. A significantly average removal efficiency of N in IVFCW that employed river sand as substrate and in IVFCW that employed a mixture of river sand and Qing sand as substrate was not found. However, the average removal efficiency of P was higher in IVFCW with a mixture of river sand and Qing sand as substrate than in IVFCW with river sand as substrate. Invertase activity in December was higher in IVFCW that used a mixture of river sand and Qing sand as substrate than in IVFCW which used only river sand as substrate. However, urease activity, nitrification potential, and total number of bacteria in December was higher in IVFCW that employed river sand as substrate than in IVFCW with a mixture of river sand and Qing sand as substrate. The addition of earthworms into the integrated vertical flow constructed wetland increased the above-ground biomass, enzyme activity (catalase, urease, and invertase), nitrification potentials, and total number of bacteria in December. The above-ground biomass of wetland plants was significantly positively correlated with urease and nitrification potentials (p < 0.01). The addition of earthworms into IVFCW increased enzyme activity and nitrification potentials in December, which resulted in improving purifying capability.

Screening of Bothrops snake venoms for L-amino acid oxidase activity

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

Pessati, M.L.; Fontana, J.D.; Guimaraes, M.F.

1995-12-31

Toxins, enzymes, and biologically active peptides are the main components of snake venoms from the genus Bothrops. Following the venom inoculation, the local effects are hemorrhage, edema, and myonecrosis. Nineteen different species of Brazilian Bothrops were screened for protein content and L-amino acid oxidase activity. B. cotiara, formerly found in the South of Brazil, is now threatened with extinction. Its venom contains a highly hemorrhagic fraction and, as expected from the deep yellow color of the corresponding lyophilized powder, a high L-amino acid oxidase (LAO) activity was also characterized. Flavin adenine dinucleotide (FAD) is its associate coenzyme. B. cotiara venommore » LAO catalyzed the oxidative deamination of several L-amino acids, and the best substrates were methionine, leucine, tryptophan, and phenylalanine, hence, its potential application for the use in biosensors for aspartame determination and for the removal of amino acids from plasma. High levels for LAO were also found in other species than B. cotiara. In addition, the technique of isoelectric focusing (IEF) was employed as a powerful tool to study the iso- or multi-enzyme distribution for LAO activity in the B. cotiara snake venom.« less

Antimicrobial and enhancement of the antibiotic activity by phenolic compounds: Gallic acid, caffeic acid and pyrogallol.

PubMed

Lima, Valéria N; Oliveira-Tintino, Cícera D M; Santos, Enaide S; Morais, Luís P; Tintino, Saulo R; Freitas, Thiago S; Geraldo, Yuri S; Pereira, Raimundo L S; Cruz, Rafael P; Menezes, Irwin R A; Coutinho, Henrique D M

2016-10-01

The indiscriminate use of antimicrobial drugs has increased the spectrum of exposure of these organisms. In our studies, these phenolic compounds were evaluated: gallic acid, caffeic acid and pyrogallol. The antibacterial, antifungal and modulatory of antibiotic activities of these compounds were assayed using microdilution method of Minimum Inhibitory Concentration (MIC) to bacteria and Minimum Fungicide Concentration (MFC) to fungi. The modulation was made by comparisons of the MIC and MFC of the compounds alone and combined with drugs against bacteria and fungi respectively, using a sub-inhibitory concentration of 128 μg/mL of substances (MIC/8). All substances not demonstrated clinically relevant antibacterial activity with a MIC above ≥1024 μg/mL. As a result, we observed that the caffeic acid presented a potentiating antibacterial effect over the 3 groups of bacteria studied. Pyrogallol showed a synergistic effect with two of the antibiotics tested, but only against Staphylococcus aureus. In general, caffeic acid was the substance that presented with the greatest number of antibiotics and with the greatest number of bacteria. In relation to the antifungal activity of all the compounds, the verified results were ≥1024 μg/mL, not demonstrating significant activity. Regarding potentiation of the effect of fluconazole, was observed synergistic effect only when assayed against Candida tropicalis, with all substances. Therefore, as can be seen, the compounds presented as substances that can be promising potentiating agents of antimicrobial drugs, even though they do not have direct antibacterial and antifungal action. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes in carbohydrate content in zucchini fruit (Cucurbita pepo L.) under low temperature stress.

PubMed

Palma, Francisco; Carvajal, Fátima; Lluch, Carmen; Jamilena, Manuel; Garrido, Dolores

2014-03-01

The postharvest handling of zucchini fruit includes low-temperature storage, making cold stress unavoidable. We have investigated the changes of soluble carbohydrates under this stress and its relation with weight loss and chilling injury in zucchini fruit during postharvest storage at 4 °C and 20 °C for up to 14 days. Two varieties with different degrees of chilling tolerance were compared: Natura, the more tolerant variety, and Sinatra, the variety that suffered more severe chilling-injury symptoms and weight loss. In both varieties, total soluble carbohydrates, reducing soluble carbohydrates and polyols content was generally higher during storage at 4 °C than at 20 °C, thus these parameters are related to the physiological response of zucchini fruit to cold stress. However, the raffinose content increased in Natura and Sinatra fruits during storage at 4 °C and 20 °C, although at 20 °C the increase in raffinose was more remarkable than at 4 °C in both varieties, so that the role of raffinose could be more likely related to dehydration than to chilling susceptibility of zucchini fruit. Glucose, fructose, pinitol, and acid invertase activity registered opposite trends in both varieties against chilling, increasing in Natura and decreasing in Sinatra. The increase in acid invertase activity in Natura fruit during cold storage could contribute in part to the increase of these reducing sugars, whose metabolism could be involved in the adaptation to postharvest cold storage. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Improving a natural enzyme activity through incorporation of unnatural amino acids.

PubMed

Ugwumba, Isaac N; Ozawa, Kiyoshi; Xu, Zhi-Qiang; Ely, Fernanda; Foo, Jee-Loon; Herlt, Anthony J; Coppin, Chris; Brown, Sue; Taylor, Matthew C; Ollis, David L; Mander, Lewis N; Schenk, Gerhard; Dixon, Nicholas E; Otting, Gottfried; Oakeshott, John G; Jackson, Colin J

2011-01-19

The bacterial phosphotriesterases catalyze hydrolysis of the pesticide paraoxon with very fast turnover rates and are thought to be near to their evolutionary limit for this activity. To test whether the naturally evolved turnover rate could be improved through the incorporation of unnatural amino acids and to probe the role of peripheral active site residues in nonchemical steps of the catalytic cycle (substrate binding and product release), we replaced the naturally occurring tyrosine amino acid at position 309 with unnatural L-(7-hydroxycoumarin-4-yl)ethylglycine (Hco) and L-(7-methylcoumarin-4-yl)ethylglycine amino acids, as well as leucine, phenylalanine, and tryptophan. Kinetic analysis suggests that the 7-hydroxyl group of Hco, particularly in its deprotonated state, contributes to an increase in the rate-limiting product release step of substrate turnover as a result of its electrostatic repulsion of the negatively charged 4-nitrophenolate product of paraoxon hydrolysis. The 8-11-fold improvement of this already highly efficient catalyst through a single rationally designed mutation using an unnatural amino acid stands in contrast to the difficulty in improving this native activity through screening hundreds of thousands of mutants with natural amino acids. These results demonstrate that designer amino acids provide easy access to new and valuable sequence and functional space for the engineering and evolution of existing enzyme functions.

Azelaic acid modulates the inflammatory response in normal human keratinocytes through PPARgamma activation.

PubMed

Mastrofrancesco, Arianna; Ottaviani, Monica; Aspite, Nicaela; Cardinali, Giorgia; Izzo, Enzo; Graupe, Klaus; Zouboulis, Christos C; Camera, Emanuela; Picardo, Mauro

2010-09-01

Azelaic acid (AzA), a nine-carbon dicarboxylic acid, is an agent for the topical treatment of acne. It has also been shown to be effective in rosacea; however, the mechanism of action has not been clarified. Because inflammation is a common feature of both conditions, we investigated the effects of azelaic acid on the inflammatory response of normal human keratinocytes to ultraviolet B light, which is a photosensitizer agent in rosacea. AzA, at 20 mM, a concentration achievable following topical application of a 15% gel, suppresses ultraviolet B light-induced interleukins-1beta, -6 and tumor necrosis factor-alpha mRNA expression and protein secretion. Mechanistically, azelaic acid significantly reduced the ultraviolet B light-induced nuclear translocation of nuclear factor kB p65 subunit and the phosphorylation of the p38 mitogen and stress-activated protein kinase. Moreover, as peroxisome proliferators-activated receptor gamma, (PPARgamma) which has a crucial role in the control of inflammation, is activated by fatty acids and products of lipid peroxidation, we further investigated the effect of azelaic acid on the expression of this nuclear receptor. AzA induced peroxisome proliferators-activated receptor-gamma mRNA and its transcriptional activity. The PPARgamma antagonist GW9662 abrogated the inhibitory effects of AzA on the UVB-induced pro-inflammatory cytokines release and on the cell proliferation. Our study provides new insights into the molecular mechanisms of the activity of azelaic acid and lands additional evidences for its therapeutic effects on inflammatory skin diseases, such as rosacea.

Tuning of acyl-ACP thioesterase activity directed for tailored fatty acid synthesis.

PubMed

Feng, Yanbin; Zhang, Yunxiu; Wang, Yayue; Liu, Jiao; Liu, Yinghui; Cao, Xupeng; Xue, Song

2018-04-01

Medium-chain fatty acids have attracted significant attention as sources of biofuels in recent years. Acyl-ACP thioesterase, which is considered as the key enzyme to determine the carbon chain length, catalyzes the termination of de novo fatty acid synthesis. Although recombinant medium-chain acyl-ACP thioesterase (TE) affects the fatty acid profile in heterologous cells, tailoring of the fatty acid composition merely by engineering a specific TE is still intractable. In this study, the activity of a C8-C10-specific thioesterase FatB2 from Cuphea hookeriana on C10-ACP was quantified twice as high as that on C8-ACP based on a synthetic C8-C16 acyl-ACP pool in vitro. Whereas in vivo, it was demonstrated that ChFatB2 preferred to accumulate C8 fatty acids with 84.9% composition in the ChFatB2-engineered E. coli strain. To achieve C10 fatty acid production, ChFatB2 was rationally tuned based on structural investigation and enzymatic analysis. An I198E mutant was identified to redistribute the C8-ACP flow, resulting in C10 fatty acid being produced as the principal component at 57.6% of total fatty acids in vivo. It was demonstrated that the activity of TE relative to β-ketoacyl-ACP synthases (KAS) directly determined the fatty acid composition. Our results provide a prospective strategy in tailoring fatty acid synthesis by tuning of TE activities based on TE-ACP interaction.

Antistaphylococcal and biofilm inhibitory activities of gallic, caffeic, and chlorogenic acids.

PubMed

Luís, Ângelo; Silva, Filomena; Sousa, Sónia; Duarte, Ana Paula; Domingues, Fernanda

2014-01-01

Staphylococcus aureus is a Gram-positive pathogen which is able to form biofilms, exhibiting a more pronounced resistance to antibiotics and disinfectants. The hurdles posed in eradicating biofilms have driven the search for new compounds able to fight these structures. Phenolic compounds constitute one of the most numerous and ubiquitous group of plant secondary metabolites with many biological activities. The aim of the present work was to study the potential antimicrobial and antibiofilm properties of gallic, caffeic, and chlorogenic acids against S. aureus as well to elucidate its mechanism of action. It was concluded that the phenolic acids studied in this work have antistaphylococcal properties. For instance, gallic acid is able to influence the adhesion properties of S. aureus. The phenolic acids tested were also able to inhibit the production of α-hemolysin by this microorganism, with the exception of chlorogenic acid. Regarding its mechanism of action, caffeic acid interferes with the stability of the cell membrane and with the metabolic activity of the cells of S. aureus.

Quantitative studies on structure-DPPH• scavenging activity relationships of food phenolic acids.

PubMed

Jing, Pu; Zhao, Shu-Juan; Jian, Wen-Jie; Qian, Bing-Jun; Dong, Ying; Pang, Jie

2012-11-01

Phenolic acids are potent antioxidants, yet the quantitative structure-activity relationships of phenolic acids remain unclear. The purpose of this study was to establish 3D-QSAR models able to predict phenolic acids with high DPPH• scavenging activity and understand their structure-activity relationships. The model has been established by using a training set of compounds with cross-validated q2 = 0.638/0.855, non-cross-validated r2 = 0.984/0.986, standard error of estimate = 0.236/0.216, and F = 139.126/208.320 for the best CoMFA/CoMSIA models. The predictive ability of the models was validated with the correlation coefficient r2(pred) = 0.971/0.996 (>0.6) for each model. Additionally, the contour map results suggested that structural characteristics of phenolics acids favorable for the high DPPH• scavenging activity might include: (1) bulky and/or electron-donating substituent groups on the phenol ring; (2) electron-donating groups at the meta-position and/or hydrophobic groups at the meta-/ortho-position; (3) hydrogen-bond donor/electron-donating groups at the ortho-position. The results have been confirmed based on structural analyses of phenolic acids and their DPPH• scavenging data from eight recent publications. The findings may provide deeper insight into the antioxidant mechanisms and provide useful information for selecting phenolic acids for free radical scavenging properties.

Selective activity of several cholic acid derivatives against human immunodeficiency virus replication in vitro.

PubMed

Baba, M; Schols, D; Nakashima, H; Pauwels, R; Parmentier, G; Meijer, D K; De Clercq, E

1989-01-01

Several cholic acid derivatives such as taurolithocholic acid, lithocholic acid 3-sulfate, taurolithocholic acid 3-sulfate, and glycolithocholic acid 3-sulfate were shown to inhibit selectively the replication of human immunodeficiency virus type 1 (HIV-1) in vitro. These compounds completely protected MT-4 cells against HIV-1-induced cytopathogenicity at a concentration of 100 micrograms/ml, whereas no toxicity for the host cells was observed at 200 micrograms/ml. They also inhibited HIV-1 antigen expression in HIV-1-infected CEM cells. The bile acids (cholic acid, deoxycholic acid, chenodeoxycholic acid, and lithocholic acid) did not show any inhibitory effect on HIV-1 replication at concentrations that were not toxic to the host (MT-4) cells. From a structure-function analysis of a number of cholic acid derivatives, the presence of either a sulfonate (as in the tauro conjugates) or a sulfate group as well as the "litho" configuration appeared to be necessary for the expression of anti-HIV-1 activity. The active cholic acid derivatives did not directly inactivate the virus particles at the concentrations that were not toxic to the host cells. Lithocholic acid 3-sulfate, taurolithocholic acid 3-sulfate, and glycolithocholic acid 3-sulfate, but not taurolithocholic acid, partially inhibited virus adsorption to MT-4 cells. These three compounds were also inhibitory to the reverse transcriptase activity associated with HIV-1.

Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

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

John, George; Nagarajan, Subbiah; Chapman, Kent

A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacyl-ethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings.

Activation of mouse and human peroxisome proliferator-activated receptor alpha by perfluoroalkyl acids of different functional groups and chain lengths.

PubMed

Wolf, Cynthia J; Takacs, Margy L; Schmid, Judith E; Lau, Christopher; Abbott, Barbara D

2008-11-01

Perfluoroalkyl acids (PFAAs) are surfactants used in consumer products and persist in the environment. Some PFAAs elicit adverse effects on rodent development and survival. PFAAs can activate peroxisome proliferator-activated receptor alpha (PPARalpha) and may act via PPARalpha to produce some of their effects. This study evaluated the ability of numerous PFAAs to induce mouse and human PPARalpha activity in a transiently transfected COS-1 cell assay. COS-1 cells were transfected with either a mouse or human PPARalpha receptor-luciferase reporter plasmid. After 24 h, cells were exposed to either negative controls (water or dimethyl sulfoxide, 0.1%); positive control (WY-14643, PPARalpha agonist); perfluorooctanoic acid or perfluorononanoic acid at 0.5-100 microM; perfluorobutanoic acid, perfluorohexanoic acid, perfluorohexane sulfonate, or perfluorodecanoic acid (PFDA) at 5-100 microM; or perfluorobutane sulfonate or perfluorooctane sulfonate at 1-250 microM. After 24 h of exposure, luciferase activity from the plasmid was measured. Each PFAA activated both mouse and human PPARalpha in a concentration-dependent fashion, except PFDA with human PPARalpha. Activation of PPARalpha by PFAA carboxylates was positively correlated with carbon chain length, up to C9. PPARalpha activity was higher in response to carboxylates compared to sulfonates. Activation of mouse PPARalpha was generally higher compared to that of human PPARalpha. We conclude that, in general, (1) PFAAs of increasing carbon backbone chain lengths induce increasing activity of the mouse and human PPARalpha with a few exceptions, (2) PFAA carboxylates are stronger activators of mouse and human PPARalpha than PFAA sulfonates, and (3) in most cases, the mouse PPARalpha appears to be more sensitive to PFAAs than the human PPARalpha in this model.

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals.

PubMed

Falås, P; Baillon-Dhumez, A; Andersen, H R; Ledin, A; la Cour Jansen, J

2012-03-15

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to the pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cadmium Phytoavailability and Enzyme Activity under Humic Acid Treatment in Fluvo-aquic Soil

NASA Astrophysics Data System (ADS)

Liu, Borui; Huang, Qing; Su, Yuefeng

2018-01-01

A pot experiment was conducted to investigate the cadmium (Cd) availability to pakchois (Brassica chinensis L.) as well as the enzyme activities in fluvo-aquic soil under humic acid treatment. The results showed that the phytoavailability of Cd in soil decreased gradually as humic acid concentration rose (0 to 12 g·kg-1), while the activities of urease (UE), alkaline phosphatase (ALP) and catalase (CAT) kept increasing (P < 0.05). The correlation analysis indicated that humic acid was effective for reducing the devastation to soil enzymes due to the Cd pollution. In conclusion, humic acid is effective for the reduction of both Cd phytoavailability and the damage to enzyme activities due to Cd pollution in fluvo-aquic soil

Cloning of a CACTA transposon-like insertion in intron I of tomato invertase Lin5 gene and identification of transposase-like sequences of Solanaceae species.

PubMed

Proels, Reinhard K; Roitsch, Thomas

2006-03-01

Very few CACTA transposon-like sequences have been described in Solanaceae species. Sequence information has been restricted to partial transposase (TPase)-like fragments, and no target gene of CACTA-like transposon insertion has been described in tomato to date. In this manuscript, we report on a CACTA transposon-like insertion in intron I of tomato (Lycopersicon esculentum) invertase gene Lin5 and TPase-like sequences of several Solanaceae species. Consensus primers deduced from the TPase region of the tomato CACTA transposon-like element allowed the amplification of similar sequences from various Solanaceae species of different subfamilies including Solaneae (Solanum tuberosum), Cestreae (Nicotiana tabacum) and Datureae (Datura stramonium). This demonstrates the ubiquitous presence of CACTA-like elements in Solanaceae genomes. The obtained partial sequences are highly conserved, and allow further detection and detailed analysis of CACTA-like transposons throughout Solanaceae species. CACTA-like transposon sequences make possible the evaluation of their use for genome analysis, functional studies of genes and the evolutionary relationships between plant species.

Mutants of Yeast Defective in Sucrose Utilization

PubMed Central

Carlson, Marian; Osmond, Barbara C.; Botstein, David

1981-01-01

Utilization of sucrose as a source of carbon and energy in yeast (Saccharomyces) is controlled by the classical SUC genes, which confer the ability to produce the sucrose-degrading enzyme invertase (Mortimer and Hawthorne 1969). Mutants of S. cerevisiae strain S288C (SUC2+) unable to grow anaerobically on sucrose, but still able to use glucose, were isolated. Two major complementation groups were identified: twenty-four recessive mutations at the SUC2 locus (suc2-); and five recessive mutations defining a new locus, SNF1 (for sucrose nonfermenting), essential for sucrose utilization. Two minor complementation groups, each comprising a single member with a leaky sucrose-nonfermenting phenotype, were also identified. The suc2 mutations isolated include four suppressible amber mutations and five mutations apparently exhibiting intragenic complementation; complementation analysis and mitotic mapping studies indicated that all of the suc2 mutations are alleles of a single gene. These results suggest that SUC2 encodes a protein, probably a dimer or multimer. No invertase activity was detected in suc2 mutants.—The SNF1 locus is not tightly linked to SUC2. The snf1 mutations were found to be pleiotropic, preventing sucrose utilization by SUC2+ and SUC7+ strains, and also preventing utilization of galactose, maltose and several nonfermentable carbon sources. Although snf1 mutants thus display a petite phenotype, classic petite mutations do not interfere with utilization of sucrose, galactose or maltose. A common feature of all the carbon utilization systems affected by SNF1 is that all are regulated by glucose repression. The snf1 mutants were found to produce the constitutive nonglycosylated form of invertase, but failed to produce the glucose-repressible, glycosylated, secreted invertase. This failure cannot be attributed to a general defect in production of glycosylated and secreted proteins because synthesis of acid phosphatase, a glycosylated secreted protein not

Ellagic acid, phenolic acids, and flavonoids in Malaysian honey extracts demonstrate in vitro anti-inflammatory activity.

PubMed

Kassim, Mustafa; Achoui, Mouna; Mustafa, Mohd Rais; Mohd, Mustafa Ali; Yusoff, Kamaruddin Mohd

2010-09-01

Natural honey has been used in traditional medicine of different cultures throughout the world. This study looked into the extraction of Malaysian honey and the evaluation of the anti-inflammatory activity of these extracts. It was hypothesized that honey extracts contain varying amounts of phenolic compounds and that they possess different in vitro anti-inflammatory activities. Honey extracts were analyzed using liquid chromatography-mass spectrometry to identify and compare phenolic compounds, whereas high-performance liquid chromatography was used for their quantification. Subsequently, honey methanol extract (HME) and honey ethyl acetate extract (HEAE) were tested in vitro for their effect on nitric oxide production in stimulated macrophages. The extracts were also tested for their effects on tumor necrosis factor-α (TNF) cytotoxicity in L929 cells. The major phenolics in the extracts were ellagic, gallic, and ferulic acids; myricetin; chlorogenic acid; and caffeic acid. Other compounds found in lower concentrations were hesperetin, p-coumaric acid, chrysin, quercetin, luteolin, and kaempferol. Ellagic acid was the most abundant of the phenolic compounds recorded, with mean concentrations of 3295.83 and 626.74 μg/100 g of honey in HME and HEAE, respectively. The median maximal effective concentrations for in vitro nitric oxide inhibition by HEAE and HME were calculated to be 37.5 and 271.7 μg/mL, respectively. The median maximal effective concentrations for protection from TNF cytotoxicity by HEAE and HME were 168.1 and 235.4 μg/mL, respectively. In conclusion, HEAE exhibited greater activity in vitro, whereas HME contained a higher concentration of phenolic compounds per 100 g of honey. Copyright © 2010 Elsevier Inc. All rights reserved.

Inhibition of bacterial activity in acid mine drainage

NASA Astrophysics Data System (ADS)

Singh, Gurdeep; Bhatnagar, Miss Mridula

1988-12-01

Acid mine drainage water give rise to rapid growth and activity of an iron- and sulphur- oxidizing bacterium Thiobacillus ferrooxidians which greatly accelerate acid producing reactions by oxidation of pyrite material associated with coal and adjoining strata. The role of this bacterium in production of acid mine drainage is described. This study presents the data which demonstrate the inhibitory effect of certain organic acids, sodium benzoate, sodium lauryl sulphate, quarternary ammonium compounds on the growth of the acidophilic aerobic autotroph Thiobacillus ferrooxidians. In each experiment, 10 milli-litres of laboratory developed culture of Thiobacillus ferrooxidians was added to 250 milli-litres Erlenmeyer flask containing 90 milli-litres of 9-k media supplemented with FeSO4 7H2O and organic compounds at various concentrations. Control experiments were also carried out. The treated and untreated (control) samples analysed at various time intervals for Ferrous Iron and pH levels. Results from this investigation showed that some organic acids, sodium benzoate, sodium lauryl sulphate and quarternary ammonium compounds at low concentration (10-2 M, 10-50 ppm concentration levels) are effective bactericides and able to inhibit and reduce the Ferrous Iron oxidation and acidity formation by inhibiting the growth of Thiobacillus ferrooxidians is also discussed and presented

Developmental toxicity of perfluorononanoic acid is dependent on peroxisome proliferator activated receptor-alpha.

EPA Science Inventory

Perfluorononanoic acid (PFNA) is one of the predominant perfluoroalkyl acids in the environment and in tissues of humans and wildlife. PFNA strongly activates the mouse and human peroxisome proliferator-activated receptor-alpha (PPARα) in vitro and negatively impacts development ...

Activation of peroxisome proliferator-activated receptor-{delta} by GW501516 prevents fatty acid-induced nuclear factor-{kappa}B activation and insulin resistance in skeletal muscle cells.

PubMed

Coll, Teresa; Alvarez-Guardia, David; Barroso, Emma; Gómez-Foix, Anna Maria; Palomer, Xavier; Laguna, Juan C; Vázquez-Carrera, Manuel

2010-04-01

Elevated plasma free fatty acids cause insulin resistance in skeletal muscle through the activation of a chronic inflammatory process. This process involves nuclear factor (NF)-kappaB activation as a result of diacylglycerol (DAG) accumulation and subsequent protein kinase Ctheta (PKCtheta) phosphorylation. At present, it is unknown whether peroxisome proliferator-activated receptor-delta (PPARdelta) activation prevents fatty acid-induced inflammation and insulin resistance in skeletal muscle cells. In C2C12 skeletal muscle cells, the PPARdelta agonist GW501516 prevented phosphorylation of insulin receptor substrate-1 at Ser(307) and the inhibition of insulin-stimulated Akt phosphorylation caused by exposure to the saturated fatty acid palmitate. This latter effect was reversed by the PPARdelta antagonist GSK0660. Treatment with the PPARdelta agonist enhanced the expression of two well known PPARdelta target genes involved in fatty acid oxidation, carnitine palmitoyltransferase-1 and pyruvate dehydrogenase kinase 4 and increased the phosphorylation of AMP-activated protein kinase, preventing the reduction in fatty acid oxidation caused by palmitate exposure. In agreement with these changes, GW501516 treatment reversed the increase in DAG and PKCtheta activation caused by palmitate. These effects were abolished in the presence of the carnitine palmitoyltransferase-1 inhibitor etomoxir, thereby indicating that increased fatty acid oxidation was involved in the changes observed. Consistent with these findings, PPARdelta activation by GW501516 blocked palmitate-induced NF-kappaB DNA-binding activity. Likewise, drug treatment inhibited the increase in IL-6 expression caused by palmitate in C2C12 and human skeletal muscle cells as well as the protein secretion of this cytokine. These findings indicate that PPARdelta attenuates fatty acid-induced NF-kappaB activation and the subsequent development of insulin resistance in skeletal muscle cells by reducing DAG accumulation

Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

DOEpatents

John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

2016-10-25

A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

PubMed

Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

2015-01-01

Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

Structure--activity studies for alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid receptors: acidic hydroxyphenylalanines.

PubMed

Hill, R A; Wallace, L J; Miller, D D; Weinstein, D M; Shams, G; Tai, H; Layer, R T; Willins, D; Uretsky, N J; Danthi, S N

1997-09-26

Antagonists of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid (AMPA) receptors may have therapeutic potential as psychotropic agents. A series of mononitro- and dinitro-2- and 3-hydroxyphenylalanines was prepared, and their activity compared with willardiine, 5-nitrowillardiine, AMPA, and 2,4,5-trihydroxyphenylalanine (6-hydroxydopa) as inhibitors of specific [3H]AMPA and [3H]kainate binding in rat brain homogenates. The most active compounds were highly acidic (pKa 3-4), namely, 2-hydroxy-3,5-dinitro-DL-phenylalanine (13; [3H]AMPA IC50 approximately equal to 25 microM) and 3-hydroxy-2,4-dinitro-DL-phenylalanine (19; [3H]AMPA IC50 approximately equal to 5 microM). Two other dinitro-3-hydroxyphenylalanines, and 3,5-dinitro-DL-tyrosine, were considerably less active. Various mononitrohydroxyphenylalanines, which are less acidic, were also less active or inactive, and 2- and 3-hydroxyphenylalanine (o- and m-tyrosine) were inactive. Compounds 13 and 19, DL-willardiine (pKa 9.3, [3H]AMPA IC50 = 2 microM), and 5-nitro-DL-willardiine (pKa 6.4, [3H]AMPA IC50 = 0.2 microM) displayed AMPA > kainate selectivity in binding studies. Compound 19 was an AMPA-like agonist, but 13 was an antagonist in an AMPA-evoked norepinephrine release assay in rat hippocampal nerve endings. Also, compound 13 injected into the rat ventral pallidum antagonized the locomotor activity elicited by systemic amphetamine.

Enhanced antiamyloidal activity of hydroxy cinnamic acids by enzymatic esterification with alkyl alcohols.

PubMed

Kondo, Hazuki; Sugiyama, Haruka; Katayama, Shigeru; Nakamura, Soichiro

2014-01-01

Lipophilic derivatives of hydroxyl cinnamic acids (HCAs) including caffeic acid (CA), ferulic acid, sinapic acid (SA), and chlorogenic acid were synthesized by esterification with butanol, octanol, or hexadecanol catalyzed by the lipase from Candida antarctica to investigate the effect of lipophilicity on their antiamyloidal activity assessed by the inhibitory activities toward fibrillization of amyloid β (Aβ) peptide. Among them, CA showed the highest activity at 50 μM, reducing the amyloid fibril formation of Aβ to 34.4 ± 6.8%. The antiamyloidal effects of HCAs were enhanced by esterification with alkyl alcohols, and the longer alkyl chain tended to be more effective except for SA. Aβ fibril formation was suppressed by the hexadecyl ester of CA, which was reduced to 8.8 ± 2.3%. In contrast, those of octyl and butyl esters were 19.3 ± 2.3% and 41.6 ± 6.1%, respectively. These results show that lipophilicity plays an important role in the antiamyloidal activities of esterified phenolic compounds. © 2013 International Union of Biochemistry and Molecular Biology, Inc.