Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pyruvic Acid”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources
PubMed1984

Possibility of diacetyl and related compounds as the 4-carbon compound necessary for the formation of riboflavin in Ashbya gossypii.

The effects of various compounds (0.5%) involved in the butanediol and the glycolytic pathways on riboflavin formation in whole cells of Ashbya gossypii at rest were examined. The addition of acetate, glycerol and diacetyl inhibited riboflavin formation, while the addition of acetoin had no effect on it, and the addition of ethanol, 2,3-butanediol, pyruvic acid and glucose accelerated it. The relation of diacetyl and acetoin to riboflavin formation during resting cell incubation in the presence of 0.5% ethanol and various concentrations of 2,3-butanediol was examined. The results quantitatively revealed a precursor-product relation between riboflavin formation and the formation of diacetyl and acetoin. The results obtained provide evidence that a high flavinogenic agent, ethanol, was converted to acetaldehyde, pyruvic acid, acetoin and diacetyl in this order, that a week flavinogenic agent, 2,3-butanediol, was transferred to diacetyl through acetoin, and that the diacetyl produced can be utilized as the 4-carbon compound for riboflavin formation in the flavinogenic mold, Ashbya gossypii. It remains obscure whether diacetyl is enzymatically involved in riboflavin formation.

Acetaldehyde↗
PubMed1969

Immunochemistry of newly found substituents of polysaccharides of Rhizobium species.

Acetyl and pyruvic acid groups were detected and estimated in the extracellular polysaccharides of Rhizobium trifolii and R. meliloti. Pyruvic acid was found also in the specific polysaccharide of pneumococcal type 27, and is believed to explain the cross-reactivity between antiserum to pneumococcal type 27 and these and other pyruvate-containing bacterial polysaccharides. Removal of pyruvate from a Rhizobium polysaccharide rendered it inactive with its homologous antiserum and with antiserum to pneumococcal type 27, but it then reacted with several antiserums to other pneumococcal types with which the intact material was unreactive.

Acetates↗
PubMed1978

[Effect of short submaximal stable-load exertion on blood serum insulin and human growth hormone concentration as well as on various biochemical and acid-base blood parameters in healthy individuals].

The studies on effect of short-term submaximal physiol exercise with stable load on blood serum concentrations of insulin, human growth hormone, free fatty acids, glucose and aminoacid nitrogen were carried out on 20 healthy men, aged 19--21 years. In addition, lactic and pyruvic acid concentrations and some parameters of capillary blood acid-base equilibrium were determined. It was found that short-term submaximal exercise with stable load caused the increase of HGH concentration and the decrease of IRI concentration. During such an exercise blood serum free fatty acid concentrations also decreased, while blood serum glucose and aminoacid nitrogen ones did not change significantly. Blood serum lactic and pyruvic acid concentrations and hydrogen ion concentration increased. Simultaneously, carbon dioxide partial pressure decreased and base excess increased. This pattern of changes indicates metabolic acidosis compensated partially by hyperventilation.

Acid-Base Equilibrium↗
PubMed1979

The effect of hemorrhagic shock on plasma amino acids and tissue energy substrates in the primate.

Levels of plasma amino acids and muscle concentrations of energy substrates and metabolites after shock in the Macaca mulatta Rhesus monkey were investigated. The hemodynamic response to shock is similar to that of previously reported studies of primates in shock. Plasma glucose and ASAT increased significantly, while levels of ALAT and pyruvic acid did not change. Lactic acid was elevated. Muscle glycogen and concentrations of lactic acid were increased, and levels of pyruvic acid, creatine phosphate, and malate fell during shock. Levels of ATP in muscle were unchanged. Nine of the 23 arterial plasma amino acids analyzed decreased significantly. Aspartic acid was increased during shock. The increased levels of tissue carbohydrates and decreased concentrations of plasma amino acids observed in this study differ from results previously reported for other animal shock models. Changes in amino acid levels are similar to the results of some clinical studies.

Adenosine Triphosphate↗
PubMedDate not supplied

[Exopolysaccharide and proteolytic enzyme synthesis by M-, S- and R-forms of Mycobacterium lacticolum].

The composition of exocellular polysaccharides was studied in the M, S and R variants of Mycobacterium lacticolum 104. The exoglycans of the M and S variants were found to be rather similar but differ considerably from the exoglycan of the R form. The polysaccharides of the M and S cells contained glucose, mannose, galactose, and pyruvic acid; the exoglycan of the R cells contained also the fourth sugar arabinose, but lacked pyruvic acid. The specific rotation of the polysaccharides from the M, S and R variants ([alpha]d20), respectively, was +207.5, +168.0 and +25.0. The caseinolytic activity of the M, S and R variants, respectively, by the seventh day of growth was 0.93+/-0.21, 0.62+/-0.07 and 0.47+/-0.07 units/ml.

Chemical Phenomena↗
PubMed1969

Growth and sporulation of Bacillus subtilis mutants blocked in the pyruvate dehydrogenase complex.

Two "ACE" mutants of Bacillus subtilis which require acetate for growth on glucose minimal medium have been isolated. They do not grow with acetoin, 2,3-butanediol, fatty acids, isoleucine, lipoic acid, malic acid, pyruvic acid, succinic acid, thiamine, or valine, but respond somewhat to glutamate or citrate. The mutants lack the activity of the pyruvate dehydrogenase complex; they excrete pyruvate and later acetoin. They grow in nutrient sporulation medium (NSMP) to one-half the normal turbidity and do not sporulate subsequently. When acetate is added to NSMP (at the optimal concentration of 0.07 m), the ACE mutants grow to the normal turbidity and then sporulate normally. Growth but not sporulation is restored in NSMP upon addition of 2,3-butanediol, citrate, glucose, glutamate, glycerol, or ribose, but not upon addition of acetoin, malate, oxaloacetate, pyruvate, and several other compounds. After growth in NSMP has stopped, the mutants incorporate uracil only at a very low rate, which can be increased by the addition of acetate, citrate, or glutamate. Furthermore, the metabolism of acetoin is prevented after growth has stopped but can be restored by the addition of acetate. All these results can be explained by a lack of reduced nicotinamide adenine dinucleotide (NADH) resulting from the deficiency in acetylcoenzyme A. In fact, after growth of the ACE mutants had stopped, the NADH concentration was at the borderline of measurability, whereas it increased significantly upon addition of glucose. The growing standard strain contains, at the same bacterial turbidity, at least 20 times more NADH (230 pmole/optical density unit at 600 nm) than the nongrowing ACE mutants. The isolated spores, obtained after growth in NSMP plus acetate, can be initiated to germinate in the presence of either l-alanine or the combination of l-asparagine, fructose, glucose, and potassium; addition of acetate is not required and has no effect.

Acetates↗
PubMedDate not supplied

Enzymatic large-scale production of 2-keto-3-deoxy-D-glycero-D-galacto-nonopyranulosonic acid in enzyme membrane reactors.

The enzymatic synthesis of 2-keto-3-deoxy-D-glycero-D-galacto-nonopyranulosonic acid (KDN) starting from D-mannose and pyruvic acid using Neu5Ac-aldolase has been scaled up. A repetitive batch ultrafiltration bioreactor was used for the KDN synthesis on 100 g scale with a conversion of up to 85%. Furthermore, a 440 mL pilot-scale enzyme membrane reactor (EMR) was performed for the continuous production of KDN. Conversion of mannose was 75% at a space--time yield of 375 g/(L d). KDN was advanteageously isolated by crystallization with an overall yield of 75%.

Bioreactors↗
PubMed1985

Number and function of sulphydryl groups of N-acetylneuraminate lyase.

The reaction between DTNB and the SH groups of N-acetylneuraminate lyase has been investigated in the presence and absence of pyruvic acid, substrate of the enzyme. It was found that DTNB inactivates N-acetylneuraminate lyase, while pyruvic acid protects the enzyme against this inactivation. When the enzyme was fully inactivated, two SH groups have reacted with DTNB. This result supports previous suggestions, that there is one cystein residue per active site responsible for enzyme activity. In the presence of SDS, approx. 6 SH groups reacted with DTNB suggesting the existence of 3 SH groups per enzyme subunit.

Clostridium perfringens↗
PubMed2001

Tyrosine and phenylalanine catabolism by Lactobacillus cheese flavor adjuncts.

Bacterial metabolism of Tyr and Phe has been associated with the formation of aromatic compounds that impart barny-utensil and floral off-flavors in cheese. In an effort to identify possible mechanisms for the origin of these compounds in Cheddar cheese, we investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar cheese-ripening (pH 5.2, 4% NaCl, 15 degrees C, no sugar) conditions. Enzyme assays of cell-free extracts indicated that L. casei strains catabolize Tyr and Phe by successive, constitutively expressed transamination and dehydrogenation reactions. Similar results were obtained with L. helveticus strains, except that the dehydrogenase enzymes were induced during incubation under cheese-ripening conditions. Micellar electrokinetic capillary chromatography of supernatants from L. casei and L. helveticus strains incubated under simulated cheese-ripening conditions confirmed that Tyr and Phe transamination and dehydrogenation pathways were active in both species and also showed these reactions were reversible. Major products of Tyr catabolism were phydroxy phenyl lactic acid and p-hydroxy phenyl acetic acid, while Phe degradation gave rise to phenyl lactic acid, phenyl acetic acid, and benzoic acid. However, some of these products were likely formed by nonenzymatic processes, since spontaneous chemical degradation of the Tyr intermediate p-hydroxy phenyl pyruvic acid produced p-hydroxy phenyl acetic acid, p-hydroxy phenyl propionic acid, and p-hydroxy benzaldehyde, while chemical degradation of the Phe intermediate phenyl pyruvic acid gave rise to phenyl acetic acid, benzoic acid, phenethanol, phenyl propionic acid, and benzaldehyde.

Cheese↗
PubMed1994

Involvement of L-tryptophan aminotransferase in indole-3-acetic acid biosynthesis in Enterobacter cloacae.

L-Tryptophan aminotransferase (L-tryptophan:2-oxoglutarate aminotransferase; EC 2.6.1.27) from Enterobacter cloacae was purified 62-fold and characterized to determine its role in indole-3-acetic acid biosynthesis. The enzyme reversibly catalyzed the transamination of L-tryptophan with 2-oxoglutarate as the amino acceptor to yield indole-3-pyruvic acid and L-glutamate, and the Km values for L-tryptophan and indole-3-pyruvic acid were 3.3 mM and 24 microM, respectively. In the indole-3-acetaldehyde synthesis experiments in vitro, 94% of L-tryptophan was efficiently converted to indole-3-acetaldehyde by the purified L-tryptophan aminotransferase plus indolepyruvate decarboxylase. Furthermore, the amounts of L-tryptophan decreased with increases in the indolepyruvate decarboxylase activity, while the amounts of indole-3-acetaldehyde increased with increases in this activity. In genetic experiments, the amounts of L-tryptophan produced by Enterobacter and Pseudomonas strains harboring the gene for indolepyruvate decarboxylase were lower than those produced by these same strains without the gene, while the amounts of indole-3-acetic acid produced by Enterobacter and Pseudomonas strains harboring the gene for indolepyruvate decarboxylase were higher than those produced by these same strains without the gene. These results clearly show that L-tryptophan aminotransferase is involved in the indole-3-acetic acid biosynthesis and that indolepyruvate decarboxylase is the rate-limiting step in this pathway.

Carboxy-Lyases↗
PubMed2006

[Stimulatory effects of some amino acids on glycerol production by Candida glycerinogenes].

By using some intermediate metabolites in EMP pathway and TCA cycle as the control, the effects of amino acid supplements on glycerol production by Candida glycerinogenes in shake-flask fermentations with urea as nitrogen resource were investigated. The results showed that ten kinds of amino acids, including L-glutamic acid, L-glutamine, L-aspartic acid, L-asparagine, L-glycin, L-lysine, L-tyrosine, L-proline, L-histidine, and L-serine, had strong promotional effects on glycerol production; The optimal concentrations of these amino acids were 0.40, 0.45, 0.36, 0.35, 0.39, 0.36, 0.35, 0.45, 0.26, and 0.45 g/L, respectively. Accordingly the optimum contents of pyruvic acid, a-oxoglutarate, oxaloacetic acid, citrate, and succinate were 0.24, 0.42, 0.40, 0.37, and 0.38 g/L, respectively. The advantageous opportunities of supplement were as follows: L-lysine at the beginning of fermentation; pyruvic acid and oxaloacetic acid at the fourteenth hour; L-glutamic acid, L-glutamine, L-histidine, L-proline, L-aspartic acid, L-tyrosine, L-glycin, alpha-oxoglutarate, and succinate at the thirtieth hour; and L-asparagine, L-serine, and citrate at the forty-eighth hour. The addition of each stimulant at the optimal conditions could significantly promote glycerol production, with the glycerol yield on initial glucose and its increased speed exceeding 60% and 16%, respectively. The possible stimulatory mechanism due to the amino acid supplements is that the increased intermediate metabolites levels from amino acids degradation may have enhanced the flux through TCA cycle, which improve cell energetics. Meanwhile, the shift of carbon metabolism flux at the glyceraldhyde-3-phosphate node can result in the incremental flux through glycerol biosynthesis pathway.

Amino Acids↗
PubMed1962

Extracellular metabolites of streptomycin mutants of Escherichia coli.

Bragg, P. D. (University of British Columbia, Vancouver, Canada) and W. J. Polglase. Extracellular metabolites of streptomycin mutants of Escherichia coli. J. Bacteriol. 84:370-374. 1962.-A comparison of the extracellular products of glucose metabolism during aerobic exponential growth of Escherichia coli showed that a streptomycin-dependent strain produced large amounts of l-valine while only trace amounts of this amino acid were produced by streptomycin-sensitive strains. A further difference between sensitive and dependent mutants was the production by the latter of lactic acid when the gas phase was changed from air to nitrogen. Resistant cultures grown in antibiotic-free medium were similar to sensitive cultures, but when dihydrostreptomycin was added, the resistant organism produced lactic and pyruvic acids. Three strains of streptomycin-sensitive E. coli accumulated pyruvic acid from glucose oxidation in the presence of concentrations of dihydrostreptomycin which inhibited multiplication. Further evidence is thus provided to implicate reactions of pyruvate as being of significance in the mechanism of action of streptomycin.

Anti-Bacterial Agents↗
PubMedDate not supplied

Catabolism of tryptophan by Trypanosoma evansi.

Trypanosoma brucei gambiense, which causes human African trypanosomiasis, catabolizes the aromatic amino acid tryptophan via an initial aminotransferase catalyzed reaction to form several indole end products, which have been suggested to contribute to the pathogenesis of trypanosomiasis. To determine if this same pathway exists in T. evansi, the closely related trypanosome pathogen of domestic animals, tryptophan catabolism was examined in vitro and in vivo. As is the case with human African trypanosomes, T. evansi catabolized tryptophan to form indole-3-pyruvic acid and smaller amounts of indole-3-acetic acid and indole-3-lactic acid. Large concentrations of indole-3-pyruvic acid are excreted in urine of trypanosome-infected mice. However, indole-3-ethanol could not be detected in incubates of T. evansi or T. b. gambiense, even though the latter species had previously been reported to form this neutral metabolite. A new, previously unreported tryptophan metabolite was isolated and partially characterized from incubates of T. evansi and T. b. gambiense. Although the functional significance of tryptophan catabolism to trypanosomatids remains obscure, the pathway is quantitatively significant in all species examined thus far.

Animals↗
PubMed1980

The binding of a fluorescent activator 2-(N-decyl)aminonaphthalene-6-sulfonic acid to pyruvate oxidase.

E. coli pyruvate oxidase (pyruvate:ferricytochrome b1 oxidoreductase, EC 1.2.2.2) is a peripheral membrane flavoenzyme which has been purified to homogeneity. In vivo the oxidase resides on the inner surface of the cytoplasmic membrane and is coupled to the bacterial electron transport chain. In vitro, the purified oxidase requires lipids for full enzymatic activity. Previous studies have characterized the conformational and energetic coupling between the lipid-binding site(s) and the catalytic active site. The affinity of the enzyme for phospholipids and detergents is significantly enhanced when the flavoprotein is in the reduced form, i.e., in the presence of pyruvate and the required cofactor, thiamin pyrophosphate. The lipid-binding studies were hindered due to the complicating factor of the self-association of the substrate-reduced flavoprotein. In this paper, fluorescence techniques are employed to measure the binding of a detergent-like activator to the oxidase. The experiments are performed at much lower protein concentrations than previously employed, so that protein aggregation is not a problem. The chromophore on the activator, 2-(N-decyl)aminonaphthalene-6-sulfonic acid is effective at quenching the pyruvate oxidase intrinsic tryptophan fluorescence. Quenching titrations are used to obtain the binding isotherm. AT DNS concentrations less than 10(-5) M, the results show a larger amount of DNS binding to the reduced flavoprotein than to the oxidized form of the enzyme. This is the concentration range where DNS is an effective activator of the enzyme. This represents a class of binding sites specifically found on pyruvate oxidase and not apparent in other proteins such as lysozyme or aldolase. At the DNS concentration which is optimum for activation approx. 20 molecules of DNS are bound per enzyme tetramer in the absence of the substrate. The pyruvate-reduced form of the enzyme binds about 40--50 molecules of DNS per tetramer. Qualitatively, the results are similar to what was previously found for both sodium dodecyl sulfate and cetyl trimethylammonium bromide. However, in both these cases, the amount of bound detergent was nearly an order of magnitude less than the values obtained using DNS.

Enzyme Activation↗
PubMed2000

Indolyl carboxylic acids by condensation of indoles with alpha-keto acids.

The novel indole derivatives 2,2-bis(3,3'-indolyl)propionic acid (1); 1,1,1,-tris(3,3',3"-indolyl)ethane (2); and 2,2-bis(3, 3'-indolyl)isocaproic acid (3) were isolated from solvent extracts of indole-supplemented supernatants of Escherichia coli and corynebacteria. The compounds were also obtained by chemical synthesis: compounds 1 and 2 from indole and pyruvic acid and compound 3 from indole and alpha-ketoisocaproic acid, following incubation at 37 degrees C in aqueous medium. Tryptophan and pyruvic acid gave the novel 2-(2-tryptophanyl)lactic acid (4). The condensation reaction between indoles and alpha-keto acids was of general nature, and the mild reaction conditions suggested it may proceed in vivo. Examples for endogenous occurrence may be the neuro-degenerative diseases phenylketonuria and maple syrup urine disease, both characterized by elevated blood levels of alpha-keto acids.

Brevibacterium↗