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PubMed1999

Modulating pyridoxamine-mediated transamination through a betabeta alpha motif peptide scaffold.

A pyridoxamine coenzyme amino acid chimera (Pam) was incorporated into a designed betabeta alpha motif peptide to explore the ability of a small synthetic peptide scaffold to influence coenzyme mediated transamination. Structural characterization of this peptide by CD and NMR spectroscopy suggested that the pyridoxamine containing residue was accommodated into the sheet region of the motif without gross structural perturbations. To investigate the ability of the peptide architecture to influence the amount and distribution of transamination product in the conversion of pyruvic acid to alanine, a family of 18 related peptides, CBP01-CBP18, was rapidly synthesized and purified in parallel. These peptides were designed to generate different peptide environments for the pyridoxamine functionality within the context of the structured betabeta alpha peptide motif. Studies of peptide-mediated transamination revealed clear trends in stereospecific production of L-alanine as a function of substitutions at positions five and seven of the motif. Furthermore, new trends favoring the other enantiomeric product resulted from the addition of copper(II) ion, a known chelator of the transamination reaction intermediates. In the presence of copper(II) ion the amount of alanine product generated was increased by up to 32-fold relative to a pyridoxamine model compound in the presence of copper(II) ion. These functional results, accompanied by further CD and NMR spectroscopic analysis of CBP14, one of the CBP family of peptides, suggest that small synthetic betabeta alpha motif peptides can be used to influence the functional properties of coenzymes.

Amination↗
PubMedDate not supplied

[Cell wall teichoic acids from Streptomyces daghestanicus VKM Ac-1722T and Streptomyces murinus INA-00524T].

The structure of cell wall teichoic acids was studied by chemical methods and NMR spectroscopy in the type strains of two actinomycete species of the "Streptomyces griseoviridis" phenetic cluster: Streptomyces daghestanicus and Streptomyces murinus. S. daghestanicus VKM Ac-1722T contained two polymers having a 1,5-poly(ribitol phosphate) structure. In one of them, the ribitol units had alpha-rhamnopyranose and 3-O-methyl-alpha-rhamnopyranose substituents; in the other, each ribitol unit was carrying 2,4-ketal-bound pyruvic acid. Such polymers were earlier found in the cell walls of Streptomyces roseolus and Nocardiopsis albus, respectively; however, their simultaneous presence in the cell wall has never been reported. The cell wall teichoic acid of Streptomyces murinus INA-00524T was is a 1,5-poly(glucosylpolyol phosphate), whose repeating unit was [-6)-beta-D-glucopyranosyl-(1 --> 2)-glycerol phosphate-(3-P-]. Such a teichoic acid was earlier found in Spirilliplanes yamanashiensis. The 13C NMR spectrum of this polymer is presented for the first time. The results of the present investigation, together with earlier published data, show that the type strains of four species of the "Streptomyces griseoviridis" phenetic cluster differ in the composition and structure of their teichoic acids; thus, teichoic acids may serve as chemotaxonomic markers of the species.

Cell Wall↗
PubMed1976

Colonial variation in Xanthomonas campestris NRRL B-1459 and characterization of the polysaccharide from a variant strain.

Stock cultures of Xanthomonas campestris NRRL B-1459 require special attention to maintenance and propagation to assure consistent production in good yields of the extracellular polysaccharide xanthan. Under customary conditions of propagative maintenance on agar slants, variant colony types develop that are smaller in size than the normal type. The rate of regression of the normal to the variant forms was diminished when the D-glucose content of the stock medium was sufficient to avoid depletion during storage and when transfer to fresh medium was reduced to 14-day intervals. Under conditions for polysaccharide production, the normal large-colony type gives crude culture liquors after 48 h of 7000 centipoise (cp) viscosity; the predominant variant form gives only 4000 cp. On the basis of 2.1% initial D-glucose, biopolymer yields for the normal and variant strains were 62 and 43%, respectively. Polysaccharide produced by the variant (small-colony type) differs adversely in solution properties from that of the parent strain (large-colony type); it differs also in its lower content of pyruvic acid and O-acetyl substituents. The molar ratios of constituent sugars (D-glucose, D-mannose, and D-glucuronic acid), however, were identical in polysaccharides with the normal and variant strains. Exclusion of colonial variants from fermentations is prerequisite to production of xanthan optimum in properties and yield.

Agar↗
PubMedDate not supplied

[The role of the nervous system in the mechanism of breakdown of carbohydrate and energy metabolism in muscle tissue under experimental botulism].

In skeletal muscle under a local botulinic intoxication and denervation the alterations in metabolism of glycogen, phosphocreatine, lactic and pyruvic acids were studied. The data obtained suggest that the dissimilarity in impairments of carbohydrate-energy metabolism in botulism and denervation was due to existence of variable types of impairments in the nerves.

Animals↗
PubMedDate not supplied

[The protective effect of energy substrates, vitamins, coenzymes and their complexes in the action on the body of the factors of an enclosed space].

Experiments on mice were performed to study a protective action of amino acids and other oxidation substrates (L-aspartic acid, pyruvate, succinate, GABA, alpha-ketoglutarate), metabolites (pyridoxal-5'-phosphate) as well as vitamin-coenzyme complexes in combination with oxidation substrate while being under closed space conditions. GABA, aspartate, glutamate possessed the highest protective effect as against alpha-ketoglutarate and succinate.

Amino Acids↗
PubMed1986

Rapid glucose-dependent increases in phosphatidic acid and phosphoinositides in rat pancreatic islets.

Glucose effects on islet phospholipids were examined during direct incubation or after 3 days of 32P prelabeling in primary culture. In both cases, glucose increased the 32P content of phosphatidic acid (PA), phosphatidylinositol (PI), and polyphosphoinositides (PPI). Glucose-induced increases in PA, PI, and PPI in the culture-prelabeling experiments were evident within 1 min, dose related, and reflective of increases in phospholipid mass, which was confirmed in direct incubations by measurement of PI phosphorus. Thus, in addition to increasing PI-PPI hydrolysis, glucose increases de novo phospholipid synthesis in pancreatic islets. The latter may result from enhanced glycolysis and substrate availability for PA-PI-PPI synthesis, since glyceraldehyde and pyruvic acid also increased PI levels. Our findings raise the possibility that increases in PA, PI, and PPI synthesis could serve as a mechanism to enhance the generation of intracellular mediators, which are purported to regulate insulin secretion.

Animals↗
PubMed2005

Aldehyde oxidase (AO) in the root nodules of Lupinus albus and Medicago truncatula: identification of AO in meristematic and infection zones.

Phytohormones are involved in the organogenesis of legume root nodules. The source of the auxin indole-3-acetic acid (IAA) in nodules has not been clearly determined. We studied the enzyme aldehyde oxidase (AO; EC 1.2.3.1), that catalyzes the last step of IAA biosynthesis in plants, in the nodules of Lupinus albus and Medicago truncatula. Primordia and young lupin nodules and mature M. truncatula nodules showed AO activity bands after native polyacrylamide gel electrophoresis. Gel activity analyses using indole-3-aldehyde as substrate indicated that the nodules of white lupin and M. truncatula have the capability to synthesize IAA via the indole-3-pyruvic acid pathway. Immunolocalization and in situ hybridization experiments revealed that AO is preferentially expressed in the meristematic and the invasion zones in Medicago nodules and in the lateral meristematic zone of Lupinus nodules. High IAA immunolabeling was also detected in the meristematic and invasion zones. Low expression levels and no AO activity were detected in lupin Fix- nodules that displayed restricted growth and early senescence. We propose that local synthesis of IAA in the root nodule meristem and modulation of AO expression and activity are involved in regulation of nodule development.

Abscisic Acid↗
PubMed1976

[Effect of sodium succinate on several carbohydrate metabolism indices of ischemic myocardium].

The influence of sodium succinate on the content of lactic, pyruvic acids and glucose in the venous blood flowing from the ischemic zone of the myocardium was studied in dogs with ligated coronary artery. The intracoronary injection of the preparation in doses of 2 and 10 mg/kg diminished the content of blood lactic acid flowing from the ischemic zone; a dose of 10 mg/kg decreased the consumption of glucose by the ischemic myocardium. Sodium succinate (100 mg/kg) intravenously reduced the content of the lactic acid significantly and inhibited the glucose consumption by the ischemic myocardium, with its increase in the arterial blood. A fall of lactacidemia can be connected with the activation of Krebs cycle and an increase of oxygen utilization by the ischemic myocardium.

Animals↗
PubMed2004

A novel type of highly negatively charged lipooligosaccharide from Pseudomonas stutzeri OX1 possessing two 4,6-O-(1-carboxy)-ethylidene residues in the outer core region.

Pseudomonas stutzeri OXI is a Gram-negative microorganism able to grow in media containing aromatic hydrocarbons. A novel lipo-oligosaccharide from P. stutzeri OX1 was isolated and characterized. For the first time, the presence of two moieties of 4,6-O-(1-carboxy)-ethylidene residues (pyruvic acid) was identified in a core region; these two residues were found to possess different absolute configuration. The structure of the oligosaccharide backbone was determined using either alkaline or acid hydrolysis. Alkaline treatment, aimed at recovering the complete carbohydrate backbone, was carried out by mild hydrazinolysis (de-O-acylation) followed by de-N-acylation using hot KOH. The lipo-oligosaccharide was also analyzed after acid treatment, attained by mild hydrolysis with acetic acid, to obtain information on the nature of the phosphate and acyl groups. The two resulting oligosaccharides were isolated by gel permeation chromatography, and investigated by compositional and methylation analyses, by MALDI mass spectrometry, and by 1H-, 31P- and 13C-NMR spectroscopy. These experiments led to the identification of the major oligosaccharide structure representative of core region-lipid A. All sugars are D-pyranoses and alpha-linked, if not stated otherwise. Based on the structure found, the hypothesis can be advanced that pyruvate residues are used to block elongation of the oligosaccharide chain. This would lead to a less hydrophilic cellular surface, indicating an adaptive response of P. sutzeri OX1 to a hydrocarbon-containing environment.

Carbohydrate Sequence↗
PubMed1975

[Pressures, blood gases, pH, lactate and pyruvate concentrations in the portal venous blood in patients after laparotomy during the first 9 days (author's transl)].

In 24 patients (16 women, 8 men, mean age 60 years), who underwent abdominal operations and who had a uncomplicated postoperative course, a teflon-tube was inserted into the portal vein at the end of laparotomy and remained there for maximal 9 days. The mean values of the portal venous pressure as well as of the portal-central venous pressure gradient are unchanged during the period of all 9 days and are between 7,4 and 7,9 mmHg, between 5,6 and 6,9 mmHg respectively. The arterio-portal venous 0(2)-content difference shows in the mean no fluctuations and is about 2 Vol.%. On the first postoperative day the lactic and pyruvic acid concentrations in the artery and portal vein are moderately, but significantly elevated and decrease to normal values until day 7. - 9.

Adult↗
PubMed1978

[Dynamics of biologically active enterotoxin release by E. coli].

Accumulation of E. coli enterotoxin in the Finkelshtein's culture medium in growing the cells in a 30-litre reactor was studied. Accumulation of active highly molecular enterotoxin occurred in the course of a 6-hour cultivation of E. coli, strain P-99 (O141: K85ab; K88ab: H4) in the fluid medium under aeration. Oxygen utilization, synthesis and release into the nutrient medium of pyruvic acid, and protein accumulation were observed. The preparation obtained was stable to the lyophylic drying, contained thermolabile and thermostable toxins and marked edema of mouse limbs. The data obtained were of significance for the industrial production of active enterotoxin preparations.

Bacterial Proteins↗
PubMedDate not supplied

[Redox processes in the retina and tunic tissues of the rat eye in experimental alkalosis].

It is shown in experiments is vivo that development of experimental metabolic alkalosis in rats is followed by changes in redox processes in the eye retina and tunic. For the first two months of the experiment the number of sulphydryl group decreases, while that of disulphide ones of water-soluble proteins and low-molecular compounds increases. The amount of oxidized metabolites of glycolysis and of a cycle of tricarboxylic acids (pyruvate, oxaloacetate, alpha-ketoglutarate) increases relative to the reduced ones (lactate, isocitrate, malate), as well as activities of hexokinase, pyruvate kinase, NAD-dependent malate dehydrogenase, while activities of fructose diphosphatase, glucoso-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase fall. The content of malonic dialdehyde increases. 90 days later disorders of certain compensatory mechanisms of the metabolic system of alkalosis regulation probably occurred in the eye retina and tunic tissues: hexokinase and pyruvate kinase activity fell to the control values, while that of NAD-dependent malate dehydrogenase--below the control level; the content of lactate increased. Activity of glutathione-dependent enzymes remained low and the amount of malonic dialdehyde grew much more than in the previous terms.

Alkalosis↗
PubMed1977

[Effect of short-term microcirculatory disorders on indices of myocardial energy metabolism].

Disturbance of the microcirculation produced by the combined injection of the high molecular weight dextran and vasopressin led as soon as the first minutes (5 min) to the intensification of glycolysis. This was testified to by the reduction of glycogen concentration by 19.4 percent, elevation of the phosphorylase "A" activity by 30-36 percent and of the pyruvic acid by 36.9 percent. The ATP, ADP, AMP, and the KP concentration remained unchanged. The observed glycolysis changes can be regarded as the initial metabolic reactions resulting from hypoxia originating in microcirculation disturbances.

Adenosine Diphosphate↗
PubMed1989

Influence of arecoline on immune system: I. Short term effects on general parameters and on the adrenal and lymphoid organs.

Arecoline, a suspected carcinogenic/cocarcinogenic alkaloid was screened to explore in detail its immunomodulatory influence in murine model system. The oral LD50 value for male mice was 371 mg/kg bw whereas it was 309 mg/kg bw for female mice. The subcutaneous LD50 value for both sexes was 97 mg/kg bw. Only a marginal difference was observed in intraperitoneal LD50 values between male (120 mg/kg bw) and female (109 mg/kg bw) mice. Arecoline was administered subcutaneously to male mice at subtoxic dose levels (5, 10, and 20 mg/kg bw) for 1, 2 and 3 weeks on a daily basis. In groups where significant decreases in body weight were present (at 20 mg/kg bw for both sexes), reductions in thymus weight were also noted. Spleen, mesenteric lymph nodes (MLN), liver, and kidney showed moderate reductions in their weights. Histopathological effects at 20 mg/kg bw included lymphocyte depletion of the thymic cortex, and the B and T lymphocyte areas in spleen and MLN. In concordance with the zona fasciculata hypertrophy of adrenals, corticosterone concentration in serum increased depending on the dose with a significant elevation at 20 mg/kg bw. While total protein, albumin, glucose, acid phosphatase and hemoglobin concentrations were not altered, increases in SGOT and SGPT levels were observed at the high dose. The white and red blood cell counts decreased in a dose-dependent manner. Marked reduction in cell number of thymus, and moderate effect on cellularity of spleen and MLN, were observed at 20 mg/kg bw. In vitro exposure of rat thymocytes to arecoline resulted in a biphasic oxygen consumption response with progressive increase in oxygen consumption, reaching a maximum value at 10(-5) M and decreasing sharply at 10(-3) M. Exogenously added substrates such as glucose, pyruvic acid and lactic acid retarded the fall in the oxygen consumption induced at 10(-3) M arecoline. These observations demonstrate the effects of arecoline on lymphoid organs, which may be due to its direct action or through the elevation of corticosterone.

Administration, Oral↗
PubMedDate not supplied

[Study of the effectiveness of using diets with a varying protein content during physical loads in an experiment on rats].

In experiments on rats subjected for 30 days to perform a graded muscular work (swimming) the influence produced by different levels of protein in the diet (6,18 and 30% by calorific value) on the accretion of body mass, physical work capacity, diurnal passage of total nitrogen, creatinine and creatine with urine was studied. At rest and following the maximum physical efforts the sugar, lactate and pyruvic acids levels were measured in the blood of rats. Food rations with low protein content (6% of the total caloricity), when used in conditions involving physical efforts, exerted an adverse effect on the growth, development and physical work capacity of the animals. The use of a protein-rich diet (30% by caloricity) did not show any substantial advantages over the standard one (18% of protein). In rats fed on diets with 18 and 30% of protein (in terms of caloricity) the body mass gain, physical work capacity and also the nature of changes in the content of lactate, pyruvate and sugar in the blood were the same.

Animals↗
PubMed1979

Effect of toxaphene on pyruvic and lactic acid levels in the rat.

Rats were given a single dose of toxaphene (120 mg/kg equilavent to 1/2 LD50) and sacrificed at 1, 5, and 15 days. No alterations of levels of pyruvic or lactic acid in blood plasma were observed. In a second experiment, rats were given 2.4 mg/kg daily and sacrificed at 1, 3, and 6 months, and again no alterations of pyruvic or lactic acid levels were found. It is concluded that observed alterations of the activity of lactic acid dehydrogenase induced by toxaphene do not give rise to physiological changes in unstressed rats.

Animals↗
PubMed1989

N5-(L-1-carboxyethyl)-L-ornithine:NADP+ oxidoreductase from Streptococcus lactis. Purification and partial characterization.

N5-(L-1-Carboxyethyl)-L-ornithine:NADP+ oxidoreductase (EC 1.5.1.-) from Streptococcus lactis K1 has been purified 8,000-fold to homogeneity. The NADPH-dependent enzyme mediates the reductive condensation between pyruvic acid and the delta- or epsilon-amino groups of L-ornithine and L-lysine to form N5-(L-1-carboxyethyl)-L-ornithine and N6-(L-1-carboxyethyl)-L-lysine, respectively. The five-step purification procedure involves ion-exchange (DE52 and phosphocellulose P-11), gel filtration (Ultrogel AcA 44), and affinity chromatography (2',5'-ADP-Sepharose 4B). Approximately 100-200 micrograms of purified enzyme of specific activity 40 units/mg were obtained from 60 g of cells, wet weight. Anionic polyacrylamide gel electrophoresis revealed a single enzymatically active protein band, whereas three species (pI 4.8-5.1) were detected by analytical electrofocusing. The purified enzyme is active over a broad pH range of 6.5-9.0 and is stable to heating at 50 degrees C for 10 min. Substrate Km values were determined to be: NADPH, 6.6 microM; pyruvate, 150 microM; ornithine, 3.3 mM; and lysine, 18.2 mM. The oxidoreductase has a relative molecular mass (Mr = 150,000) as estimated by high pressure liquid chromatography exclusion chromatography and by polyacrylamide gradient gel electrophoresis. Conventional gel filtration indicated an Mr = 78,000, and a single protein band of Mr = 38,000 was revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme is composed of identical subunits of Mr = 38,000, which may associate to yield both dimeric and tetrameric forms. Polyclonal antibody to the purified protein inhibited enzyme activity. The amino acid composition of the enzyme is reported, and the sequence of the first 37 amino acids from the NH2 terminus has been determined by stepwise Edman degradation.

Amino Acid Sequence↗
PubMed1976

[McArdle's disease (a familial case)].

The author describes a family (48 year old mother and 15 year old son) with the muscular variant of glycogenosis-McArde's metabolic myopathy. The mother has been ill since 22 years old, the son--since 7. The disease had a slowly progressive development. The clinical picture was characterized by convulsions of the type of cramps following physical loadings on muscles of the body and extremities. Convulsions were accompanied by pain, an induration and enlargment of the muscles, muscle fatigue and increased significantly in an artifical ischemia of the extremities. A histochemical study of the muscle revealed a pathological accumulation of glycogen. The content of lactic and pyruvic acid in the blood after work in ischemic conditions did not change significantly. A study of the sugar curve in the blood with a loading with glucose and a parallel determination of insulin by a radioimmune method found hyperinsulinemia and a dysfunction of the pancreas.

Adolescent↗