Des acides aminés stimulateurs et inhibiteurs à la croissance de Corynebacterium sepedonicum (Spieck. et Kott., Skapt. et Burkh.) dans des milieux synthétiques

1978 ◽  
Vol 24 (9) ◽  
pp. 1087-1092
Author(s):  
G. J. Ikin ◽  
H. J. Hope ◽  
R. A. Lachance
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ammonium Phosphate ◽  
Methionine Sulfoxide ◽  
High Rate ◽  
Molar Ratio ◽  
Corynebacterium Sepedonicum ◽  
Ring Rot ◽  
Acides Aminés ◽  
Synthetic Media

Some aspects of the growth and amino acid metabolism of Corynebacterium sepedonicum, the organism responsible for potato ring rot, have been studied in synthetic media. It has been demonstrated that organic sulfur is required for growth. Methionine supports growth and can be replaced by methionine sulfoxide and cystathionine. Methionine is a micrometabolite for this species as indicated by the fact that optimum growth can be obtained in an asparagines–methionine (asn-met) containing medium when the molar ratio of these amino acids is 56:1. Increasing the proportion of methionine does not increase the growth. Both asparagine and glutamine are metabolized very quickly and provide for equivalent rapid growth unlike aspartic and glutamic acids. In the case of the last two amino acids, growth can be increased if dibasic ammonium phosphate is added to the medium although this compound alone will not support growth in the culture medium. The intracellular soluble asparagine level is extremely low in cells from the asn-met medium indicating a high rate of metabolism compared to aspartic acid. Cystine and cysteine were found to be inhibitory to the organism: they do not affect the rate of uptake of asn or met but do alter the organism's metabolism as reflected by changes in the free amino acid pool. The concentrations of cystine and cysteine required for measurable inhibition are much higher than those found in soluble amino acids of potato tubers.

Extent of damage to amino acid availability of whey protein heated with sugar

1991 ◽  
Vol 58 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Thérèse Desrosiers ◽  
Laurent Savoie
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Whey Protein ◽  
Significant Proportion ◽  
Protein Digestibility ◽  
Heating Time ◽  
Heat Treatments ◽  
Molar Ratio ◽  
Amino Acid Availability

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.

Amino acid uptake systems in Bacteroides ruminicola

1979 ◽  
Vol 25 (10) ◽  
pp. 1161-1168 ◽  
Author(s):  
Roselynn M. W. Stevenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Sources ◽  
Amino Acid Uptake ◽  
Defined Medium ◽  
High Rate ◽  
Transport Systems ◽  
Acid Uptake ◽  
Chemical Structures ◽  
Kinetic Inhibition

Uptake of amino acids by Bacteroides ruminicola was observed in cells grown in a complete defined medium, containing ammonia as the nitrogen source. A high rate of uptake occurred only in fresh medium, as an inhibitory substance, possibly acetate, apparently accumulated during growth. All amino acids except proline were taken up and incorporated into cold trichloroacetic acid precipitable material. Different patterns of incorporation and different responses to 2,4-dinitrophenol and potassium ferricyanide indicated multiple uptake systems were involved. Kinetic inhibition patterns suggested six distinct systems were present for amino acid uptake, with specificities related to the chemical structures of the amino acids. Thus, the failure of free amino acids to act as sole nitrogen sources for growth of B. ruminicola is not due to the absence of transport systems for these compounds.

In Vitro adsorption Spectrum of Plasma Amino Acids by Coated Charcoal Hemoperfusion

1983 ◽  
Vol 6 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Z.Q. Shi ◽  
T.M.S. Chang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hepatic Coma ◽  
Aromatic Amino Acids ◽  
Molar Ratio ◽  
Adsorption Experiment ◽  
Preferential Adsorption ◽  
Branched Chain ◽  
Charcoal Hemoperfusion

In order to clarify wether coated charcoal hemoperfusion is capable of normalizing amino acid disturbances in hepatic coma, in vitro adsorption and in vitro hemoperfusion studies were carried out. We have found that collodion-coated activated charcoal beads preferentially removed much more aromatic acids (AAA) than branched chain amino acids (BCAA). In the in vitro adsorption experiment with 50 μM amino acid standards aqueous solution, 99% of AAAs were removed by charcoal while only 50 to 81% of BCAAs were removed. As the concentration of amino acids in solution was doubled from μM to 100 μM, BCAA removal was halved while about 90% of AAA was still being removed. In vitro hemoperfusion with heparinized blood from hepatic failure rats, the clearance and the removal of AAAs were significantly greater than those of BCAAs. Consequently, the molar ratio of BCAA over AAA was markedly improved from the initial 1.09 to 3.87 after 60 min of hemoperfusion. Thus, we have demonstrated the preferential adsorption of aromatic amino acids by collodion-coated charcoal beads. The correction of BCAA/AAA molar ratio is also demonstrated.

scholarly journals Determination of Amino Acid Composition of Ganirelix Acetate in an Injectable Formulation by Pre-column Derivatization with 6-Aminoquinolyl-N-hydroxysuccinimidyl Carbamate

2020 ◽  
Vol 58 (8) ◽  
pp. 687-694
Author(s):  
Kumarswamy Ummiti ◽  
J V Shanmukha Kumar
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Flash Chromatography ◽  
Molar Ratio ◽  
Acid Mixture ◽  
Injectable Formulation

Abstract Ganirelix is a synthetic decapeptide linked with nine different amino acids. To understand the peptide amino acid sequence or primary structure, the first step is to determine the amino acid composition of the peptide which can be a determining factor for the peptide immunogenicity. Edman degradation is not a suitable analytical technique to identify amino acid sequence present in Ganirelix due to the absence of uncharged N-terminal amino group. To address this challenge, a pre-column derivatization method was developed with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate reagent. In the present work, the Ganirelix active pharmaceutical ingredient present in the injectable formulation was isolated by fraction collection and further purified by flash chromatography. The amino acid composition of Ganirelix is assayed by carrying out acid hydrolysis with 6 mol L−1 hydrochloric acid solution containing 1% phenol at 100°C for 24 h and derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate reagent solution, followed by determination of individual amino acids by reverse-phase chromatography using a C18 column. High resolution was achieved for the nine amino acid mixture. The amino acid composition results of temperature-stressed Ganirelix generic product and reference listed drug are in good agreement with the theoretical molar ratio of label information.

INHIBITION OF GROWTH OF PSEUDOMONAS DENITRIFICANS BY AMINO ACIDS

1966 ◽  
Vol 12 (6) ◽  
pp. 1095-1098 ◽  
Author(s):  
Horace J. Daniels
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basal Medium ◽  
Ammonium Phosphate ◽  
Complete Medium ◽  
Mineral Salts ◽  
Culture Studies ◽  
Pseudomonas Denitrificans ◽  
Inhibition Of Growth ◽  
Amino Acid Mixtures

A large number of amino acids failed to support growth of Pseudomonas denitrificans in a basal medium composed of glucose, ammonium phosphate, and other mineral salts. Inability of an amino acid to support growth correlated well with its inhibitory action in a complete medium made up by adding L-glutamic acid to the basal medium. D-Amino acids were more toxic than the corresponding L-forms, and neutral amino acids were more toxic than acidic amino acids. Basic amino acids which were least toxic supported the best growth. The danger of the indiscriminate use of amino acid mixtures for culture studies is discussed.

scholarly journals Turnover as a control of ribonucleic acid accumulation in bacteria undergoing stepdown

1976 ◽  
Vol 154 (2) ◽  
pp. 541-552
Author(s):  
J E. M. Midgley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Turnover Rate ◽  
Amino Acid Starvation ◽  
High Rate ◽  
Glucose Medium ◽  
Amino Acid Deprivation ◽  
Acid Accumulation ◽  
Associated Proteins ◽  
Kinetics Of

The synthesis of ribosomes was compared in rel+ and rel- strains of Escherichia coli undergoing “stepdown” in growth from glucose medium to one with lactate as principal carbon source. Two strains (CP78 and CP79), isogenic except for rel, showed similar behaviour with respect to (1) the kinetics of labelling total RNA and ribosomes with exogenous uracil, (2) the proportion of newly formed protein that could be bound with nascent rRNA in mature ribosomes, and (3) the rate of induction of enzymically active β-galactosidase (relative to the rate of ribosome synthesis). It was concluded that, as there was no net accumulation of RNA during stepdown in either strain, rRNA turnover must be occurring at a high rate. The general features of ribosome maturation in rel+ and rel- cells were almost identical with those found in auxotrophic rel+ organisms starved of required amino acids. In both cases, there was a considerable delay in the maturation of new ribosomal particles, owing to a relative shortfall in the rate of synthesis of ribosome-associated proteins. Only about 4-5% of the total protein labelled during stepdown was capable of binding with newly formed rRNA. This compared with 3.5% for rel+ and 0.5% for rel- auxotrophs during amino acid starvation. The turnover rate for newly formed mRNA and rRNA was virtually the same in “stepped-down” rel+ and rel- strains and was similar to that of the same fraction in amino acid-starved rel+ cells. The functional lifetime of mRNA was also identical. It seems that in the rel- strain many of the characteristics typical of the isogenic rel+ strain are displayed under these conditions, at least as regards the speed of ribosome maturation and the induction of β-galactosidase. Studies on the thermolability of the latter enzyme induced during stepdown indicate that inaccurate translation, which occurs in rel- strains starved for only a few amino acids, is less evident in this situation than in straightforward amino acid deprivation.

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

1992 ◽  
Vol 263 (2) ◽  
pp. E317-E325 ◽  
Author(s):  
N. E. Tawa ◽  
A. L. Goldberg
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dietary Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Normal Diet ◽  
High Rate ◽  
Acid Uptake ◽  
Rapid Weight Gain

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

scholarly journals Release of selected amino acids from zinc carriers

2016 ◽  
Vol 66 (2) ◽  
pp. 269-277
Author(s):  
Renata Dyja ◽  
Barbara Dolińska ◽  
Florian Ryszka
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Molar Ratio ◽  
Time Intervals ◽  
Solubility In Water ◽  
First Order ◽  
First Order Kinetics ◽  
Acid Release ◽  
Co Precipitation ◽  
Low Solubility

Abstract The paper deals with the results of an investigation of the release of selected amino acids (histidine, tryptophan, tyrosine) from model suspensions prepared by co-precipitation with zinc chloride. It has been proven that the influence of the Zn(II)/amino acid molar ratio on dissolution profiles of the tested amino acids and dissolution half-life (t1/2) of histidine or tryptophan is significant. The amount of amino acid in the dispersed phase (supporting dose) is a determinant of the amino acid release profile. There is a minimal supporting dose (30.0 μmol of histidine or 17.4 μmol of tryptophan) that provides release of similar amounts of amino acid (4.1–4.6 μmol of histidine or 8.7–9.9 μmol of tryptophan) after the same time intervals. The tyrosine release profiles follow first order kinetics since the supporting dose (0.9–11.2 μmol) is limited by the tyrosine low solubility in water.

NUCLEOTIDE SEQUENCE OF THE STAPHYLOCOAGULASE GENE FROM STAPHYLOCOCCUS AUREUS STRAIN BB

1987 ◽  
Author(s):  
S Kaida ◽  
T Miyata ◽  
S Kawabata ◽  
T Morita ◽  
Y Yoshizawa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Tandem Repeats ◽  
Molar Ratio ◽  
Clotting Factor ◽  
Aureus Strain ◽  
Activation Process ◽  
Coding Region ◽  
Flanking Region

Staphylocoagulase (SC) is a secretary protein produced by several strains of Staphylococcus aureus (S. aureus). This protein forms a molecular complex ("staphylothrombin") with human prothrombin in a molar ratio of 1:1. The complex displays the ability to clot fibrinogen and to hydrolyze the synthetic tripeptide substrates for α-thrombin. The formation of staphylothrombin does not require proteolytic cleavage of the prothrombin molecule, and this mechanism differs markedly from the activation process by either blood-clotting factor Xa or snake venom procoagulant.In the present studies, a pAT153 library containing partial Mbo I-digested DNA prepared from aureus strain BB has been screened with a fibrin gel formation method. The identity of these clones with SC was confirmed by DNA sequence analysis and by comparison of the derived amino acid sequence with that determined for the purified SC protein. One of the positive colonies was isolated and 3.1 Kb of the insert DNA was determined by the dideoxy chain termination method. The results indicated that the insert DNA consists of 148 bp 5' flanking region, protein coding region of 715 amino acids and 746 bp 3' flanking region, and that SC from strain BB is synthesized as a precursor with a signal peptide of 26 amino acids. Thus, the mature form was composed of 689 amino acids with a molecular weight of 77,337- The NH2-terminal sequence (324 amino acids) of SC isolated from S. aureus strain 213 (S. Kawabata et al. (1986): J. Biol. Chem. 261, 527-531) was compared with that of SC derived from strain BB. The sequence homology between them was found to show 57 %. It was also found that SC derived from strain BB was composed of 8 tandem repeats (27 amino acid residues in length) in the COOH-terminal region, although their functions are not known.

scholarly journals Preparation and characterization of armadillo submandibular glycoproteins

1977 ◽  
Vol 161 (1) ◽  
pp. 37-47 ◽  
Author(s):  
A M Wu ◽  
W Pigman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mammalian Species ◽  
Chemical Properties ◽  
Glycoprotein B ◽  
Molar Ratio ◽  
Cellulose Acetate Electrophoresis ◽  
Acetylneuraminic Acid ◽  
Neutral Sugars ◽  
Mucus Glycoproteins

The nine-banded armadillo (Dasypus novemcinctus mexicanus Peters) was chosen for this study so that a comparison could be made of the salivary mucus glycoproteins of an ancient mammalian species with those derived from previously studied, more highly evolved species. Two mucus glycoproteins, armadillo submandibular glycoprotein A and armadillo submandibular glycoprotein B, were prepared from the armadillo submandibular gland by a modification of the method of Tettamanti & Pigman (1968) (Arch. Biochem. Biophys. 124, 41-50). The composition of glycoprotein A is the simplest one among the known mucus glycoproteins. Six amino acids constitute 98.5 mol/100mol of the protein of glycoprotein A and 82 mol/100 mol of that of glycoprotein B. These are serine and threonine (which make up 40-50% of the molar amino acid composition), glutamic acid, glycine alanine and valine. Proline is absent from glycoprotein A and comprises only 2.3% of glycoprotein B. For both glycoproteins, the protein content, as determined by the method of Lowry, Rosebrough, Farr & Randall (1951) (J. Biol. Chem 193, 265-275), with bovine serum albumin as standard, was nearly 60% higher than when determined by the sum of the amino acids. The ratios of total mol of amino acid/total mol of carbohydrate are 1:0.63 for glycoprotein A and 1:0.68 for glycoprotein B, N-Acetylneuraminic acid and N-acetylgalactosamine, in a molar ratio of about 0.35:1.00, are the principal carbohydrates present in both glycoproteins. Neutral sugars seem to be absent from glycoprotein A, but galactose and fucose are present in glycoprotein B. The carbohydrate side chains in glycoprotein A are composed of about two-thirds monosaccharide and one-third disaccharide residues, whereas those of glycoprotein B are more complex. For both glycoproteins, essentially all of the N-acetylgalactosamine was attached O-glycosidically to the hydroxyamino acid residues of the protein core. The linkage of N-acetylneuraminic acid glycoprotein A was extremely sensitive to dilute acid and neuraminidase. Glycoprotein B has chemical properties similar to those of glycoprotein A. However, whereas glycoprotein A was susceptible to both Clostridium perfringens and Vibrio cholerae neuraminidases, only the latter enzyme had an effect on glycoprotein B at pH 4.75. Both glycoproteins were homogeneous by cellulose acetate electrophoresis and ultracentrifugal analyses. The apparent mol.wts. of glycoprotein A and glycoprotein B were 7.8 X 10(4) and 3.1 X 10(4) respectively.

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