INCORPORATION OF C14INTO BACTERIAL PEPTIDES

1958 ◽  
Vol 4 (6) ◽  
pp. 633-648 ◽  
Author(s):  
G. E. Connell ◽  
R. W. Watson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
High Voltage ◽  
Basic Amino Acid ◽  
Paper Electrophoresis ◽  
Total Radioactivity ◽  
Before And After ◽  
Basic Peptides ◽  
Peptide Fractions

Alcoholic extracts of log-phase cells of Pseudomonas hydrophila grown on glucose as the sole carbon source were concentrated, extracted with ether, and dialyzed. After fractionation of the permeates by high voltage paper electrophoresis, five to seven ninhydrin-positive acidic, one neutral, and several basic bands appeared. As many as seven ninhydrin-positive basic bands have been found in some preparations, although they have been absent in others. Photometric analyses on eluates before and after acid hydrolysis indicated the presence of acidic, neutral, and basic peptides. Amino acid compositions of 28 of these peptides, separated by a combination of high voltage paper electrophoresis and paper chromatography, included all of the amino acids commonly found in proteins. Elution of acidic, neutral, and basic amino acid and peptide fractions from C14-labelled cells was followed by measurement of total and specific radioactivities in carboxyl-C before and after acid hydrolysis. Total radioactivity was highest in proteins even 1 minute after addition of the isotope to a log-phase culture. Specific radioactivities, plotted against time, gave parallel hyperbolic curves with peptides below the curve for amino acids and with proteins still lower and almost linear. The evidence suggests rapid synthesis of peptides from amino acids.

Net fluxes of peptide and amino acid across mesenteric-drained and portal-drained viscera of yak cows fed a straw-concentrate diet at maintenance level

2001 ◽  
Vol 136 (1) ◽  
pp. 119-127 ◽  
Author(s):  
XING-TAI HAN ◽  
BAI XUE ◽  
JI-ZENG DU ◽  
LING-HAO HU
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Portal Blood Flow ◽  
Mesenteric Vein ◽  
Before And After ◽  
The Difference ◽  
Net Fluxes ◽  
Net Release

The present experiment was conducted to quantify the net fluxes of both free and peptide amino acids across the mesenteric and stomach portions of the portal-drained viscera (PDV) of three yak cows (172·3±18·6 kg, BW) fed a straw-concentrate diet at maintenance level. Yaks had been fitted with sampling catheters in the portal vein, mesenteric artery and mesenteric vein prior to its convergence with the gastrosplenic vein. Blood flow was determined by measuring the dilution of para-aminohippurate (PAH) infused constantly into a distal mesenteric vein. Amino acids in the deproteinized plasma were analysed before and after acid hydrolysis. The increased amino acids after acid hydrolysis were considered as peptide-bound amino acids (PAA). The fluxes of free amino acids (FAA) and PAA across PDV and mesenteric-drained viscera (MDV) were calculated as the product of venoarterial differences and plasma flow. Flux across the stomach viscera (SDV) was calculated as the difference between portal and mesenteric fluxes. Portal blood flow was 389 l/h or 2·32 l/h kg BW, of which 37% was contributed by the mesenteric vein. There was net appearance of a large quantity of PAA across PDV, which accounted for 92% of the total nonprotein amino acid flux. Net release of PAA and FAA in SDV accounted for 78% and 42% of the net release in PDV, respectively. These results suggest that in yaks, peptide possibly is the primary form of amino acid absorption, and that the stomach area probably is the major site of peptide absorption.

Basic amino acid induced isomerization of a spiropyran: towards visual recognition of basic amino acids in water

2007 ◽  
Vol 31 (11) ◽  
pp. 1878 ◽  
Author(s):  
Yuanyuan Liu ◽  
Meigong Fan ◽  
Shuxiao Zhang ◽  
Xiaohai Sheng ◽  
Jiannian Yao
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Visual Recognition ◽  
Basic Amino Acid ◽  
Basic Amino Acids

scholarly journals The Possibility of Common Amino Acid Sequences in High-Sulphur Protein Fractions from Wool

1969 ◽  
Vol 22 (5) ◽  
pp. 1197 ◽  
Author(s):  
RL Darskus ◽  
JM Gillespie ◽  
H Lindley
Keyword(s):  
Amino Acid ◽  
High Voltage ◽  
Paper Electrophoresis ◽  
Structural Features ◽  
Amino Acid Sequences ◽  
Protein Fractions ◽  
Common Amino Acid ◽  
Amino Acid Compositions ◽  
Merino Wool ◽  
Derivatives Of

S-Carboxymethyl derivatives of the high-sulphur components of reduced Merino wool have been subdivided by chromatography into 17 fractions, the amino acid compositions of which are reported. Tryptic, chymotryptic, and thermolysin digests of each fraction have been studied by high-voltage paper electrophoresis at pH 3�5 and 6�5. The results suggest that the high-sulphur proteins consist of families of proteins probably containing common structural features. Evidence is presented that the heterogeneity of high-sulphur proteins is not artefactual.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

AMINO ACIDS IN THE BLOOD AND URINE OF NORMAL AND ARTHRITIC SUBJECTS BEFORE AND AFTER A GLYCINE LOAD GIVEN WITH AND WITHOUT ADRENOCORTICOTROPIN

1957 ◽  
Vol 35 (1) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. B. Derrick ◽  
Audrey P. Hanley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chromatographic Analysis ◽  
Free Amino ◽  
Serum Levels ◽  
Essential Amino Acids ◽  
Single Amino Acid ◽  
Normal Individuals ◽  
Before And After ◽  
Serum And Urine

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.

AMINO ACIDS IN THE BLOOD AND URINE OF NORMAL AND ARTHRITIC SUBJECTS BEFORE AND AFTER A GLYCINE LOAD GIVEN WITH AND WITHOUT ADRENOCORTICOTROPIN

1957 ◽  
Vol 35 (11) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. B. Derrick ◽  
Audrey P. Hanley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chromatographic Analysis ◽  
Free Amino ◽  
Serum Levels ◽  
Essential Amino Acids ◽  
Single Amino Acid ◽  
Normal Individuals ◽  
Before And After ◽  
Serum And Urine

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.

Influence of organic cations on basic amino-acid uptake by human placental villi

1995 ◽  
Vol 7 (6) ◽  
pp. 1491
Author(s):  
RB Krishna ◽  
J Dancis ◽  
M Levitz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acid ◽  
Amino Acid Uptake ◽  
Progressive Increase ◽  
Amino Acid Transporters ◽  
Acid Uptake ◽  
Chorionic Villi ◽  
Basic Amino Acids ◽  
Kinetics Of

Human placental chorionic villi were incubated for 30 min with [3H]lysine or [3H]arginine and the distribution ratios (intracellular:extracellular concentrations) were determined. The ratios remained unchanged when Na+ in Earle's buffered salt solution was replaced with Li+. When Na+ was replaced with choline there was a significant increase is distribution ratios (lysine 1.34 +/- 0.33 v. 3.99 +/- 0.15, arginine 1.95 +/- 0.37 v. 5.05 +/- 1.16). Leucine, a neutral amino acid with a Na(+)-independent transport system, was unaffected by choline substitution. The distribution ratio for alanine, which is Na(+)-dependent, was reduced (2.50 +/- 0.41 v. 1.45 +/- 0.20). Two other quarternary amines, acetyl-beta-methylcholine and tetraethylammonium chloride (TEA) caused similar increases in the distribution ratios of the basic amino acids. Hordenine, a tertiary amine, was less effective and there was little or no effect with ephedrine, a secondary amine. The choline effect was first observable at concentrations of 105 mM. With TEA, there was a progressive increase in distribution ratios beginning at 29 mM. Lysine efflux was measured after incubation of villi with lysine in Earle's buffer or choline buffer. Lysine was rapidly released to the fresh medium with 25% more retained in choline-exposed villi. The amines may cause alterations in the kinetics of basic amino-acid transporters or may modify other aspects of placental physiology permitting an increase retention of the basic amino acids.

Permeability and membrane transport in the larva of Taenia crassiceps

Parasitology ◽  
1973 ◽  
Vol 66 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Peter W. Pappas ◽  
Clark P. Read
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Molecular Species ◽  
Basic Amino Acid ◽  
Acid Transport ◽  
Taenia Crassiceps ◽  
Acid Absorption ◽  
Straight Line ◽  
Methionine Uptake

The free pool amino acids of Taenia crassiceps metacestodes (advanced larvae) were analyzed quantitatively. In addition, the uptake of L-glutamic acid, L-proline, L-phenylalanine, L-lysine, and L-methionine was studied. Proline and glutamic acid absorption followed straight-line kinetics with respect to substrate concentration, and were not inhibited by their own molecular species. Lysine, phenylalanine and methionine were found to enter larvae by a combination of diffusion and mediated processes. Lysine absorption was inhibited only by lysine, arginine and ornithine. Phenylalanine and methionine uptake was not inhibited by lysine or arginine, but was inhibited by several other amino acids. The data suggested the presence of a basic amino acid transport locus and two distinct transport loci for methionine absorption. In addition, both immature and advanced larvae were found to be impermeable to [14C]inulin (M.W. ca. 5000). These results are discussed and compared with the results of earlier investigations of protein and amino acid absorption by T. crassiceps larvae.

Comparison of some properties of soil humic acids and synthetic phenolic polymers incorporating amino derivaties

Soil Research ◽  
1966 ◽  
Vol 4 (1) ◽  
pp. 41 ◽  
Author(s):  
JN Ladd ◽  
JHA Butler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Humic Acids ◽  
Gel Filtration ◽  
Quinone Imine ◽  
Peptide Bonds ◽  
Molecular Weights ◽  
Soil Humic Acids ◽  
Properties Of Soil

Twenty-three model phenolic polymers, either nitrogen-free or incorporating amino acids, peptides, or proteins, have been prepared from p-benzoquinone and catechol under mild oxidative conditions. Two lines of experimentation have demonstrated properties of soil humic acids closely similar to those of polymers incorporating proteins, but different from those of polymers incorporating amino acids: (1) fractionation of humic acids and synthetic polymers by 'Sephadex' gel filtration showed that the percentage of components of molecular weights nominally greater than 100 000 ranged from 52-76 % for eight humic acids tested, 53-59 % for benzoquinone-protein polymers (excluding polymers containing protamine), but less than 20% for all other polymers; (2) acid hydrolysis with 6M HCl resulted in a partial release of polymer nitrogen. Amino acid nitrogen in the hydrolysates accounted for 32.4-51.9 % of humic acid nitrogen, 31.2-56.3 % of the nitrogen of polymers incorporating protein, but less than 10.8% of the nitrogen of polymers incorporating individual amino acids. Experiments with model monomeric N-phenylglycine derivatives and with polymers incorporating simple peptides showed that the bond between the carbon atom of an aromatic ring and the nitrogen atom of an a-amino acid is far more stable to acid hydrolysis than peptide bonds or bonds linking amino acids in humic acids. Glycine is, however, readily released from N-phenylglycine derivatives when conditions favour their oxidation to a quinone-imine intermediate. Incorporation of proteins into phenolic polymers prevented the detection of peptide bonds by the Folin reagent.

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