THE COMPOSITIONS OF SOME PEPTIDES PRODUCED BY AN ENZYMIC HYDROLYSIS OF WHEAT GLIADIN

1964 ◽  
Vol 42 (8) ◽  
pp. 1133-1140 ◽  
Author(s):  
A. J. Finlayson
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Enzymic Hydrolysis ◽  
Wheat Gliadin ◽  
Hydrolysis Of

Wheat gliadin was hydrolyzed extensively by treatment with pepsin and then by trypsin. A large number of peptides were produced as well as small amounts of some amino acids, thus indicating a substantial amount of hydrolysis of gliadin by the enzymes. Five peptides were obtained crystalline and two of these constitute 11.5% and 1.2% of gliadin, respectively. Their structures have been partly determined. The results indicate that wheat gliadin contains (Asp.Asp) bonds and at least 1.9% of the glutamic acid is present as glutamylglutamic acid.

Covalent attachment of amino acids to casein. 1. Chemical modification and rates of in vitro enzymic hydrolysis of derivatives

1979 ◽  
Vol 27 (5) ◽  
pp. 1098-1104 ◽  
Author(s):  
Antoine J. Puigserver ◽  
Lourminia C. Sen ◽  
Elvira Gonzales-Flores ◽  
Robert E. Feeney ◽  
John R. Whitaker
Keyword(s):  
Amino Acids ◽  
Chemical Modification ◽  
Covalent Attachment ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Of

EVIDENCE FOR ‘LIPOPEPTIDE’, PHOSPHATIDYLETHANOLAMINE, AND PHOSPHATIDYLCHOLINE IN EXCISED TOMATO ROOTS

1961 ◽  
Vol 39 (5) ◽  
pp. 1067-1078 ◽  
Author(s):  
W. G. Boll ◽  
A. A. Khan
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Water Soluble ◽  
Cysteic Acid ◽  
Sterile Culture ◽  
Peptide Fraction ◽  
Tomato Roots ◽  
Ninhydrin Reagent ◽  
Hydrolysis Of ◽  
Distinct Peptide

Evidence is presented for the existence of ‘lipopeptide’ in lipid extracted with ethanol: ether (3:1 v/v) from excised tomato roots grown in sterile culture. The amino acids released by acid hydrolysis of ‘purified’ lipid were identified by co-chromatography and color reaction with acidic and neutral ninhydrin reagent. They are cysteic acid, serine, glycine, aspartic acid, glutamic acid, glutamine, alanine, valine, leucine and/or isoleucine, and probably methionine and tyrosine. Arginine was detected on some chromatograms. Four unknown substances, three of which are ninhydrin-sensitive, were detected.Paper chromatographic fractionation of water-soluble substances in methanolyzates of 'purified' lipid failed to yield a distinct 'peptide' fraction but fractions high in ‘peptide’ also contained two of the four unknown substances.Glycerylphosphorylethanolamine and glycerylphosphorylcholine were detected in the methanolyzates. Glycerylphosphorylserine was not detected.

Reversible Inhibition of Carboxypeptidase A. IV. Inhibition of Specific Esterase Activity by Hippuric Acid and Related Species and other Amino Acid Derivatives and a Comparison with Substrate Inhibition

1975 ◽  
Vol 53 (13) ◽  
pp. 1993-2004 ◽  
Author(s):  
John W. Bunting ◽  
Chester D. Myers
Keyword(s):  
Amino Acids ◽  
Hippuric Acid ◽  
Substrate Inhibition ◽  
Enzymic Hydrolysis ◽  
Carboxypeptidase A ◽  
Phenyllactic Acid ◽  
Peptide Substrates ◽  
Uncompetitive Inhibition ◽  
Hydrolysis Of ◽  
Noncompetitive Inhibitors

The anions of each of the following carboxylic acids exhibit uncompetitive inhibition of the hydrolysis of O-hippuryl-L-3-phenyllactic acid by bovine carboxypeptidase A at pH 7.5, 25°, ionic strength 0.2: hippuric acid, p-chloro- and p-nitrohippuric acids, hippurylglycine, carbobenzoxyglycine, phenaceturic acid, N'-(3-phenylpropanoyl)glycine, benzoxyacetic acid, 3-benzoylpropanoic acid, and O-hippuryl-D-mandelic acid. In each case, this uncompetitive inhibition is consistent with the ordered binding of substrate and inhibitor to the enzyme; i.e. the inhibitor binds to E.S but not to the free enzyme. Evidence is presented for the binding site for uncompetitive inhibitors being the same as for inhibitory ester substrate molecules. Comparison of the specificities of uncompetitive inhibitors and esters which display substrate inhibition provides evidence for a critical conformational change which controls the binding of uncompetitive inhibitors and inhibitory substrate molecules.D-Phenylalanine, D-leucine, D-p-nitrophenylalanine, glycyl-L-tyrosine, glycyl-L-phenylalanine, and glycyl-L-leucine are competitive inhibitors of the enzymic hydrolysis of O-hippuryl-L-3-phenyllactic acid, whereas the N-chloroacetyl derivatives of L-tyrosine, L-phenylalanine, and L-leucine are noncompetitive inhibitors. For the above D-amino acids, glycyl dipeptides, and N-chloroacetyl amino acids, the phenylalanine derivative in each case is a considerably stronger inhibitor than the corresponding leucine derivative. This preference is similar to that observed for the binding of peptide substrates but the reverse of that observed for ester substrates and simple mono- and dicarboxylate ion inhibitors.The peptide substrates carbobenzoxyglycylglycyl-L-phenylalanine and N-chloroacetyl-L-phenylalanine are noncompetitive inhibitors of the enzymic hydrolysis of O-hippuryl-L-3-phenyllactic acid. This clearly demonstrates the presence of different ester and peptide binding sites in this enzyme, which is consistent with conclusions from recent studies in other laboratories.

Uptake of Dipeptides Containing Basic and Acidic Amino Acids by Rat Small Intestine in Vitro

1972 ◽  
Vol 43 (6) ◽  
pp. 823-837 ◽  
Author(s):  
D. Burston ◽  
Jill M. Addison ◽  
D. M. Matthews
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Tissue Uptake ◽  
Acidic Amino Acids ◽  
Hydrolysis Of

1. The characteristics of transport and hydrolysis of twenty-two dipeptides containing basic and acidic amino acids by rat ileal rings were investigated in vitro. The peptides included combinations of basic and neutral, basic and basic, basic and acidic, acidic and acidic, and acidic and neutral amino acids. 2. All peptides studied were removed intact from the bulk phase of the incubation medium, though, in general, only free amino acids appeared in the tissue. Uptake of one or both constituent amino acids was greater from the peptide than from the equivalent amino acid or amino acid mixture in the case of at least one peptide from each group and in eighteen of the twenty-two peptides studied. In general, there was no relationship between the extent of uptake of amino acids from peptides and the extent of their hydrolysis by the system. The results support the hypothesis that there is more than one mode of uptake of amino acids from peptides. 3. Hydrolysis of γ-glutamyl-l-glutamic acid by intact intestine or intestinal homogenate was slight, and intact peptide was taken up by the tissue. Uptake of free glutamic acid from this peptide was poor. Comparison of γ-glutamyl-l-glutamic acid with three other slowly hydrolysed dipeptides, glycyl-d-valine, sarcosylglycine and glycylsarcosine, suggested that all four were transported into the mucosal cells and hydrolysed intracellularly. The results indicate that the presence of a γ-linkage or a d-amino acid, or methylation of the free amino group as in sarcosylglycine, impair both transport and hydrolysis of peptide, but that attachment of a methyl group to the N of the peptide bond, as in glycylsarcosine, impairs hydrolysis but has no effect on peptide transport. 4. l-Aspartic acid and l-glutamic acid were extensively transaminated by the intestine, whether presented as free amino acids or in peptides. Evidence was obtained suggesting that production of alanine from aspartic acid resulted from direct transamination of aspartic acid with pyruvic acid, rather than from a sequence of two reactions involving aspartate and alanine aminotransferases. 5. The results show that more rapid uptake of amino acids from peptides than from free amino acids is not confined to peptides made up of neutral amino acids, and probably occurs with many small peptides. Uptake of lysine and the dicarboxylic amino acids, which are particularly slowly absorbed from free solution, was much greater from several dipeptides than from the free amino acids. The results suggest the importance of mucosal peptide uptake in protein absorption.

An extracellular proteolytic enzyme from Scopalariopsis brevicaulis. II. Hydrolysis of poly amino acids

1972 ◽  
Vol 18 (7) ◽  
pp. 1165-1167 ◽  
Author(s):  
Kartar Singh ◽  
Claude Vézina
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Proteolytic Enzyme ◽  
Ph Values ◽  
Optimum Ph ◽  
Extracellular Proteolytic Enzyme ◽  
Scopulariopsis Brevicaulis ◽  
Hydrolysis Of

Scopulariopsis brevicaulis protease hydrolyzed poly-L-lysine and poly-L-glutamic acid; optimum pH values for hydrolysis were 10.6 and 4.7 respectively. Final products of poly-L-lysine digestion by the protease were intermediate peptides from tetramer upwards. Pentalysine was not hydrolyzed by the enzyme. The protease had no action on poly-L-aspartic acid, poly-L-alanine, poly-L-glycine, poly-L-valine, or poly-L-leucine.

Structure and composition of the alkali-insoluble cell wall fraction of Coprinus macrorhizus var. microsporus

1980 ◽  
Vol 58 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Carey B. Bottom ◽  
Donald J. Siehr
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Acid Hydrolysis ◽  
Cell Walls ◽  
Cell Wall Fraction ◽  
Enzymic Hydrolysis ◽  
Methylation Analysis ◽  
Partial Acid Hydrolysis ◽  
The Core ◽  
Hydrolysis Of

The alkali-insoluble (R-) fraction from the cell walls of Coprinus macrorhizus var. microsporus is a highly branched glucan, containing α-(1 → 4), β-(1 → 3), and β-(1 → 6) linkages as shown by methylation, partial acid hydrolysis, and enzymic hydrolysis. The α-(1 → 4)-linked segments are joined by occasional β-(1 → 3) links as suggested by the identification of 2-O-α-glucopyranosyl erythritol in the hydrolysate of the reduced, periodate-oxidized glucan. Hydrolysis of the permethylated glucan gave nearly equimolar amounts of 2,4-di- and 2,3-di-O-methyl-D-glucose. Methylation analysis of the residue from enzymic hydrolysis, the "CORE-fraction," indicated the presence of glucose residues in this fraction linked through positions O1, O3, O4, and O6. Hydrolysates of the R-fraction contained mannose, glucosamine, and amino acids in addition to glucose.

THE TERMINAL AMINO ACIDS OF WHEAT GLIADIN

1955 ◽  
Vol 33 (10) ◽  
pp. 1463-1466 ◽  
Author(s):  
L. K. Ramachandran ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Hydrochloric Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Qualitative Evidence ◽  
Wheat Gliadin ◽  
Terminal Amino

Wheat gliadin has been found by two different methods to contain three N-terminal histidine residues for each molecular weight of 27,000. Trace amounts of N-terminal aspartic acid, glutamic acid, alanine, valine, and serine were also detected in the preparation used. Hydrolysis in boiling hydrochloric acid partially destroyed the di-2,4-dinitrophenyl derivative of histidine. Losses of from 5% to 25% occurred depending upon the time and conditions of hydrolysis. Carboxypeptidase did not release free amino acids from wheat gliadin but qualitative evidence for the occurrence of C-terminal glutamic acid and C-terminal "leucine" was obtained.

Specificity of the surface aminopeptidase in Moniliformis moniliformis (Acanthocephala)

1986 ◽  
Vol 60 (4) ◽  
pp. 288-292
Author(s):  
Gary L. Uglem ◽  
Mark C. Lewis
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Chromatographic Analysis ◽  
Aminopeptidase Activity ◽  
Amino Acid Residues ◽  
Bathing Medium ◽  
Transport Inhibitors ◽  
Moniliformis Moniliformis ◽  
Hydrolysis Of ◽  
Single Enzyme

ABSTRACTThe hydrolysis of various oligopeptides in solution by intact Moniliformis moniliformis was examined using paper chromatographic analysis of the incubation medium. In the presence of transport inhibitors, the respective peptide sub-units and/or amino acid residues accumulated in the bathing medium. Only peptides with serine, methionine, leucine or alanine at the NH2-terminal end of the peptide were hydrolysed. There was no hydrolysis when these amino acids were located internally or at the COOH-terminus indicating genuine aminopeptidase activity of the class, α-aminoacylpeptide hydrolase. Hydrolysis was negligible when the NH2-terminus was arginie, aspartic acid, glutamic acid, glutamic acid, glycine, histidine, lysine, phenylalanine, proline, tryptophan, tyrosine, or valine. In separate experiments, mediated uptake of 0.1 mM3H-leucine by the worms in 2 min was inhibited 100% by 5 mM unlabelled leucine or tri-serine, but only partially inhibited by 5 mM Ser-Gly (66%), 10 mM Ser-Gly (74%), 5 mM Leu-Leu (69%), 10 mM Leu-Leu (70%), 5 mM Leu-Gly (58%) or 5nM Met-Met (69%). Bacause the inhibitions produced by 5 mM Leu-Leu plus 5 mM Met-Met (79%) or 5 mM Leu-Leu plus 5 mM Ser-Gly (76%) were not additive, a single enzyme is indicated. The name serine aminopeptidase is proposed because of its preference for serine.

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