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A S Tsyperovich

Publications and source records attributed to A S Tsyperovich.

At least 19 recordsLinked to original sources
PubMed1976

[Isolation, purification and investigation of physico-chemical properties and specificity of Leu-Gly-Gly-amino peptidase].

A highly purified (237-fold) preparation of extracellular Leu-Gly-Gly aminopeptidase was isolated from the 716 strain of mould Aspergillis flavus. The enzyme was found electrophoretically and enzymatically homogeneous, using Leu-beta-naphthylimide as substrate. The pH optimum is 8.60; the temperature optimum is about 50 degrees C. The enzyme was inhibited by EDTA and completely reactivated by Co2+ ions; Ca2+ and Mn2+ ions considerably restored the enzyme activity. The enzyme showed the optimal activity during the cleavage of substrates, containing N-terminal leucine. Mild hydrolysis of leucine-free tripeptides and dipeptides with N-terminal glycine and alanine was observed. The enzyme was found to be stereospecific in some respects. Peptides with a blocked terminal NH2-group are not hydrolyzed by the enzyme.

Aminopeptidases↗
PubMed1976

[Isolation and several properties of Streptomyces griseus carboxypeptidase].

Enzymatic and physico-chemical properties of homogenous preparation of carboxypeptidase from Streptomyces griseus are studied. pH-Optimum is found to be 7.9 and 8.2 under the hydrolysis of cbs-Gly-Leu and hyppuryl-arg respectively, temperature optimum --60 degrees C. The enzyme splits more efficiently basic amino acids and leucine from N-terminal-protected dipeptides. Str. griseus carboxypeptidase is activated by reducting agents (NaCN, cisteine, ascorbic acid), it is inhibited by KMnO4 and it does not belong to "serine" type enzymes. SH-groups are essential for the enzyme activity. No significant effect of metal ions on the enzyme activity is observed. The inhibitory effect of EDTA developed only after the prolonged treatment. The enzyme has one N-terminal group (alanine), which evidences the presence of one polypeptide chain in the enzyme molecule.

Carboxypeptidases↗
PubMedDate not supplied

[Modification of the carboxyl and amine groups of the cellulolytic enzymes of Aspergillus awamori].

The activity and stability of some enzymes of Asp. awamori cellulolytic complex were studied as affected by chemical modification of carboxylic groups with N,N'-dicyclohexyl carbodiimide (DCCD) and amine groups with glutaric aldehyde. The carboxylic groups are established to be necessary for manifestation of the activities of C1- and C2-cellulases, Cx-exo- and Cx-endoglucanases. Their role is negligible in the action of beta-glucosidase. The activity of individual cellulases was studied as affected by nucleophilic substitution of DCCD-activated COOH-groups by various reagents (glycine amide, leucine amide, tyrosine amide and N-benzoyl-l-arginine-methyl ether-hydrochloride). Tyrosine amide is the least inacting reagent for all the enzymes, glycine amide is somewhat more activating. Essential differences are shown in the chemical and catalytic properties of Cx-exoglucanase and beta-glucosidase. It is found (under the effect of glutaric aldehyde) that amino groups are significant for manifestation of the activities of C1- and C2-cellulases and Cx-endoglucanase and to a less extent for that of Cs-exoglucanase and beta-glucosidase. It is supposed that electrostatic interactions of the carbolytic and amine groups might be an essential factor for stability of C1- and C2-cellulases and Cx-endoglucanase.

Amines↗
PubMedDate not supplied

[Hydrolysis of insoluble bone collagen by crystalline alpha-amylase from Aspergillus oryzae].

The paper deals with hydrolysis of bone collagen thrice recrystallized alpha-amylase. The enzyme action was estimated by the amount of released glycopeptides, free carbohydrates, alpha-amine groups and total nitrogen in the soluble part of the hydrolyzate. The protease admixture in the alpha-amylase preparation was found by means of the Aspergillus oryzae protease. The data obtained testify to the fact that hydrolysis of collagen under the effect of crystalline alpha-amylase occurs only due to the protease admixture in the amylolitic preparation. When an attempt was made to obtain acid-soluble collagen from bone insoluble collagen previously treated with the alpha-amylase preparation, it was found that under these conditions bone collagen, as distinct from skin collagen, is not solubilized in diluted acetic acid.

Amylases↗
PubMedDate not supplied

[Aminopeptidase system of Aspergillus flavus].

The aminopeptidases system contained in a complex of exocellular peptidhydrolases synthetized by Asp. flavus was studied. Separation of the system into individual enzymes of the type of leucin aminopeptidase, aminotripeptidase and specific leucyl-glycyl-glycine-aminopeptidase by the methods of salt fractionation. DEAE-Sephadex A-50 and DEAE-cellulose chromatography. These enzymes are characterized by a different degree of purification as well as by the presence of the multiple forms, anion and cation ones. The multiple forms differ in solubility, specific activity, chromatographic properties, thermostability. The presence of individual triglycine-aminotripeptidase is shown in the system. The differences are found in the properties of the enzymes splitting leucinamide and leucyl-glycine. There may be two different leucine aminopeptidases. Studies in correlation during hydrolysis of leucinamide and leucyl-glycyl-glycine and comparison of the fractions properties displaying the activities showed that there are no reasons to ascribe these both reactions to the effect of the same enzyme.

Aminopeptidases↗