Summary

To study biochemical properties of carboxypeptidase A of the untransformed tissue and malignant neoplasm of the mammalian gland. Sampling of anatomical materials for re-search was conducted with compliance of ethical and legal standards.

Excretion of this enzymes includes gradual fractionation with the (NH4)2SO4, dialysis at the presence of 2,0 мМ Zn++and gel chromatography on the sephadex - G 75. The investigation substrate specicity of the enzymes was held by hydrolysis of the substrate of carbobenzoxyphenylalanine, phe-nylalanylalanine, glutamyltyrosine, prolylalanine (2,0 mM), haemoglobin and casein (2,0 %). The in uence of inhibitors and activators was determined in presence of: Zn++, cysteine, triton X-100, soybean trypsin inhibitor, leupeptin, pepstatin, PHMB, PMSF, dimethylmolyemydanhydride, tozylheptanol, mercaptoethanol, EDTA and 1,10 - phenanthroline. The maximal velocity (Vmax), Mihaelis constant (Km), inhibition type and inhibition constant (Ki) analysed by Lineweaver - Burkmethod. Carboxypeptidase A from the untransformed tissue and malignant neoplasm of the mammalian gland better splitsthe substrates, which have hydrophobic and aromatic amino acids. The activity of carboxypeptidase A from the malignant tumor of the mammalian gland is inhibited most of all under influence of soybean trypsin inhibitor and PMSF, in contrast to untransformed tissue. For carboxypeptidase A from the untransformed tissue of the mammalian gland Km=0,24 mM and Ki=0,40 mM were determined, for carboxypeptidase A from the malignant neoplasm of the mammalian gland – Km=0,17 mM and Ki=0,65 mM. Carboxypeptidase A from the untransformed tissue and malignant neoplasm of the mammalian gland is identical as to the substrate specificity, inhibition by phenylalanine for non-competitive type, inhibition and activation effect by re-agent with the exclusion of soybean trypsin inhibitor and PMSF, but differ as to affinity to carbobenzoxyphenylalanine and sensitivity to phenylalanine.

MAY 2020

VOL. 302 No. 5

12 - 17

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Keywords

Carboxypeptidase A

Biochemical Properties

Mammalian Gland

Tumors