关于胃蛋白酶作用机制和特异性的新数据。

New data on pepsin mechanism and specificity.

作者信息

Antonov V K

出版信息

Adv Exp Med Biol. 1977;95:179-98. doi: 10.1007/978-1-4757-0719-9_11.

Abstract

New data on the specificity and mechanism of action of porcine pepsin are presented, including statistical analysis of protein cleavage by the enzyme, kinetics of synthetic substrates, enzyme inhibition and activation, kinetics of transpeptidation reaction, and 180 exchange studies. From these data it was concluded that pepsin has an extended active site being able to accomodate specifically five amino acid residues of the substrate. The orientation of the substrate molecule relative to the ethanol binding loci in pepsin crystals has been determined. Pepsin mechanism includes "amino-enzyme" formation which chemically is not an amide, formed by the enzyme carboxyl with the amino fragment of the substrate.

摘要

本文介绍了猪胃蛋白酶特异性和作用机制的新数据，包括该酶对蛋白质切割的统计分析、合成底物的动力学、酶的抑制与激活、转肽反应动力学以及18O交换研究。从这些数据得出结论，胃蛋白酶具有一个扩展的活性位点，能够特异性容纳底物的五个氨基酸残基。已经确定了底物分子相对于胃蛋白酶晶体中乙醇结合位点的取向。胃蛋白酶的作用机制包括“氨基酶”的形成，从化学角度看它不是一种酰胺，而是由酶的羧基与底物的氨基片段形成的。