Kobayashi R, Kobayashi Y, Hirs C H
J Biol Chem. 1981 Mar 10;256(5):2460-5.
A procedure for the preparation of porcine protease E is described. The availability of a convenient source of the enzyme has permitted specificity studies utilizing the macromolecular substrates oxidized insulin A and B chains and oxidized ribonuclease. The results show that protease E has a pronounced selectivity for the carbonyl bonds of serine threonine, alanine, and valine residues, with the latter most favored. The specificity is complementary to that of the chymotrypsins and we suggest that this property is physiologically significant. The k3 and Km values for the substrates acetyl-trialanine methyl ester, succinyltrialanine p-nitroanilide and benzoylalanine methyl ester are comparable to those observed by others for porcine elastase. The specificity observed in the present work, however, indicates that protease E may best be regarded as a member of the chymotrypsin group of enzymes.
本文描述了一种制备猪蛋白酶E的方法。该酶便捷来源的可得性使得利用大分子底物氧化胰岛素A链和B链以及氧化核糖核酸酶进行特异性研究成为可能。结果表明，蛋白酶E对丝氨酸、苏氨酸、丙氨酸和缬氨酸残基的羰基键具有显著的选择性，其中对缬氨酸残基最为青睐。这种特异性与胰凝乳蛋白酶互补，我们认为这种特性具有生理意义。乙酰 - 三丙氨酸甲酯、琥珀酰 - 三丙氨酸对硝基苯胺和苯甲酰丙氨酸甲酯等底物的k3和Km值与其他人观察到的猪弹性蛋白酶的值相当。然而，本研究中观察到的特异性表明，蛋白酶E最好被视为胰凝乳蛋白酶类酶的一员。
