Bai Y, Hayashi R, Hata T
J Biochem. 1975 Sep;78(3):617-26. doi: 10.1093/oxfordjournals.jbchem.a130948.
Kinetic parameters of carboxypeptidase Y are given for the hydrolyses of ester, amide, and anilide substrates. The kcat/Km values were compatible with those of chymotrypsin [EC 3.4.21.1] with a few exceptions. One ionizable group with a pK of around 5.8 was suggested to be involved in the free enzyme in hydrolyzing all the substrates, including peptide substrates. In addition, hydroxylaminolysis and the kinetic isotope effects of deuterium oxide indicated, with some reservations, a reaction mechanism which proceeds via the formation of an acyl intermediate.
给出了羧肽酶Y对酯、酰胺和苯胺底物水解的动力学参数。除少数例外，kcat/Km值与胰凝乳蛋白酶[EC 3.4.21.1]的kcat/Km值相符。有人提出，一个pK约为5.8的可电离基团参与了游离酶对包括肽底物在内的所有底物的水解。此外，羟胺解和重水的动力学同位素效应在一定程度上表明了一种通过形成酰基中间体进行的反应机制。
