人胎盘二肽基氨肽酶III：脑啡肽的水解作用及其受钴离子的刺激

Human placental dipeptidyl aminopeptidase III: hydrolysis of enkephalins and its stimulation by cobaltous ion.

作者信息

Shimamori Y, Watanabe Y, Fujimoto Y

机构信息

Department of Clinical Biochemistry, Hokkaido Institute of Pharmaceutical Sciences, Japan.

出版信息

Biochem Med Metab Biol. 1988 Dec;40(3):305-10. doi: 10.1016/0885-4505(88)90133-8.

DOI:10.1016/0885-4505(88)90133-8

PMID:3233187

Abstract

The degradation of enkephalin and related peptides by highly purified dipeptidyl aminopeptidase III (EC 3.4.14.4) was studied. The enzyme releases the N-terminal dipeptide units from substrates greater in length than the tetrapeptide. The enzyme exhibits an optimum of pH 7.5, Km of 81 microM and Vmax of 0.043 mumole/min for Leu-enkephalin. Its activity was markedly stimulated by Co2+, with both the Km and Vmax being increased. Among the enkephalin-related peptides examined, des-Tyr1-Leu-enkephalin was the most rapidly hydrolyzed with Co2+, but only slight stimulation was observed with Co2+.

摘要

研究了高纯度二肽基氨基肽酶III（EC 3.4.14.4）对脑啡肽及相关肽的降解作用。该酶从长度大于四肽的底物中释放出N端二肽单元。对于亮氨酸脑啡肽，该酶的最适pH为7.5，Km为81微摩尔，Vmax为0.043微摩尔/分钟。其活性受到Co2+的显著刺激，Km和Vmax均增加。在所检测的脑啡肽相关肽中，去酪氨酸1-亮氨酸脑啡肽在Co2+存在时水解最快，但Co2+对其刺激作用较弱。