大鼠脑中两种不同的脑啡肽水解酶的鉴定与表征

Identification and characterization of two distinct kyotorphin-hydrolyzing enzymes in rat brain.

作者信息

Akasaki K, Nakamura A, Shiomi H, Tsuji H

机构信息

Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan.

出版信息

Neuropeptides. 1991 Oct;20(2):103-7. doi: 10.1016/0143-4179(91)90059-r.

DOI:10.1016/0143-4179(91)90059-r

PMID:1798437

Abstract

We identified and characterized two kyotorphin-hydrolyzing peptidases (KTPases) in a soluble fraction of rat brain. When the soluble fraction was chromatographed with DEAE-Sephacel, the enzyme activity was resolved into two peaks, which were designated as KTPases I and II in their order of elution. KTPases I and II accounted for 95% and 5% of the KTPase activity in the soluble fraction, respectively. KTPases I and II hydrolyzed kyotorphin with Km values of 22 microM and 110 microM, respectively. By gel filtration, Mr values of KTPases I and II were determined to be 55,000 and 98,000, respectively. Immunological analyses of KTPase II with an anti-enkephalin aminopeptidase antibody indicated that KTPase II was identical to an enkephalin aminopeptidase with Mr = 98,000. However, KTPase I was a novel peptidase responsible for the major kyotorphin-degrading activity in the soluble fraction of rat brain.

摘要

我们在大鼠脑的可溶性组分中鉴定并表征了两种脑啡肽酶（KTPases）。当用DEAE - 琼脂糖凝胶对可溶性组分进行层析时，酶活性被分离为两个峰，按照洗脱顺序分别命名为KTPases I和II。KTPases I和II分别占可溶性组分中KTPase活性的95%和5%。KTPases I和II水解脑啡肽的Km值分别为22微摩尔和110微摩尔。通过凝胶过滤，确定KTPases I和II的分子量分别为55,000和98,000。用抗脑啡肽氨基肽酶抗体对KTPase II进行免疫分析表明，KTPase II与分子量为98,000的脑啡肽氨基肽酶相同。然而，KTPase I是一种新型肽酶，负责大鼠脑可溶性组分中主要的脑啡肽降解活性。