用[125I]甲硫氨酸脑啡肽进行甲硫氨酸脑啡肽氨基肽酶的测定。

The assay of Met-enkephalin aminopeptidase with [125I]Met-enkephalin.

作者信息

Caffrey J L, Hodges D H

出版信息

J Biochem Biophys Methods. 1982 Jun;6(2):133-9. doi: 10.1016/0165-022x(82)90059-8.

Abstract

Presented here are procedural modifications which permit the utilization of 125I-labeled Met-enkephalin as substrate in the assay of rat brain enkephalin aminopeptidase. Th hydrolysis of enkephalin is monitored by the release of [125I]tyrosine separated on Porapak Q. The release of tyrosine is proportionate with both increasing time and tissue concentration. The estimated Km is near 10(-4) M and the enzyme activity can be inhibited more than 95% with puromycin. The majority of the enzyme activity remains in the 100,000 x g supernatant following differential centrifugation.

摘要

本文介绍了一些程序上的改进方法，这些方法可使125I标记的甲硫氨酸脑啡肽作为底物用于大鼠脑内脑啡肽氨肽酶的测定。通过在Porapak Q上分离的[125I]酪氨酸的释放来监测脑啡肽的水解。酪氨酸的释放与时间增加和组织浓度均成正比。估计的米氏常数接近10^(-4) M，嘌呤霉素可使酶活性抑制超过95%。差速离心后，大部分酶活性保留在100,000×g的上清液中。