大鼠脑中γ-谷氨酰水解酶（共轭酶）活性的测定。

The measurement of gamma-glutamyl hydrolase (conjugase) activity in rat brain.

作者信息

Hartley D M, Snodgrass S R, Bradshaw P A

机构信息

Dept. of Neurology, Stanford University, CA 94305.

出版信息

Neurochem Res. 1988 Feb;13(2):147-51. doi: 10.1007/BF00973326.

DOI:10.1007/BF00973326

PMID:3362292

Abstract

An assay using the artificial substrate, 2,4-diamino-10-methyl-pteroylglutamyl-gamma-glutamate (MTX-G1), was developed to measure gamma-glutamyl hydrolase (conjugase), which hydrolyzes folylpolyglutamates. This assay allows us to: 1) measure conjugase for the first time in rat brain and 2) measure conjugase in a reliable, sensitive and inexpensive manner. The MTX-binding assay results were compared to samples analyzed by HPLC and found to vary by only 13%. The artificial substrate, MTX-G1, had a lower rate of hydrolysis than pteroylglutamyl-gamma-glutamate (Pte-G2), 70.7 +/- 0.64 and 92.6 +/- 0.22 nmoles/hr/mg protein respectively. Conjugase was semi-purified 24 fold in H2O and found to have a pH optimum of 5.0.

摘要

开发了一种使用人工底物2,4-二氨基-10-甲基蝶酰谷氨酰-γ-谷氨酸（MTX-G1）的测定方法，以测量水解叶酰聚谷氨酸的γ-谷氨酰水解酶（结合酶）。该测定方法使我们能够：1）首次在大鼠脑中测量结合酶，以及2）以可靠、灵敏且廉价的方式测量结合酶。将MTX结合测定结果与通过高效液相色谱分析的样品进行比较，发现差异仅为13%。人工底物MTX-G1的水解速率低于蝶酰谷氨酰-γ-谷氨酸（Pte-G2），分别为70.7±0.64和92.6±0.22纳摩尔/小时/毫克蛋白质。结合酶在水中进行了24倍的半纯化，发现其最适pH为5.0。