鲤脑一氧化氮合酶的特性分析

Characterization of Cyprinus carpio brain nitric oxide synthase.

作者信息

Conte A, Ottaviani E

机构信息

Department of Animal Biology, University of Modena, Italy.

出版信息

Neurosci Lett. 1998 Feb 20;242(3):155-8. doi: 10.1016/s0304-3940(98)00063-9.

DOI:10.1016/s0304-3940(98)00063-9

PMID:9530929

Abstract

Nitric oxide synthase (NOS) activity is found both in soluble and in particulate fractions of the carp brain. The Km values for arginine are 2.8+/-0.5 and 3.3+/-0.4 microM for the soluble and particulate fractions, respectively. K for NG-monomethyl-L-arginine inhibitor are 2.6+/-0.5 and 2.9+/-0.6 microM, and activation energy for the breakdown of the substrate-enzyme complex 8120+/-710 and 4620+/-450 cal per mole. Carp enzyme shows higher affinity than rat NOS for Ca2+ and for the competitive inhibitor 7-nitroindazole.

摘要

在鲤鱼脑的可溶性部分和颗粒部分均发现一氧化氮合酶（NOS）活性。可溶性部分和颗粒部分的精氨酸米氏常数（Km值）分别为2.8±0.5和3.3±0.4微摩尔。NG-单甲基-L-精氨酸抑制剂的解离常数（K）分别为2.6±0.5和2.9±0.6微摩尔，底物-酶复合物分解的活化能分别为每摩尔8120±710和4620±450卡。鲤鱼的该酶对钙离子和竞争性抑制剂7-硝基吲唑的亲和力高于大鼠的一氧化氮合酶。