《生命科学》 2011, 23(8): 790-795

一氧化氮合酶FMN结合结构域的电子传递及调控机制研究现状

王瑞勇，张　璐，柴亚辉，吴　静，尹瑜静，常俊标^*

(郑州大学化学系，郑州 45000)

摘　要：摘　要：生物体内NO是在一氧化氮合酶(mitric oxide synthase， NOS)催化下生成的，NOS的结构包括C端还原酶域和N端加氧酶域。还原酶域中的FMN结合结构域既可接受来自NADPH-FAD结构域的电子，又可作为提供电子的供体，在调控催化过程中的电子传递方面发挥着重要作用。主要从FMN结合结构域的构象平衡及其对不同亚型NOS的动力学差异的贡献、FMN结合结构域自身的电荷性质以及NOS中其他结构域对FMN结构域的功能调控三个方面进行了论述，以期揭示NOS独特的电子传递催化机制。
关键词：一氧化氮合酶; FMN结合结构域; 电子传递

Electron transfer and regulation mechanism of FMN subdomain in nitric oxide synthase

WANG Rui-Yong， ZHANG Lu， CHAI Ya-Hui， WU Jing， YIN Yu-Jing， CHANG Jun-Biao^*

(Department of Chemistry， Zhengzhou University， Zhengzhou 450001， China)

Abstract: Abstract: NO synthesis in vivo is catalyzed by nitric oxide synthase. Nitric-oxide synthase is composed of a C-terminal， flavin-containing reductase domain and an N-terminal， heme-containing oxidase domain. FMN domain plays a central role by acting as both an electron acceptor (receiving electrons from NADPH-FAD) and an electron donor (delivering electrons to the NOS heme). In the minireview， the following sections were presented: (i) a three-state， two-equilibrium model for the conformation of the FMN subdomain， in addition， its contribution to differences of nitric-oxide synthases I， II， and III from the view of kinetic， (ii) the surface charge of the FMN subdomain， (iii) how the partner subdomain (C-terminal residue and CaM binding) regulate the conformational equilibria of the FMN module in NOS. This helps to explain the unique electron transfer and catalytic behaviors of NOS.
Key words: nitric oxide synthase; FMN domain; electron transfer