Kemp M C, Kuonen D R, Sutton A, Roberts P J
Department of Physiology and Pharmacology, University of Southampton, U.K.
Biochem Pharmacol. 1988 Aug 15;37(16):3063-70. doi: 10.1016/0006-2952(88)90302-4.
An enzyme (NADPH-dependent diaphorase) present in rat brain microsomes has been solubilised and shown to utilise both nitrobluetetrazolium and cytochrome c as electron acceptors, when reduced by NADPH. The kinetics of the enzyme have been determined using cytochrome c (Km = 1.3 microM), NADPH (Km = 1.4 microM) and the Vmax (4.7 nmol/min/mg solubilised microsome protein). The subunit Mr is approximately 73,000 D and that of the native enzyme is 170,000-180,000 D, indicating that the enzyme is probably a dimer. Evidence is also provided to show that the enzyme is a flavoprotein, and that it has equimolar amounts of FAD and FMN with respect to the subunit concentration. It seems a possibility that the rat brain diaphorase enzyme may be cytochrome P450 reductase, EC 1.6.2.4.
大鼠脑微粒体中存在的一种酶（NADPH依赖性黄递酶）已被溶解，并显示在被NADPH还原时，它能将氮蓝四唑和细胞色素c作为电子受体。使用细胞色素c（Km = 1.3微摩尔）、NADPH（Km = 1.4微摩尔）和Vmax（4.7纳摩尔/分钟/毫克溶解的微粒体蛋白）测定了该酶的动力学。亚基的相对分子质量约为73,000 D，天然酶的相对分子质量为170,000 - 180,000 D，表明该酶可能是二聚体。还提供了证据表明该酶是一种黄素蛋白，并且相对于亚基浓度，它含有等摩尔量的FAD和FMN。大鼠脑黄递酶可能是细胞色素P450还原酶（EC 1.6.2.4），这似乎是有可能的。
