大肠杆菌亚硫酸盐还原酶的黄素蛋白组分可作为细胞色素P450c17还原酶发挥作用。

The flavoprotein component of the Escherichia coli sulfite reductase can act as a cytochrome P450c17 reductase.

作者信息

Zeghouf M, Defaye G, Fontecave M, Coves J

机构信息

Laboratoire de Chimie et Biochimie des Centres Redox Biologiques, CEA-Grenoble, DBMS/CBCRB-CNRS-Université Joseph Fourier, France.

出版信息

Biochem Biophys Res Commun. 1998 May 29;246(3):602-5. doi: 10.1006/bbrc.1998.8671.

DOI:10.1006/bbrc.1998.8671

PMID:9618257

Abstract

The flavoprotein component (SiR-FP) of the E. coli sulfite reductase was found to support 17 alpha-hydroxylation of pregnenolone in the presence of cytochrome P450c17. Half maximum activity is obtained for a 1:1 ratio of SiR-FP, expressed as monomer concentration, to P450c17. When compared to bovine NADPH-cytochrome P450 reductase, SiR-FP is about 12-15 times less efficient. P450c17 was demonstrated to interact specifically with the FMN-binding domain of the protein and the N-terminal part of SiR-FP is suspected to play a role in electron transfer. A cluster of negatively charged residues was found in SiR-FP by amino acid sequence comparison with rat cytochrome P450 reductase. These results argue in favour of the flavodoxin origin of the FMN-binding domain of SiR-FP.

摘要

已发现大肠杆菌亚硫酸盐还原酶的黄素蛋白组分（SiR-FP）在细胞色素P450c17存在的情况下支持孕烯醇酮的17α-羟基化。以单体浓度表示的SiR-FP与P450c17的比例为1:1时可获得最大活性的一半。与牛NADPH-细胞色素P450还原酶相比，SiR-FP的效率约低12 - 15倍。已证明P450c17与该蛋白的FMN结合结构域特异性相互作用，并且怀疑SiR-FP的N端部分在电子转移中起作用。通过与大鼠细胞色素P450还原酶的氨基酸序列比较，在SiR-FP中发现了一簇带负电荷的残基。这些结果支持SiR-FP的FMN结合结构域起源于黄素氧还蛋白的观点。