细胞色素P450 3A4和3A5与其中间氧化还原伙伴细胞色素b5的蛋白质-蛋白质相互作用

[Protein-protein interactions of cytochromes P450 3A4 and 3A5 with their intermediate redox partners cytochromes b5].

作者信息

Gnedenko O V, Ivanov A S, Yablokov E O, Usanov S A, Mukha D V, Sergeev G V, Kuzikov A V, Bulko T V, Moskaleva N E, Shumyantseva V V, Archakov A I

机构信息

Institute of Biomedical Chemistry, Moscow, Russia.

Institute of Bioorganic Chemistry of NAS, Minsk, Belarus.

出版信息

Biomed Khim. 2015 Jul-Aug;61(4):468-73. doi: 10.18097/PBMC20156104468.

DOI:10.18097/PBMC20156104468

PMID:26350737

Abstract

Molecular interactions between proteins redox partners (cytochromes Р450 3А4, 3А5 and cytochrome b5) within the monooxygenase system, which is known to be involved in drug biotransformation, were investigated. Human cytochromes Р450 3А4 and 3А5 (CYP3A4 and CYP3A5) form complexes with various cytochromes b5: the microsomal (b5mc) and mitochondrial (b5om) forms of this protein, as well as with 2 "chimeric" proteins, b5(om-mc), b5(mc-om). Kinetic constants and equilibrium dissociation constants were determined by the SPR biosensor. Essential distinction between CYP3A4 and CYP3A5 was only observed upon their interactions with cytochrome b5om. Electroanalytical characteristics of electrodes with immobilized hemoproteins were obtained. The electrochemical analysis of CYP3A4, CYP3A5, b5mc, b5om, b5(om-mc), and b5(mc-om) immobilized on screen printed graphite electrodes modified with membranous matrix revealed that these proteins have very close reduction potentials -0.435  -0.350 V (vs. Ag/AgCl). Cytochrome b5mc was shown to be capable of stimulating the electrocatalytic activity of CYP3A4 in the presence of its substrate testosterone.

摘要

研究了参与药物生物转化的单加氧酶系统中蛋白质氧化还原伴侣（细胞色素P450 3A4、3A5和细胞色素b5）之间的分子相互作用。人细胞色素P450 3A4和3A5（CYP3A4和CYP3A5）与各种细胞色素b5形成复合物：该蛋白的微粒体（b5mc）和线粒体（b5om）形式，以及与2种“嵌合”蛋白b5（om-mc）、b5（mc-om）。通过SPR生物传感器测定动力学常数和平衡解离常数。仅在CYP3A4和CYP3A5与细胞色素b5om相互作用时观察到它们之间的本质区别。获得了固定化血红素蛋白电极的电分析特性。对固定在经膜基质修饰的丝网印刷石墨电极上的CYP3A4、CYP3A5、b5mc、b5om、b5（om-mc）和b5（mc-om）进行电化学分析，结果表明这些蛋白质具有非常接近的还原电位-0.435÷-0.350 V（相对于Ag/AgCl）。结果表明，在其底物睾酮存在下，细胞色素b5mc能够刺激CYP3A4的电催化活性。