Human Cytochrome P450 2C9 and Its Polymorphic Modifications: Electroanalysis, Catalytic Properties, and Approaches to the Regulation of Enzymatic Activity

Victoria V Shumyantseva,Maryia S Kisel,Polina I Koroleva,Tatiana V Bulko,Irina V Haidukevich,Anna A Makhova,Evgeniya V Shikh,Andrei A Gilep

doi:10.3390/pr10020383

Abstract

The electrochemical properties of cytochrome P450 2C9 (CYP2C9) and polymorphic modifications P450 2C9*2 (CYP2C9*2) and P450 2C9*3 (CYP2C9*3) were studied. To analyze the comparative electrochemical and electrocatalytic activity, the enzymes were immobilized on electrodes modified with a membrane-like synthetic surfactant (didodecyldimethylammonium bromide (DDAB)). An adequate choice of the type of modified electrode was confirmed by cyclic voltammetry of cytochromes P450 under anaerobic conditions, demonstrating well-defined peaks of reduction and oxidation of the heme iron. The midpoint potential, Emid, of cytochrome P450 2C9 is −0.318 ± 0.01 V, and Emid = −0.324 ± 0.01 V, and Emid = −0.318 ± 0.03 V for allelic variant 2C9*2 and allelic variant 2C9*3, respectively. In the presence of substrate diclofenac under aerobic conditions, cytochrome P450 2C9 and its polymorphic modifications P450 2C9*2 and P450 2C9*3 exhibit catalytic properties. Stimulation of the metabolism of diclofenac by cytochrome P450 2C9 in the presence of antioxidant medications mexidol and taurine was shown.

Highlights

Polymorphism of drug-metabolizing enzymes, cytochromes P450, affects the biotransformation of medications and drug–drug interactions [1]
This work is aimed at studying the effect of the antioxidant metabolic drug mexidol and vitamin-like antioxidant compound taurine on the metabolic transformations of diclofenac catalyzed by cytochrome P450 2C9
Results and DiscussIinovnestigation of CYP enzyme catalytic activity involves different approaches, such as Investigatioinnosf iCliYcPo,eninzyvmiveoca, tianlyvtiictraoctmiviotydienlvsoylvsetsedmifsfe.rSenint caepptrhoeacchaetsa, lsyutcihcacsycle of cytochromes P450 is in silico, in vivo, ianssvoitcroiamteoddewl istyhsteelmecs.trSoinncetrtahnescfaetra,ltyhtiec ucysceleofofecleyctotrcohcrohmemesiPca4l50syisstems has found its practical aaspspolciciaatteiodnwfoitrhmealoepdcpterlloiinncgatrtcaiaontnsafleyfros,irtshmoefuothsdeiseolcfilnealsgesccotrafothcaehlmyemsoipiscraooltfseytinhstsie.smcslahsass foofuhnedmitsopprraocttiecianl s

Summary

Introduction

Polymorphism of drug-metabolizing enzymes, cytochromes P450, affects the biotransformation of medications and drug–drug interactions [1]. CYP2C9 is responsible for the metabolic clearance of 15–20% of all drugs undergoing metabolism Phase I, including acenocoumarol, candesartan, celecoxib, fluvastatin, glyburide, ketamine, methadone, phenytoin, tolbutamide, testosterone, phenobarbital, S-warfarin, piroxicam, losartan, tamoxifen, and many nonsteroidal antiinflammatory drugs such as diclofenac and ibuprofen [4,5,6]. Cytochrome P450 2C9*2 is characterized by a C-T substitution in the corresponding gene, which leads to the Arg144Cys mutation. Cytochrome P450 2C9*3 is characterized by A-T substitution, leading to the Ile359Leu mutation [7,8,9,10]. The catalytic activities of cytochrome P450 2C9 and its polymorphic modifications P450 2C9*2 and P450 2C9*3 are different with respect to different substrates [8,9,10]. Decreased catalytic activity in the formation of 7-hydroxy-S-warfarin catalyzed by cytochromes P450 2C9*2 and P450 2C9*3

Objectives

Methods

Results

Conclusion