Ito Miyabi, Katono Yuki, Oda Akifumi, Hirasawa Noriyasu, Hiratsuka Masahiro
Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan.
Drug Metab Pharmacokinet. 2015 Jun;30(3):247-52. doi: 10.1016/j.dmpk.2015.03.001. Epub 2015 Mar 27.
Genetic variations in cytochrome P450 1A2 (CYP1A2) are associated with interindividual variability in the metabolism and efficacy of many medications. Twenty CYP1A2 variants harboring amino acid substitutions were analyzed for functional changes in enzymatic activity. Recombinant CYP1A2 variant proteins were heterologously expressed in COS-7 cells. Enzyme kinetic analyses were performed with two representative CYP1A2 substrates, phenacetin and 7-ethoxyresorufin. Among the 20 CYP1A2 allelic variants, CYP1A24, CYP1A26, CYP1A28, CYP1A215, CYP1A216, and CYP1A221 were inactive toward both substrates. CYP1A211 showed markedly reduced activity, but the changes in Km were different between the substrates. CYP1A214 and CYP1A220 exhibited increased activity compared to the wild-type enzyme, CYP1A21. This comprehensive in vitro assessment provided insight into the specific metabolic activities of CYP1A2 proteins encoded by variant alleles, which may to be valuable when interpreting the results of in vivo studies.
细胞色素P450 1A2（CYP1A2）的基因变异与许多药物代谢及疗效的个体间差异相关。对20种携带氨基酸替换的CYP1A2变体进行了酶活性功能变化分析。重组CYP1A2变体蛋白在COS-7细胞中进行异源表达。用两种代表性的CYP1A2底物非那西丁和7-乙氧基试卤灵进行酶动力学分析。在20种CYP1A2等位基因变体中，CYP1A24、CYP1A26、CYP1A28、CYP1A215、CYP1A216和CYP1A221对两种底物均无活性。CYP1A211活性显著降低，但底物之间的Km变化不同。与野生型酶CYP1A21相比，CYP1A214和CYP1A220活性增加。这种全面的体外评估为变异等位基因编码的CYP1A2蛋白的特定代谢活性提供了见解，这在解释体内研究结果时可能很有价值。
