6种细胞色素P_(450)酶亚型特异性底物的酶动力学研究  

Enzyme Kinetics of 6 Specific Substrates of Cytochrome P_(450) Enzymes

作　　者：和凡[1,2] 赵立子[2] 毕惠嫦[2] 李建康[2] 李欣[2] 何艳玲 黄民[2] 

机构地区：[1]广州市妇女儿童医疗中心药剂科,广州市510120 [2]中山大学药学院临床药理研究所,广州市510080

出　　处：《中国药房》2009年第17期1310-1312,共3页China Pharmacy

摘　　要：目的:研究6种细胞色素P450酶亚型特异性底物的酶动力学。方法:采用高效液相色谱串联质谱电喷雾检测(LC-MS/MS)法测定6种底物相应代谢物的转化量,优化底物在人肝微粒体中孵育的条件,根据底物浓度-反应速率曲线进行酶动力学参数的求算。结果:最佳孵育时间为20min,最佳蛋白浓度为0.25mg protein·mL-1。6种底物非那西丁、甲苯磺丁脲、奥美拉唑、右美沙芬、氯唑沙宗及硝苯地平的Km分别为21.6、163.4、10.4、4.6、41.9、9.4μmol·L-1,Vmax分别为2.08、0.52、1.02、0.40、2.36、1.00nmol·min-1·mg protein-1。结论:所考察6种细胞色素P450酶亚型特异性底物的酶动力学特征,可为底物在细胞色素P450酶中的研究应用提供参考和支持。OBJECTIVE： To study the enzyme kinetics of six specific substrates of eytochrome P450 enzymes. METHODS： The transforming amount of the corresponding metabolites of six substrates was determined by LC- MS/MS. The incubation conditions of substrates in human liver microsomes were optimized and the parameters of enzyme kinetics were calculated based on substrate concentration - reaction velocity curve. RESULTS： The optimal incubation time was 20 min and the optimal enzyme concentration was 0.25 mg protein·mL^-1. The Km（μmol·L^-1） values of phenacetin, tolbutamide, omeprazole, dex- tromethorphan, chlorzoxazone and nifedipine were 21.6,163.4,10.4,4.6,41.9 and 9.4 respectively. The Vmax（nmol·min^-1·mg protein a） values were 2.08, 0.52, 1.02, 0.40, 2.36 and 1.00 respectively. CONCLUSION： The enzyme kinetics of six specific substrates of cytochrome P450 enzymes has been investigated in this study, and the study serves as a reference and support for the study and application of substrates in CYP.

关 键 词：底物 细胞色素P450 肝微粒体 酶动力学 

分 类 号：R969.1[医药卫生—药理学]