Cai Jie, Dai Da-Peng, Geng Pei-Wu, Wang Shuang-Hu, Wang Hao, Zhan Yun-Yun, Huang Xiang-Xin, Hu Guo-Xin, Cai Jian-Ping
The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, China.
Basic Clin Pharmacol Toxicol. 2016 Mar;118(3):190-9. doi: 10.1111/bcpt.12478. Epub 2015 Sep 26.
Cytochrome P450 2D6 (CYP2D6) is a highly polymorphic enzyme that metabolizes a large number of therapeutic drugs. To date, more than 100 CYP2D6 allelic variants have been reported. Among these variants, we recently identified 22 novel variants in the Chinese population. The aim of this study was to functionally characterize the enzymatic activity of these variants in vitro. A baculovirus-mediated expression system was used to express wild-type CYP2D6.1 and other variants (CYP2D6.2, CYP2D6.10 and 22 novel CYP2D6 variants) at high levels. Then, the insect microsomes containing expressed CYP2D6 proteins were incubated with bufuralol or dextromethorphan at 37°C for 20 or 25 min., respectively. After termination, the metabolites were extracted and used for the detection with high-performance liquid chromatography. Among the 24 CYP2D6 variants tested, two variants (CYP2D6.92 and CYP2D6.96) were found to be catalytically inactive. The remaining 22 variants exhibited significantly decreased intrinsic clearance values for bufuralol 1'-hydroxylation and 20 variants showed significantly lower intrinsic clearance values for dextromethorphan O-demethylation than those of the wild-type CYP2D6.1. Our in vitro results suggest that most of the variants exhibit significantly reduced catalytic activities compared with the wild-type, and these data provide valuable information for personalized medicine in Chinese and other Asian populations.
细胞色素P450 2D6（CYP2D6）是一种高度多态性的酶，可代谢大量治疗药物。迄今为止，已报道了100多种CYP2D6等位基因变体。在这些变体中，我们最近在中国人群中鉴定出22种新型变体。本研究的目的是在体外对这些变体的酶活性进行功能表征。使用杆状病毒介导的表达系统高水平表达野生型CYP2D6.1和其他变体（CYP2D6.2、CYP2D6.10和22种新型CYP2D6变体）。然后，将含有表达的CYP2D6蛋白的昆虫微粒体分别与布非洛尔或右美沙芬在37°C下孵育20或25分钟。孵育结束后，提取代谢产物并用于高效液相色谱检测。在测试的24种CYP2D6变体中，发现两种变体（CYP2D6.92和CYP2D6.96）无催化活性。其余22种变体的布非洛尔1'-羟化内在清除率值显著降低，20种变体的右美沙芬O-去甲基化内在清除率值比野生型CYP2D6.1显著降低。我们的体外结果表明，与野生型相比，大多数变体的催化活性显著降低，这些数据为中国和其他亚洲人群的个性化医疗提供了有价值的信息。
