Cytochrome P450 3A4 is a highly polymorphic enzyme and metabolizes approximately 40%–60% of therapeutic drugs. Its genetic polymorphism may significantly affect the expression and function of CYP3A4 resulting in alterations of the pharmacokinetics and pharmacodynamics of the CYP3A4-mediated drugs. The purpose of this study was to evaluate the catalytic activities of 30 CYP3A4 nonsynonymous variants and wild type toward oxycodone in vitro. CYP3A4 proteins were incubated with oxycodone for 30 min at 37 °C and the reaction was terminated by cooling to −80 °C immediately. Ultraperformance liquid chromatography tandem mass-spectrometry was used to analyze noroxycodone, and kinetic parameters Km, Vmax, and intrinsic clearance (Vmax/Km) of noroxycodone were also determined. Compared with CYP3A4.1, 24 CYP3A4 variants (CYP3A4.2–.5, -.7–.16, -.18 and -.19, -.23 and -.24, -.28 and -.29, and -.31–.34) exhibited significantly decreased relative clearance values (from 4.82% ± 0.31% to 80.98% ± 5.08%), whereas CYP3A4.6, -.17, -.20, -.21, -.26, and -.30 displayed no detectable enzyme activity. As the first study of these alleles for oxycodone metabolism in vitro, results of this study may provide insight into establishing the genotype-phenotype relationship for oxycodone and serve as a reference for clinical administrators and advance the provision of personalized precision medicine.

中文翻译：

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重组CYP3A4变体对羟考酮体外代谢的评价

细胞色素 P450 3A4 是一种高度多态性的酶，可代谢约 40%–60% 的治疗药物。其遗传多态性可能显着影响CYP3A4的表达和功能，导致CYP3A4介导的药物的药代动力学和药效学发生改变。本研究的目的是评估 30 个 CYP3A4 非同义变体和野生型对羟考酮的体外催化活性。CYP3A4 蛋白与羟考酮在 37°C 下孵育 30 分钟，并通过立即冷却至 -80°C 终止反应。使用超高效液相色谱串联质谱法分析去甲羟考酮，还测定了去甲羟考酮的动力学参数 Km、Vmax 和固有清除率 (Vmax/Km)。与 CYP3A4.1 相比，24 个 CYP3A4 变体（CYP3A4.2–.5、-.7–.16、-.18 和 -.19，-.23 和 -.24、-.28 和 -.29 以及 -.31–.34）表现出显着降低的相对清除率值（从 4.82% ± 0.31% 到 80.98% ± 5.08%），而 CYP3A4.6， -.17、-.20、-.21、-.26 和 -.30 显示没有可检测的酶活性。作为首次在体外对羟考酮代谢等位基因进行的研究，本研究的结果可为建立羟考酮的基因型-表型关系提供见解，并为临床管理人员提供参考，促进个性化精准医疗的提供。