Discovery of a Highly Selective CYP3A4 Inhibitor Suitable for Reaction Phenotyping Studies and Differentiation of CYP3A4 and CYP3A5
Discovery of a Highly Selective CYP3A4 Inhibitor Suitable for Reaction Phenotyping Studies and Differentiation of CYP3A4 and CYP3A5
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DOI：
10.1124/dmd.112.046144
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发表时间：
2012-09-01
影响因子：
3.9
通讯作者：
Cameron, Michael D.
中科院分区：
文献类型：
--
作者：
Li, Xiaohai;Song, Xinyi;Cameron, Michael D.
目前的分子工具缺乏区分生物样本中的细胞色素P3A4和细胞色素P3A5活性的能力，如人肝微粒体。动力学实验和CYP3A4晶体结构表明，这两种酶的活性部位都很大且很灵活，活性部位内有多个结合亚位。1-(4-Imidazopyridinyl-7phenyl)-3-(4‘-cyanobiphenyl)尿素(SR-9186)从最初的筛选命中通过几轮结构精炼进行了优化，获得了比CYP3A4高1000倍的选择性。表征数据显示，使用咪达唑仑和睾酮羟化试验对重组细胞色素P450、混合的人肝微粒体和单独的基因分型微粒体进行分析具有选择性。携带CYP3A5*1和*3基因的个体之间存在明显的差异。抗真菌药酮康唑是体外和体内研究中最常用的CYP3A抑制剂。在典型的实验条件下，SR-9186与酮康唑的直接比较表明，SR-9186对细胞色素P1A2、细胞色素P450_2A6、细胞色素P450_2B6、细胞色素P450_2C8、细胞色素P450_2C9、细胞色素C19、细胞色素D6、细胞色素E_2E_1和细胞色素P3A5的选择性大于或等于酮康唑。此外，SR-9186在含有1 mg/ml人肝微粒体的孵育中具有较长的半衰期(106min)，对细胞色素P3A4有持续的抑制作用。
Current molecular tools lack the ability to differentiate the activity of CYP3A4 and CYP3A5 in biological samples such as human liver microsomes. Kinetic experiments and the CYP3A4 crystal structure indicate that the active sites of both enzymes are large and flexible, and have more than one binding subsite within the active site. 1-(4-Imidazopyridinyl-7phenyl)-3-(4'-cyanobiphenyl) urea (SR-9186) was optimized through several rounds of structural refinement from an initial screening hit to obtain greater than 1000-fold selectivity for the inhibition of CYP3A4 versus CYP3A5. Characterization data demonstrate selectivity using midazolam and testosterone hydroxylation assays with recombinant cytochrome P450, pooled human liver microsomes, and individually genotyped microsomes. Clear differences are seen between individuals with CYP3A5*1 and *3 genotypes. The antifungal drug ketoconazole is the most commonly used CYP3A inhibitor for in vitro and in vivo studies. A direct comparison of SR-9186 and ketoconazole under typical assay conditions used in reaction phenotyping studies demonstrated that SR-9186 had selectivity over CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A5 greater than or equal to that of ketoconazole. In addition, the long half-life (106 min) of SR-9186 in incubations containing 1 mg/ml human liver microsomes provided sustained CYP3A4 inhibition.