PREDICTION OF DRUG DISPOSITION BY HUMAN DRUG METABOLIZING ENZYMES

通过人体药物代谢酶预测药物分布

基本信息

批准号：
11557191
负责人：
YAMAZAKI Hiroshi
金额：
$ 3.01万
依托单位：
KANAZAWA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11557191/
关键词：
P450 human liver microsomes phenytoin tegafur Individual difference P450 contents coexpressing system drug Interaction チトクロムP450 CYP3A4 組換えヒトP450 NADPH-P450還元酵素チトクロームb5 大腸菌テストステロン

项目摘要

Drug oxidation activities of twelve recombinant human cytochrome P450 (P450) coexpressed with human NADPH-P450 reductase (NPR) in bacterial membranes (P450/NPR membranes) were determined and compared with those of other recombinant systems and of human liver microsomes. Addition of exogenous membrane-bound NPR to the P450/NPR membranes enhanced the catalytic activities of CYP2C8, CYP2C9, CYP2C19, CYP3A4, and CYP3A5 ; however, enhancement of activities of CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2D6, and CYP2E1 in membranes was not observed after the addition of NPR in 4-molar excess to each P450. Exogenous purified human cytochrome b_5 (b_5) further enhanced catalytic activities of CYP2A6, CYP2B6, CYP2C8, CYP2E1, CYP3A4, and CYP3A5/NPR membranes. Catalytic activities of CYP2C9 and CYP2C19 were enhanced by addition of b_5 in reconstitution systems but not in the P450/NPR membranes. Apo b_5 (devoid of heme) enhanced catalytic activities when added to the both systems, except for CYP2E1/NPR membranes and the reconstituted systems containing purified CYP2C8 or CYP2E1 in comparison with b_5. Catalytic activities in P450/NPR membranes plus b_5 systems were roughly similar to those measured with microsomes of insect cells coexpressing P450 with NPR (and b_5) and/or of human liver microsomes, based on equivalent P450 contents. These results suggest that interactions of P450 and NPR coexpressed in membranes and reconstituted systems appear to be different in some human CYP2 family enzymes, possibly due to a conformational role of b_5. P450/NPR membrane systems containing b_5 are useful models for prediction of the rates for liver microsomal P450-dependent drug oxidations.

在细菌膜中与人NADPH-P450还原酶（NPR）共表达的十二种重组人细胞色素P450（P450）的药物氧化活性（P450/NPR膜）与其他重组系统和人肝微粒体的药物氧化活性进行了比较。在P450/NPR膜中添加外源性膜结合的NPR增强了CYP2C8，CYP2C9，CYP2C19，CYP3A4和CYP3A5的催化活性；然而，在膜中未观察到膜中CYP1A1，CYP1A2，CYP1B1，CYP2A6，CYP2A6，CYP2B6，CYP2D6和CYP2E1的活性的增强，在向每个P450中添加NPR后，在4个摩尔过量中添加NPR后，未观察到膜中的CYP2E1。外源纯化的人细胞色素B_5（B_5）进一步增强了CYP2A6，CYP2B6，CYP2C8，CYP2E1，CYP3A4和CYP3A5/NPR膜的催化活性。 CYP2C9和CYP2C19的催化活性通过在重构系统中添加B_5增强，而不是在P450/NPR膜中增强。除了CYP2E1/NPR膜和包含纯化的CYP2C8或CYP2E1的重构系统外，APO B_5（缺乏血红素）将增强催化活性。 P450/NPR膜和B_5系统中的催化活性大致与用基于等效P450含量的NPR（和B_5）和/或人类肝微粒体共表达P450的昆虫细胞测量的催化活性大致相似。这些结果表明，在某些人CYP2家族酶中，P450和NPR在膜和重建系统中共表达的相互作用似乎是不同的，这可能是由于B_5的构象作用。含有B_5的P450/NPR膜系统是预测肝微粒体P450依赖性药物氧化速率的有用模型。