Gelboin H V, Krausz K W, Goldfarb I, Buters J T, Yang S K, Gonzalez F J, Korzekwa K R, Shou M
Laboratory of Molecular Carcinogenesis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Biochem Pharmacol. 1995 Nov 27;50(11):1841-50. doi: 10.1016/0006-2952(95)02077-2.
Cytochromes P450 3A3/4 are inordinately important P450 enzymes catalyzing the metabolism of a large variety of clinically useful drugs, steroids, and carcinogens. Two monoclonal antibodies, MAb 3-29-9 and MAb 275-1-2, were prepared to human P450 3A4 from mice immunized with baculovirus-expressed human P450 3A4. MAb 3-29-9 was a powerful inhibitor of the enzymatic activity of P450 3A3/4/5. MAb 3-29-9 inhibited the P450 3A3, 3A4, and 3A5 catalyzed metabolism of substrates of divergent molecular weights, e.g., p-nitroanisole, phenanthrene, diazepam, testosterone, taxol, and cyclosporin. However, MAb 3-29-9 did not give a western blot with P450 3A3 or 3A4. MAb 275-1-2 was non-inhibitory but yielded a strong western blot with P450 3A3 and 3A4 but not with 3A5, and thus distinguished between 3A3/4 and 3A5. The two MAbs did not cross-react with human 2E1, 1A2, 2B6, 2C8, and 2C9; rat 2A1, 3A1/2, 4A1, 4A3, and 2B1; and mouse 1A1 and 1A2. MAb 3-29-9 has been used successfully to measure the quantitative contribution of P450 3A3 and 3A4 to the metabolism of the above-designated substrates in human adult liver. MAb 3-29-9 and MAb 275-1-2 are precise and sensitive reagents for P450 3A studies.
细胞色素P450 3A3/4是极其重要的P450酶，可催化多种临床常用药物、类固醇和致癌物的代谢。用杆状病毒表达的人P450 3A4免疫小鼠，制备了两种针对人P450 3A4的单克隆抗体，即单克隆抗体3-29-9和单克隆抗体275-1-2。单克隆抗体3-29-9是P450 3A3/4/5酶活性的强力抑制剂。单克隆抗体3-29-9可抑制P450 3A3、3A4和3A5催化的不同分子量底物的代谢，例如对硝基苯甲醚、菲、地西泮、睾酮、紫杉醇和环孢素。然而，单克隆抗体3-29-9不能与P450 3A3或3A4进行蛋白质免疫印迹分析。单克隆抗体275-1-2无抑制作用，但能与P450 3A3和3A4产生强蛋白质免疫印迹信号，而与3A5无反应，因此可区分3A3/4和3A5。这两种单克隆抗体与人2E1、1A2、2B6、2C8和2C9；大鼠2A1、3A1/2、4A1、4A3和2B1；以及小鼠1A1和1A2均无交叉反应。单克隆抗体3-29-9已成功用于测定P450 3A3和3A4对成人肝脏中上述指定底物代谢的定量贡献。单克隆抗体3-29-9和单克隆抗体275-1-2是用于P450 3A研究的精确且灵敏的试剂。
