检测所谓的人CYP2B6探针。

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Ekins S, VandenBranden M, Ring BJ, Wrighton SA

检测所谓的人CYP2B6探针。

药物遗传学。1997 Jun;7(3):165-79。

PubMed ID

9241656 (PubMed视图

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摘要

7-乙氧基-4-三氟甲基香豆素(7-EFC)被检测为人类肝脏微粒体中细胞色素P450 (P450)的底物，并在b淋巴母细胞中表达。7-EFC到7-羟基-4-三氟甲基香豆素(7-HFC)的o -去乙基化反应在肝库(n = 19)中变化了13倍(40-507 pmol min-1 mg-1蛋白)。与人类肝脏样本库代谢P450的形式选择性底物的能力相比，7-HFC的形成与s -甲苯妥英代谢物涅vanol的形成密切相关(r2 = 0.86, p < 0.0001)。α -萘黄酮(ANF)、二乙基二硫代氨基甲酸酯(DDC)和氯霉素(CAP)对人肝脏微粒体7-EFC o -去乙基化的抑制作用大于60%。Orphenadrine (ORP)是一种特异性CYP2B6抑制剂，与DDC或ANF相比，Orphenadrine对人肝脏微粒体形成7-HFC的抑制作用较弱。使用来自表达特定P450s的b淋巴母细胞类细胞的微粒体，发现CYP2B6和CYP1A2产生大量的7-HFC，而CYP2E1和CYP2C19产生可检测量的这种代谢物。ORP对表达的CYP2E1和CYP2B6介导的7-HFC形成的抑制程度大于对CYP1A2的抑制。甲氧氯和s -甲苯toin抑制CYP2B6的表达，但不抑制CYP1A2介导的7-EFC o -去乙基化。具有高相对速率的7-HFC形成的肝脏(n = 5)表现出双相酶动力学，低K(m)位点(平均K(m) = 3.3微米)表现出变构激活。5个7-HFC形成相对率较低的肝脏也表现出双相动力学，但缺乏低K(m)组分(平均K(m) = 2.4微米)参与变构机制的证据。 Furthermore, expressed CYP2B6 and CYP2E1 converted 7-EFC to 7-HFC with allosteric activation indicated, while CYP1A2 mediated metabolism of 7-EFC to 7-HFC best fit the classic Michaelis-Menten model. A commercially available antibody to rat CYP2B, suggested to be specific for CYP2B6, was found to cross react with all members to the CYP2 family examined including CYP2C19, which possessed a nearly identical electrophoretic mobility to that of CYP2B6 in the system examined. In total, the evidence presented indicates that multiple P450s are involved in the formation of 7-HFC from 7-EFC, therefore this does not appear to be a useful or a selective probe of CYP2B6 catalytic activity. Furthermore, the specificity of both antibody and chemical inhibitor (ORP) probes previously suggested to be specific for CYP2B6 is also questioned.

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药物酶

药物	酶	种类	生物	药理作用	行动
Orphenadrine	细胞色素P450 2E1	蛋白质	人类	未知的	抑制剂	细节