Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Pfizer, Inc., Groton, CT, USA.
Drug Metab Dispos. 2012 Sep;40(9):1686-97. doi: 10.1124/dmd.112.045302. Epub 2012 May 29.
CYP3cide (PF-4981517; 1-methyl-3-[1-methyl-5-(4-methylphenyl)-1H-pyrazol-4-yl]-4-[(3S)-3-piperidin-1-ylpyrrolidin-1-yl]-1H-pyrazolo[3,4-d]pyrimidine) is a potent, efficient, and specific time-dependent inactivator of human CYP3A4. When investigating its inhibitory properties, an extreme metabolic inactivation efficiency (k(inact)/K(I)) of 3300 to 3800 ml · min⁻¹ · μmol⁻¹ was observed using human liver microsomes from donors of nonfunctioning CYP3A5 (CYP3A5 *3/*3). This observed efficiency equated to an apparent K(I) between 420 and 480 nM with a maximal inactivation rate (k(inact)) equal to 1.6 min⁻¹. Similar results were achieved with testosterone, another CYP3A substrate, and other sources of the CYP3A4 enzyme. To further illustrate the abilities of CYP3cide, its partition ratio of inactivation was determined with recombinant CYP3A4. These studies produced a partition ratio approaching unity, thus underscoring the inactivation capacity of CYP3cide. When CYP3cide was tested at a concentration and preincubation time to completely inhibit CYP3A4 in a library of genotyped polymorphic CYP3A5 microsomes, the correlation of the remaining midazolam 1'-hydroxylase activity to CYP3A5 abundance was significant (R² value equal to 0.51, p value of <0.0001). The work presented here supports these findings by fully characterizing the inhibitory properties and exploring CYP3cide's mechanism of action. To aid the researcher, multiple commercially available sources of CYP3cide were established, and a protocol was developed to quantitatively determine CYP3A4 contribution to the metabolism of an investigational compound. Through the establishment of this protocol and the evidence provided here, we believe that CYP3cide is a very useful tool for understanding the relative roles of CYP3A4 versus CYP3A5 and the impact of CYP3A5 genetic polymorphism on a compound's pharmacokinetics.
CYP3cide（PF-4981517；1-甲基-3-[1-甲基-5-(4-甲基苯基)-1H-吡唑-4-基]-4-[(3S)-3-哌啶-1-基吡咯烷-1-基]-1H-吡唑并[3,4-d]嘧啶）是一种有效的、高效的和特异性的时间依赖性人 CYP3A4 失活剂。在研究其抑制特性时，使用无功能 CYP3A5（CYP3A5*3/*3）供体的人肝微粒体观察到极其代谢失活效率（k(inact)/K(I)）为 3300 至 3800ml·min⁻¹·μmol⁻¹。观察到的效率相当于 420 至 480nM 的表观 K(I)，最大失活速率（k(inact)）等于 1.6min⁻¹。使用睾酮（另一种 CYP3A 底物）和其他来源的 CYP3A4 酶也获得了类似的结果。为了进一步说明 CYP3cide 的能力，用重组 CYP3A4 测定了其失活的分配比。这些研究产生了接近 1 的分配比，从而强调了 CYP3cide 的失活能力。当 CYP3cide 以浓度和预孵育时间进行测试，以完全抑制基因分型多态性 CYP3A5 微粒体库中的 CYP3A4 时，剩余咪达唑仑 1'-羟化酶活性与 CYP3A5 丰度的相关性具有显著意义（R²值等于 0.51，p 值小于 0.0001）。这里介绍的工作通过充分描述抑制特性并探索 CYP3cide 的作用机制来支持这些发现。为了帮助研究人员，建立了多个市售 CYP3cide 来源，并制定了一个方案来定量确定 CYP3A4 对研究化合物代谢的贡献。通过建立该方案和这里提供的证据，我们相信 CYP3cide 是一种非常有用的工具，可以帮助理解 CYP3A4 与 CYP3A5 的相对作用以及 CYP3A5 遗传多态性对化合物药代动力学的影响。
