Université Paris Diderot, Sorbonne Paris Cité, Inserm UMR-S 973, Molécules Thérapeutiques In silico, Paris, France.
INSERM, U973, Paris, France.
PLoS One. 2018 May 10;13(5):e0197249. doi: 10.1371/journal.pone.0197249. eCollection 2018.
Cytochrome P450 2C9 (CYP2C9) metabolizes about 15% of clinically administrated drugs. The allelic variant CYP2C9*30 (A477T) is associated to diminished response to the antihypertensive effects of the prodrug losartan and affected metabolism of other drugs. Here, we investigated molecular mechanisms involved in the functional consequences of this amino-acid substitution. Molecular dynamics (MD) simulations performed for the active species of the enzyme (heme in the Compound I state), in the apo or substrate-bound state, and binding energy analyses gave insights into altered protein structure and dynamics involved in the defective drug metabolism of human CYP2C9.30. Our data revealed an increased rigidity of the key Substrate Recognition Sites SRS1 and SRS5 and shifting of the β turn 4 of SRS6 toward the helix F in CYP2C9.30. Channel and binding substrate dynamics analyses showed altered substrate channel access and active site accommodation. These conformational and dynamic changes are believed to be involved in the governing mechanism of the reduced catalytic activity. An ensemble of representative conformations of the WT and A477T mutant properly accommodating drug substrates were identified, those structures can be used for prediction of new CYP2C9 and CYP2C9.30 substrates and drug-drug interactions.
细胞色素 P450 2C9（CYP2C9）代谢约 15%的临床应用药物。等位基因变体 CYP2C9*30（A477T）与降压药物前体氯沙坦的降压效果降低以及其他药物代谢受到影响有关。在这里，我们研究了这种氨基酸取代导致功能后果的分子机制。对酶的活性物质（处于复合物 I 状态的血红素）进行分子动力学（MD）模拟，在无配体或底物结合状态下进行，并进行结合能分析，深入了解涉及人 CYP2C9.30 缺陷药物代谢的蛋白质结构和动力学的改变。我们的数据揭示了 CYP2C9.30 中关键底物识别位点 SRS1 和 SRS5 的刚性增加，以及 SRS6 的β转角 4 向 F 螺旋的移位。通道和结合底物动力学分析显示，底物通道进入和活性位点容纳发生改变。这些构象和动力学变化被认为参与了降低催化活性的调控机制。确定了一组能够适当容纳药物底物的 WT 和 A477T 突变体的代表性构象，这些结构可用于预测新的 CYP2C9 和 CYP2C9.30 底物以及药物相互作用。
