Reduced catalytic activity of human CYP2C9 natural alleles for gliclazide: Molecular dynamics simulation and docking studies
Reduced catalytic activity of human CYP2C9 natural alleles for gliclazide: Molecular dynamics simulation and docking studies
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DOI：
10.1016/j.biochi.2011.02.008
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发表时间：
2011-06-01
期刊：
影响因子：
3.9
通讯作者：
Vasanthakumar, Geetha
中科院分区：
文献类型：
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作者：
Banu, Hussaina;Renuka, N.;Vasanthakumar, Geetha
在磺酰脲类药物中，格列齐特是糖尿病患者最常用的处方药之一，通过P450 CYP2C9广泛代谢。在24个-CYP 2C9等位基因中，* 2/* 2和 * 3/* 3基因型显示格列齐特清除率显着较低，分别降低25%和57%。然而，由这些天然等位基因诱导的药物代谢活性变化的原因尚不清楚。在本研究中，我们使用分子动力学模拟和自动对接研究，为CYP2C9 * 2、* 3和 * 2/* 3突变体的格列齐特结合复合物提供模型，从而深入了解CYP2C9格列齐特相互作用，并解释在这些变体中观察到的酶活性降低。我们的数据显示，突变体中底物进入位点的大小显著降低，这限制了格列齐特进入血红素和活性位点。从基底氧化位点到血红素的距离在 * 3和 * 2/* 3中> 5 A。因此，阻碍了血红素-Fe对活性氧分子的加成。* 3中相互作用氨基酸口袋中F100、F114和F476的缺失降低了对格列齐特的催化效率。在 * 1中，格列齐特通过与R108形成两个氢键而稳定，而在突变体中不存在。此外，在 * 3和 * 2/* 3中，关键的血红素稳定残基R97稳定性大大降低。因此，这些变体的催化活性降低可以从格列齐特对血红素的访问减少来解释，并且血红素和底物之间的相互作用由于它们在活性位点的不稳定性而受到影响。(C)2011年Elsevier Masson SAS。All rights reserved.
Amongst sulfonylureas, gliclazide is one of the mostly prescribed drugs to diabetic patients and is metabolized extensively by P450 CYP2C9. Among 24-CYP2C9 alleles, the *2/*2 and *3/*3 genotypes showed significantly lower gliclazide clearances with reductions of 25 and 57%, respectively. However, the reason for the change in drug-metabolizing activity induced by these natural alleles is unknown. In the present study, we used molecular dynamics simulation and autodocking studies to provide models for gliclazide-bound complexes of CYP2C9*2, *3 and *2/*3 mutants, which give insight into CYP2C9 gliclazide interactions and explain the reduced enzymatic activity seen in these variants. Our data shows that the size of the substrate-access entry site is significantly reduced in mutants, which limits the access of gliclazide to heme and the active site. The distance from the substrate oxidation site and heme is >5 A in *3 and *2/*3. Therefore, the addition of an active oxygen molecule by heme-Fe is hindered. The absence of F100, F114 and F476 in the interacting amino acid pocket in *3 reduces catalytic efficiency toward gliclazide. In *1, gliclazide is stabilized by the formation of two hydrogen bonds with R108 while it is absent in mutants. Further in *3 and *2/*3, the key heme-stabilizing residue, R97 stabilization is greatly reduced. Therefore, the decreased catalytic activity of these variants can be explained from the reduced access of the gliclazide to heme, and the interaction between heme and substrate is affected due to their instability in the active site. (C) 2011 Elsevier Masson SAS. All rights reserved.