Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York (S.J.P., C.M.E., J.O.O., K.C.G., M.B.S.); Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California (Q.Z.); and Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe, Kyoto, Japan (K.M.).
Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York (S.J.P., C.M.E., J.O.O., K.C.G., M.B.S.); Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California (Q.Z.); and Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe, Kyoto, Japan (K.M.)
Mol Pharmacol. 2020 Nov;98(5):529-539. doi: 10.1124/molpharm.120.000042. Epub 2020 Sep 16.
The human CYP2C9 plays a crucial role in the metabolic clearance of a wide range of clinical therapeutics. The 2 allele is a prevalent genetic variation in CYP2C9 that is found in various populations. A marked reduction of catalytic activity toward many important drug substrates has been demonstrated by CYP2C92, which represents an amino acid variation at position 144 from arginine to cysteine. The crystal structure of CYP2C92 in complex with an antihypertensive drug losartan was solved using X-ray crystallography at 3.1-Å resolution. The Arg144Cys variation in the 2 complex disrupts the hydrogen-bonding interactions that were observed between the side chain of arginine and neighboring residues in the losartan complex of CYP2C9 and the wild-type (WT) ligand-free structure. The conformation of several secondary structural elements is affected, thereby altering the binding and orientation of drug and important amino acid side chains in the distal active site cavity. The new structure revealed distinct interactions of losartan in the compact active site of CYP2C92 and differed in occupancy at the other binding sites previously identified in the WT-losartan complex. Furthermore, the binding studies in solution using losartan illustrated lower activity of the CYP2C92 compared with the WT. Together, the findings yield valuable insights into the decreased hydroxylation activity of losartan in patients carrying CYP2C9*2 allele and provide a useful framework to investigate the effect of a single-nucleotide polymorphism that leads to altered metabolism of diverse drug substrates. SIGNIFICANCE STATEMENT: The 2 allele of the human drug-metabolizing enzyme CYP2C9 is found in different populations and results in significantly reduced activity toward various drug substrates. How the CYP2C92 variant induces altered drug metabolism is poorly understood given that the Arg144Cys variation is located far away from the active site. This work yield insight into the effect of distal variation using multitude of techniques that include X-ray crystallography, isothermal titration calorimetry, enzymatic characterization, and computational studies.
人类 CYP2C9 在广泛的临床治疗药物的代谢清除中起着至关重要的作用。2 等位基因是 CYP2C9 中的一种常见遗传变异，存在于各种人群中。CYP2C92 对许多重要药物底物的催化活性明显降低，这代表着位置 144 从精氨酸到半胱氨酸的氨基酸变异。使用 X 射线晶体学以 3.1-Å 的分辨率解决了与降压药洛沙坦复合物的 CYP2C92 的晶体结构。2 复合物中的 Arg144Cys 变异破坏了在 CYP2C9 与洛沙坦复合物和野生型（WT）无配体结构中观察到的精氨酸侧链与邻近残基之间的氢键相互作用。几个二级结构元件的构象受到影响，从而改变了药物和重要氨基酸侧链在远端活性位点腔中的结合和取向。新结构揭示了洛沙坦在 CYP2C92 紧密活性位点中的独特相互作用，并且与先前在 WT-洛沙坦复合物中鉴定的其他结合位点的占有率不同。此外，使用洛沙坦在溶液中的结合研究说明了 CYP2C92 与 WT 相比活性较低。总之，这些发现为携带 CYP2C92 等位基因的患者中洛沙坦羟化活性降低提供了有价值的见解，并为研究导致不同药物底物代谢改变的单核苷酸多态性的影响提供了有用的框架。意义陈述：人类药物代谢酶 CYP2C9 的2 等位基因存在于不同人群中，导致对各种药物底物的活性显著降低。鉴于 Arg144Cys 变异位于远离活性位点的位置，CYP2C9*2 变体如何诱导改变的药物代谢仍知之甚少。这项工作通过包括 X 射线晶体学、等温滴定量热法、酶学表征和计算研究在内的多种技术深入了解了远端变异的影响。
