Generation of Human Chiral Metabolites of Simvastatin and Lovastatin by Bacterial CYP102A1 Mutants
作者:Keon-Hee Kim、Ji-Yeon Kang、Dong-Hyun Kim、Sun-Ha Park、Seon Ha Park、Dooil Kim、Ki Deok Park、Young Ju Lee、Heung-Chae Jung、Jae-Gu Pan、Taeho Ahn、Chul-Ho Yun
DOI:10.1124/dmd.110.036392
日期:2011.1
Recently, the wild-type and mutant forms of cytochrome P450 BM3 (CYP102A1) from Bacillus megaterium were found to oxidize various xenobiotic substrates, including pharmaceuticals, of human P450 enzymes. Simvastatin and lovastatin, which are used to treat hyperlipidemia and hypercholesterolemia, are oxidized by human CYP3A4/5 to produce several metabolites, including 6′β-hydroxy (OH), 3″-OH, and exomethylene products. In this report, we show that the oxidation of simvastatin and lovastatin was catalyzed by wild-type CYP102A1 and a set of its mutants, which were generated by site-directed and random mutagenesis. One major hydroxylated product (6′β-OH) and one minor product (6′-exomethylene), but not other products, were produced by CYP102A1 mutants. Formation of the metabolites was confirmed by high-performance liquid chromatography, liquid chromatography-mass spectroscopy, and NMR. Chemical methods to synthesize the metabolites of simvastatin and lovastatin have not been reported. These results demonstrate that CYP102A1 mutants can be used to produce human metabolites, especially chiral metabolites, of simvastatin and lovastatin. Our computational findings suggest that a conformational change in the cavity of the mutant active sites is related to the activity change. The modeling results also suggest that the activity change results from the movement of several specific residues in the active sites of the mutants. Furthermore, our computational findings suggest a correlation between the stabilization of the binding site and the catalytic efficiency of CYP102A1 mutants toward simvastatin and lovastatin.
最近,来自巨噬细菌的细胞色素P450 BM3(CYP102A1)的野生型和突变型被发现能够氧化多种外源底物,包括人类P450酶中的药物。用于治疗高脂血症和高胆固醇血症的辛伐他汀和洛伐他汀,由人类CYP3A4/5氧化后产生几种代谢物,包括6′β-羟基(OH)、3″-OH和外亚甲基产物。在本报告中,我们展示了辛伐他汀和洛伐他汀的氧化反应是由野生型CYP102A1及其通过定点突变和随机突变法生成的一组突变体催化的。CYP102A1突变体产生了一种主要羟基化产物(6′β-OH)和一种次要产物(6′-外亚甲基),而没有产生其他产物。通过高效液相色谱、液相色谱-质谱联用法和核磁共振确认了这些代谢物的形成。尚未报道合成辛伐他汀和洛伐他汀代谢物的化学方法。这些结果表明,CYP102A1突变体可以用于产生辛伐他汀和洛伐他汀的人类代谢物,特别是手性代谢物。我们的计算结果表明,突变体活性位点的腔体中的构象变化与活性变化相关。建模结果还表明,活性变化源于突变体活性位点中若干特定残基的移动。此外,我们的计算结果还表明,结合位点的稳定性与CYP102A1突变体对辛伐他汀和洛伐他汀的催化效率之间存在相关性。