CYP2A7是研究最不足的人类细胞色素P450酶之一,其对药物代谢或内源性生物合成途径的贡献尚不清楚。因为其唯一已知的酶活性是两个原荧光素探针底物的转化。此外,CYP2A7基因包含4个单核苷酸多态性(SNPs),这些多态性会导致错义突变,并且次要等位基因频率(MAFs)高于0.5.这意味着所产生的氨基酸变化发生在大多数人中。在之前的研究中,我们采用了参考标准序列(P450命名法中称为CYP2A7*1)。对于目前的研究,我们创建了另一个CYP2A7序列,其包含所有四个氨基酸变化(Cys311,Glu169,Gly479和Arg274),并将其标记为CYP2A7-WT.因此,这项研究的目的是鉴定CYP2A7的新底物和抑制剂,并比较CYP2A7-WT与CYP2A7*1的性质。我们发现了两种酶变体的几种新的原荧光素探针底物(我们还进行了计算机模拟研究,以了解CYP2A7-WT和CYP2A7*1在特定底物上的活性差异),我们发现,虽然它们对标准CYP2A6底物尼古丁没有作用,香豆素,或者7-乙氧基香豆素,两者都可以羟基化双氯芬酸(CYP2A6也可以)。此外,我们发现了酮康唑,1-苄基咪唑,来曲唑为CYP2A7抑制剂。
CYP2A7 is one of the most understudied human cytochrome P450 enzymes and its contributions to either drug metabolism or endogenous biosynthesis pathways are not understood, as its only known enzymatic activities are the conversions of two proluciferin probe substrates. In addition, the CYP2A7 gene contains four single-nucleotide polymorphisms (SNPs) that cause missense mutations and have minor allele frequencies (MAFs) above 0.5. This means that the resulting amino acid changes occur in the majority of humans. In a previous study, we employed the reference standard sequence (called CYP2A7*1 in P450 nomenclature). For the present study, we created another CYP2A7 sequence that contains all four amino acid changes (Cys311, Glu169, Gly479, and Arg274) and labeled it CYP2A7-WT. Thus, it was the aim of this study to identify new substrates and inhibitors of CYP2A7 and to compare the properties of CYP2A7-WT with CYP2A7*1. We found several new proluciferin probe substrates for both enzyme variants (we also performed in silico studies to understand the activity difference between CYP2A7-WT and CYP2A7*1 on specific substrates), and we show that while they do not act on the standard CYP2A6 substrates nicotine, coumarin, or 7-ethoxycoumarin, both can hydroxylate diclofenac (as can CYP2A6). Moreover, we found ketoconazole, 1-benzylimidazole, and letrozole to be CYP2A7 inhibitors.