Niwa Toshiro, Hiroi Toyoko, Tsuzuki Daisuke, Yamamoto Shigeo, Narimatsu Shizuo, Fukuda Tsuyoshi, Azuma Junichi, Funae Yoshihiko
Department of Chemical Biology, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
Brain Res Mol Brain Res. 2004 Oct 22;129(1-2):117-23. doi: 10.1016/j.molbrainres.2004.06.030.
Metabolic activities toward endogenous substrates in the brain, progesterone and p-tyramine, by cytochrome P450 2D6.2 (CYP2D6.2), CYP2D6.10A, CYP2D6.10C, and P34S, G42R, R296C, and S486T mutants expressed in recombinant Saccharomyces cerevisiae were compared with those by CYP2D6.1 (wild-type) in order to clarify the effects of genetic polymorphism of CYP2D6 on the metabolism of neuroactive steroids and amines in the brain. For the 6beta-hydroxylation of progesterone, the V(max) values for CYP2D6.2, CYP2D6.10A, and the P34S and G42R mutants, were less than half of those for CYP2D6.1, and CYP2D6.10C had a higher K(m) and a lower V(max) than the wild-type. The V(max)/K(m) values for CYP2D6.10A, CYP2D6.10C, and the P34S and G42R mutants were 12-31% of that for CYP2D6. The 16alpha-hydroxylation and 21-hydroxylation of progesterone by CYP2D6.10A, CYP2D6.10C, and the P34S and G42R mutants were not detected, and the R296C mutant had a higher K(m) for the 16alpha-hydroxylation and a lower V(max) for the 21-hydroxylation than those for CYP2D6.1. For dopamine formation from p-tyramine, the K(m) values for CYP2D6.2 and the R296C mutant were higher than those for CYP2D6.1, CYP2D6.10A, and CYP2D6.10C had a higher K(m) and a lower V(max) than the wild-type. The V(max)/K(m) values for CYP2D6.2, CYP2D6.10A, CYP2D6.10C and the P34S, G42R and R296C mutants were less than 45% of those for the wild-type. These results suggest the possibility that the polymorphism of CYP2D6, including CYP2D62, CYP2D610 and CYP2D6*12, might affect an individual behavior and the central nervous system through endogenous compounds, such as neuroactive steroids and tyramine, in the brain.
为了阐明细胞色素P450 2D6（CYP2D6）基因多态性对大脑中神经活性甾体和胺类代谢的影响，比较了重组酿酒酵母中表达的细胞色素P450 2D6.2（CYP2D6.2）、CYP2D6.10A、CYP2D6.10C以及P34S、G42R、R296C和S486T突变体对大脑中内源性底物孕酮和对酪胺的代谢活性，以及CYP2D6.1（野生型）对这些底物的代谢活性。对于孕酮的6β-羟基化反应，CYP2D6.2、CYP2D6.10A以及P34S和G42R突变体的Vmax值不到CYP2D6.1的一半，并且CYP2D6.10C的Km值高于野生型，Vmax值低于野生型。CYP2D6.10A、CYP2D6.10C以及P34S和G42R突变体的Vmax/Km值为CYP2D6的12% - 31%。未检测到CYP2D6.10A、CYP2D6.10C以及P34S和G42R突变体对孕酮的16α-羟基化和21-羟基化反应，并且R296C突变体对16α-羟基化反应的Km值高于CYP2D6.1，对21-羟基化反应的Vmax值低于CYP2D6.1。对于由对酪胺生成多巴胺的反应，CYP2D6.2和R296C突变体的Km值高于CYP2D6.1，CYP2D6.10A和CYP2D6.10C的Km值高于野生型，Vmax值低于野生型。CYP2D6.2、CYP2D6.10A、CYP2D6.10C以及P34S、G42R和R296C突变体的Vmax/Km值不到野生型的45%。这些结果表明，包括CYP2D62、CYP2D610和CYP2D6*12在内的CYP2D6基因多态性可能通过大脑中的内源性化合物，如神经活性甾体和酪胺，影响个体行为和中枢神经系统。
