Espina N, Lima V, Lieber C S, Garro A J
Department of Microbiology, City University of New York Medical School, NY 10031.
Carcinogenesis. 1988 May;9(5):761-6. doi: 10.1093/carcin/9.5.761.
Human and rat O6-methylguanine transferase (O6MeGT) are inhibited in vitro by ethanol at concentrations of 10 to 50 mM and by acetaldehyde, the first metabolite of ethanol, at concentrations as low as 0.01 microM. Several other enzymes, including glyceraldehyde-3-phosphate dehydrogenase and yeast alcohol dehydrogenase, which like O6MeGT have cysteines in their active sites, were not inhibited by acetaldehyde at the levels that inhibited O6MeGT. Disulfiram, an acetaldehyde dehydrogenase inhibitor, enhanced the inhibitory effect of ethanol in vivo. These results indicate that the inhibitory effect of ethanol on O6MeGT activity is mediated primarily via its metabolite, acetaldehyde.
人源和大鼠源的O6-甲基鸟嘌呤转移酶（O6MeGT）在体外会被浓度为10至50 mM的乙醇以及乙醇的首个代谢产物乙醛（浓度低至0.01 microM）所抑制。包括3-磷酸甘油醛脱氢酶和酵母乙醇脱氢酶在内的其他几种酶，它们与O6MeGT一样在活性位点含有半胱氨酸，但在抑制O6MeGT的乙醛水平下却未受到抑制。双硫仑是一种乙醛脱氢酶抑制剂，它在体内增强了乙醇的抑制作用。这些结果表明，乙醇对O6MeGT活性的抑制作用主要是通过其代谢产物乙醛介导的。
