Dafeldecker W P, Liang S J, Vallee B L
Biochemistry. 1985 Nov 5;24(23):6474-9. doi: 10.1021/bi00344a025.
Three classes of hepatic alcohol dehydrogenase (ADH), analogous to those of human liver, are present in Macaca nemestrina. Their functional, compositional, and structural features have been established with isozymes purified to homogeneity by affinity and conventional ion-exchange chromatography. One unusual molecular form of M. nemestrina ADH is electrophoretically indistinguishable as it comigrates with one of the cathodic class I isozymes on starch gel electrophoresis. While its substrate and inhibitor specificity, a high Km value for ethanol (50 mM at pH 10), and lack of binding to the pyrazole affinity resin are consistent with the kinetics of class II ADH, the physiochemical and compositional properties are virtually identical with all other known mammalian alcohol dehydrogenases. The unexpected presence of this previously unknown ADH variant in livers of M. nemestrina demonstrates the need for prudence in assignment of ADH isozymes. Classification based solely on electrophoretic position in starch gels and enzymatic properties of human ADH but without isolation and characterization of individual isozymes may prove insufficient and inadequate. The genetic or phenotypic nature of this isozyme remains to be demonstrated.
猕猴肝脏中存在三类与人类肝脏类似的乙醇脱氢酶（ADH）。通过亲和色谱法和传统离子交换色谱法将同工酶纯化至同质后，已确定了它们的功能、组成和结构特征。猕猴ADH的一种不寻常分子形式在淀粉凝胶电泳上与一种阴极I类同工酶迁移一致，在电泳上无法区分。虽然其底物和抑制剂特异性、对乙醇的高Km值（pH 10时为50 mM）以及与吡唑亲和树脂缺乏结合与II类ADH的动力学一致，但其物理化学和组成特性实际上与所有其他已知哺乳动物乙醇脱氢酶相同。在猕猴肝脏中意外发现这种先前未知的ADH变体表明，在ADH同工酶的分类中需要谨慎。仅基于淀粉凝胶中的电泳位置和人类ADH的酶学特性进行分类，而不分离和表征单个同工酶，可能被证明是不充分和不足的。这种同工酶的遗传或表型性质仍有待证明。
