Sato K, Inazu A, Yamaguchi S, Nakayama T, Deyashiki Y, Sawada H, Hara A
Laboratory of Biochemistry, Gifu Pharmaceutical University, Japan.
Arch Biochem Biophys. 1993 Dec;307(2):286-94. doi: 10.1006/abbi.1993.1591.
3-Deoxyglucosone (3DG) is a reactive intermediate in the glucose-mediated cross-linking of proteins. An enzyme catalyzing the reduction of 3DG is thought to prevent the damage to protein by the formation of 3DG. The NADPH-dependent enzyme activity was detected in the extracts of various monkey tissues, among which kidney exhibited the highest specific activity. One dimeric enzyme with subunit M(r) of 39,000 and two monomeric enzymes with M(r) of 38,000 and 34,000 were purified from monkey kidney. The dimeric enzyme exhibited high dihydrodiol dehydrogenase activity and was immunochemically identical to dimeric dihydrodiol dehydrogenase of monkey kidney. The two monomeric enzymes exhibited aldehyde reductase activity, but were clearly distinct from each other in substrate specificity, inhibitor sensitivity, and effect of sulfate ions. One enzyme was immunologically cross-reacted with human liver aldehyde reductase, whereas sequence data of digested peptides from the other enzyme revealed > 97% identity with human placental aldose reductase. Comparison of kinetic constants among the monkey kidney enzymes and aldoketo reductases from several mammalian tissues indicated that dimeric dihydrodiol dehydrogenase and aldose reductase exhibited higher catalytic efficiency for 3DG than did aldehyde reductase, carbonyl reductase, and monomeric dihydrodiol dehydrogenase.
3-脱氧葡萄糖酮（3DG）是葡萄糖介导的蛋白质交联反应中的一种反应中间体。一种催化3DG还原的酶被认为可以通过3DG的形成来防止蛋白质受损。在各种猴组织提取物中检测到了依赖NADPH的酶活性，其中肾脏的比活性最高。从猴肾中纯化出一种亚基分子量为39,000的二聚体酶以及两种分子量分别为38,000和34,000的单体酶。该二聚体酶表现出高的二氢二醇脱氢酶活性，并且在免疫化学上与猴肾的二聚体二氢二醇脱氢酶相同。这两种单体酶表现出醛还原酶活性，但在底物特异性、抑制剂敏感性和硫酸根离子的作用方面明显彼此不同。一种酶与人肝醛还原酶发生免疫交叉反应，而另一种酶的消化肽段序列数据显示与人胎盘醛糖还原酶的同一性大于97%。对猴肾酶与几种哺乳动物组织的醛酮还原酶之间的动力学常数进行比较表明，二聚体二氢二醇脱氢酶和醛糖还原酶对3DG的催化效率高于醛还原酶、羰基还原酶和单体二氢二醇脱氢酶。
