Kondo T, Murakami K, Ohtsuka Y, Tsuji M, Gasa S, Taniguchi N, Kawakami Y
Clin Chim Acta. 1987 Jul 15;166(2-3):227-36. doi: 10.1016/0009-8981(87)90425-6.
Glycosylated form of carbonic anhydrase isozyme I was found in human erythrocytes. The percent of glycosylated enzyme of the total erythrocyte carbonic anhydrase I of patients with diabetes mellitus was significantly higher than that from normal controls. Characterization of the glycosylated carbonic anhydrase I was studied using an enzyme purified from diabetic patients. The glycosylated enzyme showed a slightly acidic isoelectric point in comparison with that of a nonglycosylated enzyme. The specific activity of the glycosylated enzyme was approximately 40% of that of the normal enzyme, and the immunological activity decreased to 52% of that of the normal enzyme. Estimation of carbohydrates which may form a ketoamine linkage with the enzyme was studied using [3H]-labelled glycosylated enzyme synthesized by incubation of the enzyme with [3H]-D-glucose in vitro, and it was found that one mol of glucose binds to one mol of enzyme. Exposure of red cells to a higher concentration of glucose in diabetics brought about glycosylation of carbonic anhydrase, which is associated with its low activity enzymatically and immunologically.
在人类红细胞中发现了碳酸酐酶同工酶I的糖基化形式。糖尿病患者红细胞中总碳酸酐酶I的糖基化酶百分比显著高于正常对照组。使用从糖尿病患者中纯化的酶对糖基化碳酸酐酶I进行了表征研究。与非糖基化酶相比，糖基化酶显示出略酸性的等电点。糖基化酶的比活性约为正常酶的40%，免疫活性降至正常酶的52%。使用通过将酶与[3H]-D-葡萄糖在体外孵育合成的[3H]-标记糖基化酶研究了可能与该酶形成酮胺键的碳水化合物的估计，发现一摩尔葡萄糖与一摩尔酶结合。糖尿病患者红细胞暴露于较高浓度的葡萄糖会导致碳酸酐酶糖基化，这与其酶活性和免疫活性较低有关。
