Inactivation of Cu,Zn-superoxide dismutase due to glycation

人红细胞铜、锌超氧化物歧化酶包括糖化和非糖化两种形式。从维尔纳综合征患者的红细胞中获得的粗提取物和纯酶制剂中，与正常对照一样，在硼酸柱结合的部分中发现了糖基化形式。然而，糖基化形式以单位/ mg Cu， zn -超氧化物歧化酶蛋白表达的比活性明显较低，酶与正常形式相比不稳定。我们得出结论，在维尔纳综合征中，无活性糖基化形式的数量增加。我们还发现，Cu、Zn-SOD的糖基化与糖尿病视网膜病变或糖尿病性白内障等糖尿病并发症高度相关。

Human erythrocyte Cu,zn-superoxide dismutase comprises both glycated and non-glycated forms. In the cases of crude extracts as well as pure enzyme preparation obtained from erythrocytes of patients with Werner's syndrome, the glycated form was found in the bound fraction with a boronate column as in normal controls. However, the specific activity of the glycated form expressed as units per mg Cu,Zn-superoxide dismutase protein was significantly low and the enzyme was unstable as compared to the normal form. We conclude that in Werner's syndrome there is an increased amount of the inactive glycated form. We also found that glycation of Cu,Zn-SOD is highly associated with diabetic complication such as diabetic rdtinopathy or diabetic cataract.