Williams S K, Howarth N L, Devenny J J, Bitensky M W
Proc Natl Acad Sci U S A. 1982 Nov;79(21):6546-50. doi: 10.1073/pnas.79.21.6546.
The extent of in vitro nonenzymatic glycosylation of purified rat brain tubulin was dependent on time and glucose concentration. Tubulin glycosylation profoundly inhibited GTP-dependent tubulin polymerization. Electron microscopy and NaDodSO4/polyacrylamide gel electrophoresis showed that glycosylated tubulin forms high molecular weight amorphous aggregates that are not disrupted by detergents or reducing agents. The amount of covalently bound NaB3H4-reducible sugars in tubulin recovered from brain of streptozotocin-induced diabetic rats was dramatically increased as compared with tubulin recovered from normal rat brain. Moreover, tubulin recovered from diabetic rat brain exhibited less GTP-induced polymerization than tubulin from nondiabetic controls. The possible implications of these data for diabetic neuropathy are discussed.
纯化的大鼠脑微管蛋白的体外非酶糖基化程度取决于时间和葡萄糖浓度。微管蛋白糖基化显著抑制了GTP依赖的微管蛋白聚合。电子显微镜和十二烷基硫酸钠/聚丙烯酰胺凝胶电泳显示，糖基化微管蛋白形成高分子量无定形聚集体，去污剂或还原剂不能使其解体。与从正常大鼠脑回收的微管蛋白相比，从链脲佐菌素诱导的糖尿病大鼠脑回收的微管蛋白中与NaB3H4可还原糖共价结合的量显著增加。此外，从糖尿病大鼠脑回收的微管蛋白比非糖尿病对照组的微管蛋白表现出更少的GTP诱导聚合。讨论了这些数据对糖尿病神经病变的可能影响。
