摘要
糖原合成酶激酶3( G S K3)在 30℃与 τ蛋白保温 4 h 可催化 17±04 m ol磷酸参入 1 m olτ蛋白 将磷酸化的 τ蛋白经胰蛋白酶消化, Fe Cl3 亲和柱分离及 C18反相高压液相层析纯化后,再用高压电泳,手工 Edm an 降解及自动氨基酸序列分析等检测技术,对其磷酸化位点进行鉴定 结果发现: G S K3 可使 τ蛋白 Thr181, Ser184, Ser262, Ser356 和 Ser400 发生磷酸化 其中 Ser262 和 Ser400 为 Alzheim er 病( A D)τ蛋白的异常磷酸化位点根据上述磷酸化作用仅轻度抑制τ蛋白生物学活性,推测: A D τ蛋白 Ser262 和 Ser400 的磷酸化可能不是决定其生物功能的关键性位点,单纯 G S K3 不能复制 A D 样 τ蛋白的病理改变
Glycogen synthetase kinase 3(GSK 3)incorporated 1 7±0 4 mol 32 P to 1 mol of τ protein in 4 h at 30℃ After digestion of phosphorylated τ protein with trypsin, 32 P labeled τ peptides were purified by a sequential FeCl 3 affinity column and a C 18 reverse phase high performance liquid chromatography The results from a combined technique of high voltage electrophoresis,manual Edman degradation and auto gas phase amino acid sequence analysis demonstrated that the phosphorylation sites of τ protein by GSK 3 were Thr 181,Ser 184,Ser 262,Ser 356 and Ser 400 Among them,Ser 262 and Ser 400 were abnormal phosphorylation sites of τ protein found in Alzheimer disease As the above phosphorylation only slightly inhibited the biological activity of τ protein,it was concluded that phosphorylation of τ protein at Ser 262 and Ser 400 might not be critical to its biofunction,and that GSK 3 alone was not enough to reproduce Alzheimer pathology of τ protein
出处
《中国生物化学与分子生物学报》
CAS
CSCD
1999年第4期589-592,共4页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金