肝素对人类神经tau蛋白分子聚集及磷酸化的影响

在老年性痴呆患者的脑中,肝素与超磷酸化的tau蛋白共存7].采用NCLK(neuronalcdc2-likekinase)及PP2B(phosphoproteinphosphatase2B)在含肝素的体系中对人类神经tau蛋白进行磷酸化和脱磷酸化,结果表明,肝素具有促进tau蛋白被磷酸化的功能,并促进该蛋白磷酸化分子二聚体的形成和单体的减少,其一级动力学常数分别为2.88×10-3s-1和1.74×10-3s-1.PP2B可使磷酸化的tau蛋白脱磷酸化,并且脱磷酸化作用随肝素浓度的增加而增强,提示肝素可能具有调节tau蛋白磷酸化状态的作用

Effect of Heparin on Aggregation and Phosphorylation of Human Neuronal tau Protein

It has been reported that heparin coexists with the hyperphosphorylated tau in the brain of the patients of Alzheimer’s disease 7] . The effect of heparin on phosphorylation by NCLK and dephosphorylation by PP2B of tau protein has been studied. Heparin was observed to improve the phosphorylation of tau, to increase the formation of tau dimers and decrease tau monomers. The first order rate constants of dimer increasing and monomer decreasing were 2 88×10 -3 s -1 and 1 74×10 -3 s -1 respectively. PP2B catalyzed dephosphorylation of the phosphorylated tau by NCLK and heparin improved such dephosphorylation. It suggests that heparin may regulate the phosphorylation and dephosphorylation of tau.