中文摘要：

在淀粉样胱抑素突变体I66Q的毕赤酵母液体培养基中添加不同浓度NaH2PO4,采用SDS-PAGE及蛋白质免疫印迹法,考察不同浓度NaH2PO4下胱抑素I66Q突变体聚集情况。结果表明：NaH2PO4对鸡胱抑素I66Q可溶性寡聚体的产生有一定促进作用。在NaH2PO4的浓度为0.1~0.5mol.L-1时,I66Q突变体蛋白多处于可溶性的寡聚体状态,并且这种稳定的寡聚体状态可以阻止多聚体或淀粉样沉淀的形成。但是,当NaH2PO4浓度为0.2mol.L-1时,单体含量已降至对照组单体含量的21%,当NaH2PO4浓度为0.3mol.L-1时,单体完全转化成寡聚体。因此NaH2PO4虽能在一定程度上保持胱抑素不发生淀粉样沉积,但却会促使可溶性单体含量降低,从而影响其蛋白酶抑制剂活性。

英文摘要：

The soluble-insoluble states of human cystatin C（HCC） in body fluids are closely related to multiple cerebral vascular disease and Alzheimer＇s disease.The study of the influence of different concentrations of sodium dihydrogen phosphate（NaH2PO4） on HCC aggregation characteristics can provide necessary information and clues on the elucidation of HCC amyloidogenic properties as well as aggregation sites in body fluids.In this study,by adding with different concentrations of NaH2PO4 in yeast liquid medium and combining with SDS-PAGE and western blot techniques,the aggregation properties of chicken cystatin（cC） mutant I66Q were studied.The results showed that NaH2PO4 had certain effects on promoting the formation of chicken cystatin I66Q oligomers when the NaH2PO4 concentrations are between 0.1 to 0.5mol.L-1.Based on this observation,we conclude that NaH2PO4 could keep cC I66Q in the soluble oligomer state.However,monomer content of cC I66Q was greatly reduced to 21% of the control group monomer content when the NaH2PO4 concentration of the culture media was 0.2mol.L-1,when the NaH2PO4 concentration increased to 0.3mol.L-1,monomer completely converted to oligomers.Therefore,although NaH2PO4 could keep cystatin from forming amyloid deposition at certain level,but it reduced the concent of soluble monomers,hence greatly influence its inhibitory activity on cystein protease.