β_2糖蛋白I纯化及其稳定性分析

Purification of β_2-glycoprotein I and analysis of its stability

目的:从正常人混合血浆中纯化获得β2糖蛋白Ⅰ(β2GPI),并对提纯蛋白的纯度及稳定性进行分析。方法:采用HClO4沉淀、Heparin Sepharose CL-6B亲和层析柱等纯化β2GPI;利用SDS-PAGE、蛋白质印迹分析提纯蛋白的纯度;观察不同温度、NaCl浓度及防腐剂等条件下的β2GPI稳定性。结果:本法获得了高纯度目的蛋白β2GPI(>95%)。β2GPI在浓度低于0.8 mol/L的NaCl溶液中,置室温及4℃保存易降解变性,但在1.6 mol/L NaCl溶液中于室温及4℃保存60天均未见蛋白明显降解。结论:利用本法能够得到高纯度的β2GPI,在使用和保存β2GPI时要考虑到其降解的可能性,注意保存条件,必要时冻干保存。

Objective： To purify β2-glycoprotein I （β2GPI）from normal human plasma and analyze its purity and stability. Methods： β2GPI was purified by Heparin Sepharose CL-6B affinity chromatography following by HClO4 precipitation. The purity of the isolated β2 GPI was identified by SDS-PAGE, Western Blot analysis. And it＇s stability was observed under different temperature, concentration of salt and antiseptics. Results： β2GPI was harvested using above methods and it＇s purity was confirmed more than 95%. The protein maintained in the concentration of lower than 0. 8 mol/L NaCl might be degraded at room temperature even though at 4%. But it was obviously stable when it was maintained in 1.6 mol/L NaCl at room temperature or 4℃. Conclusion： Human β2GPI with high-purity from the plasma can be obtained by our methods. It is important to protect β2GPI from denaturazation in the process of conservation and regular use. It is the best way to dry the protein into powder for keeping β2 GPI long time.