中文摘要：

目的：制备高纯度人β2-微球蛋白（β2m）,为其结构和功能研究奠定基础。方法：选用两种不同的表达载体p ET15b和p ET21b,表达人β2m;联合使用亲和层析、离子交换层析、凝胶过滤层析、高压液相色谱等方法,纯化人β2m;采用SDS-PAGE和MALDI-TOF-MS质谱方法,鉴定人β2m。结果：使用改造过的N端组氨酸标签载体p ET15b,在原核表达菌株E.coli 2 BL21（DE3）中,实现了人β2m稳定高效的可溶性表达;联合多种分离纯化方法,获得了色谱纯的人β2m,纯度达99%以上,质谱鉴定正确。结论：实现了人β2m的可溶性表达和制备,为进一步研究MHCⅠ类分子的结构和在免疫系统中的重要作用奠定基础。

英文摘要：

Objective To prepare high purity human β2-microglobulin（ β2m） for the study of its structure and function.Methods Two different kinds of expression vectors,p ET15 b and p ET21 b were used to express the human β2m. Then the protein was purified by affinity chromatography,ion-exchange chromatography,gel-filtration chromatography,high performance liquid chromatography（ HPLC） and identified by SDS-PAGE and MALDI-TOF-MS. Results High purity and uniform stability protein products were efficiently expressed by p ET15 b vector in the prokaryotic expression bacterial strain Escherichia coli BL21（ DE3）. The chromatography purified protein（ over 99% purity） was obtained by jointing variety separation and purification methods,and validated by mass spectrometry. Conclusion The expression and preparation of a soluble human β2m were successfully eastablished,which may provide a good foundation for further study of the structure of MHC classⅠ molecule and its role in immune system.