SPA/SPG融合蛋白在大肠杆菌中的高效表达

葡萄球菌A蛋白（SPA）和链球菌G蛋白（SPG）的IgG结合区编码基因融合后，克隆到大肠杆菌表达载体PGEX，SPA／SPG融合蛋白（SPAG）得到高效表达。可溶性SPAG～GST产物可被谷胱甘肽亲和柱一次性纯化。用琼扩和ELISA试验测定了表达产物与不同种属动物血清反应的性能。SPAG—GST与所有SPA、SPG各自反应的动物IgG结合，对小鼠IgG的反应优于SPA或SPG。在所测试的23种动物血清中，融合蛋白与大部分哺乳动物Ig反应。

High Expression of SPA/SPG Fusion Protein in E.Coli

The encoding genes of IgG binding domains of staphyloccal protein A(SPA)nd streptococcal protein G (SPG)were cloned and expressed as fusion protein using pGEX vector of E. coli. SPA/SPG fusion protein (SPAG)was highly expressed and the soluble SPAG-GST product was purified through glutahione column affinity. The binding ability of the expressed products to different animal sera was determined by AGID and ELISA. SPAG-GST could bind all the animal IgGs which react respectively with SPA the SPG and was superior to SPA or SPG in binding to mice IgG. The fusion protein could react with the most mammal Ig in 23 animal sera tested.