两种质粒编码的Borrelia burgdorfei寡肽结合蛋白(OppA)的表达和纯化

Overexpression and purification of two oligopeptide binding proteins OppA4 and OppA5 encoded by plasmid genes of Borrelia burgdorfei

为了弄清Borrelia burgdorferi中OppA4和OppA5蛋白的生物学功能,oppAIV和oppAV基因分别被克隆并在大肠杆菌中表达.大肠杆菌BL21 CodonP lus(DE3)-R IL被用来克服由A+T丰富引起的密码偏差.十二烷基-β-D-麦芽糖苷和甘油分别用于提高脂蛋白的分离效果和维护蛋白的稳定性.经过金属离子亲和层析,OppA4和OppA5纯蛋白产量可达到1 mg/L细胞以上.

To understand how OppA proteins function during pathogenesis of Borrelia burgdorferi,oppAIV and oppAVgenes are respectively cloned into pET21, and expressed in E. coli B21 CodonPlus （DE3） -RIL. Due to the fact that both OppA proteins are lipoproteins,special conditions are employed to isolate and purify OppA4 and OppA5. Homogeneous OppA proteins have been achieved using metal-ion affinity chromatography in a scale of milligrams,which provide enough protein for further investigation on substrate specificity or biological function. High similarity （73 % ） in amino acid sequences exists between OppA4 and OppA5,however, two proteins in solvent display different behaviors.