EXPRESSION AND SECRETION OF OUTER SURFACE PROTEIN (OSP-A) OF BORRELIA-BURGDORFERI FROM ESCHERICHIA-COLI

Outer surface protein A (OspA) is encoded by the ospA gene from Borrel ia burgdorferi. This protein induces immunity against infection in mic e. The cloning and expression of OspA in Escherichia coli have been pr eviously described, but the secretion of OspA into culture media in E. coli has not yet been reported. In this report we demonstrate that a chimeric OspA protein was secreted into culture media by E. coli when it also harbors the hemolysin secretion genes hlyBD. The OspA fusion p rotein was also overexpressed from a T7 promoter and purified by immob ilized metal ion chromatography. This was possible because the fusion protein contains six histidyl residues in its N-terminus.