Fusion and Prokaryotic Expression on the mpb83 and mpb63 Genes of Mycobacterium Bovis

Abstract

Based on the (Gly4Ser)3 linker, thempb83andmpb63gene were fused for raising the antigenicity of single antigen. The DNA fragments ofmpb83andmpb63were fused by splicing by overlapping extension (SOE) polymerase chain reaction (PCR) ,and the fusion gene mpb83-63 were cloned into pMD18-T vector, and then we got the recombinant plasmid pMD-83-63. pMD-83-63 and pET28a (+) were digested byBamH I andEcoR I double enzymes. The purified mpb83-63 fusion gene was subcloned into the expression vector pET28a (+),and the prokaryotic expression vector pET-83-63 was constructed. Plasmid containing pET-83-63 was transformed into competence Escherichia coli BL21(DE3).The bacterium was induced by isopropyl-β-D-thioga-lactopyranoside (IPTG) and analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE),approximately 38 kDa exogenous protein was observed on the SDS-PAGE. The protein was analyzed by using Western-blotting. The results indicated that the protein was of antigenic activity ofMycobacterium bovis. These results could serve as a basis for further studies on the usefulness of the fusion gene and its expression product in the development of DNA vaccine; living carrier vaccine; subunit vaccine and diagnostic reagents against bovine tuberculosis.