Expression of Brucella Iumazine synthase gene in E. coli system.

Abstract

Brucellosis is an important zoonosis of serious economic and public health consequences affecting livestock and human beings caused by Brucella spp. The available whole cell antigen and smooth lipopolysaccharide (sLPS) based diagnostics show false positive reactions due to cross reactivity. Therefore, in this study, Brucella lumazine synthase (BLS), an immunogenic protein of Brucella spp. coding 477 bp bls gene was amplified from DNA extracted from Brucella abortus S99 strain and the amplified product was cloned in pET directional TOPO expression vector and transformed in E. coli TOP 10F’ cells. After verifying sequence, bls recombinant clones were subsequently transformed in E. coli BL21 (DE3)/pLysS cells for expression. BLS protein expression was induced with 1mM IPTG and optimized, six hours induction yielded maximum expression of BLS protein. The expressed protein was purified by His-tag affinity purification method using Ni-NTA and characterized by SDS-PAGE and Western blot. Recombinant BLS protein expressed in E. coli has potential use as diagnostic antigen or immunogen for development of diagnostics and vaccine for brucellosis