Expression and purification of the Lipl41, a surface-exposed lipoprotein antigen of pathogenic Leptospira spp

Pathogenic species of Leptospira lead to a zoonotic disease called leptospirosis, which is spread worldwide. A major topic of investigation is to detect the antigens that induce an immune response and to utilize them in diagnostic kits or vaccine development. The outer membrane proteins (OMPs) of Leptospira are potential candidates for this purpose. Lipl41 is an OMP that is conserved among pathogenic Leptospira. The aim of this study was to express and purify the Lipl41 recombinant protein in Iranian isolates. All collected Lipl41 protein sequences were compared and analyzed using bioinformatics tools from NCBI databases. Complete codon sequences of the Iranian pattern of Lipl41 recombinant protein were codon optimized and sub-cloned into a pET32a+ expression vector, and transformed into Escherichia coli BL21 (DE3). Optimal expression of recombinant Lipl41 (47kDa) was achieved post-induction with IPTG within the inclusion body. It was then purified by denaturation using serial concentrations of urea, and the recombinant protein was confirmed by western blot. In this study, sufficient amounts of Lipl41 were expressed and purified to be used for the development of a diagnostic kit and subunit vaccine. Key words: recombinant protein Lipl41; expression; purif _ cation; pathogenic Leptospira