Cloning, expression and purification of the factor H binding protein and its interaction with factor H

BACKGROUND AND OBJECTIVE Neisseria meningitidis is a leading cause of meningitis and sepsis worldwide. The factor H binding protein (fHBP) is a key virulence factor of Neisseria meningitidis that is able to selectively bind to human factor H, the key regulator of the alternative complement pathway, which it has important implications for meningococcal pathogenesis and vaccine design. The aims of present research were cloning, expression, purification of fHbp and confirmation of the interaction between serum factor H (fH) and produced factor H binding protein. MATERIALS AND METHODS A 820 base pairs fhbp gene fragment was amplified by PCR and cloned into expression vector pET28a (+) in Bam HI and SalI restriction enzymes sites. Recombinant DNA was expressed in BL21 (DE3) cell. fHBP protein was purified by Ni-NTA agarose resin. Coupling of recombinant protein into CNBr activated Sepharose 4B resin was carried out for application in serum fH protein purification. (fH-fHBP) interaction was confirmed by SDS-PAGE and far-western blotting. RESULTS AND CONCLUSIONS SDS-PAGE results showed a 35 kDa protein band. 150 kDa fH protein was purified by designed Sepharose 4B resin. Far-western blotting confirmed (fH-fHBP) interaction and proper folding of factor H binding protein.