Design, In silico analysis, expression and evaluation of hybrid and bivalent forms of scFvs against Neisseria meningitides factor H binding protein (fHbp)

Meningococcal disease is an acute disease caused by the bacterium Neisseria meningitidis. Humans are theonly natural hosts of this bacterium. It has several pathogenic factors, among which the factor H bindingprotein (fHbp) plays a vital role in the survival of the pathogen in the host. The single-chain variable fragmentantibody (scFv) have been shown to potentially be well used in therapeutic and diagnostic applicationsagainst this factor. With the aim of stronger effect, in the present study, two scFvs with anti-fHbp potencywere constructed in hybrid format and docked to fHbp antigen. An anti-fHbp bivalent format of the scFvswas also constructed. Both formats were obtained by expression into pET۲۸a vector and purified by affinitychromatography. For determination of affinity of the hybrid and bivalent formats, ELISA method was used.According to bioinformatics results, one of the hybrid formats with a suitable structure was selected. Theaffinity of selected hybrid format was ۷.۶ × ۱۰-۹ M and the affinity for bivalent format was ۳.۷۷ × ۱۰-۹ M.The higher affinity of hybrid format indicates that development of scFv hybrid formats seems to be a bettersolution than bivalent format.

Keywords:

In silico analysis , Hybrid scFv , bivalent scFv , Neisseria meningitides , factor H binding protein