Production and characterization of recombinant light chain and carboxyterminal heavy chain fragments of tetanus toxin

ABSTRACT

Light chain [LC] and heavy chain Carboxyterminal subdomain [Hoc] fragments are the most important parts of tetanus neurotoxin [TeNT] which play hey roles in toxicity and binding of TeNT, respectively. In the present study, these two fragments were cloned and expressed in a proharyotic system and their identity was confirmed using anti-TeNT specific polyclonal and monoclonal antibodies. LC and HCc gene segments were amplified from Clostridium tetani genomic DMA by PCR, cloned into pET28b[+] cloning vector and transformed in Escherichia coli [E colt] BL21[DE3] expression host. Recombinant proteins were then purified through His-tag using Nickel-based chromatography and characterized by SDS-PAGE, Western blotting and ELISA techniques. Recombinant light chain and HCc fragments were successfully cloned and expressed in [E coli] BL21 [DE3]. Optimization of the induction protocol resulted in production of high levels of Hcc [-35% of total bacterial protein] and to lesser extends of LC [-5%]. Reactivity of the His-tag purified proteins with specific polyclonal and monoclonal antibodies confirmed their renatured structure and identity. Our results indicate successful cloning and production of recom-binant LC and H[cc] fragments of TeNT. These two recombinant proteins are potentially useful tools for screening and monitoring of anti-TeNT antibody response and vaccine production