Clone and express ctb-stx2 b fusion gene in Enterohemrrhagic escherichia coli O157:H7 Shigeai toxin 2B subunit and V cholera toxin B subunit and the detection of their immunogenicity / 中华流行病学杂志

ABSTRACT

Objective To clone and express the fusion gene encoding Enterohemrrhagic escherichia coli O157H7(EHEC O157H7)Shigela toxin 2B subunit(Stx2B)and vibrio cholera toxin B subunit (CTB)as well as to detect the immunogenicity and GM1-binding ability of fusion protein.Methods To design a primer to amplify stx2b gene and ctb-stx2b fusion gene encoding Stx2B and CTB-Stx2B respectively and to clone the genes into express plasmid pET30a(+)C in order to construct pET30a-ctb-stx2b after T-A sequencing was varified,then to transform constructed plasmid into E.coliBL21(DE3)induced by IPTG and purified by a purify kit and to detect molecular weight and immunogenicity by SDSPAGE and Western-blot.Results The amplified ctb-stx2b fragments appeared to he 750 bp and gene sequence was identical to designed sequence.The prokaryotic expression system pET30a-ctb-stx2b/BL21 could express protein weight about Mr20×103and the expressed protein could react to CTB monoclone anti-body.The fusion protein CTB-Stx2B could bind GM1.Conclusion CTB-Stx2B had successfully been expressed in prokaryotic while the expressed protein had good immunogenicity and GM1-Binding ability.This study provided information on further EHEC O157H7 vaccine research.