ABSTRACT
Objective:To clone and express the Staphylococcus aureus Efb(extracellular fibrinogen-binding protein) protein in Escherichia coli, to purify the expression product and prepare its functional antibody and to detect the functions of Efb protein for further studies on S.aureus infection.Methods: Efb gene was amplified by PCR using S.aureus NCTC-8325 genome DNA as template and cloned into the recombinant expression vectors pET28a. E.coli BL21(DE3) with the plasmid was induced with IPTG for protein production. The protein was purified by Ni~(2+) affinity chromatography. The function of Efb protein was determined by complement activity assay and inhibition ELISA.The polyclonal antibodies were prepared by immunizing the animals. Results: The purified recombinant Efb was obtained, which could inhibit the CH50 and AH50 effectively. The functional poly-antibodies of Efb were prepared.Conclusion:Efb could inhibit the classical pathway and alternative pathway of complement activation, and the antibodies against to Efb could block the inhibition of the classical pathway of complement activation induced by Efb.