Feasibility of outer membrane protein C as a protein presenting platform targeting antigen to surface of outer membrane vesicle

Abstract

<p>Objective To investigate the feasibility of outer membrane protein C（OmpC）as a protein presenting platform targeting antigen to the surface of outer membrane vesicle（OMV）.Methods The recombinant expression plasmid containing ompC gene fragment and Staphylococcus aureus EsxA antigen gene（esxA gene）was constructed,transformed to competent E. coli BL21（DE3）,induced by IPTG,and analyzed for expressed product by 12% SDS-PAGE.The total protein of recombinant strain OMV was analyzed by 12% SDS-PAGE,and the localization of fusion protein on the surface of OMV was detected by Western blot and Flow NanoAnalyzer.Results The recombinant expression plasmid containing ompC gene and esxA gene was constructed correctly as proved by sequencing.12% SDS-PAGE showed that the fusion protein OmpC-EsxA had a relative molecular mass of about 57 000,which was consistent with the expected size,while the total protein of OMV showed multiple target protein bands,indicating that recombinant strain OMV was successfully extracted.The fusion protein OmpCEsxA on the surface of recombinant strain OMV specifically bound to mouse antibody against His-Tag,and OMVs labeled with fluorescent antibody were detected by Flow NanoAnalyzer.Conclusion OmpC may be used as a protein presenting platform to locate antigen to OMV surface,which was expected to be applied in the development of antigen presentation vaccine. <br></p>