ABSTRACT
Objective To isolate and identify the putative Japanese encephalitis virus (JEV) re-ceptors from C6/36 and Vero cells. Methods Molecules binding with JEV were isolated from C6/36 and Vero cells by co-immunoprecipitation (Co-IP) approach, identified by mass spectrometry, and detected by Western blot. The location of putative JEV receptor on cells membrane and the binding with JEV were ob-served by laser scanning confocal microscopy (LCM). Results Several molecules binding with JEV were isolated from C6/36 and Vero cells by Co-IP, and only one molecule was identified as heat shock cognate 70 (HSC70) by mass spectrometry. Antibody against HSC'70 was able to detect a 74 ×103 protein isolated by Co-IP from C6/36 and Vero cells membrane in Western blot assays. It was observed by LSCM that when JEV attached on the surface of C6/36 cells, JEV and HSCT0 protein were co-localization. Conclusion 74 x 103 molecular identified as HSC70 protein from C6/36 cells may be JEV receptor.
ABSTRACT
Aim To study the mimicry peptide of JEV E protein by screening a phage 15-mer peptide library with anti-JEV E protein mAb 2H4. Methods After three rounds biopanning, the enriched positive phage clones were identified by ELISA. 10 positive phage clones were sequenced and compared homologously with JEV E protein. Results The short peptide displayed on screened positive phage could bind specifically to mAb 2H4, and the binding could be inhibited by natural JEV Ag. Amino acid sequences of the 10 positive phage clones were consensus, that is, RQDPQWPYANSTIAR. By homology analysis, two higher homologous sequences STXAR and WXXAXST were found in different regions of JEV E protein. The peptide displayed on positive phage could react specifically with the mouse antiserum against natural JEV Ag . Conclusion This peptide displayed on positive phage may mimic partial antigenicity of JEV E protein.
ABSTRACT
Objective To express Japanese encephalitis virus (JEV) E protein in Escherichia coli. Methods The gene coding for JEV E protein was amplified by using RT-PCR, and cloned into plasmid pET-28a. The constructed plasmid was transformed into E.coli BL21 (DE3). Expression of E protein by the transformants was induced by IPTG and analyzed by SDS-PAGE and Western blot. Results Five nucleotide changes leading to amino substitutions were identify in the E protein gene of our laboratory strain of JEV when compared to a published gene sequence of JEV E protein. The yield of expressed JEV E protein with relative molecular mass approximately 52?10 3 was 35% of total bacterial proteins. Conclusions JEV E protein was expressed successfully in E.coli, which should be useful for the production of diagnostic reagents and the analysis of gene structure/function of the E protein.
ABSTRACT
Objective To design and testify a novel strategy for acquiring mimetic epitope mapping by screening for a phage random peptide library using polyclonal anti keratin autoantibodies (AK auto Ab). Methods AK auto Ab were isolated and purified from pooled human sera by keratin affinity column in which keratin had been linked with CNBr Sepharose 4B,then biotinylated by the biotin ester. A 15 mer phage random peptide library was biopanned for 3 cycles and positive clones were identified by ELISA,competition assay and DNA sequencing. ResultsBy sequence comparison 23 positive clones were selected randomly and three epitopes were confirmed. Among the three epitopes SLSPMPTTNRR was the dominant epitope. The phages carrying positive clones reacted with AK auto Ab specifically and keratin could prevent interaction between AK auto Ab and positive phages. Conclusion The designed strategy is successfully applied in acquiring epitopes of polyclonal autoantibodies to keratin, which could provide a new approach for the discovery of epitope mapping which binds to natural autoantibodies.