Abstract
Culture-supernates of Yersinia (Y.) pseudotuberculosis IB carrying virulence-plasmid (p+) and virulence-plasmid lacking mutant (p-) were analyzed iin Sephacryl S-300 to identify V antigen of Yersinia. A protein-complex of 150K dalton was detected in the peak I fraction from Sephacryl S-300 of Y. pseudotuberculosis IB (p+) but not in that of IB mutant (p-). Using SDS-PAGE, this protein complex was dissociated into the proteins of molecular weights of 31K, 38K, 56k and 66K dalton in the presence of 2-mercaptoethanol and SDS. Ion exchange chromatography with DE-52 also detected a protein of a molecular weight of 38K dalton in 0.1 M NaCl fraction of the culture supernate of Y. pseudotuberculosis IB (p+). 38K dalton protein was commonly detected in several strains of different Yersinia species as the 38±2K dalton. Anti-V antigen serum reacted specifically to the peak I fraction from Sephacryl S-300 and the 0.1 M fraction from DE-52, both of which contained 38K dalton protein. From these results, 38K dalton protein was identified as V antigen. Two out of six monoclonal antibodies prepared reacted to V antigen of 38K dalton protein in SDS-PAGE and Western blotting. V antigens from different Yersinia species were found to share common reactivity but to be partly different in the reactivity from each other.
