Purification and characterization of cell wall proteins of Listeria monocytogenes.

Two proteins were purified from Listeria monocytogenes cell wall using detergent extraction, Superose 6 gel chromatography. Mono Q cation-exchange chromatography and Superose 12 gel chromatography. Proteins were shown to form complexes of ca. 300 kDa and pI 4.7. These complexes could not be dissociated in 6 M urea, however, during SDS-PAGE 79 and 39 kDa monomers were formed. Immunoblot analysis showed that the proteins under investigation were common to all listerial strains tested, but were absent in strains of other bacteria. We propose that the proteins investigated here could serve as immunoserological markers for Listeria.