Mapping of monoclonal antibodies specific to P64k: A common antigen of several isolates of Neisseria meningitidis

P64k is a minor outer membrane protein from Neisseria meningitidis. This pr otein has been produced at high levels in Escherichia coli. We generated a group of monoclonal antibodies (mAbs) against recombinant P64k, which recog nise four non-overlapping epitopes, as shown using competition assays with biotinylated mAbs. The P64k sequences involved in mAbs binding were mapped with synthetic overlapping peptides derived from the P64k protein, and loca ted in the previously determined three-dimensional structure of the protein . These antibodies were also characterised by whole-cell ELISA and bacteric idal tests against N. meningitidis. Only two of the recognised epitopes wer e exposed on the bacterial surface, and none of the mAbs showed bactericida l activity. The relationship between these results and the structural data on the epitopes bound by the mAbs is discussed.