Identification of epitopes recognized by monoclonal antibodies SM1 and SM2 which react with all pili of Neisseria gonorrhoeae but which differentiate between two structural classes of pili expressed by Neisseria meningitidis and the distribution of their encoding sequences in the genomes of Neisseria spp
Abstract
The pili expressed by all isolates of Neisseria gonorrhoeae react with two monoclonal antibodies, SM1 and SM2. In contrast, although many isolates of Neisseria meningitidis also express pili (class I) which react with antibodies SM1 and SM2, a proportion express pili (class II) which fail to react. In order to define the epitopes recognized by these antibodies, a series of overlapping peptides corresponding to the amino acid sequence of conserved regions of gonococcal pili have been synthesized. The minimum epitope recognized by antibody SM1 was found to comprise a linear peptide EYYLN, corresponding to residues 49-53 of mature pilin. In contrast, antibody SM2 reacted with a number of peptides from around the cysteine residue (Cys 1) at position 120, suggesting that an extended region may contribute to a conformational epitope recognized by this antibody in the native protein. The identification of the two epitopes defines structural differences between the classes of pili expressed by meningococci. In order to determine the distribution of pilin gene sequences in Neisseria we used as hybridization probes an oligonucleotide (PS1) with the sequence 5'-GAGTATTACCTGAATCA-3' which spans the coding region for the SM1 epitope, and a ...Continue Reading