The Preparation and Properties of   and   Pili from Variants of Neisseria gonorrhoeae P9

Abstract

The a and p type pili produced by variants of Neisseria gonorrhoeae P9 were isolated and characterized. The two types of pili showed clear differences in morphology, buoyant density (a, 1.292 g ml-l; p, 1.282 g ml-I) and isoelectric point (a, PI 5.2; p, PI 4.3). Amino acid analysis of a and / 3 pili showed that their overall composition was similar with the exception that p pili had a higher content of glutamate and alanine residues. A high degree of structural homology was seen in two-dimensional peptide maps of tryptic hydrolysates of a and /? pili.The molecular differences between a and p pili were reflected in their antigenic activity and in their ability to attach to human cells. The binding of a pili to buccal epithelial cells was pH dependent with a maximum binding of 49% at pH 6.5, whereas the attachment of p pili showed no pH optimum. The binding of pili to erythrocytes differed from binding to buccal epithelial cells in that attachment of both pili was identical with no pH optimum. Data from attachment of pili to human cells suggest that erythrocytes lack receptors for binding gonococcal pili.

Gonococcal pili. Primary structure and receptor binding domain.

“…These results are not consonant with Pearce and Buchanan's (3) finding that whole, iodinated pill bind buccal and endocervical cells equally well. This discrepancy might be explained by the observation of Lambert et al (29) that some gonococcal pill appear to bind different receptor compounds. Alternatively, binding studies conducted with undenatured pill may lack specificity because the filaments readily associate with hydrophobic surfaces including glass, plastic, latex beads (48), and synthetic lipid bilayers (G. Schoolnik, unpublished observation).…”

Pili of Neisseria meningitidis. Analysis of structure and investigation of structural and antigenic relationships to gonococcal pili.

“…If the identification of two pilins by SDS-PAGE and two morphologic types by electron microscopy are related, meningococci may elaborate pilus variants that are homopolymers composed ofpilins of different molecular mass. These variants might also exhibit different receptor-binding specificities analogous to the pili types produced by the P-9 strain of N. gonorrhoeae (40).…”

The identification and isolation of novel pilus types produced by variants of N. Gonorrhoeae P9 following selection in vivo

“…Previous studies utilising peptide mapping have shown that a and/3 pilins have regions of considerable structural homology and differ only in a 341 small region on the molecule [10]. Previous studies utilising peptide mapping have shown that a and/3 pilins have regions of considerable structural homology and differ only in a 341 small region on the molecule [10].…”