A conserved domain on enterobacterial porin protein analysed by monoclonal antibody.
Broadly cross-reactive monoclonal antibodies (MAbs) against enterobacterial outer membrane (OM) porin (Po) protein were isolated after immunization of BALB/c mice with whole cells of E. coli 055:B5. MAbs (n = 6) of the IgG class but of four different isotypes were studied. Based on a competition ELISA, all of the MAbs were directed against one and the same Po protein domain (Po I). The MAbs cross-reacted with 72 of 74 strains from 10 different genera of the Enterobacteriaceae. One Morganella and one Salmonella strain showed no cross-reactivity. Also, nine strains of various Neisseria spp. cross-reacted while 21 strains of various other nonenteric Gram-negative bacteria showed no cross-reactivity. The Po I sites were inaccessible in intact homologous bacteria but partially accessible in the OM. Digestion of OM with lysozyme or lysostaphin affected the accessibility of the Po I sites in OMs of various enterobacteria. Lysostaphin strongly enhanced the immunoaccessibility, whereas lysozyme had lesser effects. The enzymes also affected the binding by Neisseria OMs of the anti-Po I MAb. The Po I site was immunogenic both in humans and rabbits. The data indicate that Po I is an important Po protein domain, and that the effects of peptidoglycan-degrading enzymes must be considered in studies of Po protein domains.
Henriksen
A Z
AZ
Department of Microbiology, Faculty of Medicine, University of Trondheim, Norway.
Maeland
J A
JA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis* / Q000276:immunology; D003429:Cross Reactions; D004755:Enterobacteriaceae / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008248:Lysostaphin / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D009113:Muramidase / Q000494:pharmacology; D018272:Porins
D000911:Antibodies, Monoclonal; D001425:Bacterial Outer Membrane Proteins; D018272:Porins; D009113:Muramidase; D008248:Lysostaphin