title: Conformational analysis of the Campylobacter jejuni porin.
abstract: The major outer membrane protein (MOMP) of Campylobacter jejuni was purified to homogeneity by selective solubilization and fast protein liquid chromatography. The amino acid composition of the MOMP indicates the presence of cysteine residues. The amino-terminal sequence, determined over 31 residues, shows no significant homology with any other porin from gram-negative bacteria except in a discrete region. Immunocross-reactivity between Escherichia coli OmpC and the MOMP was analyzed, and a common antigenic site between these two porins was identified with an anti-peptide antibody. From circular dichroism and immunological investigations, the existence of a stable folded monomer, containing a high level of beta-sheet secondary structure, is evident. Conformational analyses show the presence of a native trimeric state generated by association of the three folded monomers; the stability of this trimer is reduced compared with that of E. coli porins. This study clearly reveals that the C. jejuni MOMP is related to the family of trimeric bacterial porins.
authors.affiliation: UPR 9027, I. F. R. C1, Centre National de la Recherche Scientifique, Marseille, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Bolla
authors.forename: E
authors.initials: E
authors.lastname: Loret
authors.forename: M
authors.initials: M
authors.lastname: Zalewski
authors.forename: J M
authors.initials: JM
authors.lastname: Pagés
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001426:Bacterial Proteins; D016123:Campylobacter jejuni / Q000737:chemistry* / Q000276:immunology; D002942:Circular Dichroism; D003429:Cross Reactions / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli; D008969:Molecular Sequence Data; D018272:Porins / Q000737:chemistry*; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D000939:Epitopes; D018272:Porins; C095080:major outer membrane protein, Campylobacter jejuni