title: Identification of a salivary agglutinin-binding domain within cell surface adhesin P1 of Streptococcus mutans.
abstract: DNA encoding the alanine-rich region (A-region) of the cell surface adhesin, P1, from Streptococcus mutans was subcloned and expressed as a fusion protein with the maltose-binding protein (MBP) of Escherichia coli. The A-region fusion protein was shown to competitively inhibit both adherence of S. mutans to salivary agglutinin-coated hydroxyapatite and fluid-phase agglutinin-mediated aggregation of this organism. MBP alone or an MBP-paramyosin fusion protein was not inhibitory. Proteolytic cleavage of the fusion protein into its component moieties, MBP and A-region, resulted in breakdown of the A-region into three main fragments. Western immunoblot analysis of calcium-dependent agglutinin binding to this preparation revealed binding specificity for a 28-kDa fragment. Thus, the A-region of P1 is an important domain which interacts directly with salivary agglutinin, and this interaction interferes with both the aggregation and the adherence mechanisms in vitro.
authors.affiliation: Department of Oral Biology, University of Florida, Gainesville 32610.
authors.forename: P J
authors.initials: PJ
authors.lastname: Crowley
authors.forename: L J
authors.initials: LJ
authors.lastname: Brady
authors.forename: D A
authors.initials: DA
authors.lastname: Piacentini
authors.forename: A S
authors.initials: AS
authors.lastname: Bleiweis
mesh_terms: D018829:Adhesins, Bacterial; D000373:Agglutinins / Q000378:metabolism; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011485:Protein Binding; D011993:Recombinant Fusion Proteins; D012471:Salivary Proteins and Peptides / Q000378:metabolism*; D013295:Streptococcus mutans / Q000166:cytology / Q000472:pathogenicity*
chemical_list: D018829:Adhesins, Bacterial; D000373:Agglutinins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D012471:Salivary Proteins and Peptides