title: Glycan-binding specificities of Streptococcus mutans and Streptococcus sobrinus lectin-like adhesins.
abstract: Since the adhesion of bacteria to the tooth surface is a prerequisite for dental plaque and subsequent caries development, a promising caries preventive strategy could be to block the lectin-glycan-mediated adherence of cariogenic bacteria. The aim of the study was to evaluate potential differences in glycan-binding specificities of two Streptococcus mutans strains (DSM 20523 and DSM 6178) and Streptococcus sobrinus (DSM 20381). A competitive enzyme-linked lectin-binding assay was used to identify the binding specificities of isolated bacterial surface lectins. Blotting of the microbial proteins on neoglycoprotein-coated PVP membranes enabled a qualitative protein analysis of all specific bacterial lectins. Different glycan-binding sites could be identified for the S. mutans strains in comparison to S. sobrinus. An earlier reported glycan-binding specificity for terminal galactose residues could be confirmed for the S. mutans strains. For the S. sobrinus strain, more than one glycan-binding specificity could be found (oligomannose and terminal sialyl residues). Each of the tested strains showed more than one surface lectin responsible for the specific lectin-binding with varying molecular weight (S. mutans, 90/155 kDa and S. sobrinus, 35/45 kDa). The established experimental setup could be used as future standard procedure for the identification of bacterial lectin-derived binding specificities. The findings from this study might serve as basis for the design of an individual 'glycan cocktail' for the competitive inhibition of lectin-mediated adhesion of mutans streptococci to oral surfaces.
authors.affiliation: Department of Operative and Preventive Dentistry, Charité, Humboldt University, Berlin, Germany.
authors.forename: Viviane
authors.initials: V
authors.lastname: Schüler
authors.forename: Adrian
authors.initials: A
authors.lastname: Lussi
authors.forename: Andreas
authors.initials: A
authors.lastname: Kage
authors.forename: Rainer
authors.initials: R
authors.lastname: Seemann
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D001422:Bacterial Adhesion / Q000502:physiology*; D001665:Binding Sites; D001667:Binding, Competitive; D037102:Lectins / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*; D013295:Streptococcus mutans / Q000378:metabolism*; D016986:Streptococcus sobrinus / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D018829:Adhesins, Bacterial; D037102:Lectins; D011134:Polysaccharides