title: Lactoperoxidase inhibits glucosyltransferases from Streptococcus mutans in vitro.
abstract: This study examines the possible effect of the antimicrobial peroxidase system on the activity of streptococcal glucosyltransferases B, C and D (GtfB, GtfC and GtfD), either in solution (GtfB and GtfC) or when adsorbed to hydroxyapatite (GtfC and GtfD) at pH 6.5. The lactoperoxidase (LP) system (LP, H(2)O(2), SCN(-)) had no effect on the activity of dissolved GtfC, but the activity of dissolved GtfB was enhanced. The LP system, however, strongly inhibited the activities of both GtfC and GtfD in their adsorbed form. LP enzyme, without its substrates, inhibited all three Gtf enzymes: GtfB and GtfC in concentrations between 10 and 100 microg/ml in liquid phase and adsorbed GtfC and GtfD in concentrations between 25 and 50 microg/ml. This inhibition was in part abolished in liquid phase, but not in solid phase, if the substrates of LP were added. This study shows that the lactoperoxidase system can exert inhibitory activity against streptococcal Gtfs without generating oxidizing agents.
authors.affiliation: Department of Cariology, Institute of Dentistry, University of Turku, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Korpela
authors.forename: X
authors.initials: X
authors.lastname: Yu
authors.forename: V
authors.initials: V
authors.lastname: Loimaranta
authors.forename: M
authors.initials: M
authors.lastname: Lenander-Lumikari
authors.forename: A
authors.initials: A
authors.lastname: Vacca-Smith
authors.forename: D
authors.initials: D
authors.lastname: Wunder
authors.forename: W H
authors.initials: WH
authors.lastname: Bowen
authors.forename: J
authors.initials: J
authors.lastname: Tenovuo
mesh_terms: D000327:Adsorption; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000378:metabolism; D002417:Cattle; D017886:Durapatite; D004791:Enzyme Inhibitors / Q000378:metabolism; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors* / Q000187:drug effects; D007784:Lactoperoxidase / Q000378:metabolism*; D012996:Solutions; D013295:Streptococcus mutans / Q000201:enzymology*; D013861:Thiocyanates / Q000378:metabolism
chemical_list: D000891:Anti-Infective Agents, Local; D004791:Enzyme Inhibitors; D012996:Solutions; D013861:Thiocyanates; C014607:hypothiocyanite ion; D017886:Durapatite; D007784:Lactoperoxidase; C036655:1,3-alpha-D-glucan synthase; D005964:Glucosyltransferases; C110463:glucosyltransferase C; C113848:glucosyltransferase D