title: Some properties of an endodextranase inhibitor from continuous cultures of Streptococcus sobrinus.
abstract: Cell-free filtrates of Streptococcus sobrinus, cultured at low growth rate in the chemostat, contain a dextranase inhibitor that can completely inhibit the activity of S. sobrinus endodextranase. The range of conditions under which inhibition occurs, and the situations in which enzyme activity can reappear, have been examined in continuous cultures of strain 6715-13WT and the dextranase-deficient mutant 6715-13-201. A purified preparation of the inhibitor was specific for S. sobrinus dextranase, having no action on dextranases from other oral streptococci. The percentage inhibition of S. sobrinus dextranase varied with the enzyme concentration, and the complete inhibition of low amounts of enzyme indicated a very tight bond between the inhibitor and the enzyme.
authors.affiliation: Institute of Dental Research, United Dental Hospital, Surry Hills, New South Wales, Australia.
authors.forename: B J
authors.initials: BJ
authors.lastname: Pearce
authors.forename: J E
authors.initials: JE
authors.lastname: Wellington
authors.forename: G J
authors.initials: GJ
authors.lastname: Walker
mesh_terms: D002845:Chromatography; D003470:Culture Media; D003910:Dextranase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D007700:Kinetics; D016986:Streptococcus sobrinus / Q000201:enzymology* / Q000254:growth & development
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D017886:Durapatite; D003910:Dextranase