title: Membrane locus and pH sensitivity of paraben inhibition of alkali production by oral streptococci.
abstract: Parabens were found to be potent inhibitors of alkali production from arginine by oral streptococci such as Streptococcus rattus, Streptococcus sanguis and Streptococcus gordonii. For example, 2 mumol butylparaben per ml completely and irreversibly inhibited arginolysis by intact cells of S. rattus FA-1 and was lethal for the organism. In contrast, butylparaben was not a very effective inhibitor of ureolysis by intact cells of Streptococcus salivarius 57.I, although it did kill the cells. Butylparaben irreversibly inhibited the cytoplasmic enzymes arginine deiminase, carbamate kinase and urease in permeabilized cells or isolated form. However, inhibition of arginolysis by intact cells appeared to be due primarily to irreversible inhibition of transport systems for arginine uptake, because butylparaben added to intact cells did not reduce levels of arginine deiminase when the cells were subsequently permeabilized after washing. The insensitivity of ureolysis by intact cells to butylparaben can be related to the known high permeability of cell membranes to urea and the cytoplasmic location of urease. The potency of butylparaben as an inhibitior of arginolysis or glycolysis and as a lethal agent was found to be greater at acid pH that at neutral or alkaline pH.
authors.affiliation: Department of Microbiology & Immunology, University of Rochester School of Medicine & Dentistry, New York, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: G C
authors.initials: GC
authors.lastname: Rutherford
authors.forename: T M
authors.initials: TM
authors.lastname: Curran
authors.forename: J S
authors.initials: JS
authors.lastname: Reidmiller
authors.forename: R E
authors.initials: RE
authors.lastname: Marquis
mesh_terms: D001120:Arginine / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability; D003593:Cytoplasm / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005520:Food Preservatives / Q000494:pharmacology*; D006019:Glycolysis / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000037:antagonists & inhibitors; D010226:Parabens / Q000494:pharmacology*; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000037:antagonists & inhibitors; D013291:Streptococcus / Q000187:drug effects* / Q000378:metabolism*; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D005520:Food Preservatives; D010226:Parabens; C038091:butylparaben; D014508:Urea; D001120:Arginine; D017851:Phosphotransferases (Carboxyl Group Acceptor); C019288:carbamate kinase; D006867:Hydrolases; D014510:Urease; C019723:arginine deiminase