title: Alternative-substrate inhibition and the kinetic mechanism of the beta-galactoside/proton symport of Escherichia coli.
abstract: The effects of competing alternative substrates on the rate of uptake by galactoside/proton symport were investigated. These experiments produced a decrease in apparent maximum velocity with increased alternative-substrate concentration that cannot be accounted for by a simple ordered mechanism. This, together with non-linearities in the variation of the apparent kinetic constants with alternative-substrate concentration, can be accounted for by a random mechanism for galactoside and proton binding.
mesh_terms: D001667:Binding, Competitive; D001692:Biological Transport / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005697:Galactosides / Q000378:metabolism* / Q000494:pharmacology*; D006027:Glycosides / Q000378:metabolism* / Q000494:pharmacology*; D006868:Hydrolysis; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D007700:Kinetics; D009598:Nitrophenylgalactosides / Q000378:metabolism; D011522:Protons; D013862:Thiogalactosides / Q000494:pharmacology
chemical_list: D005697:Galactosides; D006027:Glycosides; D011522:Protons; D013862:Thiogalactosides; C007816:beta-galactoside; D009598:Nitrophenylgalactosides; D007544:Isopropyl Thiogalactoside; C031803:thiodigalactoside