title: Chemical modifications of the Na+-H+ antiport in Escherichia coli membrane vesicles.
abstract: The effects of chemical modifications of the Na+-H+ antiport in Escherichia coli have been analyzed by studying the resulting variations of the energy-dependent, downhill Na+ efflux from membrane vesicles. The histidyl reagent diethylpyrocarbonate (EtO)2C2O3 prevents the activation of the Na+ efflux mechanism by delta microH+ or its components. Inactivation of the antiporter by (EtO)2C2O3 is completely reversed by hydroxylamine. The data suggest that histidine residues are involved in the molecular mechanism of the Na+-H+ antiport. In contrast, no conclusive evidence suggesting participation of carboxylic, tyrosine or sulfhydryl residues in the Na+-H+ exchange reaction has been obtained.
authors.forename: E
authors.initials: E
authors.lastname: Damiano
authors.forename: M
authors.initials: M
authors.lastname: Bassilana
authors.forename: G
authors.initials: G
authors.lastname: Leblanc
mesh_terms: D002264:Carboxylic Acids / Q000378:metabolism; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism*; D006639:Histidine / Q000378:metabolism; D008433:Mathematics; D008956:Models, Chemical; D017923:Sodium-Hydrogen Exchangers; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: D002264:Carboxylic Acids; D002352:Carrier Proteins; D017923:Sodium-Hydrogen Exchangers; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; D006639:Histidine; D004047:Diethyl Pyrocarbonate