Open AccessChemical modifications of the Na + – H + antiport in Escherichia coli membrane vesicles
Author(s) -
DAMIANO Evelyne,
BASSILANA Martine,
LEBLANC Gérard
Publication year - 1985
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1985.tb08823.x
Subject(s) - antiporter , chemistry , efflux , escherichia coli , hydroxylamine , histidine , vesicle , biochemistry , membrane , reagent , biophysics , enzyme , biology , organic chemistry , gene
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) 2 C 2 O 3 prevents the activation of the Na + efflux mechanism by ΔH + or its components. Inactivation of the antiporter by (EtO) 2 C 2 O 3 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.