Open AccessControl of phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli by energization of the cell membrane.
Author(s) -
Edith Reider,
Erwin F. Wagner,
Manfred Schweiger
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.11.5529
Subject(s) - pep group translocation , phosphoenolpyruvate carboxykinase , phosphotransferase , biochemistry , vesicle , membrane , cell membrane , escherichia coli , lactate dehydrogenase , chemistry , chemiosmosis , biology , enzyme , atp synthase , gene
The phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli is inhibited by the energized of the membrane. This was shown in intact cells as well as in membrane vesicles. Relaxation of the proton gradient by uncouplers stimulated the uptake of sugars via the phosphotransferase system in aerobically cultured cells. No such effect was seen in anaerobic cells, apparently because the cell membrane of these cells is poorly energized. Energization by respiration of D-lactate or ascorbate inhibited the phosphotransferase uptake system in membrane vesicles. This inhibition was reversed by the addition of cyanide. Oxamate, a specific inhibitor of lactate dehydrogenase, prevented the inhibitory effect of D-lactate. Membrane vesicles prepared from a cytochrome-less mutant were not energized by D-lactate oxidation and the phosphotransferase uptake system was not inhibited.