Mechanisms of Active Transport in Isolated Membrane Vesicles III. THE COUPLING OF REDUCED PHENAZINE METHOSULFATE TO THE CONCENTRATIVE UPTAKE OF β-GALACTOSIDES AND AMINO ACIDS

摘要: Abstract An artificial electron donor system—ascorbate and phenazine methosulfate—markedly stimulates β-galactoside transport in isolated membrane vesicles from Escherichia coli ML 308-225. Maximal rates of are dependent on the presence both ascorbate methosulfate also oxygen. Moreover, methosulfate, reduced nicotinamide adenine dinucleotide initial rate lactose transport. The effect ascorbate-phenazine is inhibited by removal oxygen or potassium cyanide, 2-heptyl-4-hydroxyquinoline-N-oxide, p-chloromercuribenzoate, sodium amytal. Oxamic acid has no significant effect. Ascorbate-phenazine reduces respiratory chain below potential level cytochrome b1, but above approximately 80% membrane-bound flavoproteins. In membranes prepared coli, Salmonella typhimurium, Pseudomonas putida, Proteus mirabilis, Bacillus megaterium, subtilis catalyze concentrative uptake proline; Staphylococcus aureus lysine; Micrococcus dentrificans glutamine.