Effects of colicin A and staphylococcin 1580 on amino acid uptake into membrane vesicles of Escherichia coli and Staphylococcus aureus

Abstract

Staphylococcin 1580 increased the relative amount of diphosphatidylglycerol and decreased the amount of phosphatidylglycerol in cells of Staphlococcus aureus, while the amounts of lysylphosphatidylglycerol, phosphatidic acid and total phospholipid remained constant. Treatment of cells of Escherichia coli and S. aureus with colicin A and staphylococcin 1580, respectively, did not affect proton impermeability but subsequent addition of carbonylcyanide- m-chlorophenylhydrazone resulted in a rapid influx of protons into the cells. Bacteriocin-resistant and -tolerant mutants of E. coli and S. aureus were isolated. The bacteriocins caused leakage of amino acids preaccumulated into membrane vesicles of resistant mutants and had no significant effect on membrane vesicles of tolerant mutants. The uptake of amino acids into membrane vesicles was inhibited by both bacteriocins, irrespective of the electron donors applied. The bacteriocin inhibition was noncompetitive. The bacteriocins did not affect oxygen consumption and dehydrogenases in membrane vesicles. Both bacteriocins suppressed the decrease in the fluorescence of 1-anilino-8-naphthalene sulfonate caused by d-lactate or α-glycerol phosphate when added to membrane vesicles. It is concluded that the bacteriocins uncouple the transport function from the electron transport system.