Energization of glucose transport by Pseudomonas fluorescens.
We have measured the capacity of Pseudomonas fluorescens to transport the glucose analog 2-deoxy-d-glucose and the amino acids l-alanine and alpha-aminoisobutyric acid under conditions in which the cells could generate (i) both a membrane proton motive force and high-energy phosphate compounds, (ii) a proton motive force but not high-energy phosphate compounds, and (iii) neither a proton motive force nor high-energy phosphate compounds. This was done by depleting cells of adenosine triphosphate stores by treatment with sodium arsenate and then suspending them in a phosphate-free medium, where they could generate a proton motive force but not phosphate bond energy, or in a phosphate-containing medium, where they could generate both a proton motive force and phosphate bond energy. Inclusion of the proton-conducting ionophore carbonyl cyanide-m-chlorophenyl hydrazone under either condition precluded the generation of both a proton motive force and phosphate bond energy. The amino acids l-alanine and alpha-aminoisobutyric acid were transported independently of phosphate bond energy and required only a proton motive force. 2-Deoxy-d-glucose was transported only under conditions in which phosphate bond energy could be generated. These results are consistent with the findings of others that Pseudomonas aeruginosa produces an inducible shock-sensitive glucose-binding protein and conform to the generalization that binding protein-associated transport systems are energized by phosphate bond energy.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000409:Alanine / Q000378:metabolism; D000621:Aminoisobutyric Acids / Q000378:metabolism; D001149:Arsenates / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004734:Energy Metabolism; D011551:Pseudomonas fluorescens / Q000378:metabolism*
D000621:Aminoisobutyric Acids; D001149:Arsenates; D003837:Deoxy Sugars; D004024:Dicyclohexylcarbodiimide; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000255:Adenosine Triphosphate; D003847:Deoxyglucose; D000409:Alanine