title: Leucine transport coupled to proton movement in membrane vesicles from Chang liver cells.
abstract: Leucine transport into membrane vesicles obtained from Chang liver cells was stimulated by an inward H+ gradient. The stimulatory effect of the proton gradient on the rate of leucine uptake (1 min) was inhibited by the presence of carbonyl cyanide p-trifluoromethoxyphenylhydrazone. When the vesicles had been preloaded with a high concentration of KCl, addition of valinomycin stimulated leucine uptake by the vesicles, showing that the leucine transport is dependent on potential gradient. Leucine-coupled H+ accumulation inside the vesicles was confirmed by measuring leucine dependent quenching of the fluorescence of 9-aminoacridine added to medium. These results imply that electrochemical gradient of proton can serve as a driving force for leucine transport across the cell membrane and proton movement is coupled to leucine transport.
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D007930:Leucine