title: Evidence for the existence of a monovalent cation-stimulated, magnesium-dependent adenosine triphosphatase activity in the isolated plasma membranes of amoebas of the slime mold dictyostelium discoideum.
abstract: Evidence for a magnesium-dependent ATPase activity that can be stimulated by Na+ and K+, or equally by Na+ or K+ alone, has been found in the plasma membranes isolated from amoebas of the slime mold Dictyostelium discoideum when the membranes are isolated from cultures grown up to the stationary phase. This ATPase activity is scarcely inhibitable by ouabain or phlorizin, but is very sensitive to low concentrations of azide or thimerosal. When the plasma membranes are isolated from amoebas growing in logarithmic phase, this monovalent cation-stimulated Mg2+-dependent activity is barely detectable.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001386:Azides / Q000494:pharmacology; D017301:Ca(2+) Mg(2+)-ATPase; D002462:Cell Membrane / Q000201:enzymology; D004023:Dictyostelium / Q000201:enzymology*; D007700:Kinetics; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013849:Thimerosal / Q000494:pharmacology
chemical_list: D001386:Azides; D013849:Thimerosal; D012964:Sodium; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D011188:Potassium