title: Subcellular localization and ionic properties of acetyl-coenzyme A synthetase in the electric organ of Torpedo marmorata.
abstract: Acetyl-CoA synthetase activity was shown to be present in pure cholinergic synaptosomes from electric organ of Torpedo marmorata. After osmotic disruption of synaptosomes a substantial part of the activity was recovered in the soluble fraction. The effects of varying pH and increasing K+ concentrations on the synaptosomal enzyme activity were shown to differ from those observed with the mitochondrial enzyme. Whereas this latter enzyme showed optimal activity above pH 8.5, and a maximal activation in the presence of 120 mM-K+, the synaptosomal enzyme exhibited an optimal activity at pH 7.9 and a moderate K+ stimulatory effect with an optimal concentration of 30 mM.
mesh_terms: D000106:Acetate-CoA Ligase / Q000378:metabolism*; D000818:Animals; D003066:Coenzyme A Ligases / Q000378:metabolism*; D004557:Electric Organ / Q000187:drug effects / Q000201:enzymology*; D005399:Fishes / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology
chemical_list: D012964:Sodium; D003066:Coenzyme A Ligases; D000106:Acetate-CoA Ligase; D011188:Potassium