title: Acetylcholine synthesizing enzymes in frog skeletal muscle.
abstract: Acetylcholine synthesis in homogenates of frog sartorius muscle was measured by a radiometric method with a low blank. Choline acetyltransferase activity was very low (Vmax, 2nmol . g-1 . h-1, Km for choline, approx. 50 microM). The enzyme was found only in the endplate area and disappeared after denervation; it was inactivated by 4-(1-naphthylvinyl)pyridine. At high substrate concentrations its activity was overshadowed by the acetylcholine-synthesizing activity of a different enzyme not saturated by 10 mM-choline. The non-specific enzyme was present at and away from the endplate area, and it was not affected by denervation.
mesh_terms: D000109:Acetylcholine / Q000096:biosynthesis*; D000818:Animals; D002794:Choline / Q000494:pharmacology; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D008297:Male; D009045:Motor Endplate / Q000201:enzymology; D009121:Muscle Denervation; D009132:Muscles / Q000201:enzymology*; D009286:Naphthylvinylpyridine / Q000494:pharmacology; D011896:Rana temporaria; D014018:Tissue Distribution
chemical_list: D009286:Naphthylvinylpyridine; D002795:Choline O-Acetyltransferase; D002794:Choline; D000109:Acetylcholine