Radiolabeling of a wound-inducible pyridoxal phosphate-utilizing enzyme: evidence for its identification as ACC synthase.
1-Aminocyclopropane-1-carboxylic acid (ACC) synthase, a pyridoxal phosphate-utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate-limiting step in the biosynthesis of the plant hormone ethylene. We report the partial purification (400-fold) of ACC synthase from wounded pink tomato pericarp. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase-enriched fraction was achieved by reduction using tritiated sodium borohydride. Evidence that this radiolabeled protein is ACC synthase is presented.
D001345:Autoradiography; D001894:Borohydrides / Q000494:pharmacology; D002845:Chromatography / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D007525:Isoelectric Focusing; D008190:Lyases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D011732:Pyridoxal Phosphate / Q000378:metabolism*
D001894:Borohydrides; D011732:Pyridoxal Phosphate; C025364:sodium borohydride; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase