Ascorbate 2-sulfate inhibits dopamine beta-hydroxylase reaction, but not ascorbate oxidase reaction.
Bovine adrenal dopamine beta-hydroxylase [EC 1.14.17.1] was considerably inhibited by ascorbate 2-sulfate. The inhibition was competitive with regard to ascorbate. The Ki value was 3.44 mM. The possibility that ascorbate 2-sulfate may play a regulatory role in the biosynthesis of norepinephrine is suggested. Another copper-containing oxidase, squash ascorbate oxidase [EC 1.10.3.3], was not inhibited by the same compound at a concentration of 150 mM.
D000313:Adrenal Medulla / Q000201:enzymology; D000818:Animals; D001204:Ascorbate Oxidase / Q000378:metabolism*; D001205:Ascorbic Acid / Q000494:pharmacology*; D002417:Cattle; D004299:Dopamine beta-Hydroxylase / Q000037:antagonists & inhibitors*; D007700:Kinetics; D010088:Oxidoreductases / Q000378:metabolism*; D010101:Oxygen Consumption; D010944:Plants / Q000201:enzymology; D013464:Sulfuric Acids / Q000494:pharmacology
D013464:Sulfuric Acids; D010088:Oxidoreductases; D001204:Ascorbate Oxidase; D004299:Dopamine beta-Hydroxylase; D001205:Ascorbic Acid