Inhibition of polyphenol oxidase obtained from various sources by 2,3-diaminopropionic acid

Abstract

This paper reports for the first time the inhibition of the catecholase activities of mushroom, artichoke (Cynara scolymus L) and Ocimum basilicum L polyphenol oxidase by 2,3-diaminopropionic acid. Polyphenol oxidases from artichoke and 0 basilicum L were purified by ammonium sulfate precipitation, dialysis and a Sepharose 4B-L-tyrosine-p-aminobenzoic acid-affinity column. In inhibition studies, 2,3-diaminopropionic acid showed uncompetitive inhibition for mushroom PPO using catechol and pyrogallol as substrates, competitive inhibition for 0 basilicum L PPO using catechol as a substrate, and uncompetitive inhibition for artichoke PPO using catechol as a substrate. Furthermore, sodium azide, which is an inhibitor of PPO, was used as an inhibitor for comparison with the inhibition potency of 2,3-diaminopropionic acid. The highest 2,3-diaminopropionic acid inhibition observed with 0 basilicum L (K-i = 0.89 mM), followed by artichoke (K-i = 1.42 mM) and mushroom (K-i = 2.47 mM), respectively. (c) 2005 Society of Chemical Industry.