Study of stereospecificity in mushroom tyrosinase

Study of stereospecificity in mushroom tyrosinase.

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase. Several enantiomorphs of monophenols and o-diphenols were assayed: L-tyrosine, D,L-tyrosine, D-tyrosine; L-alpha-methyltyrosine, D,L-alpha-methyltyrosine; L-dopa, D,L-dopa, D-dopa; L-alpha-methyldopa, D,L-alpha-methyldopa; L-isoprenaline, D,L-isoprenaline and ...

Purification of Tyrosinase from Edible Mushroom

The inhibition effects of melon on mushroom tyrosinase activity

The  inhibition effects seed and peel of melon on diphenolase activity of mashroom tyrosinase were investigated. The IC50 values and Ki values of seed and peel of melon were evaluated. increased the Km value and decreased the Vm value so it show mixed type inhibition on mushroom tyrosinase when L-DOPA was used as a substrate.

Flavonoids as mushroom tyrosinase inhibitors: a fluorescence quenching study.

Flavonoids, a group of naturally occurring antioxidants and metal chelators, can be used as tyrosinase inhibitors due to their formation of copper-flavonoid complexes. Thus, to investigate the underlying inhibition mechanism, a large group of flavonoids from several major flavones and flavonols were tested using fluorescence quenching spectroscopy. In addition, large differences in the tyrosina...

Physicochemical and kinetic properties of mushroom tyrosinase.

Tyrosinase (o-diphenol: O2 oxidoreductase, EC 1.10.3.1) has been purified from a commercial lyophilized powder prepared from edible mushrooms. Specific activities toward DL-dihydroxyphenylalanine and catechol, homogeneity, molecular weight, absorption spectrum, amino acid composition, and copper content of the preparation are comparable to other purified samples of tyrosinase prepared from fres...