Variations in IC(50) values with purity of mushroom tyrosinase.
The effects of various inhibitors on crude, commercial and partially purified commercial mushroom tyrosinase were examined by comparing IC(50) values. Kojic acid, salicylhydroxamic acid, tropolone, methimazole, and ammonium tetrathiomolybdate had relatively similar IC(50) values for the crude, commercial and partially purified enzyme. 4-Hexylresorcinol seemed to have a somewhat higher IC(50) value using crude extracts, compared to commercial or purified tyrosinase. Some inhibitors (NaCl, esculetin, biphenol, phloridzin) showed variations in IC(50) values between the enzyme samples. In contrast, hydroquinone, lysozyme, Zn(2+), and anisaldehyde showed little or no inhibition in concentration ranges reported to be effective inhibitors. Organic solvents (DMSO and ethanol) had IC(50) values that were similar for some of the tyrosinase samples. Depending of the source of tyrosinase and choice of inhibitor, variations in IC(50) values were observed.
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
Elizabeth
E
Neeley
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
George
G
Fritch
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
Autumn
A
Fuller
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
Jordan
J
Wolfe
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
Jessica
J
Wright
Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809, USA.
William
W
Flurkey
D000363:Agaricales / Q000201:enzymology; D057075:Enzyme Assays; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D006873:Hydroquinones / Q000737:chemistry; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D014443:Tyrosine / Q000737:chemistry; D014468:Umbelliferones / Q000737:chemistry
D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D006873:Hydroquinones; D014468:Umbelliferones; D014443:Tyrosine; D014442:Monophenol Monooxygenase; C007628:esculetin; C031927:hydroquinone