Extraction, Purification, and Biochemical Characterization of Tyrosinase from Agaricus bisporus: An Important Enzyme...

Tyrosinase, a copper-containing enzyme with broad biological and industrial applications, occurs widely in nature but remains underexplored in edible mushrooms such as Agaricus bisporus. This study reports the extraction, purification, and biochemical characterization of tyrosinase from A. bisporus fruiting bodies. The enzyme was purified via ammonium sulfate precipitation (60% saturation), dialysis, and Sephadex G-200 gel filtration chromatography, achieving 163 fold purification with a specific activity of 1.26 U/mg and 20% recovery. SDS-PAGE revealed a tetrameric structure with a subunit molecular mass of 128-130 kDa. Kinetic parameters were determined as Km = 0.42km = 0.42 mM for L-DOPA and Vmax = 12.5Vmax = 12.5 U/mL. The enzyme exhibited optimal activity at pH 6.5 and 50°C, with stability profiles comparable to commercial counterparts. These findings underscore the optimized purification method and the biotechnological potential of A. bisporus tyrosinase for applications in food processing, medicine, agriculture, and environmental remediation, while advancing knowledge of multicopper oxidases in fungi.