Purification and enzymatic properties of Auricularia auricula tyrosinase

Auricularia auricula (A.auricula) tyrosinase was purified and its enzymatic properties were investigated.By (NH 4) 2 SO 4 fractional precipitation, Sephadex G-100 and DEAE-Sepharose-FF column separation, electrophoretic pure A.auricula tyrosinase was obtained and the specific activity increased 21.43 fold, the enzyme recovery was 27.41%.The experimental results of enzymatic properties showed the molecular weight of protein subunit was 12.62ku.Optimal pH was 7.0 and tyrosinase was stable under neutral and alkaline conditions.Optimal temperature was 40℃ and tyrosinase exhibited a good heat stability when temperature below 50℃.When tyrosine was used as substrate, the K m was 5.88mmol /L and the V max was 64.10μmol /min.The experimental results indicated the enzymatic properties of A.auricula tyrosinase were very similar to those of other tyrosinase.