黑木耳酪氨酸酶的分离纯化与酶学性质研究
Purification and enzymatic properties of Auricularia auricula tyrosinase
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摘要: 本文分离纯化了黑木耳酪氨酸酶,并对酶学性质进行了研究。采用经硫酸铵分级沉淀、Sephadex G-100和DEAE-Sepharose-FF柱层析对粗酶液进行分离纯化,得到电泳纯的黑木耳酪氨酸酶,比活力提高了21.43倍,酶活回收率为27.41%。该酶的酶学性质研究表明:蛋白亚基分子量为12.62ku;最适pH7.0,在中性和碱性条件下稳定;最适温度为40℃,50℃以下温度条件较为稳定;以酪氨酸为底物,米氏常数K m为5.88mmol/L,V max为64.10μmol/min。实验结果表明黑木耳酪氨酸酶具有其它酪氨酸酶相似的酶学特性。Abstract: 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.
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