本文通过盐析、超滤和DEAE-Sephadex A-25离子交换层析得到毛柄金钱菌漆酶,并对其理化性质进行了研究,考察了毛柄金钱菌漆酶最适宜反应温度和pH值、热稳定性和pH值稳定性、反应动力学常数、耐溶剂性质以及金属离子对酶活的影响。实验结果表明:毛柄金钱菌漆酶在60℃时酶活达到最大,最适反应温度为60℃,低于70℃时具有较好的热稳定性;该酶最适pH为4.0,在pH4.0~4.5表现出较强的稳定性;毛柄金钱菌漆酶氧化ABTS的Km值为1.58×10^-4mmol/L;乙醇、丙酮和二氧六环作溶剂时对毛柄金钱菌漆酶活性具有较强的抑制作用;Zn^2+和Cu^2+对漆酶有激活作用,而Fe^2+、Fe^3+则有明显的抑制作用。
The laccase from Flammulina velutipes was purified by three steps including treatment of (NH4)2SO4 filtration and ion-exchange chromatography on DEAE-Sephadex A -25. It was found that the optimum temperature and pH of the laccase were 60℃ and pH 4.0 respectively, and it was stable at temperature below 70℃ and pH 4. 0 -4.5. The Km of the laccase measured was 1.58 × 10^-4 mmool/L, but it had not a good compatibility to organic solvent such as ethanol, acetone and dioxine. And its activity was slightly enhanced by Zn^2+, and Cu^2+ , but evidently inhibited by Fe^3+, and Fe^2+.