鸭卵清溶菌酶的分离纯化及性质

Isolation, Purification and Characterization of Lysozyme from Duck Egg White

通过硫酸铵的分级沉淀、CM-Sepharose阳离子交换层析、Superdex-200凝胶过滤层析等步骤,从鸭卵清中获得电泳纯的溶菌酶,该酶的比活力达到33687.26U/mg,纯化倍数为109.44,回收率为28.00%。测得该酶分子质量约为14.82kD,对溶壁微球菌的最适反应温度为50℃,最适pH值为7,且在50℃以下及pH5～9有较好的稳定性,同时在最适条件下测得其Km值为0.0864mg/mL。Fe2+、Mg2+、Mn2+等金属离子对该酶有较强的抑制作用,而Zn2+、Cu2+、Co2+对该酶有一定的激活作用。

Lysozyme was purified from duck egg white by ammonium sulfate precipitation, CM-Sepharose chromatography and Superdex-200 gel filtration chromatography. The specific activity, yield and purification fold of lysozyme were 33687.26 U/mg, 28.00% and 109.44, respectively. The molecular weight of lysozyme was estimated as approximately 14.82 kD. The optimal pH and temperature against Micrococcus lysodlekticus were 7.0 and 50 ℃, respectively. The enzyme was stable at temperatures below 50 ℃ and pH 5.0--9.0. The apparent K＋ determined by Lineweaver-Burk method under the optimum conditions was 0.0864 mg/mL. The activity of lysozyme was inhibited by Mg2＋, Mn2＋, or Fe2＋, and enhanced by Zn2＋, Cu2＋ or Co2＋.