丝孢菌Monodictys asperospera(Cooke & Massee)Ellis漆酶的分离纯化及其酶学性质

Purification and Characterization of Laccase from Monodictys asperospera (Cooke & Massee) Ellis

本研究首次发现Monodictys asperospera(Cooke&Massee)Ellis具有较好的产漆酶能力。粗酶液经硫酸铵盐析、DEAE-纤维素层析及丙烯葡聚糖凝胶S-300层析纯化,纯化倍数为8.1,回收率为5.7%。漆酶分子量约为77 kD,最适反应温度为55°C,最适反应pH 6.0,以丁香醛连氮为底物时Km为0.163 mmol/L,Vmax为0.194 mmol/(L.min),含糖量为18.14%,Cu2+对漆酶有明显抑制作用。

A new wood-degrading fungus Monodictys asperospera （Cooke ＆ Massee） Ellis with a high level of laccase production was chosen to study. This laccase was purified by ammonium sulfate precipitation, DEAE-cellulose and sephacryl S-300. Purification of about 8.1 fold was achieved with an overall yield of 5.7%. Its molecular weight was estimated to be about 77 kD. The optimum temperature and pH of the laccase activity were 55℃ and 6.0, respectively. Kinetic studies of the laccase showed that the Km and the Vmax for using syringaldazine as substrate was 0.163 mmol/L and 0.194 mmol/（L.min）, respectively. The carbohydrate content was 18.14%. In addition, it was found that laccase activity was significantly inhibited by Cu^2＋.