灵芝突变株G1502漆酶的分离纯化及酶学性质研究

Purification and Enzymology Characteristics of Laccase Derived from Ganoderma lucidum Karst Mutant G1502

对灵芝突变株G1502发酵液中漆酶的分离纯化方法及酶学性质进行了初步研究。通过聚丙烯酰胺凝胶电泳(PAGE)分析发现,G1502在发酵时只分泌一种漆酶。发酵液经透析浓缩、DEAE-纤维素柱层析,比活力提高24.28倍,酶活力回收率18.66%。以愈创木酚为底物时该酶的动力学常数Km=1.94×10-4mol/L,Vmax=2.28×10-6mol/L·min;愈创木酚浓度高时对酶活性有抑制作用。K+对酶有激活作用,Cu2+激活作用不大,Fe2+、Co2+、Ca2+、Na+、Ba2+对酶活力有抑制作用。

The laccase derived from Ganoderma lucidum Karst mutant G1502 was purified and characterized in enzymology. The result of polypropylene amine gelatin electrophoresis （PAGE） analysis indicated that this strain in the fermentation medium only produces single laccase. Its cultured liquid with laccase was condensed by dialyzing, and purified by DEAE-cellulose ion exchange chromatography. The enzymic purity increases 24.28 fold, and the recovery ratio of enzyme reaches 18.66%. The Km and Vmax for oxidizing guaiacol, the kinetic parameters of enzyme, are 1.94 × 10^-4 mol/L and 2.28 × 10^-6 mol/L.min, respectively. The activities are inhibited by Fe^2＋, Co^2＋, Ca^2＋, Na^2＋ and Ba^2＋ and induced by K^＋ and Cu^2＋, but Cu^2＋ is weak inducer.