亮菌漆酶的初步研究

Preliminary Study on Laccase from Armillariella tabescens

对亮菌(Armillariella tabescens)固体发酵产生的漆酶进行研究,其粗酶液经过硫酸铵盐析、DEAE-cellulose柱纯化,活力回收率为42.3%,得到电泳纯的亮菌漆酶,SDS-PAGE法证实其分子量约为55.6kD。实验表明,亮菌漆酶最适反应温度为50℃、最适反应pH值为4.0,催化ABTS的米氏常数为0.018mmol/L,在pH4.0～5.0的偏酸性环境中,酶活力较高,活性较稳定。酸根阴离子和金属阳离子对酶活力都有不同程度的影响,其中SO42-、Na+对亮菌漆酶的活力有促进作用,CO32-、Cu2+、Mg2+对酶的活力有抑制作用。

Laccase in Armillariella tabescens solid-state fermentation liquid was purified by ammonium sulfate salting-out and DEAE-cellulose column chromatography with an overall activity recovery of 42.3%. Electrophoretically pure laccase was obtained and its apparent molecular weight was approximately 55.6 kD, which was proved by SDS-PAGE analysis. The optimum reaction temperature and pH for this enzyme were 50^℃ and 4.0, respectively, and the Km value was 0.018 mmol/L with 2,2＇-azino-bis（3-ethylbenzthiazoline-6-sulphonic acid） （ABTS） as a substrate. This enzyme maintained high and stable activity at pH 4.0-5.0. Various acid radical ions and metal ions had different effects on laccase activity, which was revealed an enhancement effect from SO4^2- and Na~, and an inhibition effect from CO3^2-, Cu^2＋ and Mg^2＋.