乳酸菌β-葡萄糖苷酶的分离纯化及特性研究

Purification and Characterization of β-glucosidase from Lactic Acid Bacterium

本文采用硫酸铵分级沉淀、DEAE-52离子交换层析、SephadexG-100凝胶过滤方法分离纯化乳酸菌中β-葡萄糖苷酶。经SDS-PAGE测定其相对分子量约为60kD。该酶以对硝基苯酚-β-D-葡萄糖苷为底物时,最适pH值和最适温度分别为6.0和40℃。在45℃以下,pH值在4.5～7.0之间酶活力相对稳定。Hg2+和Ag+对该酶活力有明显的抑制作用。

The β-glucosidase was purified to homogeneity by fractional ammonium sulphate precipitation, ion-exchange chromatography on DEAE-52 and SephadexG-100 gel-filtration chromatography. By SDS-PAGE, the molecular weight of the enzyme was estimated to be 60kDa. The enzyme exhibited optimum activity at 40℃ and pH6.0. Its activity maintained relatively stable under the condition at 45℃, pH4.5-7.0, and strongly inhibited by Hg^2＋, Ag^＋.