黑曲霉β-葡萄糖苷酶的分离纯化及酶学性质研究

Isolation, purification and enzymatic properties of β-glucosidase from Aspergillus niger

利用硫酸铵盐析、季氨乙基-琼脂糖凝胶FF(Q-Sepharose FF)离子交换层析、苯基-琼脂糖凝胶6 FF(Phenyl-Sepharose 6 FF)疏水层析和丁基-琼脂糖凝胶HP(Butyl-Sepharose HP)疏水层析对黑曲霉来源β-葡萄糖苷酶进行分离纯化,采用十二烷基硫酸钠-聚丙酰胺凝胶电泳(SDS-PAGE)测定其分子质量,并对其酶学性质进行研究。结果表明,经分离纯化后得到分子质量约为116 k Da的β-葡萄糖苷酶,纯化倍数达到50.39倍,回收率为4.65%,比酶活为103.80 U/mg,该β-葡萄糖苷酶的最适反应温度为60℃,最适反应pH值为5.0,在温度30~50℃,pH 2.0~8.0之间具有较好的稳定性。

β-glucosidase was isolated from Aspergillus niger and purified by ammonium sulfate precipitation, quaternary aminoethyl-sepharose fast flow(Q-Sepharose FF) ion exchange chromatography, phenyl-sepharose 6 fast flow(Phenyl-Sepharose 6 FF) and butyl-sepharose high performance(Butyl Sepharose HP) hydrophobic chromatography. The molecular weight was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and the properties of the enzyme were studied. The results showed that the β-glucosidase with molecular mass 116 k Da was obtained after purification. The purification fold, recovery and specific enzyme activity were 50.39, 4.65% and 103.80 U/mg, respectively. The optimum reaction temperature and pH of the β-glucosidase were 60 ℃ and 5.0, respectively, and the enzyme had good stability at 30-50 ℃ and pH 2.0-8.0.