CAJ | 학술논문

利用硫酸铵盐析、Superdex 200凝胶柱层析等步骤，从黑曲霉发酵液中纯化得到两种β–葡萄糖苷酶蛋白，其相对分子质量分别为1.15×105和7.0×104左右，比活力分别为62.1,U/mg(相对分子质量约为1.15×105)和53.0,U/mg(相对分子质量约为7.0×104)，纯化倍数分别为1.54和1.31，回收率分别为19.6%,和19.1%，β–葡萄糖苷酶最适水解pH为4.6，最适反应温度为50～55,℃．在pH 4.2～4.8、温度40～60,℃下均能保持稳定．Mn2+、Mg2+和K+对β–葡萄糖苷酶有不同程度的激活作用，而Ca2+、Fe3+、Zn2+、Cu2+和Fe2+会抑制β–葡萄糖苷酶的酶活，Na+和Ba2+对β–葡萄糖苷酶活力影响不明显．以pNPG为底物时，该酶的Km和vmax分别为2.33,mmol/L与3.14,mmol/(L·min)．
이용류산안염석、Superdex 200응효주층석등보취，종흑곡매발효액중순화득도량충β–포도당감매단백，기상대분자질량분별위1.15×105화7.0×104좌우，비활력분별위62.1,U/mg(상대분자질량약위1.15×105)화53.0,U/mg(상대분자질량약위7.0×104)，순화배수분별위1.54화1.31，회수솔분별위19.6%,화19.1%，β–포도당감매최괄수해pH위4.6，최괄반응온도위50～55,℃．재pH 4.2～4.8、온도40～60,℃하균능보지은정．Mn2+、Mg2+화K+대β–포도당감매유불동정도적격활작용，이Ca2+、Fe3+、Zn2+、Cu2+화Fe2+회억제β–포도당감매적매활，Na+화Ba2+대β–포도당감매활력영향불명현．이pNPG위저물시，해매적Km화vmax분별위2.33,mmol/L여3.14,mmol/(L·min)．
Two kinds of beta-glucosidase protein were separated and purified from Aspergillus niger through ammonium sulfate precipitation and Superdex 200,gel filtration chromatography. The enzyme molecular weights were about 1.15×105 and 7.0×104,which were identified by SDS-PAGE. The specific activifies were 62.1 U/mg and 53.0 U/mg. And then they were purified to 1.54-fold and 1.31-fold with a recovery of 19.6%, and 19.1%,. The optimum reaction pH and temperature for beta-glucosidase were 4.6,and 50-55,℃. The enzyme is stable in the pH value range of 4.2-4.8 and at the temperature be-tween 40,℃ to 60,℃. Mn2+,Mg2+ and K+ have different degree of activation to the beta-glucosidase,while Ca2+,Fe3+, Zn2+,Cu2+and Fe2+can inhibit the activity of the beta-glucosidase. Na+and Ba2+have no obvious effect on the activity. The Km and vmax values of the enzyme are 2.33 mmol/L and 3.14 mmol/(L·min) respectively.