【摘要】 纯化的黑曲霉Aspergillus niger WM20-11所产的酸性β-甘露聚糖酶经Sephadex G-100凝胶过滤层析和SDS-PAGE分别测得相对分子质量为39 000和40 000;IEF-PAGE测得酶的等电点为4.0;最适作用pH值和温度分别为3.5和70℃;糖质量分数19.6%;Mg2+、Ca2+、Li+、Na+、K+对酶有激活作用,Pb2+、Co2+、Fe3+、Mn2+、Hg2+对酶有抑制作用;酶对角豆胶的Km和Vmax分别为66.7 g/L和333μmol/(min.mg);酶蛋白的氨基酸组成中Asp和Glu含量最高;HPLC分析角豆胶酶水解液的主要产物是低聚糖。更多还原

【Abstract】 In this manuscript,the characterization of acidic β-mannanase from Asp.niger WM20-11 was investigated.Molecular weight of the enzyme was determined as 39 000 on Sephadex G-100 gel filtration and 40 000 on SDS-PAGE.The isoelectric point was estimated to be 4.0 by IEF-PAGE.The optimum temperature and pH were 70 ℃ and 3.5.It contained 19.6% carbohydrate.The activity of the enzyme was stimulated by Mg2+、Ca2+、Li+、Na+、K+,but inhibited by Pb2+、Co2+、Fe3+、Mn2+ and Hg2+.Km and Vmax were 66.7 g/L and 333 μmol·min-1·mg-1 with locust bean gum.The content of Asp and Glu was the highest.Enzyme hydrolysis products from locust bean gum were oligosaccharides by HPLC analysis.更多还原