绿色糖单孢菌木聚糖酶的分离纯化与酶学性质研究

木聚糖酶是一种重要的具有工业应用前景的木聚糖降解酶,在充分利用自然资源、保护生态环境等方面具有十分重要的意义.通过硫酸铵分级沉淀及Sephadex G-100凝胶柱层析方法从一株中度耐热耐碱放线菌—绿色糖单孢菌的胞外酶中纯化得到单一的木聚糖酶,相对分子质量为51 kD,酶纯度提高了13.01倍.纯酶最适反应温度为60℃,最适反应pH值为7.0;75℃以下该酶具有良好的热稳定性,在pH 7～10范围内具有较强的耐受力.金属离子Ca2+、Fe2+、Zn2+对该酶具有明显促进作用,Cu2+、Mn2+、Al3+和SDS具有抑制作用而K+,Na+,Mg2+没有明显的作用.该酶为大分子质量的糖基化蛋白,含糖量为21.96%.

Studies on Purification and Characteristics of Xylanase from Saccharomonospora viridis

Xylanase is a promising xylan-degrading enzyme in industry application.It has great significance in the full use of natural resources and protection of the ecological environment.Through ammonium sulfate precipitation and Sephadex G-100 gel-filtration chromatography,a homogeneous protein is separated and pu-rified from a thermostable and alkali tolerant actinomycete—Saccharomonospora viridis.The relative molec-ular mass of purified xylanase is estimated as 51 kD,and the purification multiple of it is enhanced by 13.01.The purified xylanase exhibited the highest activity at 60 ℃ and pH 7.0.At pH 7～10 and below 75 ℃,the enzyme showed high activity and good stability.It was activated by Ca2+,Fe2+ and Zn2+,while inhibited by Cu2+,Mn2+,Al3+ and SDS.In addition,K+,Na+,Mg2+ have no significant influence on the activity of xylanase.It was a kind of high molecule mass glycoprotein containing 21.69% carbohydrate.