热稳定性α-阿拉伯糖苷酶/木糖苷酶的纯化

α 阿拉伯糖苷酶 /木糖苷酶对来源于被子植物的木聚糖类半纤维素的生物降解和转化是必不可少的。文中首次报道了国内对该酶的研究。α 阿拉伯糖苷酶 /木糖苷酶的基因工程菌在发酵罐中以LB为基质进行生长 ,以乳糖为诱导剂 ,所产生的α 阿拉伯糖苷酶 /木糖苷酶在 70℃热处理 3 0min后、经DEAE Sephacel阴离子柱层析、金属Ni2 + 的亲和层析等提纯步骤 ,达到了电泳纯 ,提纯倍数为 49 3倍 ,收率为 2 0 4%。SDS PAGE法测定α 阿拉伯糖苷酶/木糖苷酶的分子质量为 85ku ,与理论推算值相吻合

Purification of Recombinant Thermostable Arabinofuranosidase-xylosidase

The recombinant thermostable arabinofuranosidase-xylosidase from T.ethanolicus was purified from culture broth of gene engneering strain E.coli JM109 (DE3)/palter-Ex1-xar through following steps: a) heat precipetation; b) ion exchange chromatography on DEAE-sephacel; and c) immobilized metal affinity chromatography. The purified enzyme showed a single band on SDS polyacrylamide gel electrophoresis with a purification of 49.3 fold, and a yield of 20.4%. The optimum activity of arabinofuranosidase was found at pH 6.0 and 80℃,the enzyme had 1 h half-life at 75℃, The optimum activity of xylosidase was found at pH 5.7 and 85℃,the enzyme had 1 h half-life at 84℃. SDS-PAGE analysis showed that the molecular weight of expressed recombinant products was 85.90. It was in good agreement with the molecular mass of enzyme of deduced from the DNA sequence, 85ku.