文蛤纤维素酶分离纯化及性质

采用缓冲液提取、（NH4）2SO4分级沉淀、DEAE Sepharose Fast Flow阴离子交换层析和Phenyl Sepharose 6 Fast Flow疏水层析，从文蛤（Meretrix meretrix L）中分离纯化出一种纤维素酶。结果显示：纯化后的纤维素酶比活力达到40.33 U/mg，纯化倍数为13.12；SDS-PAGE检测其亚基相对分子质量为59 700；文蛤纤维素酶的最适pH为5.2，最适反应温度为45 ℃，该酶在pH 4~6和4~50 ℃范围内有较好的稳定；在最适条件下，以羧甲基纤维素钠（CMC-Na）为底物测得其Km值为0.111 mmol/L。
Electrophoresis-purity cellulase from Meretrix meretrix L was obtained through buffer solution extraction，ammonium sulfate precipitation，DEAE-Sepharose ion exchange chromato- graphy and Phenyl Sepharose 6 Fast Flow hydrophobic chromatography. The specific activity of purified cellulase was 40.33 U/mg with purification fold of 13.12. SDS-PAGE results revealed the molecular weights of the enzyme was 59 700. Its optimum temperature and pH were 45 ℃and 5.2，respectively. The cellulase was relatively stable in the range of 4~50 ℃ and pH 4~6. Furthermore，its Km value was 0.111 mmol/L under the optimal conditions. The study laid a foundation for studying the composition and structure of endogenous cellulase from animals