Purification and characterization of a Na+/K+ dependent alginate lyase from turban shell gut Vibrio sp. YKW-34
Purification and characterization of a Na+/K+ dependent alginate lyase from turban shell gut Vibrio sp. YKW-34
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DOI：
10.1016/j.enzmictec.2007.07.003
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发表时间：
2007-11-01
影响因子：
3.4
通讯作者：
Kim, Sang Moo
中科院分区：
文献类型：
--
作者：
Fu, Xiao Ting;Lin, Hong;Kim, Sang Moo
从新分离自海螺肠道的弧菌属YKW - 34中纯化出一种具有高比酶活的褐藻胶裂解酶。通过离子交换、疏水作用和凝胶过滤层析依次对该褐藻胶裂解酶进行纯化，达到均一性，回收率为7%，纯化倍数为25。这种褐藻胶裂解酶由单条多肽链组成，分子量为60 kDa，等电点为5.5 - 5.7。该褐藻胶裂解酶活性的最适pH和温度分别为pH 7.0和40℃。该酶在pH 7.0 - 10.0以及温度低于50℃时稳定。该褐藻胶裂解酶对聚古洛糖醛酸和聚甘露糖醛酸单元均具有底物特异性。对于褐藻胶（混合型）的k(cat)/K - m值为1.7×10⁶ s⁻¹ m⁻¹。该酶活性通过透析完全丧失，加入Na⁺或K⁺可恢复。在0.1 M的Na⁺或K⁺中表现出最佳活性。这种酶对变性试剂（SDS和尿素）、还原剂（β - 巯基乙醇和DTT）以及螯合剂（EGTA和EDTA）具有抗性。（C）2007爱思唯尔公司。保留所有权利。
An alginate lyase with high specific enzyme activity was purified from Vibrio sp. YKW-34, which was newly isolated from turban shell gut. The alginate lyase was purified by in order of ion exchange, hydrophobic and gel filtration chromatographies to homogeneity with a recovery of 7% and a fold of 25. This alginate lyase was composed of a single polypeptide chain with molecular mass of 60 kDa and isoelectric point of 5.5-5.7. The optimal pH and temperature for alginate lyase activity were pH 7.0 and 40 degrees C, respectively. The alginate lyase was stable over pH 7.0-10.0 and at temperature below 50 degrees C. The alginate lyase had substrate specificity for both poly-guluronate and poly-mannuronate units. The k(cat)/K-m value for alginate (heterotype) was 1.7 x 10(6)s(-1) m(-1). The enzyme activity was completely lost, by dialysis and restored by addition of Na+ or K+. The optimal activity exhibited in 0.1 M of Na+ or K+. This enzyme was resistant to denaturing reagents (SDS and urea), reducing reagents (beta-mercaptoethanol and DTT) and chelating reagents (EGTA and EDTA). (C) 2007 Elsevier Inc. All rights reserved.