Functional characterization of an extreme thermophilic class II fructose-1,6-bisphosphate aldolase.
Functional characterization of an extreme thermophilic class II fructose-1,6-bisphosphate aldolase.
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极端嗜热 II 类果糖-1,6-二磷酸醛缩酶的功能表征。
DOI：
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
J. Sygusch
中科院分区：
文献类型：
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作者：
C. de Montigny;J. Sygusch
果糖-1，6-二磷酸醛缩酶活性已从极端嗜热真细菌Thermus aquaticus中分离纯化至均一。该均相酶为II类醛缩酶，其果糖-1，6-二磷酸的裂解活性被EDTA强烈抑制，而被Co ~（2+）金属离子激活。Taq醛缩酶是一种稳定的四聚体，估计分子量为165 kDa。该酶是热稳定的，在90 ℃加热2小时后不失活，但在97 ℃加热1小时后失去80%的活性。与其他II类醛缩酶相比，对应于最大醛缩酶活性的pH曲线被置换为更酸性的值。酶活化的洗涤剂和醇和色谱行为的疏水固定相上的可溶性酶的疏水表面区域的存在是一致的。T.在高果糖-1，6-二磷酸浓度下的水生物醛缩酶显示显著的负协同性。Taq醛缩酶的NH 2-末端序列进行了测定，并与其他II类醛缩酶的可用序列进行了比较。Taq醛缩酶和嗜热脂肪芽孢杆菌的耐热醛缩酶之间存在显著的序列相似性。
Fructose-1,6-bisphosphate aldolase activity has been isolated and purified to homogeneity from the extreme thermophile eubacteria Thermus aquaticus. The homogeneous enzyme is a class II aldolase as fructose-1,6-bisphosphate cleavage activity was strongly inhibited by EDTA, and activated by Co2+ metal ion. Taq aldolase is a stable tetramer with estimated molecular mass of 165 kDa. The enzyme is thermostable and is not inactived after heating at 90 degrees C for 2 h but looses 80% of activity after 1 h at 97 degrees C. The pH profile corresponding to maximal aldolase activity is displaced to more acidic values compared to other class II aldolases. Enzyme activation by both detergents and alcohols and chromatographic behaviour on hydrophobic stationary phases is consistent with presence of hydrophobic surface regions on the soluble enzyme. Kinetic behaviour of T. aquaticus aldolase at high fructose-1,6-bisphosphate concentrations indicates significant negative cooperativity. The Taq aldolase NH2-terminal sequence was determined and compared with available sequences from other class II aldolases. Significant sequence similarity was found between Taq aldolase and the thermostable aldolase from Bacillus stearothermophilus.
影响因子：
2.9
作者：
BROWN, RE;JARVIS, KL;HYLAND, KJ
通讯作者：
HYLAND, KJ