Comparative void-volume analysis of psychrophilic and mesophilic enzymes: Structural bioinformatics of psychrophilic enzymes reveals sources of core flexibility.
Comparative void-volume analysis of psychrophilic and mesophilic enzymes: Structural bioinformatics of psychrophilic enzymes reveals sources of core flexibility.
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DOI：
10.1186/1472-6807-11-42
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发表时间：
2011-10-20
影响因子：
--
通讯作者：
Dordick JS
中科院分区：
文献类型：
--
作者：
Paredes DI;Watters K;Pitman DJ;Bystroff C;Dordick JS
嗜冷生物是一种适应低温的生物，通过多种机制适应低温环境。它们的酶在低温下具有活性，因为它们的结构比嗜温酶更灵活。尽管有一些迹象表明嗜冷酶在低温下具有催化活性的可能结构机制，但并没有一个所有嗜冷酶共有的一般结构特性。我们研究了20个同源酶对嗜冷菌和mesophiles调查灵活性作为一个关键特征冷适应。蛋白质X射线结构中的B因子是测量柔性的一种方法。比较嗜冷蛋白质B因子，嗜冷酶的5-转角和链二级结构更灵活。酶腔，确定使用CASTp在不同的探针大小，表明嗜冷酶具有较大的平均腔大小在1.4-1.5 μ m的探针半径，足够的水分子。此外，这些腔内衬的氨基酸侧链显示嗜冷酶中酸性基团的频率增加。这些发现表明，嵌入的水分子可能在腔的灵活性，因此，整体蛋白质的灵活性发挥了重要作用。因此，我们的研究结果指出了酶的灵活性在适应寒冷环境中的重要作用。
Psychrophiles, cold-adapted organisms, have adapted to live at low temperatures by using a variety of mechanisms. Their enzymes are active at cold temperatures by being structurally more flexible than mesophilic enzymes. Even though, there are some indications of the possible structural mechanisms by which psychrophilic enzymes are catalytic active at cold temperatures, there is not a generalized structural property common to all psychrophilic enzymes. We examine twenty homologous enzyme pairs from psychrophiles and mesophiles to investigate flexibility as a key characteristic for cold adaptation. B-factors in protein X-ray structures are one way to measure flexibility. Comparing psychrophilic to mesophilic protein B-factors reveals that psychrophilic enzymes are more flexible in 5-turn and strand secondary structures. Enzyme cavities, identified using CASTp at various probe sizes, indicate that psychrophilic enzymes have larger average cavity sizes at probe radii of 1.4-1.5 Å, sufficient for water molecules. Furthermore, amino acid side chains lining these cavities show an increased frequency of acidic groups in psychrophilic enzymes. These findings suggest that embedded water molecules may play a significant role in cavity flexibility, and therefore, overall protein flexibility. Thus, our results point to the important role enzyme flexibility plays in adaptation to cold environments.
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影响因子：
5.7
作者：
Aghajari, N;Feller, G;Haser, R
通讯作者：
Haser, R
DOI：
10.1016/j.bbapap.2006.06.005
发表时间：
2006-08-01
影响因子：
3.2
作者：
Papaleo, Elena;Riccardi, Laura;De Gioia, Luca
通讯作者：
De Gioia, Luca
影响因子：
5.6
作者：
Chen, JM;Stites, WE
通讯作者：
Stites, WE
影响因子：
3.4
作者：
Chiuri, R.;Maiorano, G.;Pompa, P. P.
通讯作者：
Pompa, P. P.
DOI：
10.1093/protein/15.12.959
发表时间：
2002-12-01
期刊：
PROTEIN ENGINEERING
影响因子：
--
作者：
Bystroff, C
通讯作者：
Bystroff, C