Stability curves of laboratory evolved thermostable mutants of a Bacillus subtilis lipase
Stability curves of laboratory evolved thermostable mutants of a Bacillus subtilis lipase
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DOI：
10.1016/j.bbapap.2010.06.014
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发表时间：
2010-09-01
影响因子：
3.2
通讯作者：
Rao, Nalam Madhusudhana
中科院分区：
文献类型：
--
作者：
Kamal, Md. Zahid;Ahmad, Shoeb;Rao, Nalam Madhusudhana
蛋白质稳定性曲线的形状改变以实现更高的解链温度。概括地说，这些变化被分类为向上移动（Δ G（s）增加）、向下移动（T（s）增加）和稳定性曲线平坦化（Δ C（p）降低）。同源嗜温-嗜热蛋白对的比较研究突出了这三种策略在蛋白质中的差异贡献。但仍然没有实现识别策略的明确方式，这对于蛋白质来说是首选的。我们已经进行了比较热力学研究，利用差示扫描量热仪（DSC）的耐热变种脂肪酶从枯草芽孢杆菌。这些变体是1、2、3和4轮定向进化的产物，并且与天然嗜热蛋白不同，它们具有在热稳定性方面具有明确贡献的突变。我们已经表明，向上和向上移动的稳定性曲线是该脂肪酶的主要策略。我们的研究结果沿着，从其他研究的实验室进化的木聚糖酶A表明，次优热力学参数的优化具有显着的影响，在选择的热力学策略，更高的热稳定性。(C)2010 Elsevier B. V.保留所有权利。
Shape of the protein stability curves changes to achieve higher melting temperature. Broadly, these changes have been classified as upward shift (increased Delta G(s)), rightward shift (increase in T(s)) and flattening of the stability curves (decrease in Delta C(p)). Comparative studies on homologous mesophilic-thermophilic protein pairs highlighted the differential contribution of these three strategies amongst proteins. But unambiguous way of identification of the strategies, which will be preferred for a protein, is still not achieved. We have performed comparative thermodynamic studies using differential scanning calorimeter (DSC) on thermostable variants of a lipase from Bacillus subtilis. These variants are products of 1, 2, 3 and 4 rounds of directed evolution and harbor mutations having definite contribution in thermostability unlike natural thermophilic proteins. We have shown that upward and rightward shift in stability curves are prime strategies in this lipase. Our results along with that from the other study on laboratory evolved xylanase A suggest that optimization of suboptimal thermodynamic parameters is having a dominant influence in selection of thermodynamic strategies for higher thermostability. (C) 2010 Elsevier B.V. All rights reserved.