Solubilizing and Stabilizing Proteins in Anhydrous Ionic Liquids through Formation of Protein-Polymer Surfactant Nanoconstructs
Solubilizing and Stabilizing Proteins in Anhydrous Ionic Liquids through Formation of Protein-Polymer Surfactant Nanoconstructs
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DOI：
10.1021/jacs.5b13425
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发表时间：
2016-04-06
影响因子：
15
通讯作者：
Halleet, Jason P.
中科院分区：
文献类型：
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作者：
Brogans, Alex P. S.;Halleet, Jason P.
在实验室和工业中，非水生物催化正在迅速成为化学和燃料合成的理想工具。同样，离子液体在许多工业过程中是越来越受欢迎的无水反应介质。因此，在离子液体中使用酶作为高效、环境友好的商业生物催化剂是非常有吸引力的。然而，围绕着酶在真正无水介质中的低溶解性和低稳定性的问题仍然是一个重大的挑战。在这里，我们首次证明，通过设计蛋白质表面来产生蛋白质聚合物表面活性纳米结构，可以将干燥的蛋白质溶解到干燥的离子液体中。以肌红蛋白为模型蛋白质，我们证明了这种方法可以将接近天然结构的蛋白质分子输送到亲水和疏水的无水离子液体中。值得注意的是，使用温度相关的同步辐射圆二色谱来测量半变性温度，我们的结果表明，蛋白质在离子液体中的稳定性比在水溶液中提高了55摄氏度，推动了溶液的热变性超过水的沸点。因此，本文的工作可以为在高温或无水溶剂体系中实现生物催化提供一个平台。
Nonaqueous biocatalysis is rapidly becoming a desirable tool for chemical and fuel synthesis in both the laboratory and industry. Similarly, ionic liquids are increasingly popular anhydrous reaction media for a number of industrial processes. Consequently, the use of enzymes in ionic liquids as efficient, environment-friendly, commercial biocatalysts is highly attractive. However, issues surrounding the poor solubility and low stability of enzymes in truly anhydrous media remain a significant challenge. Here, we demonstrate for the first time that engineering the surface of a protein to yield protein polymer surfactant nanoconstructs allows for dissolution of dry protein into dry ionic liquids. Using myoglobin as a model protein, we show that this method can deliver protein molecules with near native structure into both hydrophilic and hydrophobic anhydrous ionic liquids. Remarkably, using temperature-dependent synchrotron radiation circular dichroism spectroscopy to measure half-denaturation temperatures, our results show that protein stability increases by 55 degrees C in the ionic liquid as compared to aqueous solution, pushing the solution thermal denaturation beyond the boiling point of water. Therefore, the work presented herein could provide a platform for the realization of biocatalysis at high temperatures or in anhydrous solvent systems.