基于高内相乳液的酶促反应催化剂载体和微反应器的构建和特性研究

Enzymes quite often display high chemo-, regio-, and enantioselectivity, which makes them attractive for organic synthesis area. Enzymatic reaction, however, is still difficult to be widely used, because a biphasic system (mixture of water and organic solvent)is usually required for the reaction. Most of the enzymatic reaction substrates are only soluble in organic solvents, however, many enzymes are easily inactivation or denature in organic solvents. A simple and versatile method for solving this problem is to make an emulsion with an aqueous enzymatic solution and an organic medium containing the substrate. Whereas, the surfactants must be involved in the emulsification, and the presence of surfactants can severely reduce enzymatic activity and furthermore present a challenge to purification of the products. This project is intended to design and prepare polymersomes that capsulating enzyme, and make Pickering high internal phase emulsions (HIPEs) with the polymersomes as stabilizer, then synthesize the Pickering-HIPE-templated porous polymeric materials having enzyme functionalized void surfaces. The polymeric materials will be used as the enzyme catalyt support and microreactor for continuous enzymatic reaction in biphasic system. The launching of the project is expected to provide new experimental and theoretical basis for the continuous enzymatic reaction in biphasic system, and to effectively promote the development of using porous polymers as catalyst support and microreactor of enzymatic reaction, which is an interdisciplinary area of polymer scinece, biology and organic synthesis.

酶促反应因具有良好的化学选择性、区域选择性和立体选择性而在有机合成等领域具有广阔的应用前景。然而，酶促反应因通常需要水油两相条件，所以难以广泛应用。大多数酶促反应底物往往仅溶于有机溶剂，而许多酶在有机溶剂中较易失活或降低活性。常用的解决方法是将酶的水溶液和含有底物的有机介质制成乳液，但这一过程需表面活性剂等参与，易严重影响酶的活性，并且不利于产物的后处理和纯化。针对上述问题，本项目拟设计构建包裹有酶催化剂的聚合物囊泡，以该囊泡稳定高内相乳液，在此基础上，合成孔表面酶功能化的多孔材料，并将该多孔材料用于两相体系连续酶催化有机合成反应的催化剂载体和微反应器。项目的开展可望为两相体系中连续酶催化反应的发展提供新的实验和理论依据，促进聚合物多孔材料用作酶促反应的催化剂载体和微反应器这一高分子科学、有机化学和生物学多学科交叉领域的发展。

酶促反应是自然界中最重要的化学反应，然而其因通常需要水油两相条件，所以难以广泛应用。大多数酶促反应底物仅溶于有机溶剂，而许多酶在有机溶剂中较易失活或降低活性。常用的解决方法是将酶的水溶液和含有底物的有机介质制成乳液，但这一过程需表面活性剂等参与，易严重影响酶的活性，并且不利于产物的后处理和纯化。针对上述问题，本项目设计制备了封装生物酶的聚合物囊泡，发展了聚合物囊泡稳定的高内相乳液体系。以该乳液体系为模板，开发了孔壁表面聚合物囊泡修饰的酶功能化的开孔结构整体柱材料。验证了这一材料可作为连续酶促反应的微反应器和酶催化剂，其中的生物酶具有比游离酶在同等条件下高约5.9倍的比活性，证明了其具有优异的生物催化性能。循环实验表明，该整体柱具有良好的可重复使用性。项目研究过程中，项目组对粒子稳定的乳液模板法制备的开孔材料的开孔机制进行了直观的分析，探明了开孔形成的机理，为基于粒子稳定高内相乳液的开孔材料的制备提供了实验和理论参考。同时，项目开发的聚合物囊泡稳定高内相乳液证明了空心粒子也可以有效稳定高内相乳液，拓展了高内相乳液的范畴。项目的开展发展了一类新的两相酶催化体系，发展了高内相乳液及其多孔材料的新应用，也为酶促反应的实际应用提供了一新的可能途径，同时奠定了相关的理论基础。通过四年的研究，项目组共发表标注项目资助的SCI论文14篇，申请并公开中国发明专利14件，获授权专利5件。