超声-疏水性离子液体耦合处理对蛋白质酶解反应的强化机理

Enzymolysis is an effective way to achieve functions diversification and improve added value for protein. There are still low enzymolysis efficiency and low yield in protein enzymolysis. Thus, seeking efficient process has been a hot research for protein enzymolysis research. . Data from the literature show that protein can be dissolved and regenerated in ionic liquids. As a result, physicochemical properties of protein were changed. In addition, ultrasound is able to promote protein enzymolysis reaction. On this basis, ultrasound-hydrophobic ionic liquids coupling (UHILC) was firstly used to treat protein by our research team. We have proved that ultrasound could promote protein hydrolysis more strongly and thoroughly under the participation of hydrophobic ionic liquids. However, the enhancement and mechanism of UHILC for protein enzymolysis reaction is no report at home and abroad. In this project, the enhancement of UHILC for protein enzymolysis reaction will be clarified by analyzing the relationship between protein key structure change and enzymolysis efficiency. Moreover, the mechanism of UHILC for protein enzymolysis reaction will be revealed by studying changes in the relationship among protein steric hindrance, hydrolysis pathway, and hydrolysis law. This project study can provide theoretical support for application of UHILC in protein highly efficient enzymolysis.

蛋白质酶解是实现蛋白质功能多元化、提高附加值的有效途径。然而，蛋白质酶解一直存在水解效率和产量低等问题，寻求高效蛋白质酶解工艺仍然是该领域研究的热点。. 资料表明，离子液体可以使蛋白质发生溶解与再生，改变其理化特性，而超声则能够促进蛋白质酶解反应。在此基础上，本课题组首次利用超声-离子液体耦合处理蛋白质，并证明了在疏水性离子液体参与下，超声对蛋白质水解的促进作用更加强烈，水解更加彻底。但是，超声-疏水性离子液体耦合促进蛋白质酶解反应的作用机理国内外尚无报道。本项目拟通过分析蛋白质关键结构变化与酶解增效之间的关系，探讨超声-疏水性离子液体耦合处理对蛋白质酶解的强化作用；并通过研究蛋白质空间位阻、酶解途径和酶解规律之间的变化关系，揭示其作用机理，以期为超声-疏水性离子液体耦合处理在蛋白质高效酶解中的应用提供理论支撑。

蛋白质酶解是实现蛋白质功能多元化、提高附加值的有效途径。然而，蛋白质酶解一直存在水解效率和产量低等问题，寻求高效蛋白质酶解工艺仍然是该领域研究的热点。本课题采用了超声-疏水性离子液体耦合处理提高蛋白质的酶解效率和产量，研究了超声-疏水性离子液体耦合处理后蛋白质的理化特性、酶解效率、酶解反应所需的临界酶浓度、热力学参数和酶解产物特征等变化。研究结果表明，超声-疏水性离子液体耦合处理能够促进蛋白质的酶解，其处理的蛋白质一级结构通常变化不显著，二级结构变化显著，其中β-转角含量的降低有利于蛋白质的酶解。同时，超声-疏水性离子液体处理显著提高了蛋白质酶解反应的初始速率和酶解速率常数kin，显著降低了蛋白质酶解反应所需的临界酶浓度（e0）、活化能（Ea）、活化焓（ΔH）和活化熵（ΔS），明确了超声-疏水性离子液体处理促进蛋白质酶解的机理。另外，研究发现，超声-疏水性离子液体处理后蛋白质酶解产物中低分子量肽明显增多，且其生物活性也得到了提高。本项目的研究有望为超声-疏水性离子液体处理在蛋白质高效酶解及生物活性肽的制备中的应用提供理论支撑。