1,4-丁二醇/氯化胆碱低共熔溶剂对木瓜蛋白酶活性和稳定性的提高

The Enhancement of Papain Activity and Stability by 1,4-Butanediol/Choline Chloride Deep Eutectic Solvent

木瓜蛋白酶在医药、食品、日化等领域有重要应用,设法提高其活性和稳定性有利于放宽木瓜蛋白酶在工业应用中的条件限制,提高经济效益。制备了1,4-丁二醇/氯化胆碱低共熔溶剂,并研究其对木瓜蛋白酶活性和稳定性的影响。结果表明,1,4-丁二醇/氯化胆碱低共熔溶剂能够通过提高底物的传质速率和酶活性位点附近结构的灵活性来提高木瓜蛋白酶的活性。利用分子对接分析了1,4-丁二醇/氯化胆碱在木瓜蛋白酶上可能的作用位点,通过圆二色光谱证明这一作用并未造成木瓜蛋白酶二级结构的显著改变。并且将木瓜蛋白酶保存在1,4-丁二醇/氯化胆碱低共熔溶剂中能够显著提高其稳定性。当溶解在1,4-丁二醇/氯化胆碱低共熔溶剂体系中的木瓜蛋白酶被置于37℃或4℃下保存8 d后,其酶活分别保持在初始酶活的72.9%和86.1%。

Papain is widely used in fields such as medicine,food,and daily chemicals.The improvement of papain activity and stability is beneficial to relax the restrictions of papain in industrial applications and improve economic benefits.In this paper,1,4-butanediol/choline chloride deep eutectic solvent was prepared,and its influence on papain activity and stability was studied.The results show that 1,4-butanediol/choline chloride deep eutectic solvent can enhance the activity of papain by increasing the mass transfer rate of substrates and enhancing the structural flexibility near enzyme active sites.The possible interaction sites of 1,4-butanediol/choline chloride on papain were analyzed by molecular docking,and circular dichroism spectroscopy showed that the interaction did not cause significant changes in the secondary structure of papain.It is worth mentioning that storing papain in 1,4-butanediol/choline chloride deep eutectic solvent can significantly improve its stability.When papain dissolved in the 1,4-butanediol/choline chloride eutectic solvent system is stored at 37℃or 4℃for 8 days,its enzyme activity remains at 72.9%and 86.1%of the initial enzyme activity respectively.