Zhang Huihui, Su Zhongliang, Sun Yuyang, Li Lu, Lu Yanju
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong Province 266042, China.
Beijing University of Chemical Technology, Beijing 100029, China.
J Agric Food Chem. 2025 Apr 2;73(13):7906-7919. doi: 10.1021/acs.jafc.4c12952. Epub 2025 Mar 19.
The conversion of cellulosic biomass into fermentable sugars represents a pivotal stage in the environmentally friendly and sustainable production of clean fuels and chemicals. In this paper, a new strategy to enhance enzyme performance was proposed. This strategy can achieve pH-sensitive recovery of cellulase while improving the catalytic activity and stability of the enzyme. This strategy was achieved by means of a chemical modification of the cysteine residue (-SH) of the carbohydrate-binding domain (CBD) of cellulase with a PEG-based modifier (Mal-PEG-FA). It was shown that chemical modification altered the conformation of cellulase, which significantly improved the efficiency of the CBD of the enzyme, which in turn promoted the activity of the enzyme. In particular, the cellulase that was modified with a molecular weight of 10 k demonstrated the highest level of activity, with an increase of 130.02% in comparison to the native cellulase. Ultimately, the effective recovery of modified cellulase in the aqueous phase system was accomplished by adjusting the pH of the system. After five cycles, the modified cellulase still maintained 81.0% of its initial enzymatic activity. This research is of significant strategic importance for the promotion of efficient biomass utilization.
将纤维素生物质转化为可发酵糖是清洁燃料和化学品环境友好型可持续生产中的关键阶段。本文提出了一种提高酶性能的新策略。该策略可实现纤维素酶的pH敏感回收，同时提高酶的催化活性和稳定性。此策略是通过用基于聚乙二醇的修饰剂（Mal-PEG-FA）对纤维素酶的碳水化合物结合结构域（CBD）的半胱氨酸残基（-SH）进行化学修饰来实现的。结果表明，化学修饰改变了纤维素酶的构象，显著提高了酶CBD的效率，进而促进了酶的活性。特别是，分子量为10k的修饰纤维素酶表现出最高的活性水平，与天然纤维素酶相比增加了130.02%。最终，通过调节系统的pH值实现了修饰纤维素酶在水相系统中的有效回收。经过五个循环后，修饰纤维素酶仍保持其初始酶活性的81.0%。本研究对于促进生物质的高效利用具有重要的战略意义。
