美国爱荷华州立大学Yan Zhao团队报道了在水溶液和非水溶液中水解纤维素的分子印迹合成葡萄糖苷酶。相关研究成果发表在2021年3月24日出版的《美国化学会杂志》。

分子印迹是一种在交联聚合物网络中建立多功能结合位点的有效而简单的方法。

该文报道了一类通过分子印迹和交联表面活性剂胶束后功能化制备的合成葡萄糖苷酶。这些催化剂是蛋白质大小的水溶性纳米粒子，可以通过多种方式进行修饰。作为它们的天然对应物，可以结合含有葡萄糖的寡糖或多糖。在糖键附近含有数目和距离可以系统地调整的酸性基团。纤维素的水解是生物质转化的关键步骤，但由于高度结晶的纤维素纤维不易结晶而受到阻碍。合成的葡萄糖苷酶可以在各种条件下水解纤维二糖和纤维素。最佳催化剂为仿生双酸催化基序，在水缓冲液中水解纤维素的活性为工业纤维素酶的五分之一。

作为一种高度交联的聚合物纳米粒子，该合成催化剂在水溶剂和非水溶剂中均能在高温下保持稳定。在极性非质子溶剂/离子液体混合物中，它水解纤维素的速度比商业纤维素酶在水缓冲液中快数倍。当沉积在磁性纳米颗粒上时，在使用10个周期后，保留了75%的活性。

附：英文原文

Title: Molecularly Imprinted Synthetic Glucosidase for the Hydrolysis of Cellulose in Aqueous and Nonaqueous Solutions

Author: Xiaowei Li, Milad Zangiabadi, Yan Zhao

Issue&Volume: March 24, 2021

Abstract: Molecular imprinting is a powerful and yet simple method to create multifunctional binding sites within a cross-linked polymer network. We report a new class of synthetic glucosidase prepared through molecular imprinting and postfunctionalization of cross-linked surfactant micelles. These catalysts are protein-sized water-soluble nanoparticles that can be modified in multiple ways. As their natural counterparts, they bind a glucose-containing oligo- or polysaccharide. They contain acidic groups near the glycosidic bond to be cleaved, with the number and distance of the acid groups tuned systematically. Hydrolysis of cellulose in a key step in biomass conversion but is hampered by the incalcitrance of the highly crystalline cellulose fibers. The synthetic glucosidases are shown to hydrolyze cellobiose and cellulose under a variety of conditions. The best catalyst, with a biomimetic double acid catalytic motif, can hydrolyze cellulose with one-fifth of the activity of commercial cellulases in aqueous buffer. As a highly cross-linked polymeric nanoparticle, the synthetic catalyst is stable at elevated temperatures in both aqueous and nonaqueous solvents. In a polar aprotic solvent/ionic liquid mixture, it hydrolyzes cellulose several times faster than commercial cellulases in aqueous buffer. When deposited on magnetic nanoparticles, it retains 75% of its activity after 10 cycles of usage.

DOI: 10.1021/jacs.1c01352

Source: https://pubs.acs.org/doi/10.1021/jacs.1c01352