College of Pharmaceutical Science, Hebei University, Baoding 071002, China.
Department of Computer Teaching, Hebei University, Baoding 071002, China.
Bioconjug Chem. 2023 Jun 21;34(6):1045-1053. doi: 10.1021/acs.bioconjchem.3c00127. Epub 2023 Apr 25.
Here, lipase encapsulation is constructed by locking enzyme molecules in nanomolecular cages on the surface of SH-PEI@PVAC magnetic microspheres. To improve the encapsulation efficiency in enzyme loading, the thiol group is efficiently modified on the grafted polyethyleneimine (PEI) using 3-mercaptopropionic acid. N adsorption-desorption isotherms reveal the existence of mesoporous molecular cages on the microsphere surface. The robust immobilizing strength of carriers to lipase demonstrates the successful encapsulation of enzymes in nanomolecular cages. The encapsulated lipase shows high enzyme loading (52.9 mg/g) and high activity (51.4 U/mg). Different sizes of molecular cages are established, and the cage size showed important effects on lipase encapsulation. It shows that enzyme loading is low at a small size of molecular cages, which is attributed to that the nanomolecular cage is too small to house lipase. The investigation in lipase conformation suggests that the encapsulated lipase retains its active conformation. Compared with the adsorbed lipase, the encapsulated lipase shows higher thermal stability (4.9 times) and higher resistance to denaturants (5.0 times). Encouragingly, the encapsulated lipase shows high activity and reusability in lipase-catalyzed synthesis of propyl laurate, suggesting the potential application value of encapsulated lipase.
在这里，通过将酶分子锁定在 SH-PEI@PVAC 磁性微球表面的纳米笼中构建了脂肪酶包封。为了提高酶负载中的包封效率，使用 3-巯基丙酸对接枝的聚乙烯亚胺（PEI）进行了有效的巯基修饰。N 吸附-解吸等温线表明微球表面存在介孔纳米笼。载体对脂肪酶具有很强的固定化强度，表明酶成功地包封在纳米笼中。包封的脂肪酶显示出高酶负载量（52.9 mg/g）和高活性（51.4 U/mg）。建立了不同尺寸的分子笼，并且笼尺寸对脂肪酶包封显示出重要影响。结果表明，当分子笼尺寸较小时酶负载量较低，这归因于纳米分子笼太小而无法容纳脂肪酶。对脂肪酶构象的研究表明，包封的脂肪酶保留其活性构象。与吸附的脂肪酶相比，包封的脂肪酶表现出更高的热稳定性（4.9 倍）和更高的抗变性剂能力（5.0 倍）。令人鼓舞的是，包封的脂肪酶在脂肪酶催化合成丙酸月桂酯中表现出高活性和可重复使用性，表明包封的脂肪酶具有潜在的应用价值。
