State Key Laboratory of Material-Oriented Chemical Engineering, School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing 210009, China.
State Key Laboratory of Material-Oriented Chemical Engineering, School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing 210009, China.
Colloids Surf B Biointerfaces. 2017 Dec 1;160:416-422. doi: 10.1016/j.colsurfb.2017.09.037. Epub 2017 Sep 18.
Multiwalled carbon nanotubes (MWNTs) were modified by imidazole-based ionic liquids with different kinds of functional groups such as alkyl, carboxyl, amino and hydroxyl. The supports were used to immobilize Candida antarctic lipase B (CALB) and the influence of different functional groups of ionic liquids on enzymatic properties was investigated by the hydrolysis reaction of triacetin. The results revealed that the functionalization process did not destroy the structural integrity of MWNTs, and the enzymatic properities of CALB which immobilized on the MWNTs modified by ionic liquids with different kinds of functional groups were all improved. The hydroxyl functionalized ionic liquids which exhibited the best enzymatic properities was selected to investigate the effects of different carbon chain length on the enzymatic properties of immobilized CALB. Among them, CALB which immobilized on MWNTs modified by hydroxyl functionalized ionic liquid with suitable chain length (MWNTs-IL(8C)-OH-CALB) had the highest specific activity, with a specific activity of 18.11 times that of MWNTs-CALB. Furthermore, it also presented best thermal stability and reusability. The residual activity of MWNTs-IL(8C)-OH-CALB held over 64.01% of the initial activity after being incubated for 20min at 70°C, and the residual activity was 85.56% after 4 cycles of use.
多壁碳纳米管 (MWNTs) 被不同官能团的咪唑基离子液体修饰，如烷基、羧基、氨基和羟基。将载体用于固定南极假丝酵母脂肪酶 B（CALB），并通过三醋酸甘油酯的水解反应研究了不同官能团离子液体对酶性能的影响。结果表明，功能化过程没有破坏 MWNTs 的结构完整性，并且固定在具有不同官能团的离子液体修饰的 MWNTs 上的 CALB 的酶性质都得到了改善。选择表现出最佳酶性质的羟基功能化离子液体来研究不同碳链长度对固定化 CALB 酶性质的影响。其中，固定在具有合适链长的羟基功能化离子液体修饰的 MWNTs 上的 CALB（MWNTs-IL(8C)-OH-CALB）具有最高的比活性，比活性是 MWNTs-CALB 的 18.11 倍。此外，它还表现出最佳的热稳定性和可重复使用性。MWNTs-IL(8C)-OH-CALB 在 70°C 孵育 20min 后，残留活性保持在初始活性的 64.01%以上，使用 4 次后，残留活性为 85.56%。
