Abstract

Lipase B from Candida antarctica (CAL-B) was immobilised on epoxy-activated polymer support functionalised with polyethyleneimine (PEI) via preparation of enzyme aggregates by precipitation with polyethylene glycol (PEG 600). This involves adsorption of the aggregates on the functionalised polymer followed by cross-linking with glutaraldehyde. The apparent activity of the immobilised enzyme was found to be 750 TBU/g at optimum pH 7.5 and temperature 30 °C. The immobilisation yield was 24%. The immobilised enzyme was used for desymmetrization of cis-3,5-diacetoxy-1-cyclopentene in aqueous buffer (70% yield, >99% e.e.) and methyl tert-butyl ether (95% yield and > 99% e.e) to obtain (1 R,4S)-4-hydroxycyclopent-2-en-1-yl acetate. The immobilised enzyme could be recycled (5 times) in both aqueous buffer and organic solvents. Further, the expensive polymer support was also recycled (5 times) after the immobilised enzyme lost its activity by washing with 1 N HCl.

摘要

通过用聚乙二醇 (PEG 600) 沉淀制备酶聚集体，将来自南极假丝酵母的脂肪酶 B (CAL-B) 固定在用聚乙烯亚胺 (PEI) 功能化的环氧活化聚合物载体上。这涉及在官能化聚合物上吸附聚集体，然后与戊二醛交联。在最适 pH 7.5 和温度 30 °C 下，固定化酶的表观活性为 750 TBU/g。固定产率为24%。固定化酶用于顺式-3,5-二乙酰氧基-1-环戊烯在水性缓冲液（70% 产率，>99% ee）和甲基叔丁基醚（95% 产率和 >99% ee）中去对称化，得到(1  R,4 S )-4-羟基环戊-2-烯-1-乙酸酯。固定化酶可以在水性缓冲液和有机溶剂中循环（5 次）。此外，在固定化酶通过用 1 N HCl 洗涤而失去活性后，昂贵的聚合物载体也被回收（5 次）。