硬脂酸修饰Lipolase脂肪酶的性能

采用N-羟基琥珀酰亚胺活化法用硬脂酸对Lipolase脂肪酶进行了化学修饰。研究了Lipolase脂肪酶的水解活力和酯化活力,重点研究了界面催化活性和表/界面张力。实验结果表明:与未修饰酶相比,修饰Lipolase的水解活力略有下降,但正己烷中的酯化活力和界面水解活力均明显提高;修饰Lipolase降低表面张力与界面张力的能力提高。用LB技术制备Lipolase的单分子层膜,发现修饰Lipolase的∏-A曲线上移,表明修饰Lipolase更易在表面形成单分子层膜。可见Lipolase脂肪酶经硬脂酸修饰后界面活性提高、有利于在有机相或两相界面催化化学反应。

Property of lipolase modified with stearic acid

Lipolase was chemically modified with fatty acids.The hydrolysis activity,interfacial hydrolysis activity and esterification activity in hexane of the modified lipolase were assayed.The results showed that the interfacial hydrolysis activity and esterification activity of the modified lipolase increased apparently,although the hydrolysis activity decreased a little compared with the unmodified lipolase.The surface tension and the interfacial tension of the modified and unmodified lipolase were also investigated.The surface tension and interfacial tension of the solution of modified lipolase were much lower than those of unmodified lipolase.The Langmuir-Blodgtt monolayer film of modified lipolase was obtained by the use of LB technique and the surface pressure was higher than that of unmodified one,showing that it was much easier to congregate on the interface.All results showed that lipolase modified with fatty acids had an enhanced activity on the interface,making it advantageous to use modified lipolase in organic solvent and two phase system.