高等学校化学学报Issue(6)：1212-1218,7.DOI:10.7503/cjcu20131009
青霉素酰化酶交联酶聚体的制备及热失活动力学
Preparation and Thermal Kinetic Deactivation of Cross-linked Enzyme Aggregates of Penicillin Acylase
摘要
Abstract
Cross-linked enzyme aggregates(CLEAs) is an efficient approach to obtain immobilized enzymes without the use of any pre-existing carriers. The preparation of CLEAs usually consisted of two simple steps:precipitation and cross-linking. In this work, CLEAs of penicillin acylase was preparaed using 50% ammo-nium sulphate solution as precipitant and 0. 35% glutaraldehyde as cross-linking agent. The resulting CLEAs obtained an activity yield of 30. 1% and higher optimal temperature (57 ℃) than free penicillin acylase (47 ℃) as well as an obvious shift of optimal pH from 8. 3 to 10. 0. Moreover, compared with free enzyme, the thermal stability of CLEAs was largely enhanced which facilitated the application of penicillin acylase in high-temperature reaction systems. Based on the thermal deactivation kinetics study, it was found that the deactivation model of penicillin acylase changed from one-step model to serial model through immobilizing as CLEAs. The higher deactivation energy of CLEAs(549. 2 kJ/ mol) than free enzyme(248. 8 kJ/ mol) also ex-plained the excellent stability of CLEAs under high temperature environment. In addition, CLEAs exhibited favorable reusability after using 7 times.关键词
交联酶聚体/青霉素酰化酶/固定化/稳定性/热失活动力学Key words
Cross-linked enzyme aggregate(CLEA)/Penicillin acylase/Immobilization/Enzyme stability/Thermal deactivation kinetics分类
化学化工引用本文复制引用
慕洋洋,甄倩楠,王梦凡,齐崴,苏荣欣,何志敏..青霉素酰化酶交联酶聚体的制备及热失活动力学[J].高等学校化学学报,2014,(6):1212-1218,7.基金项目
国家自然科学基金(批准号:31071509,21206113)和天津市应用基础研究计划项目(批准号:13JCQNJC09300)资助. Supported by the National Natural Science Foundation of China(Nos.31071509,21206113) and the Natural Science Foundation of Tianjin, China(No.13JCQNJC09300) （批准号:31071509,21206113）
