可溶可逆聚合物Eudragit S-100对猪胰脂肪酶的固定化

Stabilization of Porcine Pancreas Lipase using a Solubility Reversible Polymer Eudragit S-100

摘要:

为了降低不溶性载体固定化对酶催化效率和回收利用的影响，本文作者采用智能性聚合物Eudragit S-100对猪胰脂肪酶进行了固定化修饰。Eudragit S-100主要由甲基丙烯酸和甲基丙烯酸甲酯共聚而成，具备pH响应的可溶可逆性。结果显示：活化后的Eudragit S-100树脂能够与脂肪酶进行共价结合，在15 ℃条件下反应6 h后，脂肪酶的平均氨基修饰率约为52.4%；荧光光谱测试表明固定化修饰使得脂肪酶分子肽链发生了一定折叠，脂肪酶的结构较修饰前更为紧凑。固定化后脂肪酶的最适温度保持不变，最适pH向碱性方向移动，总体上表现出更好的稳定性。此外，固定化脂肪酶具备pH响应的可溶可逆性，能够重复使用，经过5次重复使用后，酶活保留仍有45%左右。

Abstract:

In order to avoid the bad effect on enzyme catalytic efficiency and reuse with traditional insoluble carrier，a new kind of smart polymer named Eudragit S-100 was used for the immobilization of porcine pancreas lipase（PPL）. Eudragit S-100 is an anionic copolymer of methacrylic acid and methylmethacrylate，and has a solubility reversible. The results showed that the modification rates of free amino of PPL immobilized with Eudragit S-100 reached 52.4% at 15 ℃ after 6 hours. The fluorescence emission spectra indicated that the enzyme molecule peptide chains were fold，and finally the structure became compact. The optimum temperature of immobilized PPL did not change，but the optimum pH moved slightly to an alkaline direction. Eudragit S-100 immobilization enhanced the enzyme stability against changes of pH and temperature. Furthermore，the immobilized PPL gained the solubility reversible on the basis of pH，and they had a high reusability，retaining about 45% of its original activity after five cycles of repeated uses.