邻苯二甲酸酐修饰脂肪酶的性能研究

摘要

Pocine pancreas lipase (PPL) was modified with phthalic anhydride (PA). The optimal conditions of pH and temperature for the modified PA-PPL enzymatic reaction were assayed. The results showed that the modification yield was 30％ under the experimental conditions, and hydrolysis activity of PA-PPL increased apparently by 25％ and the stability to pH and temperature were improved obviously, although PA-PPL had the same optimal pH and temperature for enzymatic reaction as PPL. For example the thermal stability of PA-PPL was higher by one fold than that of PPL under temperature 50 ℃ conditions. During storage,PA-PPL and PPL were stable at low temperature and pH7. 0 - 8. 0. It was considered that chemical modification of PPL with PA was a simple and effective method for the improvement of enzymatic properties.%采用邻苯二甲酸酐(PA)对猪胰脂肪酶(PPL)进行了修饰.初步表征了修饰酶PA-PPL,考察了PA-PPL的最适反应条件和对酸碱、热的稳定性.结果表明:在试验条件下,PA对PPL的修饰度为30%;尽管修饰酶PA-PPL与猪胰脂肪酶PPL催化水解的最适反应pH和最适反应温度相同,但与PPL相比,PA-PPL的水解活性提高25%、pH稳定性及热稳定性较PPL明显提高,如50℃下的热稳定性提高了l倍;修饰酶PA-PPL与原酶PPL均在低温和pH7.0～8.0环境下酶活性稳定.可见采用PA对PPL进行化学修饰是一种改善脂肪酶PPL性质的有效方法.