Improvement for catalytic stability of immobilized penicillin acylase by blockage of small molecule reagents

In order to improve catalytic properties and thermal stability of penicillin acylase (PA), small molecule reagents were assembled to quench the excessive active groups of mesocellular siliceous foams (MCFs). The effects of adding mass fraction and types of small molecule reagents on the coupled yield, the catalytic activity and thermal stability of PA were investigated. The activity of immobilized PA quenched by arginine is enhanced to 1.92 folds, and the thermal stability of immobilized PA preparation blocked by glycin is increased to 2.9 folds at 50°C for 5 h. The residual activity of PA preparations of glycin and glutamic acid remain 87. 9% and 82.2%, respectively, after treatment at 50°C for 25 h. The optimum pH of PA preparations of glycin and glutamic acid shifts to neutral, and their tolerance to pH is strengthened. The results indicate that the suitable blockage with small molecule reagents can improve the catalytic properties and thermal stability of PA assembled in MCFs.