Temperature dependence of the catalytic activity of promising nanomaterials based on biopolymers: lipase and chitosan

Abstract

A study of the interactions of porcine pancreatic lipase (PPL) with chitosan is the most interesting and important in order to regulate the enzymatic properties of the future nanomaterials based on these biopolymers. A decrease in catalytic activity of pure PPL towards triacetin during prolonged operation and storage is shown: activity decreases by 24.1% within 1 hour and by 54.0% - in the case of the lipase storage in solution for 1 month. The optimum temperature of 40°C was determined for samples of pure PPL, whereas a small shift from 40° to about 45°C - for PPL:Chit complex (50:1). The catalytic activity of free PPL at 40°C was the highest (as compared to lower and higher temperatures) and stable for 20 min. However, the dynamics showed a pronounced decrease to almost 2 times within further 30-60 minutes. In contrast, at 40°C the catalytic activity of PPL in complex with chitosan (50:1) stabilized at almost the same level (although it was lower than the activity of free PPL in the first 30 minutes of measurement). The PPL:Chit complex can be considered as promising catalytic nanomaterials (based on chitosan and lipase) for further applications.