Immobilization of trypsin on sub-micron skeletal polymer monolith

A new kind of immobilized trypsin reactor based on sub-micron skeletal polymer monolith has been developed. Covalent immobilization of trypsin on this support was performed using the epoxide functional groups in either a one- or a multi-step reaction. The proteolytic activity of the immobilized trypsin was measured by monitoring the formation of N-α-benzoyl-l-arginine (BA) which is the digestion product of a substrate N-α-benzoyl-l-arginine ethyl ester (BAEE). Results showed that the digestion speed was about 300 times faster than that performed in free solution. The performance of such an enzyme reactor was further demonstrated by digesting protein myoglobin. It has been found that the protein digestion could be achieved in 88 s at 30 °C, which is comparable to 24 h digestion in solution at 37 °C. Furthermore, the immobilized trypsin exhibits increased stability even after continuous use compared to that in free solution. The present monolithic enzyme-reactor provides a promising platform for the proteomic research.