On-line trypsin-encapsulated enzyme reactor by the sol-gel method integrated into capillary electrophoresis

A novel trypsin-technique using the solgel method was developed for the preparation of an on-line enzyme reactor integrated into capillary electrophoresis. Trypsin was encapsulated in tetramedioxysilane-based hydrogel,,and its enzymatic activity, was evaluated using alpha-N-benzoyl-L-arginine ethyl ester and. two peptioes (brady-kinin and [Tyr(8)]-bradykinin). The enzyme encapsulation was carried out, in a single step under mild conditions within a capillary, and 1.5-cm gel was formed at the inlet of the,capillary. The resultant Monolithic reactor showed excellent enzymatic activity, which was similar to700 times higher than,that in free solution, without stopping the flow. Separation of the unreacted substrates and products in the same capillary also showed high "selectivity, and sample size in this system decreased 3 orders of magnitude from. conventional tryptic reaction schemes, The encapsulated, trypsin maintains its substrate specificity even in, a sol-gel matrix. Furthermore, the encapsulated trypsin:exhibits increased stability even after continuous use, compared to that in free solution.