Preparation and properties of soluble–insoluble immobilized proteases

In order to carry out an effective enzyme reaction, the preparation of soluble–insoluble immobilized enzyme was investigated. Proteases were selected as model enzymes, and their immobilization was carried out by using an enteric coating polymer as a carrier. Among the polymers tested, methacrylic acid–methylacrylate–methylmethacrylate copolymer (MPM‐06) gave the most active soluble–insoluble immobilized papain. This immobilized papain showed insoluble from below pH 4.8 and soluble form above pH 5.8; it was also soluble in water‐miscible organic solvent. It was reusable and more stable with heat and water‐miscible organic solvents than native proteases. Furthermore, various proteases could be immobilized by using MPM‐06 with high activity. Chymotrypsin immobilized by this method catalyzed the effective peptide synthesis in a heterogeneous reaction system containing water‐miscible organic solvent.