Preparation of a reversible soluble-insoluble β-d-Glucosidase with perfect stability and activity

Rebuilding enzymes with high activities, stability and reusability has been constantly pursued for application of enzymaticcatalysis in wide field. Rebuilding enzymes by chemical approaches, including immobilization and chemicalmodification, represents a simple but effective route. Here, a class of highly stable and active reversible soluble-insoluble β-d-Glucosidase (E-CB-ALD 5K) was prepared using mPEG-ALD (methoxy-polyethylene glycol aldehyde, molecular weight: 5k) as a site-specific modifier and Eudragit L-100(polyacrylic resin) as a carrier. The obtained rebuilding enzyme E-CB-ALD 5K was of high activity and recyclability. By the combination of the chemical modification and immobilization, E-CB-ALD 5K realized the homogeneous reaction and two phase separation for enzyme by controlling pH. Furthermore, E-CB-ALD 5K possesses strong thermal stability, alkaline stability, and the affinity between the enzyme and the substrate. The phenomenon was analyzed by circular dichroism analysis. The results showed that the E-CB-ALD 5K has more β-fold structure that improves its stability.