A STREPTAVIDIN-CELLULOSE-BINDING DOMAIN FUSION PROTEIN THAT BINDS BIOTINYLATED PROTEINS TO CELLULOSE

A fusion protein, Sta-CBDCex, which comprises streptavidin with a cellulose-binding domain (CBDCex) fused to its C terminus, was produced in the cytoplasm of Escherichia coli where it formed inclusion bodies. Renatured Sta-CBDCex, recovered from the inclusion bodies, adsorbed to Avicel, a microcrystalline cellulose. The cellulose bound Sta-CBDCex in turn bound biotinylated alkaline phosphatase or biotinylated P-glucosidase. The immobilized beta-glucosidase remained fully active during 2 weeks of continuous column operation at 50 degrees C.