Purification and Characterization of an a-Glucosidase from Rhizobium sp. (Robinia pseudoacacia L.) Strain USDA 4280

A novel a-glucosidase with an apparent subunit mass of 59 6 0.5 kDa was purified from protein extracts of Rhizobium sp. strain USDA 4280, a nodulating strain of black locust (Robinia pseudoacacia L), and character- ized. After purification to homogeneity (475-fold; yield, 18%) by ammonium sulfate precipitation, cation- exchange chromatography, hydrophobic chromatography, dye chromatography, and gel filtration, this enzyme had