Expression and purification of Escherichia coli beta-glucuronidase

A strong and constitutive expression vector of Escherichia coli beta -glucu ronidase with the isocitrate dehydrogenase promoter has been developed for producing a large amount of recombinant protein. More than 95% pure enzyme was obtained by a four step purification procedure-ammonium sulfate precipi tation, DEAE ion-exchange chromatography, Superose 12 gel filtration, and h ydroxyapatite steric ion-exchange chromatography. The overexpressed gene ca n produce 23 mg of pure enzyme from one liter of bacterial culture. (C) 200 1 Academic Press.