Purification and Mechanism of Action of Sucrose Phosphorylase

Sucrose phosphorylase (disaccharide glucosyltransferase) from Pseudomonas saccharophila has been highly purified. The enzyme appears to be homogeneous in the ultracentrifuge, on starch gel electrophoresis and on polyacrylamide gel disc electrophoresis. The molecular weight of the enzyme as determined by Sephadex chromatography is 80,000 to 100,000. The kinetics of the reaction was examined and found to be consistent with a double displacement mechanism involving formation of a glucose-enzyme complex and a subsequent reaction of this complex with acceptor to form the reaction products. Further evidence of the formation of a glucose-enzyme complex was obtained by isolating a denatured form of the complex. This complex contained 1 mole of glucose per mole of enzyme.