PURIFICATION AND SOME PROPERTIES OF SUCROSE PHOSPHORYLASE FROM LEUCONOSTOC-MESENTEROIDES

Sucrose phosphorylase (EC 2.4.1.7) was purified to homogeneity from Leuconostoc mesenteroides cells with a specific activity of 173.8 units per mg protein by ammonium sulfate fractionation, anion exchange HPLC on TSKgel DEAE-5PW, and hydrophobic HPLC on TSKgel Ether-5PW. The purified enzyme was an acidic protein having an isoelectric point of pH 4.6 and s20.w0 of 4.34 S. The molecular weight of this enzyme was estimated to be 56,400 by sedimentation equilibrium, 55,000 by SDS-polyacrylamide gel electrophoresis, and HPLC gel filtration on TSKgel G3000SW, suggesting that the enzyme is a monomeric protein. With regard to molecular weight, amino acid composition, and N-terminal amino acid sequence of 30 residues, this enzyme is close to the glucosyltransferase A of Streptococcus mutans.