Abstract
Sucrose phosphorylase (EC 2.4.1.7) was purified to homogeneity from Leuconostoc mesenteroides cells with a specific activity of 173.8 units per nig 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 sO2O, W 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.
