PURIFICATION AND PROPERTIES OF DEXTRANSUCRASE FROM STREPTOCOCCUS SANGUIS

Dextransucrase from Streptococcus sanguis was isolated from the supernatant fluid of a glucose-containing broth culture. Purification of this constitutive enzyme was achieved in two steps by adsorption on hydroxylapatite followed by iso-electric focusing and fractionation. This resulted in a 400-fold purification of the enzyme which was obtained in about a 15 per cent yield. The enzyme had a pH optimum between 5.2 and 7.0, Michaelis constant of 4.8 mM sucrose, optimal activity at 45 °C and an iso-electric point at pH 7.9. Certain of these properties are of significance for the accumulation of bacteria on the teeth. © 1969.