%0 Journal Article %A TSUMORI, HIDEAKI %A SHIMAMURA, ATSUNARI %A MUKASA, HIDEHIKO %T Purification and Properties of Extracellular Glucosyltransferase Synthesizing 1,3-α-d-Glucan from Streptococcus mutans Serotype α %D 1985 %J Microbiology, %V 131 %N 3 %P 553-559 %@ 1465-2080 %R https://doi.org/10.1099/00221287-131-3-553 %I Microbiology Society, %X Extracellular 1,3-α-d-glucan synthase (sucrose: 1,3-α-d-glucan 3-α-d-glucosyltransferase, EC 2.4.1. –) of Streptococcus mutans HS6 (serotype a) was purified from culture supernatant by ultrafiltration, DEAE-Sepharose chromatography and preparative isoelectric focusing. The enzyme had a molecular weight of 158000 by SDS-PAGE and an isoelectric point of pH 5·2. The specific activity of the enzyme was 48·3 i.u. (mg protein)–1. The K m for sucrose was 1·2 mm and the activity was optimal at pH 6·0. The enzyme activity was stimulated about 20-fold in the presence of dextran T10. Glucan was synthesized de novo from sucrose by the enzyme and characterized as a linear 1,3-α-d-glucan by GC–MS. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-131-3-553