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Resolution of Streptococcus mutans glucosyltransferases into two components essential to water‐insoluble glucan synthesis
Author(s) -
Fukushima Kazuo,
Motoda Ryuichi,
Takada Kazuko,
Ikeda Tadashi
Publication year - 1981
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(81)80083-x
Subject(s) - bacteriology , dentistry , streptococcus mutans , medicine , biology , bacteria , genetics
Streptococcus mutans has been implicated as a significant factor in the development of human dental plaque and subsequent caries formation [ 1,2]. The cariogenicity of this organism is mainly dependent on its ability to convert dietary sucrose to adhesive waterinsoluble glucans (WIG) which give a high proportion of o-(1 + 3) to o-(1 + 6) linkages [3-51. Many bacterial species produce extracellular glucosyltransferases (EC 2.4.1.5 ‘dextran-sucrase’) which catalyze the formation of water-soluble glucans (WSG), consisting of a-(1 + 6) glucosidic linkages primarily [S-9]. The dextransucrase from several strains of S. mutans have been purified and characterized [8-lo]. In contrast, attempts to purify the water-insoluble glucan-synthesizing glucosyltransferases (WIG-GTase) have consistently failed either because the enzyme remains in high Mr aggregates [9-131, or because the activity disappears during purification procedures [ 14,151. Therefore, the mechanism of WIG synthesis by S. mutans as well as the number of proteins required for its synthesis are still unknown. Here, we describe the isolation of the disaggregated WIG-GTase from the culture fluid of S. mutans strain B-l 3 (serotype d), and show an evidence that adhesive WIG are synthesized through an overall reaction by 2 protein components.