Localization of Streptococcus mutans GS-5 glucosyltransferases and intracellular invertase

Abstract

Antibodies directed against Streptococcus mutans GS-5 intracellular invertase and glucosyltransferase fractions capable of synthesizing primarily water-soluble or insoluble glucans were used to ultrastructurally localize the enzymes by means of the unlabeled antibody peroxidase-antiperoxidase method. This immunocytochemical procedure revealed that the intracellular invertase was associated primarily with the cytoplasmic membrane of the cariogenic organism. The glucosyltransferase complex responsible for insoluble glucan synthesis was localized as aggregates attached to the cell surface or extracellular polysaccharides of strain GS-5. In contrast, the glucosyltransferase activity synthesizing primarily watersoluble glucans was distributed uniformly over the cell surface or in association with extracellular polysaccharides. These results are discussed relative to the sucrose-metabolizing ability of Streptococcus mutans.

Identification of a 1,3-α glucosyltransferase involved in insoluble glucan synthesis by a serotype c strain of Streptococcus mutans

“…In contrast, attempts to purify mutansucrase, the enzyme complex responsible for insoluble glucan synthesis, from serotype c strains have failed. This is because mutansucrase activity is associated with an aggregate of various proteins and other extracellular components [8,9,11]. Consequently, the enzyme which catalyses the insertion of sequences of 1,3a-linked glucosyl residues into insoluble glucans has not been identified.…”

Salivary immunoglobulin A and serum antibodies to Streptococcus mutans ribosomal preparations in dental caries-free and caries-susceptible human subjects

“…A determinant cross-reactive with surface antigen I/II has previously been shown to be present on the cell surface of S. mutans 6715 (25). Furthermore, Bozzola et al (2) reported that the GTF responsible for insoluble-glucan synthesis in S. mutans was localized at the cell surface.…”

Evaluation of Total Salivary Secretory Immunoglobulin A andMutans-specific SIgA among Children having Dissimilar Caries Status

“…These bacteria promote dental plaque formation on tooth surfaces. 9,10 This formation causes breakdown of sucrose into lactic acid, which lowers the pH of the oral cavity. This, in turn, leads to demineralization of inorganic portions and destruction of organic portions of teeth.…”