Interaction of Streptococcus Mutans Glucosyltransferases with Antibodies

Abstract

The sucrose-dependent adherence of Streptococcus mutans to hard surfaces appears to be mediated by the elaboration of glucosyltransferase (GTF) (1) and dextranase (2–4) activities by these organisms. Several laboratories (4,5–8) have isolated GTF fractions synthesizing either water-insoluble or soluble glucans as their primary products. The fractions producing water-insoluble glucans appear to synthesize adherent polysaccharide while the soluble glucan synthesizing fractions by themselves do not catalyze the adherence of S. mutans to smooth surfaces (7,8). Antibody prepared against the partially purified insoluble glucan synthesizing fraction from strain GS5 (serotype c), GTF-A, has been demonstrated to inhibit the sucrose-dependent adherence of strain GS5 in vitro (9). In contrast, antibody against the purified soluble glucan synthesizing fraction, GTF-B, is much less effective in inhibiting adherence (9). These immunological results together with earlier structural characterization of GTF products (6, 10) have suggested that two or more GTF enzymes are produced by S. mutans. However, the number of GTF enzymes elaborated by these cariogenic bacteria has not yet been precisely defined.