Immunological relationships between glucosyltransferases from Streptococcus mutans serotypes

Abstract

Partially purified glucosyltransferase enzymes from Streptococcus mutans GS-5 (serotype c) have been utilized to prepare antibodies directed against the soluble glucan-synthesizing activity, GTF-B, and the insoluble-soluble glucan synthetic activity, GTF-A. Anti-GTF-A inhibited insoluble glucan formation catalyzed by the extracellular enzymes from strains GS-5 and FA-1 (serotype b) to a much greater extent than that of strain HS-6 (serotype a) or OMZ-176 (serotype d). This antibody fraction also inhibited both the cell-associated glucosyltransferase activities as well as the sucrose-mediated adherence of cells to glass surfaces by strains GS-5 and FA-1 but not that of strains HS-6 and OMZ-176. Anti-GTF-B inhibited soluble glucan formation catalyzed by the extracellular enzymes of strain GS-5 but not that of strain HS-6, FA-1, or OMZ-176. However, this antibody fraction did not strongly inhibit either the cell-associated glucosyltransferase activity or cellular adherence of any ofthe four strains. These results with both antibody fractions were also correlated with the ability of the antibodies to agglutinate the cells and form precipitin bands after immunodiffusion with the extracellular enzymes. Antibody prepared against the homogeneous soluble glucan-synthesizing enzyme demonstrated similar effects to the anti-GTF-B fraction. These results are discussed in terms ofthe antigenic relationships existing between the glucosyltransferases from different serotypes of S. mutans.

Molecular basis for the different sucrose-dependent adherence properties of Streptococcus mutans and Streptococcus sanguis

“…The classification of strain ST3 as a member of the S. sanguis group was made on the basis of its 330 colonial morphology and fermentation patterns (S. Hamada, personal communication). In addition, unlike all strains of S. mutans examined in this laboratory, antibodies directed against the GTF activities of S. mutans GS5 (21) do not inhibit the corresponding enzyme activities of S. sanguis ST3.…”

Serotype‐Dependent Inhibition of Glucan Synthesis and Cell Adherence of Streptococcus mutans by Antibody against Glucosyltransferase of Serotype e S. mutans

“…Antibodies against GTase(s) inhibit enzyme activity (1,6,7,9,10,21,23,35) and result in the reduction of experimental caries of S. mutans in rats (37). 5. mutans has been classified into seven serotypes (3,14,15,31) of which immunological specificity is based on the cell wall polysaccharide (12,17,22,23,26,27,40).…”

Localization of Streptococcus mutans GS-5 glucosyltransferases and intracellular invertase

“…Since both anti-GTF-A and anti-GTF-B cross-react with both antigens (16), it might be expected that both antibody preparations would display similar PAP-labeling patterns. However, both antibody preparations affected cell-associated GTF activity to different degrees (15,16), with anti-GTF-A showing much more reactivity than anti-GTF-B. These studies also demonstrated that anti-GTF-A readily aggregated GS-5 cells, whereas anti-GTF-B did so only weakly.…”

“…Furthermore, it is still not clear whether a single GTF species capable of producing both soluble and insoluble glucans is produced by S. mutans or whether multiple enzymes are involved. Both antibody preparations used in the present investigation will cross-react with GTF-A and GTF-B (15).…”

“…Preparation of antisera. Antisera against highly purified invertase and GTF-B, a fraction responsible for synthesizing soluble glucans, were produced as previously reported (15,19). The GTF-B fraction displays a single band on sodium dodecyl sulfate-poly- VOL.…”