Binding of glucan-binding protein C to GTFD-synthesized soluble glucan in sucrose-dependent adhesion of Streptococcus mutans

Oral Microbiol Immunol. 2006 Feb;21(1):42-6. doi: 10.1111/j.1399-302X.2005.00252.x.


Streptococcus mutans produces glucan-binding proteins (Gbp proteins) which promote the adhesion of the organism to teeth. Three Gbp proteins, GbpA protein, GbpB protein, and GbpC protein have been identified; however, the mechanism of adhesion between glucans and bacterial cell surfaces is unknown. We used glucosyltransferase (GTF)- and/or Gbp-deficient mutants to examine the role of GbpC protein in the sucrose-dependent cellular adhesion of S. mutans to glass surfaces. The wild-type strain MT8148 and a GbpA-deficient mutant strain displayed increased sucrose-dependent adhesion following the addition of rGTFD. However, a GbpC-deficient mutant strain demonstrated no changes in the level of sucrose-dependent adhesion in spite of the addition of rGTFD. Further, the binding of rGbpC protein to the glucan synthesized by rGTFD was significantly higher than that to the glucan synthesized by either rGTFB or rGTFC. These results suggest that GbpC protein may play an important role in sucrose-dependent adhesion by binding to the soluble glucan synthesized by GTFD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Adhesion*
  • Bacterial Proteins / classification
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Carrier Proteins / classification
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Glucans / biosynthesis*
  • Glucosyltransferases / metabolism*
  • Humans
  • Lectins / classification
  • Lectins / genetics
  • Lectins / metabolism*
  • Membrane Proteins / classification
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutation / genetics
  • Polysaccharides, Bacterial / biosynthesis*
  • Streptococcus mutans / genetics
  • Streptococcus mutans / metabolism*
  • Sucrose / metabolism*


  • Bacterial Proteins
  • Carrier Proteins
  • Glucans
  • Lectins
  • Membrane Proteins
  • Polysaccharides, Bacterial
  • glucan-binding proteins
  • Sucrose
  • Glucosyltransferases
  • glucosyltransferase D