title: Two-dimensional fluorescence difference gel electrophoretic analysis of Streptococcus mutans biofilms.
abstract: Compared with traditional two-dimensional (2D) proteome analysis of Streptococcus mutans grown as a biofilm from a planktonic culture at steady state (Rathsam et al., Microbiol. 2005, 151, 1823-1837), the use of 2D fluorescence difference gel electrophoresis (DIGE) led to a 3-fold increase in the number of identified protein spots that were significantly altered in their level of expression (P < 0.050). Of the 73 identified proteins, only nine were up-regulated in biofilm grown cells. The results supported the previously surmised hypothesis that general metabolic functions were down-regulated in response to a reduction in growth rate in mature S. mutans biofilms. Up-regulation of competence proteins without any concomitant increase in stress-responsive proteins was confirmed, while the levels of glucosyltransferase C (GtfC), involved in glucan formation, O-acetylserine sulfhyrylase (cysteine synthetase A; CsyK), implicated in the formation of [Fe-S] clusters, and a hypothetical protein encoded by the open reading frame, SMu0188, were also up-regulated.
authors.affiliation: Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, New South Wales, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Rathsam
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Eaton
authors.forename: Christine L
authors.initials: CL
authors.lastname: Simpson
authors.forename: Gina V
authors.initials: GV
authors.lastname: Browne
authors.forename: Valentina A
authors.initials: VA
authors.lastname: Valova
authors.forename: Derek W S
authors.initials: DW
authors.lastname: Harty
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Jacques
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D001483:Base Sequence; D018441:Biofilms; D049109:Cell Proliferation; D003547:Cysteine Synthase / Q000378:metabolism; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D005936:Glucans / Q000737:chemistry / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D010728:Phosphoenolpyruvate / Q000737:chemistry; D010770:Phosphotransferases / Q000378:metabolism; D010933:Plankton / Q000378:metabolism; D011506:Proteins / Q000737:chemistry; D020543:Proteome; D040901:Proteomics / Q000379:methods*; D013295:Streptococcus mutans / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; D005936:Glucans; D007506:Iron-Sulfur Proteins; D011506:Proteins; D020543:Proteome; D010728:Phosphoenolpyruvate; D005964:Glucosyltransferases; C110463:glucosyltransferase C; D003547:Cysteine Synthase; D010770:Phosphotransferases