Action of agents on glucosyltransferases from Streptococcus mutans in solution and adsorbed to experimental pellicle

Wunder, David; Bowen, William H.

doi:10.1016/s0003-9969(98)00129-0

Cited by 90 publications

(126 citation statements)

References 41 publications

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“…As shown in Fig. 3, glucans formed on sHA (gsHA) significantly increased S. mutans adherence to the apatite surface compared to sHA without glucans (sHA only), which is in agree- ment with previous studies (9,10,16,51). More importantly, the addition of eDNA significantly increased bacterial adherence to gsHA but not to sHA.…”

Section: S Mutans Produces Dnase I-sensitive Extracellular Nanofiberssupporting

confidence: 91%

“…The resulting cell suspension was briefly sonicated to dechain the cells and adjusted to an optical density at 600 nm (OD 600 ) of ϳ1.0 Ϯ 0.05, with cell numbers counted on a PetroffHausser cell-counting chamber (Hausser Scientific Partnership, Horsham, PA). GtfB was prepared from culture supernatants of S. anginosus KSB8 and purified to near homogeneity by using HA column chromatography as described by Wunder et al (51). GtfB activity was measured by the incorporation of [ 14 C]glucose from labeled sucrose (NEN Research Products, MA) into glucans (9).…”

Section: Methodsmentioning

confidence: 99%

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Streptococcus mutans Extracellular DNA Is Upregulated during Growth in Biofilms, Actively Released via Membrane Vesicles, and Influenced by Components of the Protein Secretion Machinery

et al. 2014

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f Streptococcus mutans, a major etiological agent of human dental caries, lives primarily on the tooth surface in biofilms. Limited information is available concerning the extracellular DNA (eDNA) as a scaffolding matrix in S. mutans biofilms. This study demonstrates that S. mutans produces eDNA by multiple avenues, including lysis-independent membrane vesicles. Unlike eDNAs from cell lysis that were abundant and mainly concentrated around broken cells or cell debris with floating open ends, eDNAs produced via the lysis-independent pathway appeared scattered but in a structured network under scanning electron microscopy. Compared to eDNA production of planktonic cultures, eDNA production in 5-and 24-h biofilms was increased by >3-and >1.6-fold, respectively. The addition of DNase I to growth medium significantly reduced biofilm formation. In an in vitro adherence assay, added chromosomal DNA alone had a limited effect on S. mutans adherence to saliva-coated hydroxylapatite beads, but in conjunction with glucans synthesized using purified glucosyltransferase B, the adherence was significantly enhanced. Deletion of sortase A, the transpeptidase that covalently couples multiple surface-associated proteins to the cell wall peptidoglycan, significantly reduced eDNA in both planktonic and biofilm cultures. Sortase A deficiency did not have a significant effect on membrane vesicle production; however, the protein profile of the mutant membrane vesicles was significantly altered, including reduction of adhesin P1 and glucan-binding proteins B and C. Relative to the wild type, deficiency of protein secretion and membrane protein insertion machinery components, including Ffh, YidC1, and YidC2, also caused significant reductions in eDNA.

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Section: S Mutans Produces Dnase I-sensitive Extracellular Nanofiberssupporting

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Streptococcus mutans Extracellular DNA Is Upregulated during Growth in Biofilms, Actively Released via Membrane Vesicles, and Influenced by Components of the Protein Secretion Machinery

et al. 2014

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“…7 On the other hand, the mechanism for this effect does not seem to be related to inhibition of EPS production by S. mutans GTFs. 12,13 Like prior in situ dental biofilm findings, 7 our results suggest that the reduction in demineralization cannot be explained by a direct effect on GTF activity. This absence of an effect on EPS production by S. mutans in the biofilm also cannot be explained based on the concentration of Fe used in this experiment, since at the highest concentration used (100 µg/mL = 1.8 mM), 80% EPS inhibition, found in previous in vitro studies, 13 would have been expected.…”

Section: Discussionsupporting

confidence: 78%

“…On the other hand, by interfering with sucrose metabolism, Fe may reduce the production of extracellular polysaccharides (EPS), which are considered virulence factors of S. mutans. 11 Moreover, it has been shown that Fe inhibits glycotransferase (GTF) enzymes produced by S. mutans in vitro 12 via an oxidative mechanism involving a Fenton-type reaction. 13 However, Fe at a concentration of 70 µg/mL (1.2 mM) has shown no in situ effect either on the acidogenicity of dental biofilm or in terms of reducing the quantity of EPS in a biofilm exposed to 10% sucrose, 7 thus suggesting the need for further studies on the mechanism of action of the anticaries effect of Fe.…”

Section: Declaration Of Interestsmentioning

confidence: 99%

The effect of iron on Streptococcus mutans biofilm and on enamel demineralization

et al. 2012

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“…reuteri 121 GTFA acceptor reaction products (as described in Methods). (A) Elution profile of a standard mixture; (B) products formed on incubation of 30 nM GTFA-CHis enzyme with 100 mM sucrose and 100 mM maltose for 60 h; (C) products formed on incubation of 30 nM GTFA-CHis enzyme with 100 mM sucrose and 100 mM isomaltose for 60 h. gtfD-encoded enzymes of Streptococcus mutans (Wunder & Bowen, 1999).…”

Section: Discussion Characterization Of Gtfamentioning

confidence: 99%

Biochemical and molecular characterization of Lactobacillus reuteri 121 reuteransucrase

et al. 2004

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Lactobacillus reuteri strain 121 uses sucrose for synthesis of a unique, soluble glucan (‘reuteran’) with mainly α-(1→4) glucosidic linkages. The gene (gtfA) encoding this glucansucrase enzyme had previously been characterized. Here, a detailed biochemical and molecular analysis of the GTFA enzyme is presented. This is believed to be the first report describing reuteransucrase enzyme kinetics and the oligosaccharides synthesized with various acceptors. Alignments of the GTFA sequence with glucansucrases from Streptococcus and Leuconostoc identified conserved amino-acid residues in the catalytic core critical for enzyme activity. Mutants Asp1024Asn, Glu1061Gln and Asp1133Asn displayed 300- to 1000-fold-reduced specific activities. To investigate the role of the relatively large N-terminal variable domain (702 amino acids) and the relatively short C-terminal putative glucan-binding domain (267 amino acids, with 11 YG repeats), various truncated derivatives of GTFA (1781 amino acids) were constructed and characterized. Deletion of the complete N-terminal variable domain of GTFA (GTFA-ΔN) had little effect on reuteran characteristics (size, distribution of glycosidic linkages), but the initial transferase activity of the mutant enzyme increased drastically. Sequential C-terminal deletions (up to six YG repeats) in GTFA-ΔN also had little effect on reuteran characteristics. However, enzyme kinetics drastically changed. Deletion of 7, 8 or 11 YG repeats resulted in dramatic loss of total enzyme activity (43-, 63- and 1000-fold-reduced specific activities, respectively). Characterization of sequential C-terminal deletion mutants of GTFA-ΔN revealed that the C-terminal domain of reuteransucrase has an important role in glucan binding.

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Action of agents on glucosyltransferases from Streptococcus mutans in solution and adsorbed to experimental pellicle

Cited by 90 publications

References 41 publications

Streptococcus mutans Extracellular DNA Is Upregulated during Growth in Biofilms, Actively Released via Membrane Vesicles, and Influenced by Components of the Protein Secretion Machinery

Streptococcus mutans Extracellular DNA Is Upregulated during Growth in Biofilms, Actively Released via Membrane Vesicles, and Influenced by Components of the Protein Secretion Machinery

The effect of iron on Streptococcus mutans biofilm and on enamel demineralization

Biochemical and molecular characterization of Lactobacillus reuteri 121 reuteransucrase

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