Interaction of Salivary alpha-Amylase and Amylase-Binding-Protein A (AbpA) of Streptococcus gordonii with Glucosyltransferase of S. gordonii and Streptococcus mutans

Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, New York, USA. <>
BMC Microbiology (Impact Factor: 2.73). 02/2007; 7(1):60. DOI: 10.1186/1471-2180-7-60
Source: PubMed


Glucosyltransferases (Gtfs), enzymes that produce extracellular glucans from dietary sucrose, contribute to dental plaque formation by Streptococcus gordonii and Streptococcus mutans. The alpha-amylase-binding protein A (AbpA) of S. gordonii, an early colonizing bacterium in dental plaque, interacts with salivary amylase and may influence dental plaque formation by this organism. We examined the interaction of amylase and recombinant AbpA (rAbpA), together with Gtfs of S. gordonii and S. mutans.
The addition of salivary alpha-amylase to culture supernatants of S. gordonii precipitated a protein complex containing amylase, AbpA, amylase-binding protein B (AbpB), and the glucosyltransferase produced by S. gordonii (Gtf-G). rAbpA was expressed from an inducible plasmid, purified from Escherichia coli and characterized. Purified rAbpA, along with purified amylase, interacted with and precipitated Gtfs from culture supernatants of both S. gordonii and S. mutans. The presence of amylase and/or rAbpA increased both the sucrase and transferase component activities of S. mutans Gtf-B. Enzyme-linked immunosorbent assay (ELISA) using anti-Gtf-B antibody verified the interaction of rAbpA and amylase with Gtf-B. A S. gordonii abpA-deficient mutant showed greater biofilm growth under static conditions than wild-type in the presence of sucrose. Interestingly, biofilm formation by every strain was inhibited in the presence of saliva.
The results suggest that an extracellular protein network of AbpA-amylase-Gtf may influence the ecology of oral biofilms, likely during initial phases of colonization.

Download full-text


Available from: Frank Scannapieco, Oct 06, 2015
113 Reads
  • Source
    • "Also, KS1gtfG colonized less well than its progenitor (absolute, p = 0.027; percent, p < 0.001). The percentage of total recoverable flora constituted by LT11 plus KS1gtfGabpA double-mutant was lower than for all other doubly inoculated rat groups (p < 0.001), suggesting complex in vivo interactive effects between AbpA and GtfG of S. gordonii and/or GtfB of S. mutans, as previously reported in vitro (Chaudhuri et al., 2007). Nonetheless, in doubly inoculated rats, S. mutans LT11 vastly predominated on the surfaces of the teeth. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Streptococcus gordonii and Streptococcus mutans avidly colonize teeth. S. gordonii glucosyltransferase (GtfG) and amylase-binding proteins (AbpA/AbpB), and S. mutans glucosyltransferase (GtfB), affect their respective oral colonization abilities. We investigated their interrelationships and caries association in a rat model of human caries, examining the sequence of colonization and non- vs. high-sucrose diets, the latter being associated with aggressive decay in humans and rats. Virulence-characterized wild-types of both species and well-defined mutants of S. gordonii with interrupted abpA and gtfG genes were studied. While both S. gordonii and S. mutans were abundant colonizers of rat's teeth in the presence of either diet, if inoculated singly, S. mutans always out-competed S. gordonii on the teeth, independent of diet, strain of S. mutans, simultaneous or sequential inoculation, or presence/absence of mutations of S. gordonii's abpA and gtfG genes known to negatively or positively affect its colonization and to interact in vitro with S. mutans GtfB. S. mutans out-competed S. gordonii in in vivo plaque biofilm. Caries induction reflected S. mutans or S. gordonii colonization abundance: the former highly cariogenic, the latter not. S. gordonii does not appear to be a good candidate for replacement therapy. These results are consistent with human data.
    Journal of dental research 03/2012; 91(5):513-9. DOI:10.1177/0022034512442894 · 4.14 Impact Factor
  • Source
    • "α-Amylase also exerts antibacterial effects, which are either drawn back to an inhibition of bacteria growth by diminishing nutrients [10] or to a direct interaction with α-amylase [11]. Regarding cell culture, known α-amylase-substrates, like starch, are usually not present in cell culture media, but an α-amylase effect by metabolism of nutrients cannot be completely excluded. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Breast cancer is one of the most diagnosed cancers in females, frequently with fatal outcome, so that new strategies for modulating cell proliferation in the mammary tissue are urgently needed. There is some, as yet inconclusive evidence that α-amylase may constitute a novel candidate for affecting cellular growth. The present investigation aimed to examine if salivary α-amylase, an enzyme well known for the metabolism of starch and recently introduced as a stress marker, is able to exert antiproliferative effects on the growth of mammary gland epithelial cells. For this purpose, primary epithelial cultures of breast tissue from two different inbred rat strains, Fischer 344 (F344) and Lewis, as well as breast tumor cells of human origin were used. Treatment with human salivary α-amylase was performed once daily for 2 days followed by cell counting (trypan blue assay) to determine alterations in cell numbers. Cell senescence after α-amylase treatment was assessed by β-galactosidase assay. Endogenous α-amylase was detected in cells from F344 and Lewis by immunofluorescence. Salivary α-amylase treatment in vitro significantly decreased the proliferation of primary cells from F344 and Lewis rats in a concentration-dependent manner. Noticeably, the sensitivity towards α-amylase was significantly higher in Lewis cells with stronger impact on cell growth after 5 and 50 U/ml compared to F344 cells. An antiproliferative effect of α-amylase was also determined in mammary tumor cells of human origin, but this effect varied depending on the donor, age, and type of the cells. The results presented here indicate for the first time that salivary α-amylase affects cell growth in rat mammary epithelial cells and in breast tumor cells of human origin. Thus, α-amylase may be considered a novel, promising target for balancing cellular growth, which may provide an interesting tool for tumor prophylaxis and treatment.
    Journal of Experimental & Clinical Cancer Research 10/2011; 30(1):102. DOI:10.1186/1756-9966-30-102 · 4.43 Impact Factor
  • Source
    • "It is also noteworthy that many oral microorganisms, including S. mutans, adsorb lysozyme, amylase and other salivary proteins [Douglas, 1983; Douglas and Russell, 1984; Ambatipudi et al., 2010], which may influence the binding of GtfB on the bacterial cell surface. The simultaneous binding of GtfB and salivary amylase and their interactions create the opportunity to synthesize complex insoluble glucans directly on the bacterial surface [Vacca-Smith et al., 1996a; Chaudhuri et al., 2007]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The importance of Streptococcus mutans in the etiology and pathogenesis of dental caries is certainly controversial, in part because excessive attention is paid to the numbers of S. mutans and acid production while the matrix within dental plaque has been neglected. S. mutans does not always dominate within plaque; many organisms are equally acidogenic and aciduric. It is also recognized that glucosyltransferases from S. mutans (Gtfs) play critical roles in the development of virulent dental plaque. Gtfs adsorb to enamel synthesizing glucans in situ, providing sites for avid colonization by microorganisms and an insoluble matrix for plaque. Gtfs also adsorb to surfaces of other oral microorganisms converting them to glucan producers. S. mutans expresses 3 genetically distinct Gtfs; each appears to play a different but overlapping role in the formation of virulent plaque. GtfC is adsorbed to enamel within pellicle whereas GtfB binds avidly to bacteria promoting tight cell clustering, and enhancing cohesion of plaque. GtfD forms a soluble, readily metabolizable polysaccharide and acts as a primer for GtfB. The behavior of soluble Gtfs does not mirror that observed with surface-adsorbed enzymes. Furthermore, the structure of polysaccharide matrix changes over time as a result of the action of mutanases and dextranases within plaque. Gtfs at distinct loci offer chemotherapeutic targets to prevent caries. Nevertheless, agents that inhibit Gtfs in solution frequently have a reduced or no effect on adsorbed enzymes. Clearly, conformational changes and reactions of Gtfs on surfaces are complex and modulate the pathogenesis of dental caries in situ, deserving further investigation.
    Caries Research 02/2011; 45(1):69-86. DOI:10.1159/000324598 · 2.28 Impact Factor
Show more