Oral Starch Degradation and Its Influence on Acid Production in Human Dental Plaque

Mörmann, Jeanette E.; Mühlemann, H

doi:10.1159/000260514

Cited by 83 publications

(47 citation statements)

References 30 publications

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“…The growth of strain MGAS5005 in maltotriose-medium was essentially identical to the growth in a medium containing glucose, the preferred carbon source for many bacteria (Table 1) (24,35). Importantly, the major habitat for GAS in humans, the oropharynx, has high levels of maltotriose and maltodextrins longer than glucose and maltose as a result of starch breakdown by salivary ␣-amylase (14,19). We next determined whether the rapid growth of strain MGAS5005 in maltotriose-medium was also observed in media with longer maltodextrins as the sole carbon sources.…”

Section: Resultsmentioning

confidence: 87%

“…Instead, the major products are maltose, maltotriose, maltotetraose, and longer maltodextrins. Importantly, maltotriose and longer maltodextrins make up more than 80% of the breakdown products resulting from starch digestion by salivary ␣-amylase, meaning that maltose production is limited (15,19). Moreover, salivary ␣-amylase is unable to break down maltotriose, which allows large quantities to accumulate on dentition and in saliva following food ingestion (14,15).…”

Section: Discussionmentioning

confidence: 99%

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MalE of Group A Streptococcus Participates in the Rapid Transport of Maltotriose and Longer Maltodextrins

et al. 2007

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Study of the maltose/maltodextrin binding protein MalE in Escherichia coli has resulted in fundamental insights into the molecular mechanisms of microbial transport. Whether gram-positive bacteria employ a similar pathway for maltodextrin transport is unclear. The maltodextrin binding protein MalE has previously been shown to be key to the ability of group A Streptococcus (GAS) to colonize the oropharynx, the major site of GAS infection in humans. Here we used a multifaceted approach to elucidate the function and binding characteristics of GAS MalE. We found that GAS MalE is a central part of a highly efficient maltodextrin transport system capable of transporting linear maltodextrins that are up to at least seven glucose molecules long. Of the carbohydrates tested, GAS MalE had the highest affinity for maltotriose, a major breakdown product of starch in the human oropharynx. The thermodynamics and fluorescence changes induced by GAS MalE-maltodextrin binding were essentially opposite those reported for E. coli MalE. Moreover, unlike E. coli MalE, GAS MalE exhibited no specific binding of maltose or cyclic maltodextrins. Our data show that GAS developed a transport system optimized for linear maltodextrins longer than two glucose molecules that has several key differences from its well-studied E. coli counterpart.Analysis of microbial carbohydrate physiology has been a fertile area of scientific research for many decades. Fundamental discoveries in the areas of transcriptional regulation, selective nutrient utilization, and molecular transport have been derived from studies of microbial carbohydrate acquisition and processing (13,27,34). For example, the uptake and utilization of maltose/maltodextrins by Escherichia coli has become a model for understanding how microbes transport and use complex sugars (3).The study of E. coli MalE, the periplasmic substrate binding protein of the maltose/maltodextrin ATP binding cassette transporter, has been a particularly fruitful area of investigation (32, 33). Although E. coli MalE binds to a variety of ␣-1,4-linked oligoglucosides, including linear, cyclic, reduced, and oxidized maltodextrins, only a portion of the bound ligands is subsequently transported into the cell (10). The interaction of purified E. coli MalE with the actively transported substrates maltose and maltotriose causes an increase in the E. coli MalE maximum emission wavelength (10, 39). The change in the fluorescence emission spectrum correlates with the closed and open forms of the E. coli . The closed form is needed for active transport to occur (11). The binding of E. coli MalE to substrates that are actively transported results in an endothermic reaction that is entropy driven (40). Conversely, the binding of E. coli MalE to nontransported substrates is exothermic and results in a decrease in the maximum fluorescence emission wavelength of E. coli MalE (9, 40). Therefore, study of E. coli MalE has generated data showing two major modes of ligand binding: one in which an endothermic reaction driven by...

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Section: Resultsmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

MalE of Group A Streptococcus Participates in the Rapid Transport of Maltotriose and Longer Maltodextrins

et al. 2007

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“…1 Several properties of latex and nonlatex elastics have been evaluated, [2][3][4][5][6][7][8][9][10][11][12] some involving saliva or simulated saliva solutions. 2,[6][7][8][13][14][15][16][17] Few studies have investigated the effects of salivary pH levels on viscoelastic force relaxation of nonlatex interarch elastics. 18 Great individual pH variability is noted within the oral cavity, and this can fluctuate with diet.…”

Section: Introductionmentioning

confidence: 99%

The effect of pH levels on nonlatex vs latex interarch elastics

Sauget¹,

Stewart²,

Katona³

2011

The Angle Orthodontist

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Objective: To evaluate the force decay characteristics of nonlatex vs latex interarch elastics within the normal range of salivary pH levels. Materials and Methods: Two nonlatex groups and one latex quasi-control group were tested. Elastics were stretched to 15 mm and were held for 10 seconds (baseline), 4 hours, 8 hours, and 12 hours in artificial saliva solutions with pH levels of 5.0, 6.0, and 7.5. Force magnitudes were measured at 25 mm of activation. Each specimen was used once. Measurements were assessed using three-way analysis of variance (ANOVA). Results: The three-way interaction between group, pH, and time was not significant (P 5 .13); the group-by-pH interaction also was not significant (P 5 .70). However, pH-by-time (P 5 .0179) and group-by-time (P 5 .0001) interactions were significant.

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“…Genes that encode carbohydrate-degrading enzymes are common in the genomes of other streptococcal pathogens and play a role in nutrient acquisition for growth and colonization on mucosal surfaces (Rollenhagen & Bumann, 2006;Shelburne et al, 2006Shelburne et al, , 2008a. Dietary sources of highly polymerized a-glycans such as starch and glycogen are abundant in the human colon (Levitt et al, 1987) and oropharynx (Mormann & Muhlemann, 1981;Shelburne et al, 2005 Shelburne et al, , 2007Virtaneva et al, 2005), as well as the epithelium of the vagina and lung (Gourlay et al, 2009;Gregoire et al, 1971; Santi et al, 2008;van Bueren et al, 2007). Degradation of starch and glycogen proceeds in most organisms via the action of amylases and pullulandegrading enzymes (e.g.…”

Section: Introductionmentioning

confidence: 99%

ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus

et al. 2010

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We have identified apuA in Streptococcus suis, which encodes a bifunctional amylopullulanase with conserved a-amylase and pullulanase substrate-binding domains and catalytic motifs. ApuA exhibited properties typical of a Gram-positive surface protein, with a putative signal sequence and LPKTGE cell-wall-anchoring motif. A recombinant protein containing the predicted N-terminal a-amylase domain of ApuA was shown to have a-(1,4) glycosidic activity. Additionally, an apuA mutant of S. suis lacked the pullulanase a-(1,6) glycosidic activity detected in a cell-surface protein extract of wild-type S. suis. ApuA was required for normal growth in complex medium containing pullulan as the major carbon source, suggesting that this enzyme plays a role in nutrient acquisition in vivo via the degradation of glycogen and food-derived starch in the nasopharyngeal and oral cavities. ApuA was shown to promote adhesion to porcine epithelium and mucus in vitro, highlighting a link between carbohydrate utilization and the ability of S. suis to colonize and infect the host. INTRODUCTIONStreptococcus suis is a major porcine pathogen of significant commercial importance worldwide. In suckling and weaning pigs, it is the principal cause of acute meningitis, but can infect other organs leading to arthritis, serositis, endocarditis, otitis media and bronchopneumonia (Beineke et al., 2008;Madsen et al., 2002). Healthy pigs asymptomatically colonized with S. suis form a reservoir for this disease and play a major role in its epidemiology (Arends et al., 1984). To date, 33 different capsule serotypes of S. suis have been identified, but serotype 2 is most commonly associated with disease worldwide Lun et al., 2007). Serotype 2 strains were also associated with recent large outbreaks of severe human infections in China and elsewhere in Asia (Mai et al., 2008;Tang et al., 2006;Wertheim et al., 2009). The recently obtained genome sequences of two virulent Chinese S. suis serotype 2 strains (98HAH12 and 05ZYH33) and P1/7, the European reference strain (http://www.sanger.ac.uk/Projects/S_suis/), led to the identification of a large number of potential surface and secreted proteins that might play a role in virulence, including a number of putative carbohydratedegrading enzymes (Baums & Valentin-Weigand, 2009). Genes that encode carbohydrate-degrading enzymes are common in the genomes of other streptococcal pathogens and play a role in nutrient acquisition for growth and colonization on mucosal surfaces (Rollenhagen & Bumann, 2006;Shelburne et al., 2006Shelburne et al., , 2008a. Dietary sources of highly polymerized a-glycans such as starch and glycogen are abundant in the human colon (Levitt et al., 1987) and oropharynx (Mormann & Muhlemann, 1981;Shelburne et al., 2005 Shelburne et al., , 2007Virtaneva et al., 2005), as well as the epithelium of the vagina and lung (Gourlay et al., 2009;Gregoire et al., 1971; Santi et al., 2008;van Bueren et al., 2007). Degradation of starch and glycogen proceeds in most organisms via the action of amylases a...

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Oral Starch Degradation and Its Influence on Acid Production in Human Dental Plaque

Cited by 83 publications

References 30 publications

MalE of Group A Streptococcus Participates in the Rapid Transport of Maltotriose and Longer Maltodextrins

MalE of Group A Streptococcus Participates in the Rapid Transport of Maltotriose and Longer Maltodextrins

The effect of pH levels on nonlatex vs latex interarch elastics

ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus

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