Determination of the structure of a broth dextran produced by a cariogenic streptococcus

Lewick, W. John; Long, Lawrence W.; Edwards, John

doi:10.1016/s0008-6215(00)81554-2

Cited by 58 publications

(17 citation statements)

References 18 publications

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“…This re sult significantly confirms the findings of others [Lewicki et al, 1971;Baird et al, 1973;Hare et al, 1978;Birkhed et al, 1979] that soluble glucans of S. mutans re present highly branched «-1,6-glucans.…”

Section: Discussionsupporting

confidence: 90%

“…The structure of extracellular polysac charides (EPS) produced by strains of Streptococcus mutans grown in sucrosecontaining media [Lewicki et al, 1971;Sidebotham et al, 1971;Usui et al, 1975;Nisizawa et al, 1976Nisizawa et al, , 1977Trautner, 1977;Freedman et al, 1978] or by glucosyltransferases synthesized by S. mutans [Gug-genheim, 1970;Ceska et al, 1972;Baird et al, 1973;Ebisu et al, 1974;Ellwood et al, 1976;Hare et al, 1978;Meyer et al, 1978] have been investigated intensively. Some authors [Ellwood et al, 1976;Meyer et al, 1978] suggested that there might exist a cor relation between some structural details of the EPS and the serotype of the strains in vestigated.…”

Section: Introductionmentioning

confidence: 99%

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Structure of Extracellular Glucans Synthesized by Streptococcus mutans of Serotypes a–e in vitro

1982

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Insoluble extracellular glucans synthesized by Streptococcus mutans in vitro were separated from bacterial cells by solubilization in potassium hydroxide. After neutralization of the alkaline solution only part of the glucans precipitated giving fraction AS-I. Another part was isolated from the neutralized solution by the addition of ethanol yielding fraction AS-II. Soluble glucans harvested from the culture supernatant were treated in the same manner giving fractions WS-I and WS-II, respectively. By methylation analysis it was shown that the insoluble glucans of fraction AS-I are characterized by a high percentage of α-1,3-linked glucosyl residues and a low degree of branching. In contrast to this, soluble glucans of fraction WS-II represent highly branched polysaccharides with a content of α-1,6-linkages between 40 and 60%. Glucans of fraction AS-II originally present in the insoluble complex are significantly different from both fractions mentioned with respect to their percentages of α-1,3- and α-1,6-linked glucosyl residues. The linkage patterns of glucans of fraction WS-I are similar to those of fraction AS-I. Thus, with respect to the linkage patterns three distinct fractions of glucan were isolated from streptococcal cultures. A comparison of the glucans of the five serotypes revealed that glucans of type b, c, and e form one group of polysaccharides characterized by a greater mean percentage of α-1,6-linkages and branching sites than the other group consisting of glucans of type a and d. Furthermore, strains of S. mutans seem to be capable of synthesizing an almost continuous series of glucans with variable proportions of different types of linkages.

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Section: Discussionsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Structure of Extracellular Glucans Synthesized by Streptococcus mutans of Serotypes a–e in vitro

1982

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“…Soluble extracellular polysaccharides such as dextrans are not resistant to enzymes indigenous in dental plaque and function, therefore, rather as an additional carbo hydrate reserve mechanism [W alker and Builder, 1967;W ood, 1969;H otz et al, 1972], These relationships provide an excellent example for the correlation between biological function and conformation of glucans [Rees and Scott, 1971]. Structural analyses of soluble streptococcal glucans using refined chemical methods [Lewicki et al, 1971;Sidebotham et al, 1971] will not add to the understanding of their biologi cal role as long as it is implied that they are the only glucans in dental plaque.…”

Section: Discussionmentioning

confidence: 99%

Caries and Plaque Inhibition by Mutanase in Rats

Guggenheim¹,

Regolati²,

Mühlemann³

1972

Caries Res

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The effects of mutanase (α-1,3 glucan 3-glucanohydrolase, free of 1,6 activity produced by Trichoderma harzianum OMZ 779) and dextranase (α-1,6 glucan 6-glucanohydrolase obtained from Penicillium funiculosum) on plaque formation and caries incidence were investigated in two groups of 36 rats each. The first group was kept in relative gnotobiosis with Streptococcus mutans OMZ 176 E, the second group harboured its indigenous flora. During the entire 28-day experimental period the animals were housed in a feeding machine and fed 18 meals per day. For the first three experimental days both groups received diet 2,000 (56% sucrose). Thereafter each of the two groups was distributed among the following treatments: O: diet 2,000; M: diet 2,000 containing mutanase (100 MU/ g); D: diet 2,000 containing dextranase (150 DU/g); M+D: diet 2,000 containing both enzymes (100 MU and 150 DU/g). Blood for white cell counts was collected prior to sacrifice by heart puncture. Extent of plaque on the smooth surfaces of the upper molars was scored under a dissection microscope after staining with erythrosin. Fissure caries was assessed on serial sections of the first and second lower molars.

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“…This procedure would have shown (l-*-4)-linkage. Structural analyses by méthylation reveal only 8% (l-*4)-linkages for glucan E49 [Lewicki et al, 1971], Technical difficulties arose in measuring the degree to which the glu cans had been hydrolyzed. High centrifugal forces (48,200 Xg) were em ployed in order to remove glucans remaining insoluble in 50% ethanol.…”

Section: Discussionmentioning

confidence: 99%

“…Such methods howev er, necessitate centrifugation to remove bacterial cells, thereby losing the insoluble glucans. Unfortunately some authors have overlooked the im portance of this insoluble fraction [Bow en , 1968;D ahlqvist et al, 1967;Lewicki et al, 1971].…”

Section: N Ewbrunmentioning

confidence: 99%

Extracellular Polysaccharides Synthesized by Glucosyltransf erases of Oral Streptococci

Newbrun¹

1972

Caries Res

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The aim of this study was to compare the chemical composition and susceptibility to enzymatic hydrolytic cleavage of several polysaccharides synthesized by glucosyltransferases obtained from oral streptococci. Glucosyltransferase enzymes were obtained from cultures of Streptococcus mutatis, strains HS-6 and AHT (antigen a), FA-1 (antigen b), Ingbritt and GS-5 (antigen c) and OMZ-176 (antigen d), and from Streptococcus sanguis, strain 804. These enzymes were partially purified by absorbing the culture supernatant fluid of the respective strains onto hydroxylapatite gel and eluting batchwise from the gel. Polysaccharides were prepared by incubating the eluted enzymes in the presence of sucrose, followed by precipitation with alcohol (1:1 v/v), washing, dialysis and finally lyophilization. Analyses indicated the polysaccharides were essentially homopolymers of glucose with 2–7% moisture, 85–98% total carbohydrate, 78–98% glucose, 0.9–2.6% fructose and about 0.5% nitrogen. Suspensions of each of the glucans were treated with 3 commercial preparations of dextranase or 3 commercially available amyloglucosidases. Amyloglucosidases were largely ineffective in hydrolyzing these bacterial glucans. The dextranase preparations hydrolized the various glucans at significantly different rates. The rate and degree of cleavage appears to be related to the antigenic grouping of the strain. The relative resistance of some glucans to degredation under these conditions may explain the ineffectiveness of the dextranase mouthwash in human clinical trials.

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Determination of the structure of a broth dextran produced by a cariogenic streptococcus

Cited by 58 publications

References 18 publications

Structure of Extracellular Glucans Synthesized by Streptococcus mutans of Serotypes a–e in vitro

Structure of Extracellular Glucans Synthesized by Streptococcus mutans of Serotypes a–e in vitro

Caries and Plaque Inhibition by Mutanase in Rats

Extracellular Polysaccharides Synthesized by Glucosyltransf erases of Oral Streptococci

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