Relative molecular masses and structures of some levans elaborated by strains of Streptococcus salivarius

Marshall, Keith; Weigel, Helmut

doi:10.1016/s0008-6215(00)84881-8

Cited by 11 publications

(3 citation statements)

References 9 publications

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“…The production of high M r fructans by the Ftf of S. sali arius is consistent with a number of physicochemical and linkage studies of the polymers which suggest that they are monodisperse spherical arborescent structures possessing multi-branched chains and M r s of the order of (20-100)i10' [40][41][42][43][44]. The spherical shape allows the fructan to be retained in dental plaque by virtue of its low diffusive properties, while being effectively hydrolysed from its outermost regions by exo-hydrolases when carbohydrate is in short supply [14].…”

Section: Comparison Of the Properties Of The Ftf Of S Salivarius Witsupporting

confidence: 76%

Purification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975

Song

Jacques

1999

Biochem. J.

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The recombinant fructosyltransferase (Ftf) of Streptococcus salivarius was expressed in Escherichia coli and purified to electrophoretic homogeneity after a combination of adsorption, ion-exchange and gel-filtration chromatography. The N-terminal signal sequence of the Ftf was removed by E. coli at the same site as in its natural host. The purified Ftf exhibited maximum activity at pH 6.0 and 37 degrees C, was activated by Ca2+, but inhibited by the metal ions Cu2+, Zn2+, Hg2+ and Fe3+. The enzyme catalysed the transfer of the fructosyl moiety of sucrose to a number of acceptors, including water, glucose and sucrose via a Ping Pong mechanism involving a fructosyl-enzyme intermediate. While this mechanism of catalysis is utilized by the levansucrases of Bacillus subtilis and Acetobacter diazotrophicus and the values of the kinetic constants for the three enzymes are similar, sucrose was a far more efficient fructosyl-acceptor for the Ftf of S. salivarius than for the two other enzymes.

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Section: Comparison Of the Properties Of The Ftf Of S Salivarius Witsupporting

confidence: 76%

Purification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975

Song

Jacques

1999

Biochem. J.

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“…Levans from Curcuma kwangsiensis (Dong et al 2015) and Brachybacterium sp. CA-KOV3 (Djurić et al 2017) were reported to have branches that were only one residue long whereas levan isolated from Streptococcus salivarius cultures had branches that were four residues in length (Marshall and Weigel 1980). Unfortunately this is about all that is known concerning the length of levan branches.…”

Section: Why Is Levan Such a Strong Adhesive?mentioning

confidence: 99%

From healing wounds to resorbable electronics, levan can fill bioadhesive roles in scores of markets

Combie¹,

Öner

2018

Bioinspir. Biomim.

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Levan is a fructose homopolysaccharide which gained attention recently for its unusual combination of properties distinguishing it from other natural biodegradable polysaccharides like chitosan, cellulose or starch. Among the strongest bioadhesives, film-forming levan is garnering interest for its role in some simple solutions to difficult problems. One of these is illustrated by the elegant research using laser-based techniques to construct levan films for healing wounds and burned tissue. Another is the development of bioresorbable electronic implants. Levan has been found in habitats as diverse as salterns and thermal waters to tropical plants and sugar factories. This review of the low viscosity, levan adhesive describes the mechanisms by which it forms bonds and the reasons behind some of its practical and industrial applications. Here we present descriptions from the literature for feasible approaches ready to transition from the laboratory to those searching for answers in fields as varied as medicine, packaging and furniture assembly.

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“…Actinomyces viscosus, Streptococcus salivarius, and Bacillus subtilis also possess fructosyltransferase activity and produce extracellular levan-type fructans composed of a backbone of beta- (2)(3)(4)(5)(6) linkages with side chains in the 1 position (2, 11,43). The high molecular weight (>106) and extensive branching of these polysaccharides result in a large, globular polymer with low intrinsic viscosity (12,27,28,32). These characteristics would likely prevent its diffusion from the plaque matrix, allowing it to serve as an extracellular carbohydrate reserve (14,29,32).…”

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confidence: 99%

Genetic analysis of fructan-hyperproducing strains of Streptococcus mutans

Kiska

Macrina

1994

Infect Immun

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Fructan polymer, synthesized from sucrose by the extracellular fructosyltransferase of Streptococcus mutans, is thought to contribute to the progression of dental caries. It may serve as an extracellular storage polysaccharide facilitating survival and acid production. It may also have a role in adherence or accumulation of bacterial cells on the tooth surface. A number of clinical isolates of S. mutans which produce large, mucoid colonies on sucrose-containing agar as a result of increased production of fructan have been discovered. By using eight independent isolates, we sought to determine if such fructan-hyperproducing strains represented a genetically homogeneous group of organisms. Restriction fragment patterns of total cellular DNA were examined by using pulsed-field and conventional gel electrophoresis. Four genetic types which appeared to correlate with the serotype of the organism and the geographic site of isolation were evident. Southern blot analysis of several genetic loci for extracellular enzymes revealed some minor differences between the strains, but the basic genomic organizations of these loci were similar. To evaluate whether the excess fructan produced by these strains enhanced the virulence of these organisms in the oral cavity, it was of interest to create mutants deficient in fructosidase (FruA), the extracellular enzyme which degrades this polymer. The fruA gene was inactivated by allelic exchange in two fructan-hyperproducing strains as well as in S. mutans GS5, a strain which does not hyperproduce fructan. All of the fruA mutant strains were devoid of fructan hydrolase activity when levan was used as a substrate. However, the fructan-hyperproducing strains retained the ability to hydrolyze inulin, suggesting the presence of a second fructosidase with specificity for inulin in these strains.

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Relative molecular masses and structures of some levans elaborated by strains of Streptococcus salivarius

Cited by 11 publications

References 9 publications

Purification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975

Purification and enzymic properties of the fructosyltransferase of Streptococcus salivarius ATCC 25975

From healing wounds to resorbable electronics, levan can fill bioadhesive roles in scores of markets

Genetic analysis of fructan-hyperproducing strains of Streptococcus mutans

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