Structure of the linear, low molecular weight dextran synthesized by a d-glucosyltransferase (GTF-S3) of Streptococcus sobrinus
| Autor: | Gwen J. Walker, Morey E. Slodki, Norman W.H. Cheetham |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
chemistry.chemical_classification
Sucrose Polymers and Plastics biology Organic Chemistry biology.organism_classification Streptococcus sobrinus stomatognathic diseases chemistry.chemical_compound Enzyme Glucosyltransferases Dextran chemistry Biochemistry Biosynthesis Materials Chemistry Extracellular Moiety |
| Zdroj: | Carbohydrate Polymers. 16:341-353 |
| ISSN: | 0144-8617 |
| Popis: | Four extracellular α- d -glucosyltransferases (GTF) have been separated from cultures of Streptococcus sobrinus strains grown in continuous culture. Three of the GTF synthesized soluble dextrans from sucrose, and one of these enzymes, GTF-S3, catalysed the production of a low molecular weight, linear dextran. Methylation analysis and high field proton NMR spectroscopy on the intact S3 glucans confirmed that these dextrans were small (dp 20–30) and linear, with the majority of chains terminated with a sucrosyl moiety. Enzymic hydrolysis, followed by analytical and semi-preparative HPLC, led to the isolation of only linear oligosaccharides, one of which was identified as 6 G -glucosylsucrose. The results are accommodated by the two-site insertion mechanism for dextran synthesis proposed by Robyt et al. (1974) (Arch. Biochem. Biophys., 165 , 634). |
| Databáze: | OpenAIRE |
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