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| Titel: |
Characterization of α-(1→3) Branched Oligosaccharides Synthesized by Acceptor Reaction with the Extracellular Glucosyltransferases from L. Mesenteroides NRRL B-742 |
| Auteur: |
Remaud, M. Paul, F. Monsan, P. Lopez-Munguia, A. Vignon, M. |
| Verschenen in: |
Journal of carbohydrate chemistry |
| Paginering: | Jaargang 11 (1992) nr. 3 pagina's 359-378 |
| Jaar: |
1992-04-01 |
| Inhoud: |
The glucosyltransferases from L. mesenteroides are known to catalyze the transfer of the D-glucosyl group of sucrose onto sugars, now commonly named acceptors. We investigated in the present work, the acceptor reaction catalyzed by the extracellular glucosyltransferases from L. mesenteroides NRRL B-742. The enzymes of the culture supernatant, purified by aqueous two-phase partition between dextran and polyethylene glycol solutions, were found to efficiently transfer the glucose moiety of sucrose onto maltose acceptor. By increasing the sucrose/maltose ratio (S/M), it was possible to catalyze the synthesis of oligosaccharides of increasing degree of polymerisation (d.p.). For an S/M ratio of 7, both linear oligosaccharides (only composed of α-(1→6) linkages and a maltose residue at the reducing end) and branched oligosaccharides were produced. A glucanase treatment permitted isolation of the branched products which were then analyzed by carbon 13 NMR spectroscopy. The chemical shifts arising from the purified glucanase-resistant oligosaccharides clearly established that α-(1→3) linkages had been synthesized. A d.p. 6 oligosaccharide was found to be the smallest α-(1→3) branched oligosaccharide synthesized by acceptor reaction. The structure of this product which is in agreement with the enzyme hydrolysis, the NMR chemical shifts and spin-lattice relaxation data was determined as 63-O-α-D-isomaltosyl [33-O-α-D-glucosyl]panose. The analysis of the oligosaccharides of smaller d.p., which resulted from the glucanase treatment, also demonstrated that the glucosyl group could be transferred at various O-3 position of the characterized oligosaccharides. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 39 van 252 gevonden artikelen
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