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Research article - Peer-reviewed, 2010

Synthesis of Cyclic β-Glucan Using Laminarinase 16A Glycosynthase Mutant from the Basidiomycete Phanerochaete chrysosporium

Vasur Jonas, Kawai Rie, Jonsson K Hanna M, Widmalm Göran, Engström Åke, Frank Martin, Andersson Evalena, Hansson Henrik, Forsberg Zarah, Igarashi Kiyohiko, Samejima Masahiro, Sandgren Mats, Ståhlberg Jerry

Abstract

Glycosynthases are precise molecular instruments for making specifically linked oligosaccharides. X-ray crystallography screening of ligands bound to the 1,3(4)-beta-D-glucanase nucleophile mutant E115S of Phanerochaete chrysosporium Laminarinase 16A (Lam16A) showed that laminariheptaose (L7) bound in an arch with the reducing and nonreducing ends occupying either side of the catalytic cleft of the enzyme. The X-ray structure of Lam16A E115S in complex with alpha-laminariheptaosyl fluoride (alphaL7F) revealed how alphaL7F could make a nucleophilic attack upon itself. Indeed, when Lam16A E115S was allowed to react with alphaL7F the major product was a cyclic beta-1,3-heptaglucan, as shown by mass spectrometry. NMR confirmed uniquely beta-1,3-linkages and no reducing end. Molecular dynamics simulations indicate that the cyclic laminariheptaose molecule is not completely planar and that torsion angles at the glycosidic linkages fluctuate between two energy minima. This is the first report of a glycosynthase that joins the reducing and nonreducing ends of a single oligosaccharide and the first reported synthesis of cyclic beta-glucan

Published in

Journal of the American Chemical Society
2010, Volume: 132, number: 5, pages: 1724-1730

      SLU Authors

    • Vasur, Jonas

      • Department of Molecular Biology, Swedish University of Agricultural Sciences
      • Andersson, Evalena

        • Department of Molecular Biology, Swedish University of Agricultural Sciences
        • Hansson, Henrik

          • Department of Molecular Biology, Swedish University of Agricultural Sciences
          • Sandgren, Mats

            • Department of Molecular Biology, Swedish University of Agricultural Sciences
            • Ståhlberg, Jerry

              • Department of Molecular Biology, Swedish University of Agricultural Sciences

            UKÄ Subject classification

            Renewable Bioenergy Research

            Publication identifier

            DOI: https://doi.org/10.1021/ja909129b

            Permanent link to this page (URI)

            https://res.slu.se/id/publ/30910