title: A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility.
abstract: The macromolecular conformation of the constituent polysaccharides in lignocellulosic biomass influences their supramolecular interactions, and therefore their function in plants and their performance in technical products. The flexibility of glycosidic linkages from the backbone of hemicelluloses was studied by evaluating the conformational freedom of the φ and ψ dihedral angles using molecular dynamic simulations, additionally selected molecules were correlated with experimental data by nuclear magnetic resonance spectroscopy. Three types of β-(1→4) glycosidic linkages involving the monosaccharides (Glcp, Xylp and Manp) present in the backbone of hemicelluloses were defined. Different di- and tetrasaccharides with combinations of such sugar monomers from hemicelluloses were simulated, and free energy maps of the φ - ψ space and hydrogen-bonding patterns were obtained. The glycosidic linkage between Glc-Glc or Glc-Man (C-type) was the stiffest with mainly one probable conformation; the linkage from Man-Man or Man-Glc (M-type) was similar but with an increased probability for an alternative conformation making it more flexible, and the linkage between two Xyl-units (X-type) was the most flexible with two almost equally populated conformations. Glycosidic linkages of the same type showed essentially the same conformational space in both disaccharides and in the central region of tetrasaccharides. Different probabilities of glycosidic linkage conformations in the backbone of hemicelluloses can be directly estimated from the free energy maps, which to a large degree affect the overall macromolecular conformations of these polymers. The information gained contributes to an increased understanding of the function of hemicelluloses both in the cell wall and in technical products.
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.
authors.forename: Jennie
authors.initials: J
authors.lastname: Berglund
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden.
authors.forename: Thibault
authors.initials: T
authors.lastname: Angles d'Ortoli
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.|Division of Glycoscience, School of Biotechnology, Royal Institute of Technology KTH, AlbaNova University Centre, SE-106 91, Stockholm, Sweden.
authors.forename: Francisco
authors.initials: F
authors.lastname: Vilaplana
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Widmalm
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Bergenstråhle-Wohlert
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Lawoko
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Henriksson
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Lindström
authors.affiliation: Wallenberg Wood Science Centre (WWSC), Department of Fiber and Polymer Technology, School of Chemical Engineering, Royal Institute of Technology KTH, SE-100 44, Stockholm, Sweden. jacke@kth.se.
authors.forename: Jakob
authors.identifier: 0000-0001-6732-2571
authors.initials: J
authors.lastname: Wohlert
mesh_terms: D005936:Glucans / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D011134:Polysaccharides / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry
chemical_list: D005936:Glucans; D008351:Mannans; D011134:Polysaccharides; D014990:Xylans; C022901:(1-6)-alpha-glucomannan; C029353:xyloglucan; C007916:hemicellulose
keywords: computer simulation; glucomannan; nuclear magnetic resonance spectroscopy; xylan; xyloglucan