title: Temperature Dependence of Hydroxymethyl Group Rotamer Populations in Cellooligomers.
abstract: Empirical force fields for computer simulations of carbohydrates are often implicitly assumed to be valid also at temperatures different from room temperature for which they were optimized. Herein, the temperature dependence of the hydroxymethyl group rotamer populations in short oligosaccharides is investigated using molecular dynamics simulations and NMR spectroscopy. Two oligosaccharides, viz., methyl β-cellobioside and β-cellotetraose were simulated using three different carbohydrate force fields (CHARMM C35, GLYCAM06, and GROMOS 56Acarbo) in combination with different water models (SPC, SPC/E, and TIP3P) using replica exchange molecular dynamics simulations. For comparison, hydroxymethyl group rotamer populations were investigated for methyl β-cellobioside and cellopentaose based on measured NMR (3)JH5,H6 coupling constants, in the latter case by using a chemical shift selective NMR-filter. Molecular dynamics simulations in combination with NMR spectroscopy show that the temperature dependence of the hydroxymethyl rotamer population in these short cellooligomers, in the range 263-344 K, generally becomes exaggerated in simulations when compared to experimental data, but also that it is dependent on simulation conditions, and most notably properties of the water model.
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 Center, and the Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Nils A
authors.initials: NA
authors.lastname: Sjöberg
authors.affiliation: ‡Wallenberg Wood Science Center, and the Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Polina
authors.initials: P
authors.lastname: Vasiljeva
authors.affiliation: ‡Wallenberg Wood Science Center, and the Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Lindman
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 Center, and the Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Bergenstråhle-Wohlert
authors.affiliation: ‡Wallenberg Wood Science Center, and the Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Jakob
authors.initials: J
authors.lastname: Wohlert
mesh_terms: D002236:Carbohydrate Conformation; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D009844:Oligosaccharides / Q000737:chemistry*; D013696:Temperature; D013780:Tetroses / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D009844:Oligosaccharides; D013780:Tetroses; D014867:Water; C048468:cellotetraose; D002482:Cellulose