title: 'Naked' and hydrated conformers of the conserved core pentasaccharide of N-linked glycoproteins and its building blocks.
abstract: N-glycosylation of eukaryotic proteins is widespread and vital to survival. The pentasaccharide unit -Man3GlcNAc2- lies at the protein-junction core of all oligosaccharides attached to asparagine side chains during this process. Although its absolute conservation implies an indispensable role, associated perhaps with its structure, its unbiased conformation and the potential modulating role of solvation are unknown; both have now been explored through a combination of synthesis, laser spectroscopy, and computation. The proximal -GlcNAc-GlcNAc- unit acts as a rigid rod, while the central, and unusual, -Man-β-1,4-GlcNAc- linkage is more flexible and is modulated by the distal Man-α-1,3- and Man-α-1,6- branching units. Solvation stiffens the 'rod' but leaves the distal residues flexible, through a β-Man pivot, ensuring anchored projection from the protein shell while allowing flexible interaction of the distal portion of N-glycosylation with bulk water and biomolecular assemblies.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom.
authors.forename: Conor S
authors.initials: CS
authors.lastname: Barry
authors.forename: Emilio J
authors.initials: EJ
authors.lastname: Cocinero
authors.forename: Pierre
authors.initials: P
authors.lastname: Carçabal
authors.forename: David P
authors.initials: DP
authors.lastname: Gamblin
authors.forename: E Cristina
authors.initials: EC
authors.lastname: Stanca-Kaposta
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Remmert
authors.forename: María C
authors.initials: MC
authors.lastname: Fernández-Alonso
authors.forename: Svemir
authors.initials: S
authors.lastname: Rudić
authors.forename: John P
authors.initials: JP
authors.lastname: Simons
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Davis
mesh_terms: D001216:Asparagine; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*
chemical_list: D006023:Glycoproteins; C503888:Man(3)GlcNAc(2); D009844:Oligosaccharides; D001216:Asparagine