Low-temperature neutron diffraction structures of N -glycoprotein linkage models and analogues: Structure refinement and trifurcated hydrogen bonds

The biological addition of oligosaccharide moieties to asparagine residues of N-glycoproteins influences the properties and bioactivities of these macromolecules. The low-temperature neutron crystal structures of three N-glycoprotein linkage models and analogues provide accurate characterization of the three-dimensional structure of the conserved GlcNAc - Asn linkage. These first crystal structures of N-acetylated carbohydrates obtained by neutron diffraction provide high-resolution geometrical parameters that can be used for force-field parametrization and subsequent molecular dynamics simulation of N-glycoproteins. The correct localization of hydrogen atoms demonstrates the occurrence of trifurcated hydrogen bonds and hydrophobic contacts. © 2011 American Chemical Society.