title: The relative orientation of the lipid and carbohydrate moieties of lipochitooligosaccharides related to nodulation factors depends on lipid chain saturation.
abstract: Lipochitooligosaccharides (LCOs) signal the symbiosis of rhizobia with legumes and the formation of nitrogen-fixing root nodules. LCOs 1 and 2 share identical tetrasaccharide scaffolds but different lipid moieties (1, LCO-IV(C16:1[9Z], SNa) and , LCO-IV(C16:2[2E,9Z], SNa)). The conformational behaviors of both LCOs were studied by molecular modeling and NMR. Modeling predicts that a small lipid modification would result in a different relative orientation of the lipid and tetrasaccharide moieties. Diffusion ordered spectroscopy reports that both LCOs form small aggregates above 1 mM. Nuclear Overhauser spectroscopy (NOESY) data, collected under monomeric conditions, reveals lipid-carbohydrate contacts only for 1, in agreement with the modeling data. The distinct molecular structures of 1 and 2 have the potential to contribute to their selective binding by legume proteins.
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, Madrid, Spain.
authors.forename: Patrick
authors.initials: P
authors.lastname: Groves
authors.forename: Stefanie
authors.initials: S
authors.lastname: Offermann
authors.forename: Martin Ohsten
authors.initials: MO
authors.lastname: Rasmussen
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Canada
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Bono
authors.forename: Hugues
authors.initials: H
authors.lastname: Driguez
authors.forename: Anne
authors.initials: A
authors.lastname: Imberty
authors.forename: Jesus
authors.initials: J
authors.lastname: Jimenez-Barbero
mesh_terms: D002236:Carbohydrate Conformation; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular
chemical_list: D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides