The relative orientation of the lipid and carbohydrate moieties of lipochitooligosaccharides related to nodulation factors depends on lipid chain saturation.
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.
Groves
Patrick
P
Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, Madrid, Spain.
Offermann
Stefanie
S
Rasmussen
Martin Ohsten
MO
Canada
F Javier
FJ
Bono
Jean-Jacques
JJ
Driguez
Hugues
H
Imberty
Anne
A
Jimenez-Barbero
Jesus
J
D002236:Carbohydrate Conformation; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular
D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides