Application of homonuclear 3D NMR experiments and 1D analogs to study the conformation of sialyl Lewis^x bound to E-selectin
Source: Journal of Biomolecular NMR, Volume 9, Number 4, June 1997 , pp. 423-436(14)
The conformation of the sialyl Lewis^x tetrasaccharide bound to E-selectin was previously determined from transfer NOE (trNOE) experiments in conjunction with a distance-geometry analysis. However, the orientation of the tetrasaccharide ligand in the binding site of E-selectin is still unknown. It can be predicted that the accurate quantitative analysis of all trNOEs, including those originating from spin diffusion, is one key to analyze the orientation of sialyl Lewis^x in the binding pocket of E-selectin. Therefore, we applied homonuclear 3D NMR experiments and 1D analogs to obtain trNOEs that could not unambiguously be assigned from previous 2D trNOESY spectra, due to severe resonance-signal overlap. A 3D TOCSY-trNOESY experiment, a 1D TOCSY-trNOESY experiment, and a 1D trNOESY-TOCSY experiment of the sialyl Lewis^x/E-selectin complex furnished new interglycosidic trNOEs and provided additional information for the interpretation of trNOEs that have been described before. A 2D trROESY spectrum of the sialyl Lewis^x/E-selectin complex allowed one to identify the amount of spin-diffusion contributions to trNOEs. Finally, an unambiguous assignment of all trNOEs, and an analysis of spin-diffusion pathways, was obtained, creating a basis for a quantitative analysis of trNOEs in the sialyl Lewis^x/E-selectin complex.
Document Type: Regular paper
Affiliations: 1: Institute for Chemistry, Medical University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany 2: Institute for Biological Sciences, National Research Council, Ottawa, ON, Canada K1A 0R6 3: Bruker Analytik GmbH, Silberstreifen, D-76287 Rheinstetten, Germany 4: Glyco Tech Corporation, 14915 Broschart Road, Rockville, MD 20850, U.S.A. 5: Zentrale Forschungslaboratorien, Rosental, Ciba-Geigy AG, CH-4002 Basel, Switzerland
Publication date: 1997-06-01