Structural Analysis of a Glycolipid Head Group with One- and Two-State NMR Pseudoenergy Approaches

The solution conformation of the oligosaccharide head group of the glycolipid globoside has been determined with the use of ¹H two-dimensional NMR methods. The intensities of cross peaks in cross relaxation correlated experiments have been analyzed in terms of interproton distances, and the distances have been incorporated as a pseudoenergy in a conformational energy calculation. Minimum energy conformations have been determined by using both one- and two-state models. Conformations are consistent with a previously proposed “L” shape for the molecule. Comparison of the results from the two models suggests the possibility of conformational flexibility to exist for the terminal residue of the head group.