ASSIGNMENT OF H-1 AND C-13 NUCLEAR MAGNETIC RESONANCES OF GANGLIOSIDEG(A1)

Investigation of the structures of the gangliosides has proven to be v ery important in the understanding of their biological roles such as r egulation of differentiation and growth of cells. We used nuclear magn etic resonance spectroscopy in order to investigate the structure of G (A1). In order to do this, the assignment of spectra is a prerequisite . Since G(A1) does not have polar sialic acid, the spectral overlap is severe. In order to solve this problem, we use 2D NMR spectroscopy an d heteronuclear H-1/C-13 correlated spectroscopy in this study. Here, we report the complete assignment of the proton and the carbon spectra of the G(A1) in DMSO-d(6)-D2O (98:2, v/v). These assignments will be useful for interpreting H-1 and WC NMR data from uncharacterized oligo saccharides and for determining the linkage position, the number of su gar rings, and the sequence of new ganglioside. Amide proton in ring I II shows many interring nOes and has intramolecular hydrogen bonding. This appears to be an important factor in tertiary folding of G(A1). B ased on this assignment, determination of three dimensional structure of G(A1) will be carried out. Studies on the conformational properties of G(A1) may lead to a better understanding of the molecular basis of its functions.