SOLUTION CONFORMATION OF FORSSMAN ANTIGEN PROBED BY NOE AND EXCHANGE INTERACTIONS

The conformation of Forssman glycolipid, GalNAcαl-3GalNAcβl-3Galαl-4Galβl-4Glcβl-1ceramide, was analysed with the aid of the rotating frame NOE and Hartmann-Hahn spectroscopy. NOE contacts between C-, O-, and N-linked protons were used for distance mapping. The glycosidic bonds that are common to globotriaosylceramide and globoside showed a similar flexibility as found for these compounds [Poppe et al., (1990) Eur. J. Biochem. 189, 313-325; J. Am. Chem. Soc. 112, 7762-7771]. In contrast, the conformational mobility of the terminal GalNAcαl-3GalNAcβ linkage appears to be restrained. A new approach, based on 2D exchange spectroscopy, was proposed for revealing of spatial proximities between exchangeable protons in Me2SO solution. © 1991.