Lectin affinity chromatography has proven to be a powerful method to separate oligosaccharides based on their stereochemical structure. Since glycolipids form micelles in aqueous solutions, studying their interactions with lectins is not amenable to methods used to study water soluble glycopeptides has been developed. In addition to an immunoautoradiographic method to detect lectin-binding glycolipids on thin layer chromatograms. A lectin affinity chromatographic method for the purification of intact glycolipids has been developed. This method is based on the ability of Helix pomatia lectin colums to bind its oligosaccharide ligands in aqueous solutions of tetrahydrafuran, which inhibit glycolipid miccelle formation and permit the separation of nonspecifically bound glycolipids. The general application of this method to other lectins will provide a novel approach to the purification of glycolipids. The ability to purify human blood group A-active glycolipds from a total lipid extract in a single chromatographic step on a column of Helix pomatia lectin will be exploited to structurally characterize metabolically labeled blood group A active glycolipids and glycopeptides form a huam epidermoid cell line A-431. This metabolically active cell line will provide an excellent system to investigate the biosynthetic pathway of an oligosaccharide antigen synthesized by a single group of glycosyltransferases acting on different glyoconjugate precursors. Lectins are proteins which have a specific affinity for certain carbohydrates. The lectins can be attached to inert supports and placed in glass columns which can then be used to separate substances on the basis of their affinity for the lectins. This technique has been very useful in the separation of glyko proteins and carbohydrates, but not for lipids (fatty substances) because the latter are not soluble in water. The P.I. has now developed a method for using these columns in organic solvents in which the lipids are soluble. This technique is of great promise in furthering our understanding of the metabolism of these lipids and how they function in cell membranes.
