Interactions between carbohydrates at cell surfaces can mediate cellular recognition—for example, lymphoma and melanoma cells interact through the Gg3 and GM3 glycolipids. How these interactions actually lead to signal transduction has been unclear, in part because the binding strength between carbohydrate groups has been difficult to quantitate. Matsuura et al. show that surface plasmon resonance has sufficient sensitivity to identity the determinants of binding. They attached carbohydrates to sphingolipids on gold-coated glass slides and exposed them to solutions that contained N-glycosides linked to polystyrene. Comparisons between different binding pairs show that removing the acetylated amino group of the sialic acid reduces by one order of magnitude the binding affinity between GM3 and Gg3. — PDS
J. Am. Chem. Soc., in press.