[Elucidation of carbohydrate functions in cell membranes--development of molecular tool containing carbohydrate ligand and elucidation of interface phenomena of glycolipid].

Glycosphingolids and glycoproteins in cell membrane are thought to play important roles in variety biological phenomena. Our interests focused on elucidation of their functions at the molecular level. We are especially interested in organic chemistry and physical chemistry of carbohydrates. Physical part-Surface of Langmuir-Blodgett (LB) films which comprised of various gangliosides, sphingolipids and cholesterol are observed by atomic force microscopy (AFM). We studied distribution of model compounds related to an antigenic epitope from Bupleurum falcatum L. in G(M3) (GM3)-DPPC monolayers. We also investigated relation between disease and glycolids in cell membrane. Chemical part-New molecular tools for the elucidation of carbohydrate roles using photoaffinity labeling were developed. We showed that the structural difference between closed ring- and open ring-type carbohydrates affected binding affinity to proteins. This study confirmed that carbohydrate structure, in both non-reducing end and reducing end sugars, is deeply related to the recognition event between carbohydrates and proteins. As a result, they will be used in future studies to elucidate carbohydrate functions on cell surfaces.