The development of new molecular tools containing a chemically synthesized carbohydrate ligand for the elucidation of carbohydrate roles via photoaffinity labeling: Carbohydrate–protein interactions are affected by the structures of the glycosidic bonds and the reducing-end sugar

• Published in: Bioorganic & medicinal chemistry 2014-08, Vol.22 (15), p.3829-3837
• Main Authors: Ohtsuka, Isao, Sadakane, Yutaka, Hada, Noriyasu, Higuchi, Mari, Atsumi, Toshiyuki, Kakiuchi, Nobuko
• Format: Article
• Language: English
• Subjects: Agglutinins - chemistry; Agglutinins - metabolism; Carbohydrates - chemical synthesis; Carbohydrates - chemistry; Carbohydrate–lectin interactions; Different glycosidic bonds; Disaccharides - chemistry; Disaccharides - metabolism; Erythrina - metabolism; Lectins - chemistry; Lectins - metabolism; Ligands; Molecular tool; Oligosaccharide synthesis; Photoaffinity labeling; Photoaffinity Labels - chemistry; Protein Binding; Ultraviolet Rays
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/j.bmc.2014.06.049

Three kinds of molecular tools containing Galp–GlcpNAc ligand and photoreactive group (1, 2, 3) were synthesized, and were examined to potentional recognition by the differenece of galactose bonding position. Photoaffinity labeling technology is a highly efficient method for cloning carbohydrate-binding proteins. When the carbohydrate probes are synthesized according to conventional methods, however, the reducing terminus of the sugar is opened to provide an acyclic structure. Our continued efforts to solve this problem led to the development of new molecular tools with an oligosaccharide structure that contains a phenyldiazirine group for the elucidation of carbohydrate–protein interactions. We investigated whether carbohydrate–lectin interactions are affected by differences in the glycosidic formation and synthesized three types of molecular tools containing Galp–GlcpNAc disaccharide ligands and a photoreactive group (1, 2, 3). Photoaffinity labeling validated the recognition of the new ligand by different glycosidic bonds. Photoaffinity labeling also demonstrated that both the reducing end sugar and non-reducing end sugar recognized the Erythrina cristagalli agglutinin.