title: Conformational differences in liganded and unliganded states of Galectin-3.
abstract: The conformation of the carbohydrate recognition domain of Galectin-3, a lectin known to bind galactose containing oligosaccharides in mammalian systems, has been investigated in the absence of ligand and in the presence of N-acetylactosamine. A new methodology based on the measurement of residual dipolar couplings from NMR spectra has been used to characterize differences in protein structure along the backbone in the presence and absence of ligand, as well as the binding geometry of the ligand itself. The data on the ligand are consistent with the ligand binding geometry found in a crystal structure of the complexed state. However, a significant rearrangement of backbone loops near the binding site appears to occur in the absence of ligand. The implications for ligand specificity and protein functionality are discussed.
authors.affiliation: Department of Chemistry, International Christian University, Tokyo, Japan 1818585.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Umemoto
authors.forename: Hakon
authors.initials: H
authors.lastname: Leffler
authors.forename: Andre
authors.initials: A
authors.lastname: Venot
authors.forename: Homay
authors.initials: H
authors.lastname: Valafar
authors.forename: J H
authors.initials: JH
authors.lastname: Prestegard
mesh_terms: D000606:Amino Sugars / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D003460:Crystallization; D018360:Crystallography, X-Ray; D037502:Galectin 3 / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D000606:Amino Sugars; D037502:Galectin 3; D008024:Ligands; C000458:N-acetyllactosamine