Sensing ligand binding to a clinically relevant lectin by tryptophan fluorescence anisotropy

摘要: Increasing insights into the involvement of endogenous lectins in disease processes fuel interest to develop potent inhibitors. As a consequence, robust assay procedures are required. Due their activity as adhesion/growth-regulatory effectors this study focussed on galectins. The human proto-type galectin-1 was selected representative family with conserved presence tryptophan moiety binding site. This structural feature taken advantage establish its use reporter for ligand contact measuring polarized fluorescence emission. experimentally determined anisotropy r0 about 0.2, altered by 5% cognate disaccharide lactose. parameter change enabled calculating equilibrium constant and kinetic rate constants. detailed analysis depolarization process further indicated fast conformational dynamics within Since an inherent property protein exploited, no labeling is needed. Owing tryptophan's carbohydrate-binding sites, also other classes well modules glycoenzymes (glycosyltransferases, glycosidases), procedure can have relevance beyond