10.1021/jo951430o.s001 Ross V. Weatherman Ross V. Weatherman Laura L. Kiessling Laura L. Kiessling Fluorescence Anisotropy Assays Reveal Affinities of <i>C</i>- and <i>O</i>-Glycosides for Concanavalin A<sup>1</sup> American Chemical Society 1996 binding energies concanavalin 0.5 kcal mol Fluorescence Anisotropy Assays Reveal Affinities ligand glycosides lectin carbohydrate binding site 1996-01-26 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Fluorescence_Anisotropy_Assays_Reveal_Affinities_of_i_C_i_-_and_i_O_i_-Glycosides_for_Concanavalin_A_sup_1_sup_/3700941 The free energies of binding of various <i>C</i>- and <i>O</i>-glycosides to the lectin concanavalin A were measured using fluorescence anisotropy. Fluorescein derivatives of mannose and glucose were synthesized and were shown to bind to concanavalin A with free energies of −5.1 and −4.3 kcal mol<sup>-1</sup>, respectively. Competition experiments were performed to determine the binding energies of different nonfluorescent carbohydrates, and the results were in excellent agreement with the binding energies determined by microcalorimetry. The minimum carbohydrate epitope that fills the lectin carbohydrate binding site, methyl 3,6-di-<i>O</i>-(α-mannopyranosyl)-α-mannopyranoside, competes directly for the site with the fluorescent ligands, indicating that the fluorescent ligands bind specifically. The binding affinities of <i>C</i>-glycosides to concanavalin A were compared with those of <i>O-</i>glycosides. The free energies of binding for corresponding <i>C</i>- and <i>O</i>-glycosides differed by less than 0.5 kcal mol<sup>-1</sup>, indicating that recognition properties of <i>C</i>- and <i>O-</i>glycosides are very similar. It was found that for some ligands the use of a carbon linkage rather than an oxygen linkage caused the specificity of binding to decrease slightly.