Bernhard, Samuel P.Goodman, Candace K.Norton, Erienne G.Alme, Daniel G.Lawrence, C. MartinCloninger, Mary J.2021-12-032021-12-032020-11Bernhard, Samuel P., Candace K. Goodman, Erienne G. Norton, Daniel G. Alme, C. Martin Lawrence, and Mary J. Cloninger. “Time-Dependent Fluorescence Spectroscopy to Quantify Complex Binding Interactions.” ACS Omega 5, no. 45 (November 6, 2020): 29017–29024. doi:10.1021/acsomega.0c03416.2470-1343https://scholarworks.montana.edu/handle/1/16561Measuring the binding affinity for proteins that can aggregate or undergo complex binding motifs presents a variety of challenges. In this study, fluorescence lifetime measurements using intrinsic tryptophan fluorescence were performed to address these challenges and to quantify the binding of a series of carbohydrates and carbohydrate-functionalized dendrimers to recombinant human galectin-3. Collectively, galectins represent an important target for study; in particular, galectin-3 plays a variety of roles in cancer biology. Galectin-3 binding dissociation constants (KD) were quantified: lactoside (73 ± 4 μM), methyllactoside (54 ± 10 μM), and lactoside-functionalized G(2), G(4), and G(6)-PAMAM dendrimers (120 ± 58 μM, 100 ± 45 μM, and 130 ± 25 μM, respectively). The chosen examples showcase the widespread utility of time-dependent fluorescence spectroscopy for determining binding constants, including interactions for which standard methods have significant limitations.en-USArticle