High-Throughput Evaluation System based on Fluorescence Intensity Distribution Analysis-Polarization to Investigate Carbohydrate–Carbohydrate Interactions

Abstract

We synthesized rhodamine-labeled β-lactoside and assessed its rotatory diffusion rates in aqueous media containing various oligosaccharides through fluorescence intensity distribution analysis-polarization measurements to find that its rotatory diffusion rates decrease in the presence of the coexisting oligosaccharides. Especially, the coexisting lactose lowered the rotatory diffusion rate more effectively than the other disaccharides did. This restrained rotatory diffusion arises from intermolecular carbohydrate–carbohydrate interactions between the rhodamine-labeled β-lactoside and the coexisting lactose. We also detected intermolecular bindings between the rhodamine-labeled β-lactoside and monosialyl-disaccharides (3′- and 6′-sialyllactoses). These data clearly show that the fluorescence intensity distribution analysis-polarization-based system is quite advantageous to probe carbohydrate–carbohydrate interactions.