Development of Lectin Modified Fluorescent Magnetic Particles for Highly Sensitive Detection of Glycoconjugates.

I conducted this study to develop an improved method for glycome detection using fluorescent magnetic beads, whose surfaces were modified using lectins, for the highly sensitive detection of saccharides or glycoproteins via fluorescence quenching using a novel fluorescence emitter and quencher pair. The emitter (Cy3 fluorophore) was incorporated into magnetic beads, and a fluorescence quencher (cyanopyranyl group) was bound to glycomes via covalent bonding. The fluorescence intensities of fluorescent magnetic beads containing lectins decreased specifically in the presence of glycomes, which was a result of fluorescence quenching from Cy3 to cyanopyranyl groups due to the formation of a stable complex between lectins and glycome. Fluorescence intensities were plotted as a function of glycoprotein concentration, and good linear relationships were observed. This method enabled the fluorescent reading-out of a series of lectin-glycome interactions on the basis of recognition selectivity and affinity of immobilized lectins without tedious washing processes. Moreover, a simple profiling process was performed using this assay for diverse glycoconjugates, which not only included simple saccharides but also glycoproteins and glycome in cell lysates. These results clearly indicate that the combination of magnetic beads with the novel emitter-quencher pair enabled the highly sensitive detection of lectin-glycome interactions.