Trifunctional Fluorogenic Probes for Fluorescence Imaging and Isolation of Glycosidases in Cells.

For both fluorescence imaging and isolation of glycosidases in cells, we prepared novel activity-based, trifunctional fluorogenic probes that consist of (1) a sugar moiety as a glycosidase substrate, (2) a fluoromethylated coumarin for fluorescent labeling, and (3) an alkyne tag for click reaction to enable isolation of the labeled enzyme. One probe, β-GlcNAc-CM-F, was employed to fluorescently detect endogenous O-GlcNAcase in cells and to isolate the labeled enzyme by affinity chromatography.