Detection of Human α- L -Fucosidases by a Quinone Methide-Generating Probe: Enhanced Activities in Response to Helicobacter pylori Infection

α-L-Fucosidase activity is associated with several diseases. To study the enzymatic activity change under pathological conditions, we developed a quinone methide-generating activity-based probe useful for examining the presence, activity, and localization of human α-L-fucosidase in vivo in the context of Helicobacter pylori infection. In particular, an increase in intracellular fucosidase (Fuca1) activity was found in gastric epithelial cells upon bacterial infection. We further studied the effect of several bacterial stimulants on this enhanced Fuca1 activity and identified lipopolysaccharides to be a major contributing factor. Probing for answers: We monitored α-L-fucosidase activity in vitro and in vivo using a quinone methide-based probe. The probe was applied for detecting increases in the activity of human fucosidases 1 and 2 in gastric epithelial cells upon H. pylori infection, with lipopolysaccharides identified as a primary contributing factor. ? 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.