earticle

영어

Alpha-L-fucosidase catalyzes the removal of L-Fucose residues from the non-reducing end of glycoconjugates. There are two fucosidases in human, including  α-L-fucosidase-1 (FUCA1) and α-L-fucosidase-2 (FUCA2). Abnormal fucosidase activity has been associated with many diseases, such as fucosidosis (one of the lysosomal storage disorders), hepatocellular cancer and breast cancer. We previously demonstrated that gastric epithelial cells secrete FUCA2 extracellularly upon the infection of Helicobacter pylori, a strategy tomodify the cell surface glycoconjugates to prevent the bacterial adhesion. However the role and physiological function of FUCA2 still remains ambiguous, not mentioning the difficulty that the enzyme is highly unstable and the activity is often too small for detection. We developed an activity-based probe for sensitive detection of the enzyme activity in vitro and in vivo. First of all, the probe was utilized for dot-blot assay to measure the H. pylori-induced fucosidase activity in a quantitative manner. Secondly, the probe provided a real-time detection of the increased fucosidase activity by using confocal microscopy. The result also supported the idea that the bacterial infection not only leads to an increase in the extracellular activity of FUCA2, but also an intracellular increase of fucosidase activity. Western blotting analysis by FUCA1- and FUCA2-specific antibodies further corroborated the aforementioned increase levels of FUCA1 and FUCA2 activities, respectively. Our current emphasis is placed to search for the factors of H. pylori in association with the secretion of fucosidase during infection.