Fucosidase Alpha L1, Tissue (FUCa1) is an enzyme that catalyzes the hydrolysis of fucose residues from glycoproteins and glycolipids. It is widely present in human tissues, especially in the liver, spleen and placenta. FUCa1 plays a role in the degradation and recycling of fucose-containing glycoconjugates within the celland is involved in a variety of biochemical pathways, including cell signaling, cell adhesion, and immune response. Besides, Phosphoglucomutase 2 (PGM2) has been identified as an interactor of FUCa1, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human FUCa1 and recombinant human PGM2. Briefly, FUCa1 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to PGM2-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-FUCa1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 μL stop solution to the wells and read at 450/630 nm immediately. The binding activity of recombinant human FUCa1 and recombinant human PGM2 was shown in Figure 1, the EC50?for this effect is 0.93 ug/mL.