Transglutaminase 3 (TGM3), an enzyme reported to Catalyze the calcium-dependent formation of isopeptide cross-links between glutamine and lysine residues in various proteins and the conjugation of polyamines to proteins, is widely expressed in the small intestine, brain, skin, and mucosa . TGM3 is mainly expressed in the suprabasal layers of the stratified squamous epithelium, and responsible for the formation and assembly of protein aggregates in the epidermis, so it is also called “epidermal TGM” . It plays a role in various biological processes including cell growth, differentiation, and apoptosis.Besides,Caspase 14 (CASP14) has been identified as an interactor of TGM3, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant humant TGM3 and recombinant rat CASP14. Briefly,TGM3 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to CASP14-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-TGM3 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 450/630nm immediately. The binding activity of recombinant humant TGM3 and recombinant rat CASP14 was shown in Figure 1, the EC50?for this effect is 0.072ug/mL.