Microfibrillar Associated Protein 2 (MFAP2) is an O-glycosylated protein that is secreted into the extracellular space and matrix. It plays a crucial role in connecting with biglycan and elastin in a ternary complex, supporting and maintaining the distensibility of the juxtacanalicular region of collector channels.It is reported that BGN can be combined with MFAP2 to help maintain tissue elasticity and toughness, which is particularly important for tissues such as blood vessels and skin that require a high degree of flexibility and toughness.Thus a functional ELISA assay was conducted to detect the interaction of recombinant mouse MFAP2 and recombinant rat BGN. Briefly, MFAP2 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to BGN-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-MFAP2 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 mouse MFAP2 and recombinant rat BGN was shown in Figure 1, the EC50?for this effect is 0.031ug/mL.