Microfibrillar-associated protein 2 (MFAP2) is an O-glycosylated protein which excreted to the extracellular space and the extracellular matrix. MFAP2 combine biglycan and elastin to form a ternary complex. MFAP2 plays a key role in the support and distensibility of the juxtacanalicular region of these collector channels. It also can inhibit LTB-1 binding to fibrillin-1, stimulate the phosphorylation of Smad2, and thereby mediate the subsequent extracellular deposition of latent TGFbeta. Besides, Fibrillin 1 (FBN1) has been identified as an interactor of MFAP2, thus a binding ELISA assay was conducted to detect the interaction of recombinant human MFAP2 and recombinant human FBN1. Briefly, MFAP2 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100uL were then transferred to FBN1-coated microtiter wells and incubated for 2h 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, wells were aspirated and washed 3 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µL stop solution to the wells and read at 450nm immediately. The binding activity of MFAP2 and FBN1 was shown in Figure 1, and this effect was in a dose dependent manner.