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 degree C. 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 degree C. Finally, add 50uL 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.