Surfactant Associated Protein C (SPC) is one of the pulmonary surfactant proteins. It is a membrane protein which manufactures surfactant. The propeptide of pulmonary surfactant C has an N-terminal alpha-helical segment whose suggested function was stabilization of the protein structure, since the latter can irreversibly transform from its native alpha-helical structure to beta-sheet aggregates and form amyloid fibrils. Besides, Monokine Induced By Interferon Gamma (MIg) has been identified as an interactor of SPC, thus a binding ELISA assay was conducted to detect the interaction of recombinant rat SPC and recombinant rat MIg. Briefly, SPC were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μL were then transferred to MIg-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-SPC 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 SPC and MIg was shown in Figure 1, and this effect was in a dose dependent manner.
Figure. The binding activity of SPC with MIg.