FIGURE 1.
Kinetic and thermodynamic analysis of BMP9 binding to ALK1, ActRIIB, ActRIIA, and BMPRII. A, SPR sensograms of ALK1ECD-Fc, ActRIIBECD-Fc, ActRIIAECD-Fc, and BMPRIIECD-Fc binding to BMP9 at 25 and 37 °C. Raw data (colored lines) were overlaid with a global fit to a 1:1 model with mass transport limitations (black lines). ActRIIAECD-Fc data were analyzed using affinity fit in SigmaPlot. B, kinetic parameters for receptor-ligand interactions. C, comparison of thermodynamic parameters of ALK1ECD-Fc, ActRIIBECD-Fc, and ActRIIAECD-Fc interactions with BMP9 at 25 °C.