Fig 3.
Comparison of the interactions of promyostatin, latent myostatin and mature myostatin with ECD_ACRIIB. Promyostatin (100, 500, and 1000 nm) (A), latent myostatin (25, 100, 200, 350, 500, and 1000 nm (B) or mature myostatin (10, 20, 35, 50, 100, and 200 nm (C) in 20 mm Hepes, 150 mm NaCl, 5 mm EDTA and 0.005% Tween-20 (pH 7.5) were injected over the surface of CM5 sensorchips containing the ligand-binding extracellular domain of ACRIIB. The insert in (B) shows the apparent association rate constants kobs as a function of latent myostatin concentration. The observation that the value of kobs did not increase linearly with the increase in analyte concentration indicates that the proportion of receptor-binding species decreased with the increase in total latent myostatin concentration. RU - SPR Response Units.