Saturation curve demonstrates the binding of endothelin-1 to DCs. DC cell membranes were made from immature and mature DCs, and the saturation binding studies were performed with 8 different concentrations of ¹²⁵I-ET-1 (3.9 to 2000 pM). Representative saturation plots from 3 independent experiments are shown for immature and mature DCs (Bmax: 285.8 ± 86.5 fmol/mg protein and 760.3 ± 162.6 fmol/mg protein, respectively; K_d: 1.78 ± 0.9 nM and 1.81 ± 0.6 nM, respectively). Dashed and solid lines represent saturation curves for unstimulated and stimulated DCs, respectively.