Fig. 3.
Association of RGDPEG-avidin with endothelial cells. Subconfluent HUVEC were incubated with radiolabeled echistatin, which is a known ligand for αvβ3 integrin, and RGDPEG-avidin, free RGDpeptide or unmodified avidin. Panel A: Binding specificity. Echistatin was displaced by excess of RGDPEG-avidin or free RGD-peptide (both at 10 μM) but not by excess of avidin. *P < 0.05. Panel B: Affinity of binding. Echistatin binding was displaced by different concentrations of the added competing ligands, showing the increased affinity of RGPEG-avidin over the single RGDpeptide ligand