Effect of PF-4–derived peptides on binding and cross-linking of ¹²⁵I-FGF-2 to CHOmFGFR1 cells. CHOmFGFR1 cells are incubated with 10 ng/mL ¹²⁵I-FGF-2 with or without 2 μg/mL unlabeled ligand, 10 μg/mL PF-4 or PF-4–derived peptides in the absence (A) or presence (B, C) of 100 ng/mL heparin. 47-70 (▴); 34-58 (•); 17-58 (⧫). (A and C) Concentration dependency; (B) 10 μmol/L PF-4–derived peptides. Cross-linking (D) is done with the different peptides in the presence of 100 ng/mL heparin. Peptide 47-58 (5.3 μmol/L), 34-58 (5.3 μmol/L), 47-70 (1, 0.65 μmol/L; 2, 1.3 μmol/L; 3, 2.6 μmol/L; 4, 4.1 μmol/L). Binding or cross-linking experiments are performed as indicated in Materials and Methods. Results (A-C) are expressed as the mean± SD of experiments done in duplicates.