FIGURE 5.

Effect of leucine substitution for the serine residue immediately after the RGD motif in the 10th FNIII domain of fibronectin on its αvβ8 integrin binding activity. A, amino acid sequences of wild-type and leucine-substituted mutants of FNIII7–10. RGD motifs are underlined, and the subsequent residues are shown in bold. B, titration curves of αvβ8 integrin bound to wild-type FNIII7–10 (closed circles), RGDL mutant (open circles), RGEL mutant (asterisks), and latent TGF-β1 (triangles). The assays were performed as described in the legend for Fig. 2. The results represent the means of three independent determinations.