The cell binding fragment of fibronectin is chemotactic for fibroblasts.

The fibroblast chemoattractant property of fibronectin is retained in the proteolytically produced 160 kilodalton peptide that contains the heparin binding and cell binding domains of the molecule, while the 40 kilodalton collagen binding peptide is inactive. Further degradation of the 160 kilodalton peptide leads to destruction of chemoattractant activity. An analysis of the migration of fibroblasts in varied gradients of the 160 K peptide shows that the effect is chemotactic, i.e. directed migration of cells towards a higher concentration of the peptide.