Isolation of an actin-binding fragment of fibronectin

Abstract

A specific actin-binding site in the adhesive glycoprotein fibronectin, isolated from chicken fibroblasts, was identified. Affinity chromatography of fragments, released from fibronectin by limited proteolysis with trypsin, chymotrypsin and subtilisin, on actin-Sepharose and other protein-Sepharose columns was used to locate the binding site. A 27,000 MW subtilisin-digest fragment bound efficiently to actin. The results suggest that the actin-binding site is close to, but not identical with, the reported collagen-binding site.