Binding of soluble form of fibroblast surface protein, fibronectin, to collagen

TLDR

The study employed a solid‑phase enzyme immunoassay with collagen or gelatin adsorbed to plastic, detecting fibronectin binding via alkaline‑phosphatase‑conjugated antibodies, and purified fibronectin by gelatin‑Sepharose affinity chromatography. Fibronectin, both circulating and from fibroblast cultures, binds specifically to collagen and gelatin, whereas malignant fibroblasts lack surface fibronectin, suggesting impaired anchorage may promote malignant growth.

Abstract

Abstract Fibronectin, a plasma protein immunologically identical with a major surface protein of normal fibroblasts, was found to bind to collagen and gelatin. A solid phase enzyme immunoassay was used for the binding tests. Collagen, gelatin or various control proteins were adsorbed to a plastic surface. Binding of fibronectin was detected using purified fibronectin antibodies conjugated to alkaline phosphatase. Circulating fibronectin and fibronectin obtained from fibroblast cultures both showed specific binding to collagen and gelatin. Preparative affinity chromatography of plasma on gelatin coupled to Sepharose gave electrophoretically and immunologically pure fibronectin in high yields. Malignantly transformed fibroblasts lack surface fibronectin. Our findings suggest the possibility that this results in a lack of anchorage to the surrounding intercellular matrix, which could contribute to the malignant growth behavior.