Binding of fibronectin to gelatin and heparin: effect of surface denaturation and detergents.

The specific binding of fibronectin to collagen and heparan sulfate is important in cell adhesion and formation of connective tissue. We have used miniaturized affinity chromatography of 125I-labeled fibronectin on gelatin- or heparin-conjugated Sepharose as a model system to further study features of these interactions after a variety of treatments of the fibronectin. We find that fibronectin's affinity is abolished following adsorption and desorption from tissue culture plastic, diminished by the strong ionic detergent sodium dodecyl sulfate (SDS), and unaffected by nonionic detergents or the zwitterionic detergent Zwittergent 3-12. This identifies the latter as a gentle extractant suitable for a variety of uses in studying cell-substratum adhesion.