Binding specificity of mouse serum amyloid P-component for fibronectin.
Binding between purified mouse serum amyloid P-component (SAP) and plasma fibronectin (Fn) occurred when either one of the proteins was immobilized by specific antibody and the second protein was offered in a soluble form. Binding of Fn to immobilized SAP was cooperative and saturable at a molar ratio of SAP/Fn = 7.1. The molar ratio at saturation was 3.7 for SAP/Fn when SAP was allowed to bind to immobilized Fn. The binding required 2 to 3mM amounts of Ca++. The binding of SAP to Fn was selectively inhibited by a monoclonal antibody specific for the mid-molecule region of Fn, by soluble gelatin, and by heparin in the presence of 3mM Ca++. We conclude that the SAP binding site was localized at the mid-molecule region of Fn that includes the adjacent gelatin-binding domain and the heparin-I binding domain.
D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D001667:Binding, Competitive; D002118:Calcium / Q000494:pharmacology; D005353:Fibronectins / Q000037:antagonists & inhibitors / Q000097:blood* / Q000276:immunology; D005780:Gelatin / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D011485:Protein Binding; D000683:Serum Amyloid P-Component / Q000037:antagonists & inhibitors / Q000097:blood* / Q000276:immunology
D000911:Antibodies, Monoclonal; D005353:Fibronectins; D000683:Serum Amyloid P-Component; D005780:Gelatin; D006493:Heparin; D002118:Calcium