Fibronectin

Fibronectins are a family of plasma and extracellular matrix glycoproteins that contain multiple sites for various ligands and cells. The region of fibronectin that mediates cell adhesion in a majority of cell types is in the carboxy terminal domain and involves the binding of the Arg-Gly-Asp (RGD) sequence to a specific polypeptide cell surface receptor. Although the mechanisms of fibronectin extracellular matrix assembly are not well understood, specific antibodies have been used to determine the domains involved in matrix assembly.This antibody stains the extracellular adhesive glycoprotein of fibronectin in connective tissues and vessels. It does not recognize the soluble dimeric form of fibronectin (plasma fibronectin) but strongly stains matrix fibronectin in tissues. Animal biodistribution experiments have shown that after intravenous administration, this antibody localizes to tumor vessels where it binds to the underlying basement membrane. The antigen is not accessible in normal tissues to circulating antibody indicating that this antibody can be used to target tumor vessels specifically in vivo.