Partial characterization of endothelial FGF receptor functional domain by monoclonal antibody VBS-1.

Polypeptide growth factors mediate their cellular responses by binding to and activating specific cell surface receptors. Monoclonal antibody (MAb) VBS-1, produced against native fibroblast growth factor receptor-1 (FGFR-1), inhibited the binding of fibroblast growth factor-2 (FGF-2) to its receptor on coronary venular endothelial cells (CVECs) as determined by 125I-FGF-2 Scatchard analysis and [3H]thymidine uptake assays (ED50 = 80 ng/mL). Enzyme studies demonstrated that MAb VBS-1 binds to a protein epitope.