Competition of heparin and [γ-32P]ATP for binding to VEGF-A
. VEGF-A165 (3 μg) was labeled with [γ-32P]ATP (5 μCi) in Tris-HCl (pH 7.5) at 37°C for 30 min. (A) Heparin was added prior to ATP to give final concentrations of 1 to 100 μg/mL. (B) Heparin was added at a fixed concentration of 100 μg/mL and times (t) indicated.