Figure 4: (a) Chymotrypsin Limited Proteolysis: reactions for the indicated times were performed with mixtures containing 𝛼 -chymotrypsin and PEDF substrate at a ratio of 1 : 10 (w/w). Reactions were resolved by SDS-PAGE (0.1 μg per lane) followed by western blotting with anti-PEDF. Cleaved and the uncleaved forms are shown to the right. (b) Binding to Heparin. PEDF-1 and PEDF-2 were subjected to heparin-affinity column chromatography. Unbound (U) and bound (B) material was analyzed by SDS-PAGE and immunostained with anti-PEDF.