Effect of GAG lyases and chlorate on 125 I-PEDF binding to retinoblastoma Y-79 cells. Human retinoblastoma Y-79 cells (5 × 105 cells/ml) were cultured in serum-free media at 37°C and treated with GAG lyases or chlorate. Binding to the treated cells was performed with 2 nM 125I-PEDF. Free and bound PEDF were separated by filtration through glass-fiber filters under vacuum. Non-specific binding was determined from binding reactions in the presence of 50-fold excess of unlabeled ligand. Specific binding was calculated by subtracting non-specific binding from total binding. Panel A. Cells cultured for 16 h were treated with hyaluronidase, heparinase and heparitinase at 37°C for 120 min. All experimental points are given as the average of quadruplicates. Panel B. Cells were cultured with or without 30 mM sodium chlorate and 10 mM sodium sulfate at 37°C for 16 h before the radioligand was added. The binding reactions were at 4°C for 30 min. All experimental points are given as the average of triplicates.