Prostaglandin F Binding to Bovine Ocular and Synthetic Melanins in Vitro

Abstract
The binding of 3H-prostaglandin F to bovine iris and synthetic melanin was studied in vitro using a ligand binding assay. Prostaglandin F was reversibly bound to both types of melanin. The binding was saturable and the Scatchard analysis revealed the existence of at least two binding sites with the corresponding KD values of 3.71 nM and 1.99 μM for natural and 4.99 nM and 0.19 μM for synthetic melanin, respectively. The high affinity Bmax values were 3.4 nM/g for natural and 2.5 nM/g for synthetic melanin. The dissociation of prostaglandin F from melanin after dilution of the complex was rapid and uniform.