Binding of prostaglandins E1 (alprostadil), E2 (dinoprostone), F1 alpha, and F2 alpha (dinoprost) to human serum proteins.

Prostaglandins E1 (alprostadil), E2 (dinoprostone), F1 alpha, and F2 alpha (dinoprost) were characterized in terms of binding to human serum, albumin, gamma-globulin II, beta-globulin III, alpha-globulin IV-1, and alpha-globulin IV-4. By using equilibrium dialysis and tritium-labeled ligands, the percent binding for all four ligands was found to decrease in the following order: human serum, albumin, and alpha-globulin IV-4. For the other three proteins, the order was not consistent with the four ligands, and less than 10% binding was observed. In general, prostaglandins E1 and E2 showed a higher percent binding for all fractions than prostaglandins F1 alpha and F2 alpha. All four ligands can be characterized as showing significant binding to human serum, albumin, and alpha-globulin IV-4.