Interaction of prostaglandins with blood plasma proteins. Comparative binding of prostaglandins A2, F2α and E2 to human plasma proteins

摘要

p1. The binding of prostaglandin Asub2/sub and prostaglandin Fsub2α/sub to human plasma proteins was investigated by DEAE-Sephadex chromatography and polyacrylamide-gel electrophoresis. Both prostaglandins, when added to human plasma iin vitro/i, were found to become bound mainly to plasma albumin. 2. The extent of binding of prostaglandins added to human plasma in low to moderate concentrations was found to be approx. 88, 73 and 58% for prostaglandins Asub2/sub, Esub2/sub and Fsub2α/sub respectively. The order of affinities for the binding of the three prostaglandins to albumin appear to be Asub2/sub&Esub2/sub&Fsub2α/sub. 3. The apparent association constants for the binding of these prostaglandins to human serum albumin were estimated to be approx. 4.8×10sup4/sup, 2.4×10sup4/sup and 0.9×10sup4/sup litre/mol for prostaglandins Asub2/sub, Esub2/sub and Fsub2α/sub respectively. The results are compared with previously reported association constants for the binding of long-chain fatty acids to both human and bovine albumins./p