The proposed research involves studies of aspects of enzymatic conversion of appropriate unsaturated fatty acids to prostaglandins, and a simpler system that is similar to the first step of the PG biosynthetic process involving the oxygenation of linoleate to its hydroperoxide. The prostaglandin synthetase reaction, using a mammalian seminal vesicle microsomal fraction, will be examined as to roles of cofactors and mode of inhibition by anti-arthritic non-steroidal drugs and other substances. Several effectors change PGE to PGF ratios, thereby having potential physiological effects on blood platelet aggregation, the cardiovascular, reproductive, and respiratory systems as well as on inflammation. The broad objective is sorting out the step and mode of action of effectors, and approaching the nature of the individual enzymes in the complex. With soybean lipoxygenase it is planned to examine the mechanism of the peroxidation reaction of unsaturated fatty acids with molecular oxygen, a process at least formally related to the first step in PG synthetase. Approaches involving physical spectroscopic and kinetic experiments are described. It is also proposed to use kinetics and particularly F19 nmr to investigate the nature of the enzyme-fatty acid binding in this system - which shows a similar specificity to many other oxidases, hydroxylases, and desaturates that function throughout biological systems on fatty acid substrates.