Enzymatic properties of prostaglandin synthetase from bovine seminal vesicles.

The relative quantities of PGE2 and PGF2alpha biosynthesized are strictly dependent on the concentration of the precursor, arachidonate, on the nature and on the quantity of sulfhydrylated cofactor present. The sigmoid aspect of the curve of PGF2alpha biosynthesis as a function of arachidonate concentration is directly dependent on the GSH concentration. Treatment of the microsomes by low concentrations of HgCl (5 muM) modifies the kinetics of PGE2 and PGF2alpha biosynthesis. Similarly, the presence of L-8027, a competitive inhibitor, alters qualitatively and quantitatively the production of PGE2 and PGF2alpha as a function of arachidonate concentration.