Studies on a 15-hydroxyprostaglandin dehydrogenase from human placenta. Purification and partial characterization

A 15-dyroxyprostaglandin dehydrogenase has been purified from human placenta to apparent monodispersity. The reaction catalyzed by this enzyme is freely reversible with an equilibrium constant of approximately 6.5 times 10-8 M. The activation energy is 9900 calories per mol. The molecular weight of the enzyme determined by gel filtration is 51,500; sodium dodecyl sulfate disc gel electrophoresis gives a value of 42,000. No evidence was obtained for the existence of multiple forms of the enzyme or for subunits.