displays very large kinetic isotope effects. In this work, substrate and solvent kinetic isotope
effects as well as the viscosity dependence of the oxidation of arachidonic acid were
investigated. The hydrogen atom abstraction step was rate-determining at all temperatures,
but was partially masked by a viscosity-dependent step at ambient temperatures. The
observed KIEs on kcat were large (∼ 100 at 25° C).