[super 18]O kinetic isotope effects in non-heme iron enzymes: probing the nature of Fe/[O.sub.2] intermediates

The [super 18]O kinetic isotope effects (KIEs) of different non-heme iron enzymes with different reductants are calculated to explain the [O.sub.2] activation process taking place in them. These enzymes are shown to be widely used in the catalysis of a large number of oxygenation and oxidation reactions.