The structure and electronic properties of oxy intermediates in the enzymatic cycle of cytochrome P450s

Cytochrome P450s are a class of heme proteins involved in the metabolism of a wide variety of xenobiotic substances in many species in nature. In mammalian species, these enzymes are found in a number of organs, most notably the liver, and are the enzymes primarily responsible for the transformation of a number of exogenous compounds into products which are soluble, benign forms and may be excreted. The products of such P450 metabolism, however, can be toxic or even carcinogenic and hence the importance of fundamental studies of determinants of both enzymatic efficacy and product specificity.