Reactive intermediates in cytochrome p450 catalysis.

Mass spectrometric characterization of protein adducts of multiple cytochrome P450-dependent reactive intermediates of diclofenac to human glutathione-S- transferase P1-1 Adapted from: Mass spectrometric characterization of protein adducts of multiple cytochrome P450-dependent reactive intermediates of diclofenac to human glutathione-S-transferase P1-1

Haem-oxygen reactive intermediates: catalysis by the two-step.

The catalytic schemes of a variety of haem enzymes, including the P450 mono-oxygenases, consist of a number of common reactive haem-oxygen adducts. The characterization of these intermediates by optical and EPR spectroscopies has reinforced the similarity of these intermediate states in a number of haem enzyme systems. Furthermore, the reactivity of these states in P450 and horseradish peroxida...

Identification of Intracellular Sources Responsible for Endogenous Reactive Oxygen Species Formation

The endogenous reactive oxygen species ("ROS") formation is associated with many pathologic states such as inflammatory diseases, neurodegenerative diseases, brain and heart ischemic injuries, cancer, and aging. The purpose of this study was to investigate the endogenous sources for "ROS" formation in intact isolated rat hepatocytes, in particular, peroxisomal oxidases, monoamine oxidase, xanth...

Identification of binding sites of non-I-helix water molecules in mammalian cytochromes p450.

The cytochromes P450 (P450s) enzymes are integral in determining the disposition of many therapeutic compounds. At the molecular level, the details of P450 catalysis are still under investigation, but the importance of water-mediated proton shuttles seems evident in the catalytic cycle as it progresses through various heme iron-oxygen enzyme intermediates. The study of P450-bound waters has bee...

Significantly shorter Fe-S bond in cytochrome P450-I is consistent with greater reactivity relative to chloroperoxidase

Cytochrome P450 (P450) and chloroperoxidase (CPO) are thiolate-ligated haem proteins that catalyse the activation of carbon hydrogen bonds. The principal intermediate in these reactions is a ferryl radical species called compound I. P450 compound I (P450-I) is significantly more reactive than CPO-I, which only cleaves activated C-H bonds. To provide insight into the differing reactivities of th...