Cytochrome P450 Compound I: Capture, Characterization, and C-H Bond Activation Kinetics

The Power Behind P450

Drugs, toxins and a range of metabolic substrates are detoxified in the liver by family of iron-containing enzymes called cytochrome P450. The iron component transfers oxygen to compounds that are often highly resistant to chemical reaction, but we know very little about the mechanism of this vital detoxification process. Rittle and Green (p. 933 ; see the Perspective by Sligar ) have managed to capture the P450 reaction intermediate by freezing a solution of the enzyme as it reacts with an oxidant. Spectroscopic techniques and kinetic studies then revealed an iron(IV)oxo intermediate that passes its oxygen along to the substrate with remarkable speed.