Inhibition of cytochrome P450 enzymes

Abstract

Three steps in the catalytic cycle of cytochrome P450 (P450, CYP; see Chapters 5 and 6) are particularly vulnerable to inhibition: (a) the binding of substrates, (b) the binding of molecular oxygen subsequent to the first electron transfer, and (c) the catalytic step in which the substrate is actually oxidized. Only inhibitors that act at one of these three steps will be considered in this chapter. Inhibitors that act at other steps in the catalytic cycle, such as agents that interfere with the electron supply to the hemoprotein by accepting electrons directly from P450 reductase1-3, are not discussed here.