cytochrome p450
Created | Updated Apr 27, 2006
Cytochrome P450 enzymes constitute a large superfamily of monooxygenases involved in the oxidative metabolism of a wide variety of both exogenous and endogenous compounds . They are responsible from the initial step in the biotransformation and elimination of a wide variety of drugs and potential toxicants and they are abundant in the liver tissue .
57 Cytochrome P450 gene families have been identified so far, at least 12 cytochrome P450 being in humans, which are known to be involved in the common drug biotransformations. These families are the cytochrome P450 1, 2 and 3 (named as CYP1, CYP2 and CYP3) and are then divided into subfamilies which are designated by capital letters following the family title (i.e. CYP3A). CYP3A4 is the major form of cytochrome P450 in the human liver and metabolizes most of the drugs. A single hepatocyte can contain a variety of cytochrome P450 enzymes. Besides, an individual enzyme of cytochrome P450 may be able of metabolizing many different drugs, but a given drug may be primarily metabolized by a single enzyme.
57 Cytochrome P450 gene families have been identified so far, at least 12 cytochrome P450 being in humans, which are known to be involved in the common drug biotransformations. These families are the cytochrome P450 1, 2 and 3 (named as CYP1, CYP2 and CYP3) and are then divided into subfamilies which are designated by capital letters following the family title (i.e. CYP3A). CYP3A4 is the major form of cytochrome P450 in the human liver and metabolizes most of the drugs. A single hepatocyte can contain a variety of cytochrome P450 enzymes. Besides, an individual enzyme of cytochrome P450 may be able of metabolizing many different drugs, but a given drug may be primarily metabolized by a single enzyme.
