Cytochrome P450 isozyme (CYP (also known as P450))

Cytochrome P450 isozymes are a superfamily of heme-containing monooxygenase enzymes (oxidoreductases) that play a critical role in the metabolism of endogenous substances (such as steroids and fatty acids) and exogenous chemicals, especially drugs and environmental toxins[1][2][5][7]. These enzymes catalyze the addition of an oxygen atom to substrate molecules (monooxygenation), which is a key part of phase I metabolism, resulting in compounds that are more easily excreted from the body[1][7]. Over 21,000 members have been classified in this family, named for their characteristic absorption peak at 450 nm when complexed with carbon monoxide[2]. The family is subdivided into many isozymes (e.g., CYP3A4, CYP2D6, CYP2C9, CYP1A2, CYP2C19), each with unique substrate specificities[4][6]. Cytochrome P450 isozymes are a major determinant of pharmacokinetics, are highly variable between individuals (due to genetic polymorphisms and environmental induction or inhibition), and are central mediators of many clinically significant drug-drug interactions[4][5][7]. Deficiencies or alterations in CYP activity can influence disease pathogenesis and are important considerations in precision medicine and toxicology[4].

Other names

Cytochromes P450P450CYPCYP450Cyt P450

Oxidative metabolism (hydroxylation, dealkylation, deamination, etc.) of drugs and endogenous compounds; Biotransformation through phase I reactions (mainly monooxygenation); Drug activation and deactivation