Cytochrome P450 family 3 subfamily A member 9 (CYP3A9) (CYP3A9)

Cytochrome P450 family 3 subfamily A member 9 (CYP3A9) is a prominent phase I drug-metabolizing enzyme primarily expressed in the liver and intestinal tissues of rats [UniProt: P15162]. As a member of the CYP3A subfamily, it plays a vital role in the oxidative biotransformation of a wide range of exogenous compounds, including over 50% of therapeutic drugs, as well as endogenous steroids like testosterone and progesterone [NCBI Gene: 25050]. CYP3A9 is considered the functional rat homolog of the human CYP3A4 enzyme, making it a critical component in preclinical pharmacological and toxicological assessments [PubMed: 10644514]. The enzyme functions as a monooxygenase, utilizing heme and NADPH to catalyze the hydroxylation or dealkylation of lipophilic substrates to facilitate their elimination from the body [StatPearls: NBK557669]. Because it interacts with a vast number of therapeutic agents, CYP3A9 is a major site for drug-drug interactions, where its inhibition or induction by one agent can significantly alter the pharmacokinetics and safety profile of co-administered medications [PubMed: 15581595]. Furthermore, the enzyme's activity can lead to the metabolic activation of certain pro-toxins or pro-carcinogens, adding a layer of complexity to its role in chemical safety [PubMed: 12107046].

Other names

Cytochrome P450 3A9P450-PCN2P450/6-beta-ACYP3A9Cyp3a9

Substrate oxidation via the heme-thiolate monooxygenase system, utilizing NADPH and molecular oxygen to catalyze hydroxylation or dealkylation reactions.