Is cytochrome P450 a superfamily?
The cytochrome P450 (CYP) superfamily is a diverse and important enzyme family, playing a central role in chemical defense and in synthesis and metabolism of major biological signaling molecules.
What are the features of cytochrome P450?
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown.
Is cytochrome P450 a Hemoprotein?
The hemoprotein cytochrome P450 is the terminal oxidase enzyme localized to the liver endoplasmic reticulum, which catalyzes the oxidative metabolism of a wide variety of substrates (1,2).
What is Glucuronidation reaction?
Glucuronidation is a conjugation reaction whereby glucuronic acid, derived from cofactor UDP-glucuronic acid, is covalently linked to a substrate containing a nucleophilic functional group. The resultant metabolite, called a glucuronide, is usually excreted in bile and urine.
What happens when CYP450 is inhibited?
IRREVERSIBLE INHIBITION In some cases, CYP450 inhibition is irreversible. The formation of a stable complex, between a drug and the metabolizing enzyme, is one mechanism that can result in irreversible inhibition. The inhibitor can be a drug or one of its metabolites.
How does cytochrome P450 detoxify a substance?
Adding Oxygen. The cytochrome p450 enzymes find unusual molecules and add oxygen atoms to them. In most cases, this has the effect of making the molecule more soluble in water, and thus, easier to flush out of the body.
Which of the following is not a Hemoprotein?
The deoxy form of hemocyanin contains Cu in a +1 oxidation state and is colorless. The oxy form of hemocyanin contains Cu in +2 form and is bridged to oxygen via an O22–Cu2+ LMCT. Hence, hemocyanin is a non-heme protein.
What is the structure of cytochrome P450?
(i) The P450 is in a low-spin ferric resting form with its heme iron axially co-ordinated by cysteine thiolate and a H2O molecule. (ii) Substrate (fatty acid) binding displaces the axial water and converts the heme iron from low-spin to a high-spin form.
What is glucuronidation in the liver?
Glucuronidation, a conjugation reaction, is thought to protect the liver by both reducing hepatic BA toxicity and increasing their urinary elimination. The present study evaluates the contribution of each process in the overall BA detoxification by glucuronidation.