What is the function of Carboxylesterase?
Carboxylesterases are a multigene family of mammalian enzymes widely distributed throughout the body that catalyze the hydrolysis of esters, amides, thioesters, and carbamates. In humans, two carboxylesterases, hCE1 and hCE2, are important mediators of drug metabolism.
What is a Phase 2 reaction?
Phase II reactions consist of adding hydrophilic groups to the original molecule, a toxic intermediate or a nontoxic metabolite formed in phase I, that requires further transformation to increase its polarity. These reactions include conjugation reactions, glucuronidation, acetylation, and sulfation.
What is CES1A1?
What is CES1A1? The CES1A1 gene encodes carboxylesterase 1, an enzyme involved in the metabolism of several therapeutic medications and some illicit drugs. 2 One of the more studied polymorphisms of the CES1A1 gene is a G>A substitution at codon 143.
What do phase 2 enzymes do?
Phase 2 enzymes are major detoxification enzymes and an important part of cellular defense against carcinogens, oxidants, and other toxic chemicals. The cancer-preventive role of many phase 2 enzymes has been well documented.
What is the difference between Phase 1 and Phase 2 reaction?
Phase I reactions of drug metabolism involve oxidation, reduction, or hydrolysis of the parent drug, resulting in its conversion to a more polar molecule. Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine.
Where are Carboxylesterases found?
The carboxylesterases are located in the cytoplasm and endoplasmic reticulum of numerous tissues including the liver, small intestine, kidney, and lungs, but the greatest quantities are found in the liver and small intestine where they contribute significantly to the first-pass metabolic hydrolysis of substrate drugs.
What is the purpose of glucuronidation?
Glucuronidation is a major mechanism for the formation of water-soluble substrates from xenobiotics, leading to their elimination from the body in bile or urine.
What is glucuronidation metabolism?
n. a metabolic process by which drugs or other substances are combined with glucuronic acid to form more water-soluble compounds, which are more readily excreted by the kidneys or in bile. Glucuronidation is the most prevalent of the Phase II reactions of drug metabolism.
What is the difference between phase1 and Phase 2 metabolism?
The key difference between phase I and phase II metabolism is that the phase I metabolism converts a parent drug to polar active metabolites while phase II metabolism converts a parent drug to polar inactive metabolites. Metabolism (drug metabolism) is the anabolic and catabolic breakdown of drugs by living organisms.
What does the CYP1A2 gene do?
Function. CYP1A2 is a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids.
What is CYP2D6 enzyme?
The CYP2D6 enzyme catalyses the metabolism of a large number of clinically important drugs including antidepressants, neuroleptics, some antiarrhythmics, lipophilic β-adrenoceptor blockers and opioids.
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.
What is the function of glucuronidation?
What enzyme does glucuronidation?
Glucuronidation reactions are catalyzed by a family of enzymes called uridine diphosphate-glucuronosyltransferases (UGTs), which likely evolved in response to the need to excrete lipophilic compounds from the body.
What are the 3 phases of metabolism?
The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion.
What does CYP3A4 do in the body?
CYP3A4 is a major cytochrome P450. It catalyses a broad range of substrates including xenobiotics such as clinically used drugs and endogenous compounds bile acids. Its function to detoxify bile acids could be used for treating cholestasis, which is a condition characterised by accumulation of bile acids.