Geography 2152F/G Lecture Notes - Lecture 5: Paracetamol, P-Glycoprotein, Felodipine
Document Summary
Found in number of tissues but important for human drug metabolism in liver and small intestine. Found within hepatocytes and enterocytes within the smooth endoplasmic reticulum: on the membrane so that the enzyme has most of its active site facing the cytosol. Enzyme contains heme molecule which helps bing molecular oxygen. Associated with cyp is another protein called nadph p450 oxidoreductase: this enzyme donates electrons from nadph to cytochrome p450. Called p450 because it has a peak of 450 nm for absorption of light when bound to carbon monoxide. Aromatic: turns the ring into a phenol. The cytochrome adds an oxygen to the carbon next to the hetero for the dealkylations of either nitrogen or oxygen. In doing so it breaks up the drug into two pieces. Can also add an oxygen directly on a hetero atom (bottom ones) Each cyp can metabolize a single drug to many metabolites: several cyp enzymes can metabolise a single drug.