Mixed Function Oxygenase

Mixed function oxygenases, also known as mixed-function oxidases, monooxygenases, or hydroxylases, are a widely distributed class of enzymes that catalyze oxidation-reduction (redox) reactions. In these reactions, one atom of molecular oxygen (O₂) is incorporated into an organic substrate while the other oxygen atom is reduced and combined with hydrogen ions to form water. These enzymes play a crucial role in the metabolism of both endogenous compounds and xenobiotics (foreign substances such as drugs), making them essential for detoxification and drug metabolism in organisms. A major family within this group is the cytochrome P450 enzymes. These are heme-containing proteins found primarily in liver microsomes but also present throughout various tissues. They require electron transfer from NADPH via cytochrome P450 reductase for activity. Cytochrome P450s are responsible for metabolizing a wide range of substrates including drugs, steroids, fatty acids, and carcinogens. Alterations in mixed function oxidase activity can affect drug efficacy and toxicity. These enzymes are also studied for their roles in cancer susceptibility due to their involvement in activating certain procarcinogens.

Other names

MonooxygenaseHydroxylase

Inhibiting or inducing enzyme activity, leading to altered drug metabolism.