What is the Origin of Cytochrome P-450?

The name is derived from the observation that these enzymes, when bound to carbon monoxide, exhibit a distinct spectral peak at a wavelength of 450 nanometers, hence "P-450" for pigment at 450. The cytochrome prefix denotes a cellular pigment involved in electron transfer. This enzyme system was first identified in the 1960s during studies of drug metabolism in liver microsomes, rapidly becoming a cornerstone of pharmacology and toxicology.

What is the Mechanism of Cytochrome P-450?

The mechanism involves the enzyme's iron-containing heme group binding to both molecular oxygen and the substrate compound, facilitating the transfer of electrons from NADPH to reduce the iron atom. This complex process results in the insertion of one oxygen atom into the substrate molecule, making it more polar and water-soluble, thereby preparing it for excretion or further modification by phase II enzymes. Genetic polymorphisms within the CYP450 genes can dramatically alter an individual's metabolic capacity, impacting hormone levels and the efficacy or toxicity of hormonal therapies.

Cytochrome P-450 ∞ Area

Cytochrome P-450

Meaning

Cytochrome P-450, often abbreviated as CYP450, refers to a superfamily of heme-containing monooxygenase enzymes predominantly located in the liver and intestinal epithelial cells, playing a central role in xenobiotic and endogenous compound metabolism. These enzymes are critical for the phase I detoxification pathway, responsible for oxidizing, reducing, or hydrolyzing substances, including approximately 75% of all clinically used drugs. In the context of hormonal health, CYP450 enzymes are vital for both the biosynthesis of steroid hormones, such as testosterone and estrogen, and their subsequent catabolism and clearance from the circulation.