myeloperoksüdaas

Myeloperoxidase (MPO) is an enzyme found in neutrophils, a type of white blood cell. It is a heme-containing enzyme that plays a crucial role in the innate immune system. MPO is abundant in the azurophilic granules of neutrophils. When neutrophils encounter pathogens, they release MPO into the phagosome, the cellular compartment where the pathogen is engulfed. Within the phagosome, MPO catalyzes the oxidation of chloride ions by hydrogen peroxide, producing hypochlorous acid (HOCl). Hypochlorous acid is a potent antimicrobial agent that can kill bacteria, fungi, and viruses.

The production of reactive oxygen species by MPO is essential for host defense. However, uncontrolled MPO activity can also lead to tissue damage. Elevated levels of MPO are associated with various inflammatory and cardiovascular diseases, including atherosclerosis, rheumatoid arthritis, and inflammatory bowel disease. MPO can contribute to oxidative stress and inflammation by generating reactive nitrogen species and modifying proteins. These modifications can alter protein function and promote pro-inflammatory signaling pathways. Due to its involvement in disease, MPO has been investigated as a potential therapeutic target. Inhibitors of MPO are being explored to reduce inflammation and oxidative damage in certain conditions. The presence of MPO in neutrophils makes it a useful biomarker for neutrophil activation and inflammation.