Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
NADPH oxidase is an enzyme complex found in phagocytes that produces reactive oxygen species (ROS) to combat pathogens. It plays a crucial role in the immune response by generating superoxide radicals during the respiratory burst.
5 Must Know Facts For Your Next Test
NADPH oxidase deficiency leads to Chronic Granulomatous Disease (CGD), which results in recurrent bacterial and fungal infections.
The enzyme complex consists of multiple subunits, including gp91phox, p22phox, p67phox, p47phox, and Rac2.
Activation of NADPH oxidase occurs when phagocytes engulf pathogens, triggering the assembly of its subunits at the plasma membrane or within phagosomes.
Patients with CGD often present with granulomas due to the body's inability to effectively kill ingested microbes.
Diagnosis of NADPH oxidase deficiency can be performed using tests like the nitroblue tetrazolium (NBT) test or dihydrorhodamine (DHR) flow cytometry assay.
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Related terms
Chronic Granulomatous Disease (CGD): A genetic disorder resulting from defective NADPH oxidase, leading to recurrent infections and granuloma formation.
Respiratory Burst: A rapid release of reactive oxygen species by phagocytes upon encountering pathogens.
Reactive Oxygen Species (ROS): Chemically reactive molecules containing oxygen produced by enzymes like NADPH oxidase to destroy pathogens.