Enzymes In Health & Disease Flashcards
What is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase?
Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is an enzyme complex produced by neutrophils that converts oxygen (O2) to the free radical superoxide (O2-). NADPH oxidase is required for phagocytic killing of catalase positive organisms.
This enzyme complex is deficient in chronic granulomatous disease.
What is myeloperoxidase?
Myeloperoxidase is an enzyme found principally in neutrophils and monocytes that generates hypochlorous acid from hydrogen peroxide and chloride ions. The enzyme is released into plasma in infectious and inflammatory diseases.
Myeloperoxidase deficiency is a common inherited immunodeficiency syndrome characterized by the inablity to produce hypochlorous acid within phagolysosomes as part of the oxidative burst.
What is superoxide dismutase (SOD)?
Superoxide dismutase (SOD) is an enzyme that catalyzes the conversion of superoxide (O2-) to hydrogen peroxide.
Mutations in the SOD1 gene that codes for the enzyme superoxide dismutase have been associated with amyotrophic lateral sclerosis.
What is catalase?
Catalase is an enzyme that is present in almost all cells and catalyzes the decomposition of hydrogen peroxide to water and oxygen.
Microorganisms that are catalase-positive include Aspergillus spp., Burkolderia cepacia, and Staphylococcus aureus. Patients with chronic granulomatous disease have increased susceptibility to catalase positive organisms.
What is urease?
Urease is an enzyme that accelerates the hydrolysis of urea into carbon dioxide and ammonia.
Urease is an enzyme used by certain microorganisms to facilitate their existence in otherwise inhospitable body locations.
What is glutathione peroxidase?
Glutathione peroxidase is an antioxidant enzyme that scavenges hydrogen peroxide from blood and other tissues. Deficiencies of the enzyme have been linked to an increased risk of acute coronary syndrome.
What is monoamine oxidase?
Monoamine oxidase is an enzyme that catalyzes the oxidative deamination of biogenic amines (eg, epinephrine, norepinephrine, domaine, serotonin).
