OxidantDamage Flashcards
What is the Cytochrome Oxidase reaction?
O2 + 4e- + 4H+ —> 2H2O
What is P450 Catalysis equation?
P450 + Substrate + NADPH + O2
—> P450 + Substrate-OH + NADP+ + H2O
What happens in P450 Uncoupling?
P450 + Substrate + NADPH + O2
—> P450 + substrate + NADP+ + H2O2
What do macrophages produce when activated?
Superoxide: NADPH Oxidase
O2 + NADPH —> O2- + NADP+
Hydrogen Peroxide: Superoxide dismutase
2O2- + 2H+ —> H2O2 + O2
Bleach: Myeloperoxidase
H2O2 + Cl- + H+ —> H2O +HOCL —> H+ + OCL-
What is the Fenton Reaction?
H2O2 + Fe2+ —> HO* + HO- + Fe3+
What is the HaberWeiss Reaction?
H2O2 + O2- —> O2 + HO- + HO*
What radical products can be produced from Nitric Oxide?
NO* + O2- —> ONOO-
Peroxynitrite
What are the three Nitric Oxide Sythases?
nNOS (Neuronal Type I)
INOS (inductively Type II)
ENOS (endothelial Type III)
What is the Nitric Oxide Synthase reaction.
Arginine —> Citrulline
Produces NO* and 2H20
What effect does Nitrite have on hemoglobin?
Converts HbFe3+ —> HbFe2+
Ho can reactive O2/N species affects proteins?
- Cysteine oxidation and Cross-linking
- Tryptophan destroyed
- Tyrosine and methionine modified
What is the physiological significance of lipid oxidation?
Lipid peroxide stimulate prostaglandins and affect cell growth
4-Hydroxyalkenals
- affect adenylyl cyclase activity
- reduce cell growth and promote differentiation
- Inhibit platelet aggregation
- black macrophages action
What are peroxiredoxins?
Antioxidant enzymes which control cytokine induced peroxide levels which mediate signal transduction
What are most prevalent diseases of oxidant defense?
Chronic Granulomatous Disease (MAcrophages cannot kill microbes)
Acatalasemia
G6P DH Deficiency
