Exam 3 Material (Cumulative) Flashcards
Cuprous
Reduced, Cu1+
Cupric
Oxidized, Cu2+
CTR1
trasnports Cu1+ (reduced) into enterocyte, trimer
ATP7A
copper (Cu1+) exporter, via basolateral membrane of enterocyte to portal blood, ATPase, mutations in this protein cause Menkes’ disease
CCS
Copper chaperone for SOD1, delivers copper to SOD1 so copper doesn’t form a new radical
SOD
super oxide dismutase
ATOX1
delivers copper to TGN (trans golgi network)
Metallothionein (MT)
copper storage protein, has 20 cysteines, can bind 7 atoms of copper, zinc storage protein
Factors enhancing copper absorption
histidine, methionine, cysteine**, glutathione, citrate
Factors inhibiting copper absorption
phytate**, zinc, iron, molydenum, calcium, phosphorus, vitamin C
ATP7B
copper exporter in TGN, transports Cu1+ into TGN to be incorporated into ceruloplasmin or to be secreted in bile, mutations lead to Wilson’s disease
Ceruloplasmin (CP)
in liver, plasma Cu protein, ferroxidase (oxidizes iron), Cu deficient - decrease Fe release from liver, bad copper assessment (sensitive to acute inflammation)
Hephaestin (HP)
ferroxidase (oxidizes iron), copper enzyme in intestine, upregulated in iron deficiency, mutations result in anemia, Cu deficient –> decrease Fe absorption
SOD1
antioxidant enzyme, 1 Cu (catalytic) + 1 Zn (structural), catalyzes dismutation of superoxide -> converts it to hydrogen peroxide, in mitochondria for ETS
Dopamine monooxygenase
dopamine beta-hydroxylase, converts dopamine to norepinephrine, vitamin C reduces Cu2+ to Cu1+ so it can work on dopamine
Lysyl oxidase
Cu-containing extracellular enzyme that crosslinks collagens or elastin to extracellular matrix, deaminates lysine in presence of O2
Tyrosinase
Cu-containing enzyme that converts tyrosine to melanin for skin darkening, copper deficiency can cause albinism
Neutropenia
low leukocytes
Menkes disease
mutation of ATP7A gene, x-linked recessive, rare, transport of Cu out of intestine is impaired, kinky hair disease (slow growth, hypothermia, seizures, degeneration of brain tissue, defective arterial walls, depigmentation of skin and hair, death at young age), treated with daily cu-histidine injections
Wilson’s disease
copper overload, rare, autosomal recessive mutation of ATP7B, too much Cu in liver leaks into blood to other organs, can be fatal, unbound Cu, hemolytic anemia, organ damage, liver/brain/kidneys, cornea of eye, treated with penicillamine or zinc
Penicillamine
chelation therapy, binds copper for excretion, treatment for Wilson’s disease
Kayser-Fleisher ring
cornea of eye has copper build up so copper atoms form rings around eye
Ferrous
Fe2+, bioavailable because it will be soluble in intestine, reduced, precipitates out at high pH
Ferric
Fe3+, oxidized, precipitates out at low pH, less bioavailable
DMT1
DMT1 transports Fe2+ through apical membrane with Dcytb, mutations cause anemia, induced by iron deficiency, needed for erythropoiesis
Dcytb
ferrireductase (duodenal cytochrome b), reduces Fe3+ to Fe2+ for absorption into enterocyte via DMT1, induced by iron deficiency, utilizes ascorbate
Ferroportin
export iron at basolateral membrane of enterocyte, induced by iron deficiency (or iron loading at macrophage), main regulated point of entry for iron
Hephaestin
ferroxidase, oxidize Fe2+ to Fe3+ so it can bind transferrin, basolateral surface of enterocyte, induced by iron deficiency, mutation results in anemia
Transferrin
transports iron to RBC for erythropoiesis, has IRE at 3’UTR, receptor upregulated by iron deficiency, receptor downregulated in adequate iron