Ferritin 470107 222834124 2008-07-01T10:05:09Z DOI bot 6652755 Citation maintenance. Formatted: title. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{protein | Name = [[Ferritin light chain|ferritin, light polypeptide]] | caption = Structure of the ferritin complex | image = Ferritin.png | width = 200 | HGNCid = 3999 | Symbol = [[Ferritin light chain|FTL]] | AltSymbols = | EntrezGene = 2512 | OMIM = 134790 | RefSeq = NM_000146 | UniProt = P02792 | PDB = | ECnumber = | Chromosome = 19 | Arm = q | Band = 13.3-13.4 | LocusSupplementaryData = }} {{protein | Name = [[FTH1|ferritin, heavy polypeptide 1]] | caption = | image = | width = | HGNCid = 3976 | Symbol = [[FTH1]] | AltSymbols = FTHL6 | EntrezGene = 2495 | OMIM = 134770 | RefSeq = NM_002032 | UniProt = P02794 | PDB = | ECnumber = | Chromosome = 11 | Arm = q | Band = 13 | LocusSupplementaryData = }} {{protein | Name = ferritin mitochondrial | caption = | image = | width = | HGNCid = 17345 | Symbol = FTMT | AltSymbols = | EntrezGene = 94033 | OMIM = 608847 | RefSeq = NM_177478 | UniProt = Q8N4E7 | PDB = | ECnumber = | Chromosome = 5 | Arm = q | Band = 23.1 | LocusSupplementaryData = }} {{Expert-verify|date=May 2008}} '''Ferritin''' is a [[globular protein]] complex consisting of 24 protein subunits and is the main intracellular iron storage protein in both [[prokaryote]]s and [[eukaryote]]s, keeping it in a soluble and non-toxic form. Ferritin which is not combined with iron is called '''apoferritin'''. == Description == Ferritin, a 450 k.Da. protein consisting of 24 subunits is present in every cell type. In vertebrates, these subunits are both the light (L) and the heavy (H) type with a apperent molecular weight of 19 kDA or 21 kDA respectively. In plants and bacteria the complex only consists of the H-chain type. Inside the ferritin shell, iron ions form [[crystallite]]s together with [[phosphate]] and [[hydroxide]] ions. The resulting particle is similar to the mineral [[ferrihydrite]]. Each ferritin complex can store about 4500 [[iron]] (Fe<sup>3+</sup>) ions. Some ferritin complexes in [[vertebrate]]s are hetero-oligomers of two highly-related [[gene]] products with slightly different [[physiological]] properties. The ratio of the two [[homologous]] [[protein]]s in the complex depends on the relative expression levels of the two genes. == Function== Free iron is [[toxic]] to [[Cell (biology)|cells]] as it acts as a catalyst in the formation of free radicals from [[reactive oxygen species]] via the [[Fenton Reaction]].<ref>{{cite journal | author = Orino K, Lehman L, Tsuji Y, Ayaki H, Torti SV, Torti FM | title = Ferritin and the response to oxidative stress | journal = Biochem J | volume = 357 | issue = 1 | pages = 241–7 | year = 2001 | pmid = 11415455 | doi = 10.1042/0264-6021:3570241}}</ref> Hence organisms have evolved an elaborate set of protective mechanisms to bind iron in various [[Biological tissue|tissue]] compartments. Within cells, iron is stored complexed to protein as ferritin or [[hemosiderin]]. [[Apoferritin]] binds to free ferrous iron and stores it in the ferric state. As ferritin accumulates within cells of the [[reticuloendothelial system]], protein aggregates are formed as [[hemosiderin]]. Iron in ferritin or hemosiderin can be extracted for release by the RE cells although hemosiderin is less readily available. Under [[steady state]] conditions, the [[serum]] ferritin level correlates with total body iron stores; thus, the serum ferritin level is the most convenient laboratory test to estimate iron stores. Ferritin is also used in materials science as a precursor in making iron [[nanoparticle]]s for [[carbon nanotube]] growth by [[chemical vapor deposition]]. == Diagnostic uses == [[blood plasma|Serum]] ferritin levels are measured in [[patient]]s as part of the '''iron studies''' workup for [[anemia]] and for [[restless leg syndrome]]. The ferritin levels measured have a direct correlation with the total amount of iron stored in the body (except in certain circumstances, such as [[anemia of chronic disease]]). If ferritin is high there is iron in excess, which would be [[excrete]]d in the [[stool]]. If ferritin is low there is a risk for lack in iron which sooner or later could lead to [[anemia]]. Low ferritin levels have been associated with symptoms of [[restless leg syndrome]] even in the absence of anemia. Normal [[blood levels]] are 30-300 ng/mL for males and 15-200 ng/mL for females. ((according to clinical medicine by : Kumar & clark page 428 )) <ref>Beyond Cholesterol, Julius Torelli MD, 2005 ISBN 0-312-34863-0 p.84</ref><ref>[http://www.nlm.nih.gov/medlineplus/ency/article/003490.htm MedlinePlus Medical Encyclopedia: Ferritin<!-- Bot generated title -->]</ref> In the setting of [[anemia]], [[serum]] ferritin is the most [[sensitivity (tests)|sensitive]] lab test for [[iron deficiency anemia]].<ref>{{cite journal | author = Guyatt G, Patterson C, Ali M, Singer J, Levine M, Turpie I, Meyer R | title = Diagnosis of iron-deficiency anemia in the elderly | journal = Am J Med | volume = 88 | issue = 3 | pages = 205–9 | year = 1990 | pmid = 2178409 | doi = 10.1016/0002-9343(90)90143-2}}</ref> Ferritin is also used as a [[marker]] for [[iron overload disorder]]s, such as [[hemochromatosis]] and [[porphyria]] in which the ferritin level may be abnormally raised. As ferritin is also an [[acute phase proteins|acute-phase reactant]], it is often elevated in the course of [[disease]]. A normal [[C-reactive protein]] can be used to exclude elevated ferritin caused by acute phase reactions. Ferritin can be elevated during periods of acute [[Malnutrition|malnourishment]].<ref>{{cite journal | author = Kennedy A, Kohn M, Lammi A, Clarke S | title = Iron status and haematological changes in adolescent female inpatients with anorexia nervosa | journal = J Paediatr Child Health | volume = 40 | issue = 8 | pages = 430–2 | year = 2004 | pmid = 15265182 | doi = 10.1111/j.1440-1754.2004.00432.x}}</ref> == See also == *[[Bacterioferritin]] *[[Transferrin]] *[[Ferritin light chain]] ==References== <references/> ==External links== * http://sickle.bwh.harvard.edu/iron_transport.html {{Iron-binding proteins}} [[Category:Blood tests]] [[Category:Chemical pathology]] [[Category:acute phase proteins]] [[de:Ferritin]] [[es:Ferritina]] [[fr:Ferritine]] [[it:Ferritina]] [[nl:Ferritine]] [[no:Ferritin]] [[pl:Ferrytyna]] [[pt:Ferritina]] [[sl:Feritin]] [[fi:Ferritiini]] [[sv:Ferritin]]