Hephaestin

Hephaestin, wanda kuma aka fi sani da HEPH, furotin ne wanda a cikin mutane ke ɓoye ta hanyar halittar HEPH.Ishikawa K, Nagase T, Suyama M, Miyajima N, Tanaka A, Kotani H, Nomura N, Ohara O (June 1998). "Prediction of the coding sequences of unidentified human genes. X. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro". DNA Res. 5 (3): 169–76. doi:10.1093/dnares/5.3.169. PMID 9734811"Entrez Gene: Hephaestin"Vulpe CD, Kuo YM, Murphy TL, Cowley L, Askwith C, Libina N, Gitschier J, Anderson GJ (February 1999). "Hephaestin, a ceruloplasmin homologue implicated in intestinal iron transport, is defective in the sla mouse". Nat. Genet. 21 (2): 195–9. doi:10.1038/5979. PMID 9988272. S2CID 25530044.

 Aiki 
Hephaestin yana shiga cikin metabolism da homeostasis na ƙarfe da yuwuwar jan ƙarfe. Ferroxidase mai dogaro da jan ƙarfe ne mai transmembrane wanda ke da alhakin jigilar ƙarfe na abinci daga enterocytes na hanji zuwa cikin tsarin jini. Ana samun mafi girman magana na hephaestin a cikin ƙananan hanji. Yana iyakance ga enterocytes na villi (inda ƙwayar ƙarfe ke faruwa),Chen H, Huang G, Su T, Gao H, Attieh ZK, McKie AT, Anderson GJ, Vulpe CD (May 2006). "Decreased hephaestin activity in the intestine of copper-deficient mice causes systemic iron deficiency". J. Nutr. 136 (5): 1236–41. doi:10.1093/jn/136.5.1236. PMID 16614410. kasancewar kusan babu a cikin ƙwayoyin crypt. Hephaestin yana jujjuya baƙin ƙarfe (II), Fe2 + zuwa baƙin ƙarfe (III), Fe3 +, kuma yana yin sulhu da baƙin ƙarfe mai yuwuwa tare da haɗin gwiwa tare da jigilar ƙarfe na basolateral, ferroportin 1. Har zuwa ƙaramin hephaestin an gano shi a cikin hanji, splin, koda, nono, placenta da kasusuwa trabecular sel amma rawar da yake takawa a cikin waɗannan kyallen takarda ya kasance a kafa. Hephaestin yana gabatar da homology tare da ceruloplasmin, furotin dehydrogenase na jini wanda ke shiga cikin lalatawar jan karfe da adanawa.

Hephaestin furotin ne na aminoacids 1135 da aka samu daga mafarin amino acid 1158 kuma shine 130.4 kDa. Ana annabta cewa za a ɗaure ions tagulla guda 6 akan kowane monomer.Chen H, Attieh ZK, Su T, Syed BA, Gao H, Alaeddine RM, Fox TC, Usta J, Naylor CE, Evans RW, McKie AT, Anderson GJ, Vulpe CD (May 2004). "Hephaestin is a ferroxidase that maintains partial activity in sex-linked anemia mice". Blood. 103 (10): 3933–9. doi:10.1182/blood-2003-09-3139. PMID 14751926

 Ganowa 
Dokta Christopher D. Vulpe na Jami'ar California, Berkeley ne ya fara gano Hephaestin a cikin 1999. Sun sanya sunan sabon sunadarin sunadaran Hephaestus, allahn Girka na ƙarfe na aiki.

Yawancin abin da aka sani game da hephaestin ya fito ne daga nazarin halittu masu gado na murine iron metabolism. An gano furotin kuma an gano shi ta hanyar nazarin berayen da ke da anemia mai alaƙa da jima'i, ko sla mice, wanda a cikinsa akwai ƙwayar mucosal na yau da kullun na ƙarfe na abinci amma rashin jigilar baƙin ƙarfe daga enterocytes na hanji zuwa wurare dabam dabam. sla mice harbor wani juzu'i na maye gurbi na kwayar halittar HEPH, wanda ya haifar da bayyanar da furotin na hephaestin wanda amino acid 194 ke datse. Bincike ya nuna cewa wannan furotin na hephaestin da aka datse yana riƙe da ɗan ƙaranci, duk da haka ana iya ganowa da ƙididdige matakin aikin ferrooxidase. Wannan yana haifar da yuwuwar wasu dalilai na iya taimakawa ga raguwar kwararar baƙin ƙarfe da aka gani a cikin sla phenotype.

Baya ga guguwar furotin na asali, sla phenotype ɗin da ba shi da ƙarfe kuma ana iya bayyana shi ta hanyar ɓarna a cikin salula na hephaestin. Nau'in namun daji hephaestin yana ganowa a cikin wani yanki na nukiliya da kuma saman basolateralC. N. Roy; C. A. Enns (December 2000). "Iron homeostasis: new tales from the crypt". Blood. 96 (13): 4020–4027. doi:10.1182/blood.V96.13.4020. PMID 11110669.. Sabanin haka, sla hephaestin yana da alama yana cikin rukunin supranucelar ne kawai amma ba a iya gano shi a ƙarshen. Ganin aikin hephaestin da aka kafa na sauƙaƙe fitar da baƙin ƙarfe na basolateral, wannan ɓarna na iya yin bayanin tarin baƙin ƙarfe na hanji mai banƙyama da ƙarancin ƙarfe na tsarin da aka gani a cikin mice.Y. M. Kuo; T. Su; H. Chen; Z. Attieh; B. A. Syed; A. T. McKie; G. J. Anderson; J. Gitschier; C. D. Vulpe (February 2004). "Mislocalisation of hephaestin, a multicopper ferroxidase involved in basolateral intestinal iron transport, in the sex linked anaemia mouse". Gut. 53 (2): 201–206. doi:10.1136/gut.2003.019026. PMC 1774920. PMID 14724150.

Hephaestin na ɗan adam, wanda ba shi da yanki mai ɗaukar hoto, an fara bayyana shi a cikin 2005 ta Dr. Tanya Griffiths, Grant Mauk, da Ross MacGillivray a Jami'ar British Columbia. Sun nuna cewa recombinant ɗan adam hephaestin (rhHp) daure jan karfe (ƙaddara ta hanyar inductively hade plasma mass spectrometry) da kuma nuna matsakaicin sha a ~ 610 nm daidai da sauran blue multicopper oxidases kamar ceruloplasmin. Ta amfani da ferrous ammonium sulfate a matsayin substrate, rhHp an nuna yana da aikin ferrooxidase tare da km na 2.1 μM don Fe(II).Griffiths TA, Mauk AG, MacGillivray RT (November 2005). "Recombinant expression and functional characterization of human hephaestin: a multicopper oxidase with ferroxidase activity". Biochemistry. 44 (45): 14725–31. doi:10.1021/bi051559k. hdl:2429/18540. PMID 16274220.

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