World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0002897252
Reproduction Date:

Title: Hemopexin  
Author: World Heritage Encyclopedia
Language: English
Subject: Human serum albumin, C-reactive protein, Transcortin, Transferrin, Alpha-2-Macroglobulin
Publisher: World Heritage Encyclopedia


Symbols  ; HX
External IDs GeneCards:
EC number
RNA expression pattern
Species Human Mouse
RefSeq (mRNA)
RefSeq (protein)
Location (UCSC)
PubMed search

Hemopexin (or haemopexin; HPX), also known as beta-1B-glycoprotein is a protein that in humans is encoded by the HPX gene[1][2][3] and belongs to hemopexin family of proteins.[4]


  • Function 1
  • Clinical significance 2
  • References 3
  • Further reading 4
  • External links 5
  • See also 6


Hemopexin binds heme with the highest affinity of any known protein. Its function is scavenging the heme released or lost by the turnover of heme proteins such as hemoglobin and thus protects the body from the oxidative damage that free heme can cause. In addition, hemopexin releases its bound ligand for internalisation upon interacting with a specific receptor situated on the surface of liver cells. This function of hemopexin is to preserve the body's iron.[5]

Clinical significance

Its levels in serum reflect how much heme is present in the blood. Therefore, low hemopexin levels indicates that there has been significant degradation of heme containing compounds and hemopexin is made to scavenge any heme it can. Low hemopexin levels are one of the diagnostic features of an intravascular hemolytic anemia.[6]


  1. ^ "Entrez Gene: HPX hemopexin". 
  2. ^ Altruda F, Poli V, Restagno G, Silengo L (1988). "Structure of the human hemopexin gene and evidence for intron-mediated evolution". J. Mol. Evol. 27 (2): 102–8.  
  3. ^ Altruda F, Poli V, Restagno G, Argos P, Cortese R, Silengo L (June 1985). "The primary structure of human hemopexin deduced from cDNA sequence: evidence for internal, repeating homology". Nucleic Acids Res. 13 (11): 3841–59.  
  4. ^ Bode W (June 1995). "A helping hand for collagenases: the haemopexin-like domain". Structure 3 (6): 527–30.  
  5. ^ Tolosano E, Altruda F (April 2002). "Hemopexin: structure, function, and regulation". DNA Cell Biol. 21 (4): 297–306.  
  6. ^ Hoffbrand, A.V.; Moss, P.A.H.; Pettit, J.E. (2006). Essential Haematology (5th ed.). Oxford: Blackwell Publishing. p. 60.  

Further reading

  • Piccard H, Van den Steen PE, Opdenakker G (2007). "Hemopexin domains as multifunctional liganding modules in matrix metalloproteinases and other proteins.". J. Leukoc. Biol. 81 (4): 870–92.  
  • Morgan WT, Muller-Eberhard U, Lamola AA (1978). "Interaction of rabbit hemopexin with bilirubin.". Biochim. Biophys. Acta 532 (1): 57–64.  
  • Liu HM, Atack JR, Rapoport SI (1989). "Immunohistochemical localization of intracellular plasma proteins in the human central nervous system.". Acta Neuropathol. 78 (1): 16–21.  
  • Smith A, Tatum FM, Muster P, et al. (1988). "Importance of ligand-induced conformational changes in hemopexin for receptor-mediated heme transport.". J. Biol. Chem. 263 (11): 5224–9.  
  • Altruda F, Poli V, Restagno G, Silengo L (1988). "Structure of the human hemopexin gene and evidence for intron-mediated evolution.". J. Mol. Evol. 27 (2): 102–8.  
  • Altruda F, Poli V, Restagno G, et al. (1985). "The primary structure of human hemopexin deduced from cDNA sequence: evidence for internal, repeating homology.". Nucleic Acids Res. 13 (11): 3841–59.  
  • Taketani S, Kohno H, Naitoh Y, Tokunaga R (1987). "Isolation of the hemopexin receptor from human placenta.". J. Biol. Chem. 262 (18): 8668–71.  
  • Law ML, Cai GY, Hartz JA, et al. (1989). "The hemopexin gene maps to the same location as the beta-globin gene cluster on human chromosome 11.". Genomics 3 (1): 48–52.  
  • Morgan WT, Alam J, Deaciuc V, et al. (1988). "Interaction of hemopexin with Sn-protoporphyrin IX, an inhibitor of heme oxygenase. Role for hemopexin in hepatic uptake of Sn-protoporphyrin IX and induction of mRNA for heme oxygenase.". J. Biol. Chem. 263 (17): 8226–31.  
  • Takahashi N, Takahashi Y, Putnam FW (1985). "Complete amino acid sequence of human hemopexin, the heme-binding protein of serum.". Proc. Natl. Acad. Sci. U.S.A. 82 (1): 73–7.  
  • Takahashi N, Takahashi Y, Putnam FW (1984). "Structure of human hemopexin: O-glycosyl and N-glycosyl sites and unusual clustering of tryptophan residues.". Proc. Natl. Acad. Sci. U.S.A. 81 (7): 2021–5.  
  • Frantíková V, Borvák J, Kluh I, Morávek L (1985). "Amino acid sequence of the N-terminal region of human hemopexin.". FEBS Lett. 178 (2): 213–6.  
  • Smith A, Alam J, Escriba PV, Morgan WT (1993). "Regulation of heme oxygenase and metallothionein gene expression by the heme analogs, cobalt-, and tin-protoporphyrin.". J. Biol. Chem. 268 (10): 7365–71.  
  • Morris CM, Candy JM, Edwardson JA, et al. (1993). "Evidence for the localization of haemopexin immunoreactivity in neurones in the human brain.". Neurosci. Lett. 149 (2): 141–4.  
  • Hrkal Z, Kuzelová K, Muller-Eberhard U, Stern R (1996). "Hyaluronan-binding properties of human serum hemopexin.". FEBS Lett. 383 (1-2): 72–4.  
  • Hunt RC, Hunt DM, Gaur N, Smith A (1996). "Hemopexin in the human retina: protection of the retina against heme-mediated toxicity.". J. Cell. Physiol. 168 (1): 71–80.  
  • Miller YI, Smith A, Morgan WT, Shaklai N (1996). "Role of hemopexin in protection of low-density lipoprotein against hemoglobin-induced oxidation.". Biochemistry 35 (40): 13112–7.  
  • Grinberg LN, O'Brien PJ, Hrkal Z (1999). "The effects of heme-binding proteins on the peroxidative and catalatic activities of hemin.". Free Radic. Biol. Med. 27 (1-2): 214–9.  
  • Nakajima S, Moriyama T, Hayashi H, et al. (2000). "Hemopexin as a carrier protein of tumor-localizing Ga-metalloporphyrin-ATN-2.". Cancer Lett. 149 (1-2): 221–6.  
  • Shipulina N, Smith A, Morgan WT (2001). "Heme binding by hemopexin: evidence for multiple modes of binding and functional implications.". J. Protein Chem. 19 (3): 239–48.  

External links

See also

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.