The hemopexin family is a family of evolutionarily related proteins. Hemopexin-like repeats occur in vitronectin and some matrix metalloproteinases family (matrixins).[1] The HX repeats of some matrixins bind tissue inhibitor of metallopeptidases (TIMPs).

Hemopexin
Identifiers
SymbolHemopexin
PfamPF00045
InterProIPR000585
SMARTHX
PROSITEPDOC00023
SCOP21hxn / SCOPe / SUPFAM
Membranome536
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

Hemopexin (EC 3.2.1.35) is a serum glycoprotein that binds haem and transports it to the liver for breakdown and iron recovery, after which the free hemopexin returns to the circulation.[2] Hemopexin prevents haem-mediated oxidative stress. Structurally hemopexin consists of two similar halves of approximately two hundred amino acid residues connected by a histidine-rich hinge region. Each half is itself formed by the repetition of a basic unit of some 35 to 45 residues. Hemopexin-like domains have been found in two other types of proteins, vitronectin,[3] a cell adhesion and spreading factor found in plasma and tissues, and matrixins MMP-1, MMP-2, MMP-3, MMP-9, MMP-10, MMP-11, MMP-12, MMP-14, MMP-15 and MMP-16, members of the matrix metalloproteinase family that cleave extracellular matrix constituents.[4] These zinc endopeptidases, which belong to MEROPS peptidase subfamily M10A, have a single hemopexin-like domain in their C-terminal section. It is suggested that the hemopexin domain facilitates binding to a variety of molecules and proteins, for example the HX repeats of some matrixins bind tissue inhibitor of metallopeptidases (TIMPs).

Examples

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Human gene encoding proteins containing hemopexin-like repeats include:

References

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  1. ^ Bode W (June 1995). "A helping hand for collagenases: the haemopexin-like domain". Structure. 3 (6): 527–30. doi:10.1016/s0969-2126(01)00185-x. PMID 8590012.
  2. ^ Altruda F, Tolosano E (2002). "Hemopexin: structure, function, and regulation". DNA Cell Biol. 21 (4): 297–306. doi:10.1089/104454902753759717. PMID 12042069.
  3. ^ Kojima K, Ogawa H, Matsumoto I, Yoneda A (1998). "Characterization of the ligand binding activities of vitronectin: interaction of vitronectin with lipids and identification of the binding domains for various ligands using recombinant domains". Biochemistry. 37 (18): 6351–6360. doi:10.1021/bi972247n. PMID 9572850.
  4. ^ Das S, Mandal M, Chakraborti T, Mandal A, Chakraborti S (2003). "Structure and evolutionary aspects of matrix metalloproteinases: a brief overview". Mol. Cell. Biochem. 253 (1–2): 31–40. doi:10.1023/A:1026093016148. PMID 14619953.
This article incorporates text from the public domain Pfam and InterPro: IPR000585