Alpha-1-Microglobulin/Bikunin Precursor (a1M)

AMBP; UTI; HCP; EDC1; HI30; IATIL; ITILC; ITI; ITIL; Alpha 1 Microglobulin/Bikunin Precursor; Growth-inhibiting protein 19; Uristatin; Uronic-Acid-Rich Protein; Trypstatin

SPN	W527
HGNC	453
MGI	88002
PubMed	15256311
RGD	2102
UniProt	P02760
Wiki	AMBP

Alpha-1-microglobulin (A1M), also known as protein HC (for Heterogeneous Charge), is a low molecular weight protein component of plasma first discovered in pathological human urine. It is a member of the lipocalin superfamily. Although much is now known of its structure and properties, the function and physiological role of A1M remains unclear, although evidence suggests that it functions in the regulation of the immune system. A1M is known to exist in both a free form and complexed to other macromolecules: immunoglobulin A (IgA) in humans and alpha-1-inhibitor-3 in the rat. Free A1M is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link.

Reference

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Nucleic Acids Res. 14:6340-6340(1986) [PubMed] [Europe PMC] [Abstract]

"The mRNA for a proteinase inhibitor related to the HI-30 domain of inter-alpha-trypsin inhibitor also encodes alpha-1-microglobulin (protein HC)."
Nucleic Acids Res. 14:7839-7850(1986) [PubMed] [Europe PMC] [Abstract]

"Structure of the human alpha 1-microglobulin-bikunin gene."
Biol. Chem. Hoppe-Seyler 371:1185-1196(1990) [PubMed] [Europe PMC] [Abstract]

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Nature 429:369-374(2004) [PubMed] [Europe PMC] [Abstract]

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Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]

"The complete amino acid sequence of human complex-forming glycoprotein heterogeneous in charge (protein HC) from one individual."
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"Complete amino acid sequence of human alpha 1-microglobulin."
Biochem. Biophys. Res. Commun. 98:997-1001(1981) [PubMed] [Europe PMC] [Abstract]

"Human protein HC displays variability in its carboxyl-terminal amino acid sequence."
FEBS Lett. 144:349-353(1982)

"Location of a novel type of interpolypeptide chain linkage in the human protein HC-IgA complex (HC-IgA) and identification of a heterogeneous chromophore associated with the complex."
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"Human inter-alpha-trypsin inhibitor: localization of the Kunitz-type domains in the N-terminal part of the molecule and their release by a trypsin-like proteinase."
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"Chondroitin 4-sulfate covalently cross-links the chains of the human blood protein pre-alpha-inhibitor."
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"Presence of the protein-glycosaminoglycan-protein covalent cross-link in the inter-alpha-inhibitor-related proteinase inhibitor heavy chain 2/bikunin."
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"The reactive site of human inter-alpha-trypsin inhibitor is in the amino-terminal half of the protein."
Biol. Chem. Hoppe-Seyler 366:19-21(1985) [PubMed] [Europe PMC] [Abstract]

"Location and characterization of the three carbohydrate prosthetic groups of human protein HC."
FEBS Lett. 266:167-170(1990) [PubMed] [Europe PMC] [Abstract]

"The protein HC chromophore is linked to the cysteine residue at position 34 of the polypeptide chain by a reduction-resistant bond and causes the charge heterogeneity of protein HC."
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"Alpha1-microglobulin chromophores are located to three lysine residues semiburied in the lipocalin pocket and associated with a novel lipophilic compound."
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"Human alpha-1-microglobulin is covalently bound to kynurenine-derived chromophores."
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"The ORF3 protein of hepatitis E virus interacts with liver-specific alpha1-microglobulin and its precursor alpha1-microglobulin/bikunin precursor (AMBP) and expedites their export from the hepatocyte."
J. Biol. Chem. 279:29308-29319(2004) [PubMed] [Europe PMC] [Abstract]

"The 41-amino-acid C-terminal region of the hepatitis E virus ORF3 protein interacts with bikunin, a Kunitz-type serine protease inhibitor."
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"The crystal structure of bikunin from the inter-alpha-inhibitor complex: a serine protease inhibitor with two Kunitz domains."
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