hemopexin; beta-1B-glycoprotein (HPX)

Function: - binds heme & transports it to the liver for breakdown & iron recovery, after which the free hemopexin returns to the circulation - interacts with HEV ORF3 protein. interacts with FLVCR1 Structure: - N-lycosylated & O-glycosylated - O-glycosylated with core 1 glycan or possibly core 8 glycan - belongs to the hemopexin family - contains 5 hemopexin-like domains Compartment: secreted Expression: expressed by the liver & secreted into plasma Notes: - the isolated N-terminal domain binds one heme - the full-length protein also binds one heme, but at a different site (significance unknown)

General

acute phase protein beta globulin carrier protein (transporter) glycoprotein

Properties

SIZE: entity length = 462 aa MW = 52 kD COMPARTMENT: plasma MOTIF: signal sequence {1-23} O-glycosylated at one, two and three sites {24-47} MOTIF: Thr glycosylation site {T24} cysteine residue {C50} MODIFICATION: cysteine residue {C231} Hemopexin-like 1 {56-95} MOTIF: N-glycosylation site {N64} Iron [Fe]-binding site SITE: 79-79 Hemopexin-like 2 {97-141} cysteine residue {C149} MODIFICATION: cysteine residue {C154} Iron [Fe]-binding site SITE: 150-150 cysteine residue {C154} MODIFICATION: cysteine residue {C149} N-glycosylation site {N187} Hemopexin-like 3 {188-231} MOTIF: cysteine residue {C188} MODIFICATION: cysteine residue {C200} cysteine residue {C200} MODIFICATION: cysteine residue {C188} cysteine residue {C231} MODIFICATION: cysteine residue {C50} Iron [Fe]-binding site SITE: 236-236 N-glycosylation site {N240} N-glycosylation site {N246} cysteine residue {C257} MODIFICATION: cysteine residue {C460} Hemopexin-like 4 {263-306} MOTIF: Iron [Fe]-binding site SITE: 293-293 Hemopexin-like 5 {308-353} cysteine residue {C366} MODIFICATION: cysteine residue {C408} cysteine residue {C408} MODIFICATION: cysteine residue {C366} cysteine residue {C418} MODIFICATION: cysteine residue {C435} cysteine residue {C435} MODIFICATION: cysteine residue {C418} N-glycosylation site {N453} cysteine residue {C460} MODIFICATION: cysteine residue {C257} SECRETED-BY: hepatocyte MISC-INFO: CONCENTRATION 50-120 MG/DL

Database Correlations

OMIM 142290 UniProt P02790 Pfam PF00045 Entrez Gene 3263 Kegg hsa:3263