Isolation of the hemopexin receptor from human placenta.
A hemopexin receptor detected in detergent-solubilized placental membranes was purified from the human placenta, using hemopexin-Sepharose affinity chromatography. The solubilized membranes exhibited binding sites of 2.77 pmol of hemopexin/mg of protein with a dissociation constant (Kd) of 6.6 X 10(-8) M. The purified receptor has a molecular weight of 80,000, determined on sodium dodecyl sulfate-gel electrophoresis. Immunoinhibition experiments using the antibody against the placental receptor revealed inhibition of binding of 125I-hemopexin to human leukemia K562 and HL 60 cells, thereby strongly supporting that the polypeptide isolated from the human placenta was the hemopexin receptor.
D000596:Amino Acids / Q000032:analysis; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D006466:Hemopexin / Q000378:metabolism; D006801:Humans; D005779:Immunodiffusion; D007700:Kinetics; D008970:Molecular Weight; D010920:Placenta / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000302:isolation & purification* / Q000378:metabolism; D018000:Receptors, Peptide
D000596:Amino Acids; D011956:Receptors, Cell Surface; D018000:Receptors, Peptide; C047453:hemopexin receptor; D006466:Hemopexin