Identification of a detergent-solubilized plasma membrane protein from rat liver recognizing apolipoprotein A-IV.
Apolipoprotein A-IV (apo A-IV) is present in plasma associated to both HDL and as a complex with lipids that cannot be floated by ultracentrifugation at 1.21 g/ml density. Apo A-IV is likely an important molecular determinant in HDL binding to the liver. In this communication, data are presented supporting the view that a specific liver plasma membrane protein of Mr 95,000 is a constituent of the apo A-IV binding site. The protein was solubilized with CHAPS from purified rat liver plasma membranes and subjected to SDS-PAGE. Transblotted to nitrocellulose sheet could be identified as recognizing 125I-apo A-IV-DMPC by autoradiography. 125I-apo A-I-DMPC and radioiodinated rat apo E-poor HDL, also bound to the protein. Apo B-100 (as human LDL) and apo C-III did not bind. The protein identified is likely to be the same that has been previously identified by Graham and Oram [1987) J. Biol. Chem. 262, 7439-7442) as 'HDL receptor protein'.
Ghiselli
G
G
Baylor College of Medicine, Houston, TX.
Crump
W
W
Musanti
R
R
Gotto
A M
AM
D000818:Animals; D001054:Apolipoproteins A / Q000378:metabolism*; D001665:Binding Sites; D002462:Cell Membrane / Q000032:analysis; D002793:Cholic Acids; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008099:Liver / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility
D001054:Apolipoproteins A; D002793:Cholic Acids; D003902:Detergents; D008565:Membrane Proteins; C022205:apolipoprotein A-IV; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate