Inhibition of the binding of low density lipoproteins to liver membrane receptors by rat serum phosphorylcholine binding protein.
Rat serum phosphorylcholine binding protein (PCBP) is characterized by its Ca2+ dependent property to bind phosphorylcholine ligand. PCBP immobilized on sepharose has been shown to selectively bind human plasma apo B and E containing lipoproteins. The present report describes an inhibitory effect of PCBP on the binding of human 125I-LDL to LDL receptors on estradiol treated rat liver membranes. Pre-incubation of liver membranes with PCBP did not affect the binding of 125I-LDL to the membranes. Gel filtration analysis of the incubation products from the LDL-receptor assay showed a concentration dependent binding of 125I-PCBP to LDL. The inhibitory effect of PCBP is likely due to the formation of LDL-PCBP complex and not due to the binding of PCBP to the LDL receptor site.
D000818:Animals; D001055:Apolipoproteins B / Q000378:metabolism; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D066298:In Vitro Techniques; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051381:Rats; D011973:Receptors, LDL / Q000378:metabolism*
D001055:Apolipoproteins B; D002352:Carrier Proteins; C030929:Crp protein, rat; D008077:Lipoproteins, LDL; D011973:Receptors, LDL; D002118:Calcium