Binding of chylomicron remnants and beta-very low density lipoproteins to hepatic and extrahepatic lipoprotein receptors. A process independent of apolipoprotein B48

J Biol Chem. 1984 Dec 25;259(24):15060-8.


The ability of apolipoprotein (apo-) B48 to interact with lipoprotein receptors was investigated using three different types of lipoproteins. First, canine chylomicron remnants, which contained apo-B48 as their primary apoprotein constituent, were generated by the hydrolysis of chylomicrons with milk lipoprotein lipase. These apo-B48-containing chylomicron remnants are deficient in apo-E and reacted very poorly with apo-E receptors on adult dog liver membranes and the low density lipoprotein (apo-B,E) receptors on human fibroblasts. Addition of normal human apo-E3 restored the receptor binding activity of these lipoproteins. Second, beta-very low density lipoproteins (beta-VLDL) from cholesterol-fed dogs were subfractionated into distinct classes containing apo-E along with either apo-B48 or apo-B100. Both classes bound to the apo-B,E and apo-E receptors. Their binding was almost completely mediated by apo-E, as evidenced by the ability of the anti-apo-E to inhibit the receptor interaction. Third, beta-VLDL from type III hyperlipoproteinemic patients were subfractionated by immunoaffinity chromatography into lipoproteins containing apo-E plus either apo-B48 or apo-B100. Both subfractions bound poorly to apo-B,E and apo-E receptors due to the presence of defective apo-E2. However, the residual binding of the apo-B48-containing and apo-B100-containing human beta-VLDL was inhibited by the anti-apo-E. After lipase hydrolysis, apo-B100 became a more prominant determinant responsible for mediating receptor binding to the apo-B,E receptor. By contrast, lipase hydrolysis did not increase the binding activity of the apo-B48-containing beta-VLDL. These results indicate that apo-B48 does not play a direct role in mediating the interaction of lipoproteins with receptors on fibroblasts or liver membranes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antigen-Antibody Complex
  • Apolipoproteins E / metabolism
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Chylomicrons / metabolism*
  • Dogs
  • Fibroblasts / metabolism
  • Humans
  • Infant
  • Kinetics
  • Lipoprotein Lipase / metabolism
  • Lipoproteins, VLDL / metabolism*
  • Liver / metabolism*
  • Lymph
  • Male
  • Peptide Fragments / metabolism
  • Receptors, Cell Surface / metabolism*
  • Receptors, LDL / metabolism*
  • Receptors, Lipoprotein*


  • Antibodies, Monoclonal
  • Antigen-Antibody Complex
  • Apolipoproteins E
  • Chylomicrons
  • Lipoproteins, VLDL
  • Peptide Fragments
  • Receptors, Cell Surface
  • Receptors, LDL
  • Receptors, Lipoprotein
  • VLDL receptor
  • chylomicron receptor
  • Lipoprotein Lipase