Selective isolation of human plasma low-density lipoprotein particles containing apolipoproteins B and E by use of a monoclonal antibody to apolipoprotein B.
A monoclonal antibody to human plasma apolipoprotein B was used in a single-step immunoaffinity chromatography procedure to isolate a subpopulation of low-density lipoprotein particles from normolipidemic human plasma. The isolated particles were homogeneous in terms of size (20 nm), flotation coefficient (Sf = 9.5), and electrophoretic mobility (beta band). Their protein moiety consisted of apolipoproteins B and E in a molar ratio close to 2. The lipid moiety consisted of 47.3% cholesterol, 4.7% triglycerides, and 48.0% phospholipids. To indicate its characteristic apolipoprotein composition and hydrated density properties, this family of particles was named LP-B:EL2. In most normolipidemic subjects, LP-B:EL2 particles accounted for less than 10% of the total plasma apolipoprotein B content. The LP-B:EL2 particles bound to the membranes of the human hepatoma HepG2 cells in a specific and saturable manner indicative of receptor-mediated binding. Their binding was significantly higher than that of low-density lipoprotein particles containing only apolipoprotein B.
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001055:Apolipoproteins B / Q000097:blood* / Q000302:isolation & purification; D001057:Apolipoproteins E / Q000097:blood* / Q000302:isolation & purification; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity / Q000379:methods; D006801:Humans; D008077:Lipoproteins, LDL / Q000302:isolation & purification*; D008854:Microscopy, Electron; D011973:Receptors, LDL / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001055:Apolipoproteins B; D001057:Apolipoproteins E; D008077:Lipoproteins, LDL; D011973:Receptors, LDL