Journal of Lipid Research, Vol 31, 1247-1253, Copyright © 1990 by Lipid Research, Inc.

ARTICLES

Interaction of lipoprotein Lp[a] with the B/E-receptor: a study using isolated bovine adrenal cortex and human fibroblast receptors

E Steyrer and GM Kostner
Institute of Medical Biochemisty, University of Graz, Austria.

The ability of different lipoprotein Lp[a] preparations to compete with LDL-binding to the B/E-receptor was investigated by ligand blot and filter assays. Lp[a] was purified from donors with various genetic polymorphic forms by affinity chromatography using lysine-Sepharose or specific immunoadsorbers. These preparations were free of "LDL-like" material. Part of Lp[a] was reduced and freed from specific apo[a] antigen yielding "Lpa-." 125I-labeled low density lipoproteins (LDL) were incubated with B/E-receptor preparations from bovine adrenal cortex or from human skin fibroblasts, and the competition with unlabeled LDL, Lp[a], Lpa-, apo[a], and apoE-free HDL was studied by a ligand blot or filter assay technique. The following results were obtained. 1) LDL and Lpa- were equally potent in displacing 125I- labeled from B/E-receptor in the ligand blot and the filter assay. Lpa + ( = Lp[a]) also displaced LDL but to a much lesser degree: 50% displacement was observed with LDL and Lpa- at a 1-fold excess, whereas a 7.5-fold excess was required of Lpa +. 2) Apo[a], as well as apoE- free HDL, did not compete with LDL binding. 3) Competition experiments using B/E-receptors from bovine adrenal cortex or from human skin fibroblasts were comparable. 4) There was no difference in the behavior of Lp[a] isolated from the two affinity chromatography methods. 5) Lp[a] of different genetic variants behaved virtually identically. The results are discussed from the point of view of the in vivo metabolism of Lp[a].
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. M. Kostner, G. Maurer, K. Huber, T. Stefenelli, H. Dieplinger, E. Steyrer, and G. M. Kostner Urinary Excretion of Apo(a) Fragments: Role in Apo(a) Catabolism Arterioscler. Thromb. Vasc. Biol., August 1, 1996; 16(8): 905 - 911. [Abstract] [Full Text]

				R. Carmena, S. Lussier-Cacan, M. Roy, A. Minnich, A. Lingenhel, F. Kronenberg, and J. Davignon Lp(a) Levels and Atherosclerotic Vascular Disease in a Sample of Patients With Familial Hypercholesterolemia Sharing the Same Gene Defect Arterioscler. Thromb. Vasc. Biol., January 1, 1996; 16(1): 129 - 136. [Abstract] [Full Text]

				S. Frank, S. Durovic, K. Kostner, and G. M. Kostner Inhibitors for the In Vitro Assembly of Lp(a) Arterioscler. Thromb. Vasc. Biol., October 1, 1995; 15(10): 1774 - 1780. [Abstract] [Full Text]