Related Experiment Video
Updated: Sep 7, 2026

PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions
Published on: July 27, 2017
Apoprotein-phospholipid interactions in Lp(a)
A Hermetter1, A Sommer, R Gorges
1Department of Biochemistry and Food Chemistry, Technische Universität Graz, Austria.
Abstract:
Lipoprotein (a) (Lp(a)) and low-density lipoprotein (LDL) are structurally related to each other. Both exhibit identical phospholipid compositions and possess one molecule of apoprotein B-100 (apoB). Lp(a) contains, in addition, apoprotein (a) (apo(a)), which localizes to the particle surface and interacts with the apoB component by non-covalent and covalent forces. Protein-protein interaction is probably interrelated with protein-lipid interaction. Fluorescent analogs of phosphatidylcholine and sphingomyelin were inserted into the surface layer of LDL and Lp(a). The obtained fluorescence data reflecting mobility and distributional heterogeneity of the labeled lipids provided evidence that apo-proteins discriminate between choline phospholipids and preferentially associate with phosphatidylcholine. This effect is enhanced in Lp(a) because of the presence of apolipoprotein (a). Higher affinity for Lp(a) as compared with LDL was also observed with a fluorescent diether analog of phosphatidylcholine in native serum. In contrast, the time-dependent transfer of the same lipid into Lp(a) was slower compared with LDL, probably as a consequence of the more rigid surface of the former lipoprotein.
More Related Videos
08:49Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes
Published on: March 14, 2021
10:31A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA2
Published on: September 26, 2025
Related Concept Videos
What are Lipids?
Receptor-mediated Endocytosis
Membrane Lipids
Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin are the most common phospholipids present in mammalian membranes. At physiological pH, phosphatidylserine is negatively charged, while the other three...
Asymmetric Lipid Bilayer
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...