ApoE and ApoE Nascent-Like HDL Particles at Model Cellular Membranes: Effect of Protein Isoform and Membrane Composition

Apolipoprotein E (ApoE), an important mediator of lipid transportation in plasma and the nervous system, plays a large role diseases such as atherosclerosis Alzheimer's. The major allele variants ApoE3 ApoE4 differ only by one amino acid. However, this difference has consequences for physiological behaviour each variant. In paper, we follow (i) initial interaction lipid-free ApoE with model membranes function saturation, (ii) formation reconstituted High-Density Lipoprotein-like particles (rHDL) their structural characterisation, (iii) rHDL ability to exchange lipids made saturated presence absence cholesterol [1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) without 20 mol% cholesterol]. Our neutron reflection results demonstrate that protein interact differently membranes, adopting different conformations. Moreover, structure at membrane is sensitive level unsaturation. Small-angle scattering shows containing form elliptical disc-like structures, similar shape but larger than nascent discoidal HDL based on A1 (ApoA1). Neutron ApoE-rHDL do not remove rather lipids, occurs brain. contrast, ApoA1-containing greater extent elsewhere body.