Surface Tensiometry of Apolipoprotein B Domains at Lipid Interfaces Suggests a New Model for the Initial Steps in Triglyceride-rich Lipoprotein Assembly

Abstract

Background: Apolipoprotein B (apoB) is the essential protein component of chylomicrons and very low density lipoprotein that transports lipids in plasma. Results: Domains of apoB interact with model membranes dependent on lipid composition and surface pressure. Conclusion: ApoB domains interact with membranes to initiate lipid recruitment. Significance: The apoB lipid recruitment mechanism provides a target to regulate the secretion of VLDL.

A Pressure-dependent Model for the Regulation of Lipoprotein Lipase by Apolipoprotein C-II

“…Our technique provides physiologically relevant biophysical characteristics, such as ⌬⌸, ⌸ EX , and ⌸ ENV , for peptides at various lipid surfaces and reveals the exchangeability of peptides (30). In contrast to helical peptides at lipid surfaces, we previously showed that the ␤-strand-rich regions of apoB were non-exchangeable and elastic and had a higher affinity for TG than phospholipid (30,63,70).…”

“…To test this hypothesis, we used a recently developed protocol (32,63) to analyze the surface pressure response of apoC-II at TO/W and POPC/TO/W interfaces to washout and compression. Whereas the pre-washout ⌸ eq varied with the bulk phase concentration of apoC-II, the post-washout pressure of apoC-II/ TO/W interfaces was a constant (⌸ WO ϭ 16.6 Ϯ 0.2 mN/m) ( Table 1 and Fig.…”

Assembly and Secretion of Triglyceride-Rich Lipoproteins

“…Mitsche and colleagues (Mitsche et al, 2014) have described a model for the initiation of lipid recruitment by the βα1 domain of apoB. Lipid acquisition may be initiated only by apoB sequences or may be facilitated by MTP.…”

Reference values assessment in a Mediterranean population for small dense low-density lipoprotein concentration isolated by an optimized precipitation method

“…The increased atherogenicity of sd-LDL particles is due to their small size and density, which facilitates their infiltration in the subendothelial layer of arteries. It is also known that sd-LDL particles have a different apolipoprotein B conformation with a lower affinity for LDL receptors in the liver resulting in a decrease of LDL particle clearance 12. The sd-LDL particles are associated with hypertriglyceridemia and low HDL-c concentration.…”

“…It is also known that sd-LDL particles have a different apolipoprotein B conformation with a lower affinity for LDL receptors in the liver resulting in a decrease of LDL particle clearance. 12 The sd-LDL particles are associated with hypertriglyceridemia and low HDL-c concentration. These three lipid abnormalities are usually called the lipid triad (LT) and are frequent in patients with premature CHD.…”