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Interfacial tension and surface pressure of high density lipoprotein, low density lipoprotein, and related lipid droplets.

Ollila, Samuli LU ; Lamberg, Antti; Lehtivaara, Maria; Koivuniemi, Artturi and Vattulainen, Ilpo (2012) In Biophysical Journal 103(6). p.1236-1244
Abstract
Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface. Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in... (More)
Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface. Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence of interfacial tension becomes significant for particles with a radius of ∼5 nm, when the area per molecule in the surface region is <1.4 nm(2). Further, interfacial tensions in the used HDL and LDL models are essentially unaffected by single apo-proteins at the surface. Finally, interfacial tensions of lipoproteins are higher than in thermodynamically stable droplets, suggesting that HDL and LDL are kinetically trapped into a metastable state. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biophysical Journal
volume
103
issue
6
pages
1236 - 1244
publisher
Cell Press
external identifiers
  • wos:000309017800016
  • pmid:22995496
  • scopus:84866514776
ISSN
1542-0086
DOI
10.1016/j.bpj.2012.08.023
language
English
LU publication?
yes
id
7c8e4f6d-b294-44de-81fa-26389bab7e1d (old id 3123826)
date added to LUP
2012-10-16 16:53:19
date last changed
2017-09-03 03:21:05
@article{7c8e4f6d-b294-44de-81fa-26389bab7e1d,
  abstract     = {Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface. Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence of interfacial tension becomes significant for particles with a radius of ∼5 nm, when the area per molecule in the surface region is &lt;1.4 nm(2). Further, interfacial tensions in the used HDL and LDL models are essentially unaffected by single apo-proteins at the surface. Finally, interfacial tensions of lipoproteins are higher than in thermodynamically stable droplets, suggesting that HDL and LDL are kinetically trapped into a metastable state.},
  author       = {Ollila, Samuli and Lamberg, Antti and Lehtivaara, Maria and Koivuniemi, Artturi and Vattulainen, Ilpo},
  issn         = {1542-0086},
  language     = {eng},
  number       = {6},
  pages        = {1236--1244},
  publisher    = {Cell Press},
  series       = {Biophysical Journal},
  title        = {Interfacial tension and surface pressure of high density lipoprotein, low density lipoprotein, and related lipid droplets.},
  url          = {http://dx.doi.org/10.1016/j.bpj.2012.08.023},
  volume       = {103},
  year         = {2012},
}