Mixed DPPC/POPC Monolayers: All-atom Molecular Dynamics Simulations and Langmuir Monolayer Experiments
Language English Country Netherlands Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
27664500
DOI
10.1016/j.bbamem.2016.09.015
PII: S0005-2736(16)30313-3
Knihovny.cz E-resources
- Keywords
- Langmuir trough, Lung surfactant, Molecular dynamics, Phospholipid monolayers,
- MeSH
- 1,2-Dipalmitoylphosphatidylcholine analogs & derivatives chemistry MeSH
- Phosphatidylcholines chemistry MeSH
- Lipids chemistry MeSH
- Molecular Conformation MeSH
- Molecular Dynamics Simulation * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- 1,2-dipalmitoyl-sn-glycero-3-ethylphosphocholine MeSH Browser
- 1,2-Dipalmitoylphosphatidylcholine MeSH
- 1,2-oleoylphosphatidylcholine MeSH Browser
- Phosphatidylcholines MeSH
- Lipids MeSH
To elucidate the consequences of the saturated-unsaturated nature of lipid surface films, monolayers formed by an equimolar mixture of 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipids are investigated in a wide range of surface pressures. As such mixtures share some features with naturally-occurring surfactants, for example the lung surfactant, the systems are studied at the temperature relevant for human body. All-atom molecular dynamics simulations and Langmuir trough experiments are employed. The binary lipid mixture is compared with the corresponding one-component systems. Atomistic-level alterations of monolayer molecular properties upon lateral compression are scrutinized. These involve elevation of lateral ordering of lipid chains, modulation of chain and headgroup orientation, and reduction of lipid hydration. The presence of the unsaturated POPC in the DPPC/POPC mixture reduces the liquid expanded-liquid condensed coexistence region and moderates the phase transition. Simulations predict that nanoscale lipid de-mixing occurs with small transient DPPC clusters emerging due to local fluctuations of the lateral lipid arrangement. A vertical sorting of lipids induced by lateral compression is also observed, with DPPC transferred toward the water phase. Both the conformational lipid alterations due to monolayer compression as well as the existence of lateral dynamic inhomogeneities of the lipid film are potentially pertain to dynamic and non-homogeneous lipid interfacial systems.
References provided by Crossref.org
