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Title: Bilayer Structure and Lipid Dynamics in a Model Stratum Corneum with Oleic Acid

Abstract

The stratum corneum is the uppermost layer of the skin and acts as a barrier to keep out contaminants and retain moisture. Understanding the molecular structure and behavior of this layer will provide guidance for optimizing its biological function. In this study we use a model mixture comprised of equimolar portions of ceramide NS (24:0), lignoceric acid, and cholesterol to model the effect of the addition of small amounts of oleic acid to the bilayer at 300 and 340 K. Five systems at each temperature have been simulated with concentrations between 0 and 0.1 mol % oleic acid. Our major finding is that subdiffusive behavior over the 200 ns time scale is evident in systems at 340 K, with cholesterol diffusion being enhanced with increased oleic acid. Importantly, cholesterol and other species diffuse faster when radial densities indicate nearest neighbors include more cholesterol. We also find that, with the addition of oleic acid, the bilayer midplane and interfacial densities are reduced and there is a 3% decrease in total thickness occurring mostly near the hydrophilic interface at 300 K with reduced overall density at 340 K. Increased interdigitation occurs independent of oleic acid with a temperature increase. Slight ordering ofmore » the long non-hydroxy fatty acid of the ceramide occurs near the hydrophilic interface as a function of the oleic acid concentration, but no significant impact on hydrogen bonding is seen in the chosen oleic acid concentrations.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1012849
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B, 115(12):3164-3171
Additional Journal Information:
Journal Volume: 115; Journal Issue: 12; Journal ID: ISSN 1520-6106
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; BIOLOGICAL FUNCTIONS; BONDING; CARBOXYLIC ACIDS; CHOLESTEROL; DIFFUSION; HYDROGEN; LIPIDS; MIXTURES; MOISTURE; MOLECULAR STRUCTURE; OLEIC ACID; THICKNESS; Environmental Molecular Sciences Laboratory

Citation Formats

Hoopes, Matthew I, Noro, Massimo G, Longo, Marjorie L, and Faller, Roland. Bilayer Structure and Lipid Dynamics in a Model Stratum Corneum with Oleic Acid. United States: N. p., 2011. Web. doi:10.1021/jp109563s.
Hoopes, Matthew I, Noro, Massimo G, Longo, Marjorie L, & Faller, Roland. Bilayer Structure and Lipid Dynamics in a Model Stratum Corneum with Oleic Acid. United States. doi:10.1021/jp109563s.
Hoopes, Matthew I, Noro, Massimo G, Longo, Marjorie L, and Faller, Roland. Thu . "Bilayer Structure and Lipid Dynamics in a Model Stratum Corneum with Oleic Acid". United States. doi:10.1021/jp109563s.
@article{osti_1012849,
title = {Bilayer Structure and Lipid Dynamics in a Model Stratum Corneum with Oleic Acid},
author = {Hoopes, Matthew I and Noro, Massimo G and Longo, Marjorie L and Faller, Roland},
abstractNote = {The stratum corneum is the uppermost layer of the skin and acts as a barrier to keep out contaminants and retain moisture. Understanding the molecular structure and behavior of this layer will provide guidance for optimizing its biological function. In this study we use a model mixture comprised of equimolar portions of ceramide NS (24:0), lignoceric acid, and cholesterol to model the effect of the addition of small amounts of oleic acid to the bilayer at 300 and 340 K. Five systems at each temperature have been simulated with concentrations between 0 and 0.1 mol % oleic acid. Our major finding is that subdiffusive behavior over the 200 ns time scale is evident in systems at 340 K, with cholesterol diffusion being enhanced with increased oleic acid. Importantly, cholesterol and other species diffuse faster when radial densities indicate nearest neighbors include more cholesterol. We also find that, with the addition of oleic acid, the bilayer midplane and interfacial densities are reduced and there is a 3% decrease in total thickness occurring mostly near the hydrophilic interface at 300 K with reduced overall density at 340 K. Increased interdigitation occurs independent of oleic acid with a temperature increase. Slight ordering of the long non-hydroxy fatty acid of the ceramide occurs near the hydrophilic interface as a function of the oleic acid concentration, but no significant impact on hydrogen bonding is seen in the chosen oleic acid concentrations.},
doi = {10.1021/jp109563s},
journal = {Journal of Physical Chemistry B, 115(12):3164-3171},
issn = {1520-6106},
number = 12,
volume = 115,
place = {United States},
year = {2011},
month = {3}
}