Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11160%2F17%3A10364881" target="_blank" >RIV/00216208:11160/17:10364881 - isvavai.cz</a>

Výsledek na webu

<a href="http://pubs.rsc.org/en/content/articlehtml/2017/sm/c6sm02356h" target="_blank" >http://pubs.rsc.org/en/content/articlehtml/2017/sm/c6sm02356h</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c6sm02356h" target="_blank" >10.1039/c6sm02356h</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR

Popis výsledku v původním jazyce

The stratum corneum is the outermost layer of the skin and protects the organism against external influences as well as water loss. It consists of corneocytes embedded in a mixture of ceramides, fatty acids, and cholesterol in a molar ratio of roughly 1 : 1 : 1. The unique structural and compositional arrangement of these stratum corneum lipids is responsible for the skin barrier properties. Many studies investigated the organization of these barrier lipids and, in particular, the exact conformation of ceramides. However, so far no consensus has been reached. In this study, we investigate a model system comprised of N-(nonhydroxy-tetracosanoyl)-phytosphingosine/cholesterol/tetracosanoic acid (CER[NP]-C24/CHOL/TA) at a 1 : 1 : 1 molar ratio using neutron diffraction and H-2 solid-state NMR spectroscopy at temperatures from 25 degrees C to 80 degrees C. Deuterated variants of all three lipid components of the model system were used to enable their separate investigation in the NMR spectra and quantification of the amount of molecules in each phase. Neutron scattering experiments show the coexistence of two lipid phases at low temperatures with repeat spacings of 54.2 angstrom and 43.0 angstrom at a physiological skin temperature of 32 degrees C. They appear to be indistinguishable in the H-2 NMR spectra as both phases are crystalline and ceramide molecules do not rotate around their long axis on a microsecond timescale. The evolution of these phases upon heating is followed and with increasing temperature fluid and even isotropically mobile molecules are observed. A model of the organization of the lamellar phases is proposed in which the thicker phase consists of CER[NP]-C24 in a hairpin conformation mixed with CHOL and TA, while the phase with a repeat spacing of 43.0 angstrom contains CER[NP]-C24 in a V-shape conformation.

Název v anglickém jazyce

Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR

Popis výsledku anglicky

The stratum corneum is the outermost layer of the skin and protects the organism against external influences as well as water loss. It consists of corneocytes embedded in a mixture of ceramides, fatty acids, and cholesterol in a molar ratio of roughly 1 : 1 : 1. The unique structural and compositional arrangement of these stratum corneum lipids is responsible for the skin barrier properties. Many studies investigated the organization of these barrier lipids and, in particular, the exact conformation of ceramides. However, so far no consensus has been reached. In this study, we investigate a model system comprised of N-(nonhydroxy-tetracosanoyl)-phytosphingosine/cholesterol/tetracosanoic acid (CER[NP]-C24/CHOL/TA) at a 1 : 1 : 1 molar ratio using neutron diffraction and H-2 solid-state NMR spectroscopy at temperatures from 25 degrees C to 80 degrees C. Deuterated variants of all three lipid components of the model system were used to enable their separate investigation in the NMR spectra and quantification of the amount of molecules in each phase. Neutron scattering experiments show the coexistence of two lipid phases at low temperatures with repeat spacings of 54.2 angstrom and 43.0 angstrom at a physiological skin temperature of 32 degrees C. They appear to be indistinguishable in the H-2 NMR spectra as both phases are crystalline and ceramide molecules do not rotate around their long axis on a microsecond timescale. The evolution of these phases upon heating is followed and with increasing temperature fluid and even isotropically mobile molecules are observed. A model of the organization of the lamellar phases is proposed in which the thicker phase consists of CER[NP]-C24 in a hairpin conformation mixed with CHOL and TA, while the phase with a repeat spacing of 43.0 angstrom contains CER[NP]-C24 in a V-shape conformation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30104 - Pharmacology and pharmacy

Projekt

<a href="/cs/project/GA13-23891S" target="_blank" >GA13-23891S: Modely lipidových membrán - nový nástroj pro studium patofyziologie kožních onemocnění na molekulární úrovni</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Soft Matter

ISSN

1744-683X

e-ISSN

—

Svazek periodika

13

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

2107-2119

Kód UT WoS článku

000396291300018

EID výsledku v databázi Scopus

2-s2.0-85015018363