IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
The effect of cholesterol on membrane dynamics on different timescales in lipid bilayers from fast field-cycling NMR relaxometry studies of unilamellar vesicles
Autor/es:
FRAENZA, CARLA CECILIA; MELEDANDRI C. J.; ANOARDO, ESTEBAN; BROUGHAM D.F.
Revista:
Chemphyschem
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Lugar: Weinheim; Año: 2014 vol. 15 p. 425 - 435
ISSN:
1439-4235
Resumen:
The general applicability of fast field-cycling nuclear magnetic
resonance relaxometry in the study of dynamics in lipid bilayers
is demonstrated through analysis of binary unilamellar liposomes
composed of 1,2-dioleoyl-sn-glycero-3-posphocholine
(DOPC) and cholesterol. We extend an evidence-based method
to simulating the NMR relaxation response, previously validated
for single-component membranes, to evaluate the effect of
the sterol molecule on local ordering and dynamics over multiple
timescales. The relaxometric results are found to be most
consistent with the partitioning of the lipid molecules into affected
and unaffected portions, rather than a single averaged
phase. Our analysis suggests that up to 25 mol%, each cholesterol
molecule orders three DOPC molecules, providing experimental
backup to the findings of many molecular dynamics
studies. A methodology is established for studying dynamics
on multiple timescales in unilamellar membranes of more complex
compositions.