English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/11623
Compartir / Impacto:
Estadísticas
Add this article to your Mendeley library MendeleyBASE
Citado 5 veces en Web of Knowledge®  |  Pub MebCentral Ver citas en PubMed Central  |  Ver citas en Google académico
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Título

Dynamics of bolaamphiphilic fluorescent polyenes in lipid bilayers from polarization emission spectroscopy

AutorAcuña, A. Ulises ; Amat-Guerri, Francisco ; Quesada, Ernesto ; Vélez, Marisela
Palabras clavePolyenes
Fluorescence anisotropy
Bolaamphiphiles
Transmembrane lipids
Lipid bilayers
Fecha de publicación20-jun-2006
EditorElsevier
CitaciónBiophysical Chemistry 122(1): 27-35 (2006)
ResumenThe rotational motions of the biamphiphilic polyenes (bolapolyenes) dimethyl all-(E)-octacosa-10,12,14,16,18-pentaenedioate (DE28:5) and dimethyl all-(E)-tetratriaconta-13,15,17,19,21-pentaenedioate (DE34:5), with head-to-head distances of 34 and 42Å, respectively, have been examined by fluorescence anisotropy methods. The membrane-spanning bolapolyenes, which contain a central emitting pentaene group tethered to two methoxycarbonyl opposite polar heads by symmetric C8 (DE28:5) and C11 (DE34:5) polymethylene chains, were dispersed in lipid bilayers of DPPC or DMPC, and the stationary and picosecond-resolved emission was recorded as a function of temperature. In fluid-phase DMPC bilayers, three relaxation times could be determined, assigned to fast (0.2 and 2ns) single-bond isomerization processes localized on the alkyl chains, and to whole-molecule oscillations (∼11ns), respectively. The anisotropy decay parameters were further analyzed in terms of a diffusive model for wobbling in a Gaussian ordering potential, to assess the anchoring effect of the symmetric polar heads. In this way, the average rotational diffusion constant of the bolapolyenes, D⊥, could be estimated as 0.022–0.026rad2 ns−1 (DMPC bilayers, 35°C), a value that is only 1/ 3 of that corresponding to the related pentaene fatty acid spanning a single membrane monolayer. In contrast, the amplitude of the equilibrium orientational distribution (θhalf-cone∼50°) is very similar for both the transmembrane and the single-headed polyenes. The reorientational oscillations of the central emitting group in the bolapolyenes necessarily would produce large-amplitude (2–5Å) and very fast (ns) translational motions of the polar heads.
Versión del editorhttp://dx.doi.org/10.1016/j.bpc.2006.02.004
URIhttp://hdl.handle.net/10261/11623
DOI10.1016/j.bpc.2006.02.004
ISSN0301-4622
Aparece en las colecciones: (IQFR) Artículos
(IQOG) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
bolaamphiphilic_fluorescent_Acuna.pdf633,21 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 



NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.