INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Interaction of cholesterol with sphingomyelins: kinetics of cholesterol extraction by ciclodextrin from natural and model membranes
Autor/es:
A.DAZA-MILLONE; V. HERLAX; M. ELENA VELA; L. BAKÁS; S.MATÉ
Reunión:
Congreso; XLII Reunión Anual de SAB; 2014
Resumen:
Preferential interaction between sphingomyelin (SM) and
cholesterol (Chol) in both cell and model membranes has been
proposed as central for the formation of Chol and SM-rich domains
in membranes. However, Chol does not interact equally with
different SMs; in fact, we have recently found that when an
unsaturated sphingolipid, N-nervonoyl sphingomyelin (24:1Δ15), that
is abundant in mammalian erythrocytes is included in the bilayers,
no lateral phase separation is detected (1). The desorption kinetics
of Chol from membranes can be used as a sensitive indicator of
Chol/phospholipid interactions. In this concern, it was reported that
lateral organization and SM content of the membrane affects Chol
extraction. The aim of this work was to explore the degree of
interaction between Chol and different SMs in model (SUVs) and
natural membranes (erythrocytes), by measuring Chol efflux using
cyclodextrin. We employed a Surface Plasmon Resonance
approach, which allows monitoring the extraction process in real
time, to address the question of kinetics of Chol extraction from
membranes of different lateral organization. Finally, we studied the
effects of Chol-depletion on the packing properties of erythrocytemembranes by determining the GP values of Laurdan by two
photon microscopy