INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Structural and functional properties of a central domain of human apolipoprotein A-I
Autor/es:
GARDA H A
Lugar:
Rosario
Reunión:
Simposio; XLII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular. Simposio sobre "Lipidos"; 2006
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)
Resumen:
S-01
STRUCTURAL AND FUNCTIONAL PROPERTIES OF A
CENTRAL DOMAIN OF HUMAN APOLIPOPROTEIN A-I
Garda, H. A.
Instituto de Investigaciones Bioqu¨ªmicas de La Plata (CONICETUNLP)
Calles 60 y 120. 1900-La Plata
E-mail: hgarda@atlas.med.unlp.edu.ar
Apolipoprotein A-I (apoAI) plays a key role in several steps of
reverse cholesterol transport, a process of antiatherogenic
relevance that removes cholesterol excess of peripheral tissues.
ApoAI is constituted almost exclusively by amphipathic ¦Á-helices
and undergoes large conformational changes to exchange
among lipid-free and different lipid-bound states during its
functional cycle. Identification of domains involved in the different
apoAI functions, and knowing the characteristics that make them
critical for its activity, would provide valuable information on the
mechanism of cellular lipid efflux mediated by this protein. I will
focus here on a central pair of ¦Á-helices having a particular
charge distribution in their polar face. The behavior of a synthetic
peptide suggests that these helices constitute a functional and
structural domain with relative independence from the rest of
apoAI molecule. This domain inserts preferentially into
cholesterol-containing membranes where it facilitates cholesterol
desorption. Recent studies revealed that the central domain is
also responsible for triggering mobilization of intracellular
cholesterol depots toward the cell membrane. For its activity, a
specific sequence is not required, but the charge distribution of
class ¡°Y¡± amphipathic ¦Á-helices and an adequate orientation of
the hydrophobic and hydrophilic helix faces would be necessary