INVESTIGADORES
DUPUY Fernando Gabriel
artículos
Título:
Microcin J25 membrane interaction: Selectivity toward gel phase
Autor/es:
DUPUY, FERNANDO; MORERO, ROBERTO
Revista:
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 1808 p. 1764 - 1771
ISSN:
0005-2736
Resumen:
The interaction of the tryptophan-containing variant of microcin J25,
MccJ25 I13W, with phosphatidylcholine membranes was studied by
fluorescence spectroscopy techniques. The peptide was able to interact
with dimiristoylphophatidylcholine and dipalmitoylphosphatidylcholine
liposomes only when the membranes were in gel phase, as was demonstrated
by the blue shift of the intrinsic fluorescence of MccJ25 I13W. The
binding isotherm showed a cooperative partition of the peptide toward
the membrane and the binding constant increased as the temperature
decreased and the order parameter increased. No interaction with liquid
crystalline membranes was observed. Studies of dynamic quenching of the
fluorescence indicated that the peptide penetrated the lipid bilayer and
was located primarily in the interfacial region. Our results suggest
that MccJ25 I13W interacts with gel phase phospholipids and increases
both its own affinity for the bilayer and the membrane permeability of
small ions.