INVESTIGADORES
CUTRO Andrea Carmen
congresos y reuniones científicas
Título:
Phenyalanine lipid membrane interaction assessed by surface pressure studies
Autor/es:
MATURANA PATRICIA; CEJAS JIMENA; FRÍAS MARIA DE LOS ÁNGELES; ANDREA C. CUTRÓ; HOLMANN AXEL; ANIBAL E. DISALVO
Lugar:
Sierra de la Ventana
Reunión:
Congreso; XLIII Reunión Anual SAB 2014; 2014
Institución organizadora:
sociedad argentina de biofísica
Resumen:
Small amphyphilic molecules may partition in lipid
membranes, among them, aromatic amino acids such as Tyr, Trp and Phe have an
amphiphilic character due to the hydrophobicity of the indol and phenyl rings (1).
In particular, Phe has been shown to damage thylakoid membranes at very low
concentrations during freezing. Also, in liposomes, it also induces leakage and
membrane fusion (2). Apparently, at relatively low concentrations the damage is
produced on membranes under stress conditions, i.e. partial dehydration. Many
amphiphilic compounds may protect membranes from oxidative stress under
conditions of low water availability. Therefore, the influence of aminoacids
such as Phe on the stability of membranes can be regulated by the water stress.
It is well known that water/lipid ratio can be modified in lipid monolayers by
changing the surface pressure. Thus, in order to evaluate the effects of
Phe on the water-lipid interphase, the changes in the surface pressure of DPPC
monolayers at different initial surface pressure (14mN/m; 26 mN/m and 40 mN/m)
were evaluated in a Langmuir balance. The results suggest that in condensed
membranes (40 mN/m), i.e. with less hydration, Phe are able to induce a higher
changes of the initial surface pressure. Also with the aim to evaluate the role
of the charges on the Phe-membrane interactions, the experiments were carried
out at two different pHs, 5 close to Ip of
Phe and 7.3 were higher changes were observed.
1. Petelska, AD et al.,
Cell Biochem Biophys. (2011), 289.
2. Popova, AV et al., Biochimica et Biophysica Acta
(2002), 109.