Water Pockets Between Acyl Chains And Its Relation To Peptide Insertion In Lipid Membranes

FRIAS, M DE LOS ANGELES; DISALVO, EDGARDO ANÍBAL; BOUCHET, ANA

Philadelphia, Pennsylvania

Congreso; Biophysical Society 57th Annual Meeting; 2013

Biophysical Society US.

Presence of water in the membrane structure has been invoked to interpret the insertion of highly hydrophilic aminoacid moieties in pools between acyl chains, described as water pockets. Analysis of the band corresponding to the frequency of vibrational symmetric stretching mode of methylenes and the bands of water below and above the phase transition of different lipids by Fourier transform infrared spectroscopy give strong support to the formation of confined water pockets in between the lipid acyl chains. We present a rational description of the water pockets creation and the influence of the adjacent wall formed at the phase transition by analyzing the changes of FTIR-ATR spectra in the regions corresponding to the CH2 and water bands shifts with temperature. The presence of water in these packing defects gives support to the creation of regions with free energy excess due to reinforcement of the water structure. This high energy defects explains the insertion of peptides and aminoacid residues and translocation of peptides through the biomembrane.