Interaction of Phenylalanine with DPPC Membranes by FTIR-ATR: Influence of Hydration

ROSA ANTONIO SEBASTIÁN; DISALVO EDGARDO ANIBAL; FRIAS MARÍA DE LOS ANGELES

Sierra de la Ventana

Congreso; Reunión Anual de la Sociedad Argentina de Biofísica XLIII; 2014

Sociedad Argentina de Biofísica

Amino acids are ubiquitously found in all living cells [1, 2].Therefore, although they are usually only present in lowconcentrations in cells, amino acids represent interesting modelsubstances to examining the interaction between amino acids andbilayer lipid membranes. Aromatic amino acids such asphenylalanine (Phe), has an aromatic ring of different characteristicsizes and hydrophilicity, which is expected to influence moleculararrangements, therefore, the polycondensation monolayers.According to results obtained with DPPC monolayers, Pheproduces an association with the PC molecules which suggests amolecular interaction of the head groups with Phe residues atdifferent hydration states .FTIR results indicate that the symmetricstretching of the phosphate group, which is quite sensible tohydration, is affected in a great extent by Phe. Also, the waterbands of the phospholipids are significantly modified. Topologicalchanges may modify the exposure to water of different residues ofthe lipid molecules such as CH2 and carbonyl groups, to wateraffecting the Phe-PC interaction.