Changes in topology and electrical properties of PC monolayer induced by the interaction of amino acid that form amyloid fibrils

CUTRO, ANDREA C.; FRIAS, M DE LOS ANGELES; DISALVO, E ANIBAL

Santiago del Estero

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Biofísica; 2015

Sociedad Argentina de Biofísica

Changes in topology and electrical properties of PC monolayer induced by the interaction of amino acid that form amyloid fibrils.The aromatic amino acid residues have many different functions in biological systems as affect the interaction between peptides and proteins with membranes, the regulation of channels in the membrane and the deleterious formation of amyloid structures [1,2]. It has been shown that L-phenylalanine (Phe) is capable of forming amyloid structures at high concentrations, which has been associated with lipid-peptide interactions [3,4]. In order to understand more about this process, we decided to study the effect of the interaction of L-Phe on 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers on the topology and the electrical properties by using Langmuir trough methods, Brewster angle microscopy and the determination of dipole potential. The data obtained show that the amino acid would be inserted into membrane increasing the distance between the lipid molecules, reducing the degree of order of the dipoles in the membrane and creating a lower total dipole, this effect seems to depend on the other conditions such as the pH [5].