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

ANDREA C. CUTRÓ; ANIBAL E. DISALVO; MARIANGELES FRIAS

Santiago del Estero

Congreso; Reunion Anual Sociedad Argentina de Biofísica 2015; 2015

sociedad argentina de biofísica

AbstractThe aromatic amino acid residues such as in L-phenylalanine (Phe) have many different functions in biological systems affecting 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-Phe is capable of forming amyloid structures at high concentrations, which has been associated with lipid-peptide interactions [3, 4]. In order to understand this process, we studied the interaction of this amino acid with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers and its effects on the topological and the electrical properties by using, compression isotherms, Brewster angle microscopy and the dipole potential determinations. 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 decreasing the total dipole. This effect is pH dependent [5]. References[1] Van Kan, E. J.M., Demel, R. A., van der Bent, A, Kruijf, B Biochimica et Biophysica Acta 1615 (2003) 84? 92[2] Abramovich, A., Vaks, L., Carny, O., Trudler, D., Magno, A., Caflisch, A., Frenkel, D., Gazit, E. Nature Chemical Biology 8 (2012), 701 ? 706.[3] Griffith, E.C., Perkins, R.J., Telesford, D.M., Adams, E. M., Cwiklik, L., Allen, H. C., Roeselová, M., Vaida, V. Doi: The Journal of Physical Chemistry B (2014), DOI: 10.1021/jp508473w[4] Virender Singh, Ratan Kumar Rai, Ashish Arora, Neeraj Sinha, Ashwani Kumar Thakur. Scientific Reports, 4: 3875 (2014), DOI: 10.1038/srep03875, 1-8.[5] Cutró, A. C, Hollmann, A., Cejas, J., Maturana, P., Disalvo, E. A., Frías, M. A. Colloids and Surfaces B: Biointerfaces, (2015) DOI:10.1016/j.colsurfb.2015.07.059