1. Self-assembling of ionic-complementary peptides
- Author
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D'AURIA, GABRIELLA, FALCIGNO, LUCIA, PADUANO, LUIGI, M.a. Vacatello, G. Mangiapia, L. Calvanese, R. Gambaretto, M. Dettin, L. Paolillo, D'Auria, Gabriella, Vacatello, M. a., Falcigno, Lucia, Paduano, Luigi, G., Mangiapia, L., Calvanese, R., Gambaretto, M., Dettin, and L., Paolillo
- Subjects
conformation ,peptide ,self-assembling - Abstract
Self-complementary synthetic peptides, composed by 8 and 16 residues, were analyzed by CD, NMR and small angle neutron scattering (SANS) techniques in order to investigate the relevance of charge and hydrophobic interactions in determining their self-assembling properties. All the sequences are potentially able to form fibrils and membranes as they share, with the prototype EAK16, a strictly alternating arrangement of polar and nonpolar residues. We find that 16-mer peptides show higher self-assembling propensities than the 8-mer analogs and that the aggregation processes are favored by salts and neutral pH. Peptide hydrophobic character appears as the most relevant factor in determining self-assembling. Solution conformational analysis, diffusion and SANS measurements all together show that the sequences with a higher self-assemble propensity are distributed, in mild conditions, between light and heavy forms. For some of the systems, the light form is mostly constituted by monomers in a random conformation, while the heavy one is constituted by β-aggregates. In our study we also verified that sequences designed to adopt extended conformation, when dissolved in alcohol-water mixtures, can easily fold in helix structures. In that media, the prototype of the series appears distributed between helical monomers and β-aggregates. It is worth noticing that the structural conversion from helical monomer to β-aggregates, mimics β-amyloid peptide aggregation mechanisms. Copyright_c 2008 European Peptide Society and JohnWiley & Sons, Ltd.
- Published
- 2009