INVESTIGADORES
FIDELIO Gerardo Daniel
congresos y reuniones científicas
Título:
Molecular amphipathicity impacts on peptide surface behaviour
Autor/es:
AMBROGGIO EE,; FIDELIO GD.
Lugar:
VILLA CARLOS PAZ, CORDOBA
Reunión:
Congreso; XLII REUNION ANUAL DE LA SOCIEDAD ARGENTINA DE BIOFISICA; 2013
Institución organizadora:
SOC ARG BIOFISICA
Resumen:
Protein primary structure has all the information for
a specific protein/peptide folding. This sequence can define specific
amphiphilic regions in the molecules important for the interaction with
interfaces. In order to shed light how amphipathicity has a role in the surface
properties of proteins, we designed three pairs of peptides where all six type
of molecules have the same hydrophobic residues but different hydrophilic amino
acids: positively, negatively and non-charged. The sequence the peptides is inverted
in comparison to their pair. This inversion provokes that one kind of peptide
has the N-terminal region hydrophilic and the C-terminus hydrophobic and the
other kind of peptide, with the same type of amino acids, the opposite
distribution. We evaluated how amphiphilicity has a role in peptide lateral
stability at the air-water interface by using the Langmuir monolayer technique.
We also performed peptide/peptide mixtures to understand whether there is a
coupling within opposed charges and if amphipathicity may contribute to the
global lateral stability of the peptide film. In addition we measured membrane
destabilization (leakage of a fluorescent solution trapped inside liposomes)
and membrane association of these molecules. Finally we analyzed the peptide
secondary structure by ATR-FTIR. Our results show a distinctive surface
behaviour for each kind of molecule whereas all presented the same secondary
structure.