Reversing the peptide sequence impacts on molecular surface behaviour

AMBROGGIO E.E.,; CARUSO, B.,; VILLARREAL M.A.,; RAUSSENS, V.,; FIDELIO G.D.

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 139 p. 25 - 32

0927-7765

The protein?s primary structure has all the information for specific protein/peptide folding and, in manycases, can define specific amphiphilic regions along molecules that are important for interaction withmembranes. In order to shed light on how peptide sequence is important for the surface propertiesof amphiphilic peptides, we designed three pairs of peptides with the following characteristics: (1) allmolecules have the same hydrophobic residues; (2) the couples differ from each other in their hydrophilicamino acids: positively, negatively and non-charged; (3) each pair has the same residues (same globalmolecular hydrophobicity) but the primary structure is reversed in comparison to its partner (retro-isomer), giving a molecule with a hydrophilic N or C-terminus and a hydrophobic C or N-terminus.Using the Langmuir monolayer approach, we observed that sequence reversal has a central role in thelateral stability of peptide monolayers, in the ability of the molecules to partition into the air?waterinterface and in the rheological properties of peptide films, whereas the peptide?s secondary structure,determined by ATR-FTIR, was the same for all peptides. Reversing the sequence also gives a differentialway of peptide/lipid interaction when peptides are in the presence of POPC lipid bilayers. Our resultsshow how sequence inversion confers a distinctive peptide surface behaviour and lipid interaction formolecules with a similar structure.