Reversing the peptide sequence impacts on molecular surface behaviour

ERNESTO E AMBROGGIO; BENJAMÍN CARUSO; MARCOS VILLARREAL; VINCENT RAUSSENS; GERARDO D FIDELIO

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

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

0927-7765

The protein primarystructure has all the information for a specific protein/peptide folding and,in many cases, can define specific amphiphilic regions along molecules that areimportant for the interaction with membranes. In order to shed light on how peptidesequence is important for the surface properties of amphiphilic peptides, wedesigned three pairs of peptides with the following characteristics: 1-allmolecules have the same hydrophobic residues; 2-the couples differ each otheron their hydrophilic amino acids: positively, negatively and non-charged;3-each pair has the same residues (same global molecular hydrophobicity) but theprimary sequence is reversed in comparison to its partner (retro-isomer) givinga molecule with a hydrophilic N or C-terminus and a hydrophobic C orN-terminus. Using the Langmuir monolayer approach, we observed that sequence reversionhas a central role on the lateral stability of peptide monolayers, on theability of the molecules to partition into the air-water interface and on therheological properties of peptide films whereas the peptide secondary structure,determined by ATR-FTIR, was the same for all peptides. In addition, sequencereversion also gives a differential way of peptide/lipid interaction whenpeptides were in presence of POPC lipid bilayers. Our results show how sequenceinversion confers a distinctive peptide surface behavior and lipid interaction formolecules that adopt a similar structure.