Reversing the peptide sequence impacts on molecular surface behaviour

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 139; pp. 25 - 32
• Main Authors: Ambroggio, Ernesto E., Caruso, Benjamín, Villarreal, Marcos A., Raussens, Vincent, Fidelio, Gerardo D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-03-2016
• Subjects: Amino Acid Sequence; Amino acids; Biological Transport; Hydrophobic and Hydrophilic Interactions; Inversions; Lipids; Molecular Sequence Data; Molecular structure; Monolayers; Peptide adsorption/penetration into interfaces; Peptide Langmuir monolayer stability; Peptide Langmuir rheology monolayer; Peptide retro-isomers; Peptide/membrane interaction; Peptides; Peptides - chemistry; Permeability; Phosphatidylcholines - chemistry; Protein Structure, Secondary; Residues; Reversing; Spectroscopy, Fourier Transform Infrared; Static Electricity; Structure-Activity Relationship; Unilamellar Liposomes - chemistry; Peptide adsorption/penetration into interfaces; Peptide/membrane interaction; Peptide Langmuir rheology monolayer; Peptide retro-isomers; Peptide Langmuir monolayer stability
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2015.12.008

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•Peptide sequence reversion confers a distinctive peptide surface behaviuor and rheology.•Langmuir monolayers of peptides with a hydrophilic N-terminus have high stability.•Peptides with a hydrophilic N-terminus present higher affinity for interfaces.
The protein’s primary structure has all the information for specific protein/peptide folding and, in many cases, can define specific amphiphilic regions along molecules that are important for interaction with membranes. In order to shed light on how peptide sequence is important for the surface properties of amphiphilic peptides, we designed three pairs of peptides with the following characteristics: (1) all molecules have the same hydrophobic residues; (2) the couples differ from each other in their hydrophilic amino acids: positively, negatively and non-charged; (3) each pair has the same residues (same global molecular 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 the lateral stability of peptide monolayers, in the ability of the molecules to partition into the air–water interface 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 differential way of peptide/lipid interaction when peptides are in the presence of POPC lipid bilayers. Our results show how sequence inversion confers a distinctive peptide surface behaviour and lipid interaction for molecules with a similar structure.