Molecular Description of Surfactant-like Peptide Based Membranes

Abstract

For first time surfactant-like peptide (SLP) based membranes were investigated by full atomistic molecular dynamics simulations. Two different classes of membranes were simulated to quantify the impact of both nonpolar tail and hydrophilic head on the membrane properties. Structural analysis in terms of planar RDFs, density mass profiles, and 2D thickness maps was performed to evaluate the influence of the hydrophobic tail and hydrophilic head in the membrane structural pattern. Unlike what is observed in case of SLP membrane, a lipid membrane has low and short-range local ordering that imposes a significant difference between the two types of membranes. While the lipid membrane interactions are mainly van der Waals for the SLP membrane, both contributions are relevant. This result indirectly implies lower conformational flexibility of SLP and, therefore, their lower potential for live systems. On the basis of the pattern of structuring the membrane in equilibrium, we classified roughly into three different types: (a) those uniform and well ordered, with small variations in thickness and without water inside and therefore no flaw in the hydrogen bond network, (b) those with appreciable variations in structure, with fixed small holes that act as pores for water confinement and defects in the hydrogen bonding network, and (c) a group that has the same properties of the group (a) but present an undulating surface rather than a planar surface.

Progress and perspectives in exploiting photosynthetic biomolecules for solar energy harnessing

“…50 It was for the first time that the RCs were used in an electrolyte-less energy device when Rupa das et al reported the photoelectric performance of an RC immobilized solid state set up (Fig 4(d)). 26 Surfactant like peptides [111][112][113][114] have been used to stabilize the RC complexes and a subnanometer thick layer of 55 amorphous organic semiconductor has been deposited in between the RC and the metal electrode to serve as a solid state antenna enhancing the light absorption. 26 Rupa das et al constructed an RC based solid state electronic device with a conductive ITO coated glass electrode, coated further by a nanolayer of gold 60 anode (with a Cr adhesion layer in between Au and ITO) to which MHisRCs are oriented by an Ni-NTA SAM on the gold surface.…”

Assessing the interaction between surfactant-like peptides and lipid membranes

“…Unlike conventional surfactants whose hydrophobic tails interact in all directions through hydrophobic interactions, the amphiphilic peptide tail contains not only hydrophobic groups but also hydrophilic sites. 14,15 This feature allows the SLPs to stabilize nanostructures in one direction through hydrophobic interactions and in the orthogonal direction by hydrogen bonds. 14,15 Hydrogen bonds associated with hydrophobic interactions can stabilize even more complex secondary structures such as helices and sheets, whereas conventional lipids/surfactants are basically organized into micelles, vesicles and nanotubes.…”

“…14,15 This feature allows the SLPs to stabilize nanostructures in one direction through hydrophobic interactions and in the orthogonal direction by hydrogen bonds. 14,15 Hydrogen bonds associated with hydrophobic interactions can stabilize even more complex secondary structures such as helices and sheets, whereas conventional lipids/surfactants are basically organized into micelles, vesicles and nanotubes. 14,15 In addition to the remarkable characteristics related to self-assembly, amphiphilic peptides also have desirable antibacterial properties.…”

“…14,15 Hydrogen bonds associated with hydrophobic interactions can stabilize even more complex secondary structures such as helices and sheets, whereas conventional lipids/surfactants are basically organized into micelles, vesicles and nanotubes. 14,15 In addition to the remarkable characteristics related to self-assembly, amphiphilic peptides also have desirable antibacterial properties. 13,[16][17][18] The relationship between the antibacterial activity of surfactant-type peptides and their propensity to form nanostructures has been investigated experimentally.…”

Computationally efficient prediction of area per lipid

“…Physical chemical properties of self-assembling systems [1][2][3] and bilayers [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] constitute a large body of biophysical research. Computer simulation, in particular molecular dynamics (MD), provides an important contribution to these investigations as an atomistic-precision tool.…”