title: Free energy of translocating an arginine-rich cell-penetrating peptide across a lipid bilayer suggests pore formation.
abstract: The molecular mechanism and energetics of the translocation of arginine-rich, cell-penetrating peptides through membranes are still under debate. One possible mechanism involves the formation of a water pore in the membrane such that the hydrophilic residues of the peptide are solvated throughout the translocating process. In this work, employing two different order parameters, we calculate the free energies of translocating a cyclic Arg(9) peptide into a lipid bilayer along one path that involves a water-pore formation and another path that does not form a separate pore. The free-energy barrier of translocating the peptide along a pore path is 80 kJ/mol lower than along a pore-free path. This suggests that the peptide translocation is more likely associated with a water-pore formation.
authors: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York, USA.
authors: Kun
authors: K
authors: Huang
authors: Angel E
authors: AE
authors: García
mesh_terms: D001120:Arginine / Q000378:metabolism*; D057846:Cell-Penetrating Peptides / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D016062:Porosity; D011485:Protein Binding; D021381:Protein Transport; D013816:Thermodynamics; D014867:Water / Q000378:metabolism
chemical_list: D057846:Cell-Penetrating Peptides; D008051:Lipid Bilayers; D014867:Water; D001120:Arginine