Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York, USA.
Biophys J. 2013 Jan 22;104(2):412-20. doi: 10.1016/j.bpj.2012.10.027.
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.
精氨酸丰富的细胞穿透肽通过膜的转运的分子机制和能量学仍存在争议。一种可能的机制涉及在膜中形成水孔，使得肽的亲水性残基在整个转运过程中被溶剂化。在这项工作中，我们采用了两个不同的序参数，计算了一个环状 Arg(9)肽沿着一条涉及形成水孔的路径和另一条不形成单独孔的路径进入脂质双层的自由能。沿着孔道路径转运肽的自由能势垒比沿着无孔道路径低 80 kJ/mol。这表明肽的转运更可能与水孔的形成有关。
