Comparative molecular dynamics simulations of the antimicrobial peptide CM15 in model lipid bilayers

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• 作者：Yi Wang^a ; ^{yiwang@ucsd.edu} ; Diana E. Schlamadinger^b ; Judy E. Kim^b ; J. Andrew McCammon^a
• 关键词：Antimicrobial peptide ; Molecular dynamics ; cm15 ; Selectivity ; popc ; popg
• 刊名：Biochimica et Biophysica Acta (BBA)/Biomembranes
• 出版年：2012
• 期刊代码：14_00052736
• 类别：bio
• 出版时间：May, 2012
• 卷：1818
• 期：5
• 页码：1402-1409
• 文件大小：1482 K

摘要

We report altogether 3-渭s molecular dynamics (MD) simulations of the antimicrobial peptide CM15 to systematically investigate its interaction with two model lipid bilayers, pure POPC and mixed POPG:POPC (1:2). Starting with either an m>伪m>-helical or a random-coil conformation, CM15 is found to insert into both bilayers. Peptide-lipid interaction is stronger with the anionic POPG:POPC than the zwitterionic POPC, which is largely attributed to the electrostatic attraction between CM15 and the negatively charged POPG. Simulations initiated with CM15 as a random coil allowed us to study peptide folding at the lipid-water interface. Interestingly, CM15 folding appears to be faster in POPC than POPG:POPC, which may be explained by a lower activation energy barrier of structural rearrangement in the former system. Our data also suggest that compared with the random-coil conformation, CM15 in a pre-folded m>伪m>-helix has significantly reduced interactions with the lipids, indicating that peptide initial structures may bias the simulation results considerably on the 100-ns timescale. The implications of this result should be considered when preparing and interpreting future AMP simulations.