2. Academic Validation
  3. Molecular Dynamics Simulations of Human Antimicrobial Peptide LL-37 in Model POPC and POPG Lipid Bilayers

Molecular Dynamics Simulations of Human Antimicrobial Peptide LL-37 in Model POPC and POPG Lipid Bilayers

  • Int J Mol Sci. 2018 Apr 13;19(4):1186. doi: 10.3390/ijms19041186.
Liling Zhao 1 2,  Zanxia Cao 3 4,  Yunqiang Bian 5 6,  Guodong Hu 7 8,  Jihua Wang 9 10,  Yaoqi Zhou 11 12
Affiliations

Affiliations

  • 1 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 2 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China. [email protected].
  • 3 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 4 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China. [email protected].
  • 5 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 6 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China. [email protected].
  • 7 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 8 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China. [email protected].
  • 9 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 10 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China. [email protected].
  • 11 Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China. [email protected].
  • 12 Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr, Southport, Queensland 4222, Australia. [email protected].
PMID: 29652823 DOI: 10.3390/ijms19041186
Abstract

Cathelicidins are a large family of cationic antimicrobial peptides (AMPs) found in mammals with broad spectrum antimicrobial activity. LL-37 is the sole amphipathic α-helical AMP from human Cathelicidins family. In addition to its bactericidal capability, LL-37 has Antiviral, anti-tumor, and immunoregulatory activity. Despite many experimental studies, its molecular mechanism of action is not yet fully understood. Here, we performed three independent molecular dynamics simulations (600 ns or more) of a LL-37 peptide in the presence of 256 lipid bilayers with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) mimicking Bacterial and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) mimicking mammalian membranes. We found that LL-37 can be quickly absorbed onto the POPG bilayer without loss of its helical conformation in the core region and with the helix lying in parallel to the bilayer. The POPG bilayer was deformed. In contrast, LL-37 is slower in reaching the POPC surface and loss much of its helical conformation during the interaction with the bilayer. LL-37 only partially entered the POPC bilayer without significant deformation of the membrane. The observed difference for different bilayers is largely due to the fact that LL-37 is positively charged, POPG is negatively charged, and POPC is neutral. Our simulation results demonstrated the initial stage of disruption of the Bacterial membrane by LL-37 in atomic details. Comparison to experimental results on LL-37 and simulation studies in Other systems was made.

Keywords

LL-37; model membranes; molecular dynamics simulations.

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