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Study of somuncurin-1 behavior in two membrane models using Molecular Dynamics Simulations
* 1 , 2 , 1 , 3
2  Dept. of Chemistry, Univ. of Bath.
Academic Editor: Guangshun Wang (registering DOI)

The antibacterial effects of antimicrobial peptides (AMPs) are related to their ability to disrupt bacterial membranes. Understanding the interaction between AMPs and membranes helps the active peptide design. Molecular dynamics simulations are a powerful tool to access the atomic-level scale of the peptide interaction with membranes. Somuncurin-1 is a small AMP isolated from the Patagonian frog Pleurodema somuncurense that showed moderate antimicrobial activity against E. coli and S. aureus, along with low cytotoxicity. To propose modifications in the somuncurin-1 sequence that could increase its performance, we studied its behavior against two membrane models using molecular dynamics simulations. Two types of lipid bilayers were considered: mixtures of palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and lipid mix of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) and 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE), which are simple models to mimic mammalian and bacterial membranes, respectively. The results show a differential behavior on these membranes. We found cooperative effects in the peptide-lipid bilayer interaction. Somuncurin-1 was distributed at the hydrophobic core-water interface, and simulations were conducted at temperatures of 303 K, 310 K, and 320 K. Somuncurin-1 exhibited distinct behavior in bilayer-peptide interaction: they display a strong affinity for the lipid interface of the bacterial model. Lys residue is found to anchor at the lipid water interface due to electrostatic interactions with the lipid heads. These simulations provide valuable insights into the behavior somuncurin-1 as a function of its concentration, temperature, and membrane composition in its interactions with lipid bilayers, offering a foundation for optimizing its therapeutic potential.

Keywords: Antimicrobial Peptides; Molecular dynamics simulations; membranes interactions