Interactions of GF-17 derived from LL-37 antimicrobial peptide with bacterial membranes: a molecular dynamics simulation study.
Aghazadeh. Hossein H; Ganjali Koli. Mokhtar M; Ranjbar. Reza R; Pooshang Bagheri. Kamran K
Key Findings
- GF-17 penetrates negatively‑charged DPPG membranes more easily than mixed DPPE/DPPG membranes
- The peptide increases membrane area per lipid and lipid lateral diffusion but does not alter bilayer thickness
- In pure DPPG membranes GF-17 adopts a more compact, rigid structure while retaining α‑helix and coil elements
Practical Outcomes
- The findings support the idea that GF-17 could be an effective antimicrobial agent, but because the study is only a molecular dynamics simulation, it offers no dosage, safety, or real‑world usage guidance. Biohackers should treat this as early‑stage evidence that warrants further lab testing before considering any self‑experimentation.
Summary
Scientists used computer simulations to see how a short piece of the LL-37 peptide, called GF-17, interacts with bacterial cell membranes. They found GF-17 can slip into the membrane, especially ones that are negatively charged, without changing the membrane’s thickness, and it becomes more compact and rigid. This helps explain why GF-17 might kill bacteria, but the work is purely theoretical.
Abstract
Human cathelicidin LL-37 has recently attracted interest as a potential therapeutic agent, mostly because of its ability to kill a wide variety of pathogens and cancer cells. In this study, we used molecular dynamics simulation aimed to get insights that help to correlate with the antibacterial activity of previously designed LL-37 anticancer derivative (i.e. GF-17). Two independent molecular dynamics simulation involving four units of GF-17 peptide in the mixture (9:1) of 1,2-dipalmitoyl-sn-glycero-3-phosphorylethanolamine (DPPE) and 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG), and the pure DPPG lipids were performed. Various properties of membranes such as mass density distributions, area per lipid, bilayer thickness, and lateral diffusion were examined in both systems. The results showed that the thickness of the bilayer was not affected by the presence of GF-17, while the area per lipid and lateral diffusion of lipids showed an increase. Moreover, the potential of the mean force (PMF) method was used to calculate the free energy profile for transferring GF-17 from the bulk water into both kinds of membranes. It revealed that penetration of GF-17 into the DPPG membrane was more favorable than the DPPE/DPPG membrane, and there was no energy barrier for crossing through the bilayer center. Investigation of the radius of gyration (Rg) and root mean square fluctuation (RMSF) of peptides in two membranes showed that GF-17 had more compactness and rigidity in the pure DPPG system. By examining the secondary structure of GF-17 peptide, it was seen that the α-helix, and coil structures in both DPPE/DPPG and pure DPPG membranes are dominant.
Study Information
pubmed
2020
2020-10-03T00:00:00.000Z
10.1007/s10822-020-00348-4
26
71