Interactions of surfactin with ether-linked and ester-linked lipid membranes: A molecular dynamics simulation study

Area of Science:

• Biochemistry
• Membrane Biophysics
• Computational Biology

Background:

• Surfactin, a potent biosurfactant, exhibits antibacterial and antiviral properties by destabilizing lipid bilayers.
• Previous research linked surfactin's membrane disruption to hydration changes around ester carbonyl groups.
• Archaeal membranes, rich in stable ether-linked lipids, present a unique system to study biosurfactant interactions.

Purpose of the Study:

• To investigate the effect of surfactin on ether-linked lipids using molecular dynamics simulations.
• To compare the destabilization effects of surfactin on archaeal ether-linked lipids versus conventional ester-linked lipids.
• To elucidate the role of lipid linkage chemistry and architecture in membrane susceptibility to surfactin.

Main Methods:

• Molecular dynamics simulations were performed to model surfactin interactions with different lipid bilayers.
• Systems included archaeal tetraether lipids (macrocyclic and non-macrocyclic), a diether lipid, and an ester-linked analogue.
• Analysis focused on membrane structural changes, hydration patterns, and lipid-surfactin interactions.

Main Results:

• Surfactin significantly destabilized the ester-linked analogue, causing compression and increased water penetration.
• The macrocyclic tetraether lipid showed the most pronounced response among ether-linked systems.
• The diether lipid exhibited minimal perturbation, indicating lower susceptibility to surfactin.
• Lipid linkage chemistry and backbone structure critically influence membrane response to surfactin.

Conclusions:

• Membrane susceptibility to surfactin is dictated by lipid linkage type and molecular architecture.
• Ester linkages and tetraether structures enhance membrane destabilization by surfactin compared to diether lipids.
• Findings provide insights into the interaction of biosurfactants with diverse membrane types, including resilient archaeal membranes.