Antimicrobial peptides at (lipid) interfaces: Insights from monolayer models

Area of Science:

• Biophysics
• Biochemistry
• Materials Science

Background:

• Antimicrobial peptides (AMPs) are crucial for innate immunity and show potential as anticancer and anti-senescence agents.
• AMP efficacy depends on selective membrane disruption, but quantifying interactions in complex systems is difficult.
• Lipid monolayers offer a simplified model of cell membranes to study AMP selectivity.

Purpose of the Study:

• To critically analyze how lipid properties influence AMP adsorption and insertion.
• To integrate thermodynamic and structural data for a comprehensive understanding of AMP-membrane interactions.
• To establish a framework for using interfacial insights to design peptide therapeutics.

Main Methods:

• Lipid monolayer characterization using surface pressure, compressibility, and mixing energy measurements.
• Advanced structural and morphological analysis via IRRAS, GIXD, SFG, BAM, fluorescence, and AFM.
• Integration of experimental data with Molecular Dynamics (MD) simulations.

Main Results:

• Lipid composition, packing density, and phase behavior significantly modulate AMP adsorption and insertion.
• Spectroscopic and microscopic techniques reveal peptide orientation, secondary structure changes, and lipid domain remodeling.
• MD simulations provide atomistic insights that complement macroscopic measurements.

Conclusions:

• Lipid monolayers are valuable reductionist models for studying AMP-membrane interactions.
• Combining experimental and simulation approaches offers a powerful feedback loop for understanding interfacial phenomena.
• This framework facilitates the rational design of peptide therapeutics and nanobiotechnological applications.