Fluorescent peptides for membrane tension and domain structure reporting.

Area of Science:

• Cellular mechanics
• Biophysics
• Molecular biology

Background:

• Cell mechanics are vital for cell functions like division, migration, and differentiation.
• Existing fluorescent sensors primarily track forces in cytoskeletal elements, not cell membrane tension.
• A significant discrepancy exists between membrane tension estimates and mechanosensitive channel activation thresholds.

Purpose of the Study:

• To develop novel fluorescent probes for measuring two-dimensional cell membrane tension.
• To introduce a new principle for tension detection based on peptide-lipid interactions.
• To provide a tool for non-invasive monitoring of localized and dynamic membrane tension.

Main Methods:

• Utilized GsMTx4 peptide scaffold for fluorescent probe design.
• Engineered probes with fluorescent moieties that alter quantum yield based on membrane immersion depth.
• Tested probes in liposomes, giant vesicles, and cell-derived membrane vesicles.

Main Results:

• Probes exhibited near-linear fluorescence response to physiological bilayer tensions.
• Response varied with membrane composition, including lipid charge and ordering components.
• Demonstrated probe selectivity for distinct membrane domains in cell-derived vesicles.

Conclusions:

• The developed fluorescent probes offer a promising method for monitoring biological membrane tension.
• The GsMTx4-based probes provide a new principle for tension detection in cell membranes.
• These probes can be used at low, non-inhibitory concentrations to study membrane tension dynamics.