Bubbles, gating, and anesthetics in ion channels

Area of Science:

• Biophysics
• Physical Chemistry

Background:

• Cell membrane channels exhibit complex gating mechanisms.
• Simulations suggest spontaneous channel emptying, but results are often unstable.
• Existing experiments hint at gas layers and near-bubble formation on hydrophobic surfaces.

Purpose of the Study:

• To propose bubbles as the fundamental bistable hydrophobic gates for channel gating.
• To present a thermodynamic model for bubble gate mechanisms.
• To explore the implications for gas anesthesia and hydrostatic pressure effects.

Main Methods:

• Thermodynamic analysis using morphometric density functional theory.
• Classical (non-quantum) mechanics framework.
• Comparison with simulation-based approaches.

Main Results:

• Bubbles, formed by capillary evaporation, provide a unified physical mechanism for channel gating.
• Thermodynamic analysis offers a reproducible and stable approach to studying these phase transitions.
• The bubble gate model offers a potential explanation for inert gas anesthesia and hydrostatic pressure interactions.

Conclusions:

• Bubbles are proposed as the universal bistable hydrophobic gates for ion channel gating.
• The thermodynamic model provides a robust framework for understanding channel gating and anesthesia.
• Experimental validation, including direct bubble observation, is crucial to confirm this hypothesis.