Cholesteric liquid crystals in living matter.

Area of Science:

• Biophysics
• Materials Science
• Structural Biology

Background:

• Liquid crystals are crucial for biological self-organization and structure formation.
• Cholesteric liquid crystals, characterized by a helical structure, are prevalent in diverse biological materials.
• This recurring motif suggests evolutionary optimization for specific functions.

Purpose of the Study:

• To review recent advances in understanding cholesteric liquid crystal organization in biological systems.
• To explore the diverse roles and functions of biological cholesteric liquid crystals.
• To discuss the implications and future perspectives of this widespread biological structure.

Main Methods:

• Literature review of recent research on cholesteric liquid crystals in biology.
• Analysis of cholesteric organization in various biomolecules and structures (DNA, chitin, collagen, viruses, etc.).
• Discussion of the functional consequences of cholesteric geometry in living matter.

Main Results:

• Cholesteric liquid crystal structures are found across the animal and plant kingdoms, including DNA, chromatin, chitin, cellulose, collagen, viruses, silk, and atherosclerotic lesions.
• These structures exhibit a prevalent left-handed helical organization, indicating convergent evolution.
• Observed in diverse entities like bacteriophages, bacterial nucleoids, plant cell walls, and arterial lesions.

Conclusions:

• Biological cholesteric liquid crystals play significant roles in maximizing packing efficiency, morphogenesis, and mechanical stability.
• Their functions extend to optical information, radiation protection, and potentially influencing evolutionary pressures.
• Further research is needed to fully define and understand the consequences of cholesteric geometry in living systems.