Entropy-Driven Amino Acid-Based Coacervates with Enzyme-Free Metabolism and Prebiotic Robustness.

Area of Science:

• Origin of Life Studies
• Astrobiology
• Supramolecular Chemistry

Background:

• Protocells are key models for understanding life's origins, but existing designs often lack prebiotic relevance and robustness.
• Early Earth conditions and extraterrestrial environments may have provided simple building blocks for protocell formation.

Purpose of the Study:

• To investigate the formation and properties of protocells from simple amino acid derivatives under simulated prebiotic conditions.
• To assess the robustness, metabolic capabilities, and energy transduction of these novel protocell models.

Main Methods:

• Utilized entropy-driven liquid-liquid phase separation (self-coacervation) of amino acid derivatives.
• Studied nonenzymatic reactions, including sulfur metabolism and pigment synthesis, within coacervate microdroplets.
• Assessed protocell resilience to stressors like high salinity, divalent cations, UV radiation, and temperature fluctuations.
• Investigated proton gradient generation and adaptive morphological changes.

Main Results:

• Demonstrated self-coacervation of amino acid derivatives into membraneless protocells.
• Observed enhanced enzyme-free reactions and metabolite enrichment within coacervates.
• Showcased exceptional resilience to harsh, prebiotically relevant environmental conditions.
• Confirmed autonomous proton gradient generation and primitive chemiosmotic coupling.
• Documented adaptive remodeling of protocell morphology in response to environmental changes.

Conclusions:

• Coacervate-based protocells offer a geochemically plausible pathway for the origin and persistence of functional cellular life.
• These minimalist, amino acid-based structures integrate essential cellular functions, bridging the gap between nonliving and living systems.
• The findings highlight the potential of coacervates to sustain biochemical complexity under prebiotic conditions.