Prebiotic Protocell Model Based on Dynamic Protein Membranes Accommodating Anabolic Reactions

Area of Science:

• Origin of Life studies
• Biochemistry
• Astrobiology

Background:

• Current protocell models often rely on lipid-based membranes, facing challenges with stability and synthesis under early Earth conditions.
• Amino acids are abundant under early Earth conditions and have been previously proposed for protocell formation.
• Existing models require separate molecules for compartment formation and catalytic functions.

Purpose of the Study:

• To propose and investigate a novel protocell model using protein-based membranes derived from prebiotic amino acids.
• To assess the stability and functionality of these protein membrane-based compartments (PMBCs).
• To explore the potential of PMBCs as ancestors to modern lipid-based cells.

Main Methods:

• Construction of protocell model membranes from amphiphilic proteins assembled from prebiotic amino acids.
• Characterization of self-assembled dynamic protein membrane-based compartments (PMBCs).
• Assessment of PMBC compatibility with cellular components and embedding of essential cellular processes.

Main Results:

• Demonstrated impressive stability of protein-only or hybrid protein-lipid membranes.
• Showcased compatibility with existing cellular membrane constituents.
• Confirmed the ability of PMBCs to enclose molecules, undergo membrane fusion, phase separation, and embed biosynthetic elements.

Conclusions:

• Prebiotic protein membrane-based compartments (PMBCs) offer a viable alternative to lipid-based protocells.
• PMBCs represent a potential ancestral form of current lipid-based cells.
• The PMBC model provides a framework for designing artificial cells and studying early life evolution.