Fatty acid membrane assembly on coacervate microdroplets as a step towards a hybrid protocell model.
Mechanisms of prebiotic compartmentalization are central to providing insights into how protocellular systems emerged on the early Earth. Protocell models are based predominantly on the membrane self-assembly of fatty-acid vesicles, although membrane-free scenarios that involve liquid-liquid microphase separation (coacervation) have also been considered. Here we integrate these alternative models of prebiotic compartmentalization and develop a hybrid protocell model based on the spontaneous self-assembly of a continuous fatty-acid membrane at the surface of preformed coacervate microdroplets prepared from cationic peptides/polyelectrolytes and adenosine triphosphate or oligo/polyribonucleotides. We show that the coacervate-supported membrane is multilamellar, and mediates the selective uptake or exclusion of small and large molecules. The coacervate interior can be disassembled without loss of membrane integrity, and fusion and growth of the hybrid protocells can be induced under conditions of high ionic strength. Our results highlight how notions of membrane-mediated compartmentalization, chemical enrichment and internalized structuration can be integrated in protocell models via simple chemical and physical processes.
Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
T-Y
TY
Dora Tang
Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
C
C
Rohaida Che Hak
Chemistry Department, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
Alexander J
AJ
Thompson
Chemistry Department, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
Marina K
MK
Kuimova
Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
D S
DS
Williams
Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
Adam W
AW
Perriman
Centre for Protolife Research and Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
Stephen
S
Mann
D000255:Adenosine Triphosphate / Q000737:chemistry; D058045:Artificial Cells; D002462:Cell Membrane / Q000737:chemistry*; D004655:Emulsions; D005227:Fatty Acids / Q000737:chemistry*; D008561:Membrane Fusion; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D053758:Nanoparticles / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry; D009843:Oligoribonucleotides / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
D004655:Emulsions; D005227:Fatty Acids; D009843:Oligoribonucleotides; D010446:Peptide Fragments; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D019301:Oleic Acid; D000255:Adenosine Triphosphate