Origin & Evolution of Life

Structural Phenomena in a Vesicle Membrane Obtained through an Evolution Experiment: A Study Based on MD Simulations

By Keith Cowing

Status Report

Life

September 6, 2023

Filed under biochemistry, chemistry, evolution, genomics, origin of life, Peptide, prebiotic, vesicle membranes

Structural Phenomena in a Vesicle Membrane Obtained through an Evolution Experiment: A Study Based on MD Simulations — Effect of temperature on the peptide aggregation process. Left: side view of (ODAP—STEP) bilayer systems with peptides at 0 ns (a) and 500 ns at 353 K (b), 338 K (c), and 323 K (d); KSPFPFAA peptides are shown in mauve, while ODAP and STEP are in gray and green, respectively. Right: number of the clusters as a function of time formed during the 500 ns MD simulation with cutoff 0.6 nm at 353 K (e) (previously reported by the authors in Ref. [44]), 338 K (f), and 323 (g) — Life

The chemical evolution of biomolecules was clearly affected by the overall extreme environmental conditions found on Early Earth.

Periodic temperature changes inside the Earth’s crust may have played a role in the emergence and survival of functional peptides embedded in vesicular compartments. In this study, all-atom molecular dynamic (MD) simulations were used to elucidate the effect of temperature on the properties of functionalized vesicle membranes.

A plausible prebiotic system was selected, constituted by a model membrane bilayer from an equimolar mixture of long-chain fatty acids and fatty amines, and an octapeptide, KSPFPFAA, previously identified as an optimized functional peptide in an evolution experiment. This peptide tends to form the largest spontaneous aggregates at higher temperatures, thereby enhancing the pore-formation process and the eventual transfer of essential molecules in a prebiotic scenario.

The analyses also suggest that peptide–amphiphile interactions affect the structural properties of the membrane, with a significant increase in the degree of interdigitation at the lowest temperatures under study.

María J. Dávila and Christian Mayer

Structural Phenomena in a Vesicle Membrane Obtained through an Evolution Experiment: A Study Based on MD Simulations, Life 2023, 13(8), 1735; DOI: 10.3390/life13081735 (open access)

Astrobiology

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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