engleski

Vesicle compartments from prebiotically relevant amphiphiles

Vesicles are considered as reasonable models of protocells, the precursor structures of the first cells that may have appeared during the prebiotical evolution. Short-chain fatty acids belong to the bilayer-forming amphiphiles that may have been present on the early Earth, since they are chemically simple and since they have been found in carbonaceous meteorites. By using different experimental techniques, the aggregation behaviour of dilute aqueous dispersions of fatty acids (mainly decanoic acid) has been investigated, focusing particulary on the formation and properties of vesicles. The techniques used include electron microscopy, differential scanning calorimetry and electron paramagnetic resonance spectroscopy (using nitroxide labeled spin probes). Vesicle formation in the case os decanoic acid is limited to a pH range between 6.8 and 7.8, the vesicles being always present in equilibrium with non-associated decanoate (about 10-20 mM). For vesicle formation at lower pH, sodium dodecylbenzenesulfonate can be added at equimolar amounts.

vesicles; amphiphiles; prebiotical evolution

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