Cyclophospholipids Increase Protocellular Stability to Metal Ions

Short chain, prebiotically plausible lipids with a cyclic phosphate headgroup spontaneously form vesicles that are resistant to high concentrations of Na+, Mg2+, and Ca2+ individually and together. Stability to Mg2+ and Ca2+ is improved by the presence of environmental concentrations of Na+. Lipids of similar characteristics may have been crucial to support the transition from abiotic to biotic chemistry. AbstractModel protocells have long been constructed with fatty acids, because these lipids are prebiotically plausible and can, at least theoretically, support a protocell life cycle. However, fatty acid protocells are stable only within a narrow range of pH and metal ion concentration. This instability is particularly problematic as the early Earth would have had a range of conditions, and extant life is completely reliant on metal ions for catalysis and the folding and activity of biological polymers. Here, prebiotically plausible monoacyl cyclophospholipids are shown to form robust vesicles that survive a broad range of pH and high concentrations of Mg2+, Ca2+, and Na+. Importantly, stability to Mg2+ and Ca2+ is improved by the presence of environmental concentrations of Na+. These results suggest that cyclophospholipids, or lipids with similar characteristics, may have played a central role during the emergence of Darwinian evolution.
Source: Small - Category: Nanotechnology Authors: Tags: Full Paper Source Type: research