Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India.
Sci Rep. 2020 Mar 11;10(1):4483. doi: 10.1038/s41598-020-61372-w.
Protocellular membranes are thought to be composed of mixtures of single chain amphiphiles, such as fatty acids and their derivatives, moieties that would have been part of the complex prebiotic chemical landscape. The composition and physico-chemical properties of these prebiological membranes would have been significantly affected and regulated by their environment. In this study, pertinent properties were systematically characterized, under early Earth conditions. Two different fatty acids were mixed with their respective alcohol and/or glycerol monoester derivatives to generate combinations of binary and tertiary membrane systems. Their properties were then evaluated as a function of multiple factors including their stability under varying pH, varying Mg ion concentrations, dilution regimes, and their permeability to calcein. Our results demonstrate how environmental constraints would have acted as important prebiotic selection pressures to shape the evolution of prebiological membranes. The study also illustrates that compositionally diverse membrane systems are more stable and robust to multiple selection pressures, thereby making them more suitable for supporting protocellular life.
原核细胞膜被认为是由单链两亲分子的混合物组成的，如脂肪酸及其衍生物，这些部分是复杂的前生物化学景观的一部分。这些原始生物膜的组成和物理化学性质将受到其环境的显著影响和调节。在这项研究中，在早期地球条件下，系统地对相关特性进行了表征。两种不同的脂肪酸与各自的醇和/或甘油单酯衍生物混合，生成二元和三元膜系统的组合。然后，根据多种因素评估它们的性质，包括在不同 pH 值、不同镁离子浓度、稀释条件下的稳定性，以及它们对钙黄绿素的通透性。我们的研究结果表明，环境约束如何作为重要的前生物选择压力，塑造原核细胞膜的进化。该研究还表明，组成多样化的膜系统对多种选择压力更稳定和更健壮，从而使它们更适合支持原核生命。
