Membrane Catalysed Formation of Nucleotide Clusters and Its Role in the Origins of Life

Non-enzymatic polymerisation explained how life could assemble spontaneously on the early Earth. Prior research has discovered that the non-enzymatic polymerisation can be mediated by various environmental settings, most widely accepted are the reactions driven by the cycles of hydration and dehydration and organising matrices such as clay, salt, membranes and mineral surface. Membranes have a unique feature which prepares it as a sensitive organising matrix, as compared to mineral surface and clay, which transforms its phase with small changes in temperature, hydration and composition of lipids. Multi-component membranes can show phase separation where two or more distinct phases can co-exist. To the best of our knowledge, this is for the fi?rst time the influence of different phases of the membrane in the nucleotide organisation and polymerisation in a simulated prebiotic setting in this work have been explored. This study encompasses the energetics of inserting a mononucleotide, UMP, in distinct membrane settings which is probed utilising the PMF. The preferential partitioning of UMP is also investigated; which is coupled to the location of the insertion and the composition of the PSM/DOPC/Chol membranes. Combined with umbrella-sampling calculations, AA-MD simulations were performed to estimate the role of the

monophasic and diphasic membrane in modifying the behaviour of UMPs and their clustering mechanism. A mathematical model was also developed based on lattice model and random walk and some of the parameters were trained from the AA-MD simulations. The results indicated that the membranes were capable of concentrating nucleotides and organised into anisotropic clusters, and the thermodynamic studies along with mathematical model showed that it had a sharp preference for the Lo/Ld domain interface for clustering.