Self-replicating peptides/proteins

The division of function between DNA (genetic information storage) and protein (catalysis) was, according to the RNA world hypothesis, a later development. New variants of self-replicating RNA molecules developed, with the additional ability to catalyze the condensation of amino acids into peptides. Occasionally, the peptide (s) thus formed would reinforce the self-replicating ability of the RNA, and the pair—RNA... 

Among the hot debate between theories concerning either a gradual change from RNA self-replication to RNA coded protein synthesis as in the RNA-world, or a merger of systems involving co-evolved RNA and catalytic peptides, another type of molecule - lipids - have until recently been overlooked. 

To make the existence of an RNA world as a step in prebiotic evolution feasible, not only self-replicating ribozymes are essential, but also a second type of catalytically active molecules. The transition from a world based on RNA catalysis to a world of protein enzymes demands ribozymes which are able to synthezise peptides from activated amino acids. 

Templaied synthesis plays a central role in any discussion about the emergence of life. This is because it was certainly involved in two stages of the evolution of life— self-replication and translation (protein synthesis) — and possibly in the third, polymerization of monomers or shorter oligomers of amino acids and nucleotides into peptides and (longer) oligonucleotides. The role of templated synthesis in supramolecular chemistry is ubiquitous and well documented. Before going further, it is... 

One particular asset of structured self-assemblies is their ability to create nano- to microsized domains, snch as cavities, that could be exploited for chemical synthesis and catalysis. Many kinds of organized self-assemblies have been proved to act as efficient nanoreactors, and several chapters of this book discnss some of them such as small discrete supramolecular vessels (Chapter Reactivity In Nanoscale Vessels, Supramolecular Reactivity), dendrimers (Chapter Supramolecular Dendrlmer Chemistry, Soft Matter), or protein cages and virus capsids (Chapter Viruses as Self-Assembled Templates, Self-Processes). In this chapter, we focus on larger and softer self-assembled structures such as micelles, vesicles, liquid crystals (LCs), or gels, which are made of surfactants, block copolymers, or amphiphilic peptides. In addition, only the systems that present a high kinetic lability (i.e., dynamic) of their aggregated building blocks are considered more static objects such as most of polymersomes and molecularly imprinted polymers are discussed elsewhere (Chapters Assembly of Block Copolymers and Molecularly Imprinted Polymers, Soft Matter, respectively). Finally, for each of these dynamic systems, we describe their functional properties with respect to their potential for the promotion and catalysis of molecular and biomolecu-lar transformations, polymerization, self-replication, metal colloid formation, and mineralization processes. 

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