Albany 2013: Book of Abstracts
June 11-15 2013
©Adenine Press (2012)
Synthesis of informational polymers by guided polymerization reactions in liquid crystalline matrices of lipids
The fundamental question of how life originated is one of the greatest scientific mysteries. In particular, the processes by which polymers capable of catalysis and replication emerged on early Earth are still elusive. We investigate guided polymerization reactions that can occur in organized liquid crystalline matrices of amphiphilic lipids. These result from spontaneous self-assembly of amphiphiles that form orderly structures like multilamellar phases, which can concentrate reactants, yet also permit diffusional mobility. These lamellae enhance reaction rates by promoting self-aggregation of reactants in configurations that enhance polymerization and prevent side reactions (Wächtershäuser, 1988). Monomers form highly ordered 2-dimensional films between the lamellae, thereby overcoming entropic barriers. The conditions also produce a chemical potential that reduces water activity and shifts reaction equilibrium towards condensation. Using relatively simple amphiphilic lipids, we are discerning the process underlying oligomerization of biologically relevant monomers like nucleotides, amino acids etc, that might have resulted in the formation of complex mixtures of oligomers under prebiotic conditions. I will present some preliminary data towards this end.
Delineating the mechanisms underlying lipid-catalyzed reactions has implications for emergence of informational molecules on prebiotic earth. It is also relevant for gaining an understanding of how amphiphilic boundary structures contributed to the emergence of cellular life as it has been postulated that, on early earth, encapsulated compartments containing evolving replicating molecules, might have existed in the form of stable micelles (Orgel, 2004). Additionally, it is also believed that lipids might have played a potentially important metabolic role in the emergence of life on Earth (Segré et al., 2001).
Orgel LE. (2004). Prebiotic chemistry and the origin of the RNA World. Crit Rev Biochem Mol Biol. 39, 99-123.
Segré D, Ben-Eli D, Deamer DW, Lancet D. (2001). The Lipid World. Orig Life Evol Biosph. 31, 119–145.
Department of Biology