Resumen de Computational studies on the interaction of amino acids and peptides with tio2 surfaces: adsorption and reactivity
How life began is one of the most intriguing and unsolved problems of science. The events cascade that led to the formation of complex systems such as polymeric macromolecules like proteins, DNA, RNA, sugars, etc., starting from small and simple molecules like H2O, CH4, CO, CO2, NH3, H2, is already an object of intense studies. One of the crucial steps of the origin of life is the condensation reaction between amino acids to form peptides. The peptide bond formation reaction is thermodynamically and kinetically unfavourable in gas phase, but also in water. Considering the reaction between two glycine molecules:
Gly + Gly ⇄ Digly + H2O the equilibrium constant is around 10-5, and it is clear that in a water environment, for the Le Chatelier's principle, the reaction goes back to reagents, since water is one of the products. According to the seminal hypothesis proposed by Bernal, this crucial step for life formation could have seen the light at the interface with mineral surfaces. Therefore, in this thesis we will focus on the interaction of amino acids with TiO2 surfaces elucidating the peptide bond formation mechanism occurring on these surfaces. Then we will analyse the adsorption of secondary structures (α-helices and β-sheets), and the role of the mineral surface in the peptide folding.
