Ionització i activació per cations metàl·lics de sistemes d'interès bioquímic. Estudis teòrics i d'espectrometria de masses

The main goal of this coordinated project is to study the effects of ionization and cationization by transition metals on the reactivity of small biomolecules, by means of accurate quantum chemical methods and mass spectrometry (Electrospray-Ion Trap) experiments. In particular, we will analyze the role of metal cations on the activation of aminoacids and peptides, on the intermolecular proton transfer reactions of DNA base pairs, and on the activitation of O\sub 2\nosub and CH bonds. Moreover, we will study the isomerization and fragmentation reactions of aminoacids and peptides radical cations. With the study of these systems we want to move one step forward on the knowledge of the role of metal cations on the structure and function of metaloenzymes or nucleic acids, and on the understanding of the damage caused by ionizing radiation or oxidizing agents. A second important motivation is that the study of the fragmentations produced in these systems can reveal new strategies for peptide sequencing through mass spectrometry techniques. The development of efficient theoretical methods and analysis tools will be essential to understand wchich factors control the structure and intrinsic reactivity of these compounds and therefore, to interpret the mass spectrometry expeiments. Because on that, an important goal in this project is to develop new theoretical methods for treating these systems