Ferredoxins are small proteins containing at least one iron-sulfur cluster that generally participate in electron transfer processes in biological systems. The role that ligands and aminoacids surroundings the cluster have in driving the individual oxidation state of each iron atom as well as in its electronic distribution is nowadays subject of debate. Although a large variety of spectroscopic methods have been applied in the study of ferredoxins, Nuclear Magnetic Resonance is the unique technique to address which are the specific iron atoms that directly participate in the redox transfer process.
The study of these proteins by NMR is not only interesting by the biological point of view, but also represents a challenge in the development of the NMR technique applied to paramagnetic systems. In this sense, one of the objetives of the present Project is to develop a methodology in which new restraints derived from relaxation parameters can be accounted for in the Distance Geometry calculations, improving the resolution of the structures of these proteins. If this is achieved, the proximity of the cluster can be characterized in solution and new information on its electronic structure will be available
On the other hand, the comparison of the structure of native ferredoxins with the solution structure of analogous synthetic proteins can give a detailed information of the specific features responsible for the redox potential of these proteins.