RESEARCH ACTIVITY

Key words Bioinorganic, Biophysics, Biocatalysis, Energy Bioconversion (Hydrogen) Role of metals in Biology (heme and non-heme iron, molybdenum, tungsten, nickel , vanadium and cobalt) Inorganic systems as models for biocatalysis Spectroscopy (NMR, EPR and Mössbauer), (Bio) Electrochemistry 

Main goal is the understanding of electron transfer chains (ETC) of sulphate reducing bacteria (SRB) and methane forming bacteria (MFB). SRB have complex ETC systems which allow the reduction of sulphate by oxidation of either organic compounds or molecular hydrogen. The result of the bacterial activity results in the formation of large amounts of sulphide which presents serious health and environmental problems (metal corrosion, poisoning, etc). Another interest of these microorganisms is due to the fact that can either use or produce molecular hydrogen. In this last case, hydrogen is oxidized by other microbial groups (MFB) producing methane by reduction of carbon dioxide. The understanding of the involved mechanisms is important to study the use of new forms of energy (bioconversion - biological production of hydrogen and methane). A necessary step is the identification and isolation of metalloenzymes involved. The main goal is the use of spectroscopic techniques namely electron paramagnetic resonance (RPE) and related methods (ENDOR and ESEEM), uni- and multi-dimensional nuclear magnetic resonance RMN) and Mossbauer spectroscopy on the study of structure-function relationship of metallo-proteins and reconstitution of electron transfer chains (protein/protein interactions using Molecular graphics). The active centers that have been studied include iron-sulphur clusters (rubredoxin type, [2Fe -2S], [3Fe-4S], [4Fe-4S] and novel Fe-S centers), as well as associations with molybdenum and nickel) and hemes. Special relevance has been given to the characterization of bacterial hydrogenases (the role of the nickel in hydrogen evolution/ consumption) and to the topics: engineering of iron-sulphur proteins, chemical modification of active centers, synthesis of novel metal clusters (formation of clusters containing hetero-atoms) and molecular modeling. Research highlights: Discovery of a novel 3Fe center and Heterometallic Fe-S sites Isolation of novel Metalloproteins Role of Nickel in Hydrogenases Role of Molybdenum (and Tungsten) in Biology Electron Transfer and Protein-Protein Interactions in Metalloproteins