The research carried out is basic science applied to the chemical processes occurring in the environmental and human biosphere. The systems under study are comprised within the natural cycles of nitrogen, carbon, and phosphorus. The metal-containing biomolecules are obtained from natural sources or using a molecular biology approach, and they are characterized at the molecular level. The main goal is the determination of the molecular structure of the metal-containing biomolecule, mainly proteins and enzymes, the elucidation of the structure-function relationships, the reciprocal influence of the metal ions and the protein matrix, and the interaction modes of the metallo-protein with substrates, inhibitors, and other biological substrates such as proteins and DNA. These goals are pursued using a structural biology approach, applying high resolution NMR spectroscopy, biocrystallography, and other techniques such as X-ray absorption spectroscopy, circular dichroism, fluorescence spectroscopy, light-scattering, and calorimetry. A significant branch of the research is dedicated to the application of computational methods and biomolecular structural modelling to the elucidation of structures and reaction mechanisms.