Inorganic Biochemistry and NMR
The Inorganic Biochemistry and NMR Laboratory is devoted to the structural and functional characterization of redox proteins that participate in the anaerobic bioenergetic metabolism of microorganisms, using biophysical methods.
Ricardo O. Louro
Phone (+351) 214469309
This laboratory is currently engaged in the study of the molecular bases for coupling exchange of electrons with exogenous solid substrates to energy conservation in several anaerobic organisms. Iron based anoxygenic photosynthesis is one of the most ancient forms of metabolism that left geological evidence soon following the origin of Life on Earth, whereas extracellular metal respiration is fast becoming a hot-spot of biotechnological research on the development of novel bioremediation strategies for metal contaminated sites, and for the development of microbial fuel cells for environmentally sustainable power generation.
These bioenergetic processes rely on the presence of complex networks of electron transfer proteins that provide the link between the extracellular solids and the membrane associated metabolism where energy transduction takes place and ATP is produced. A large fraction of the proteins that have been assigned to these bioenergetic networks are cytochromes but the structure and detailed functional mechanism of the majority of them is not known.
Lack of detailed knowledge on the energy metabolism of metal-respiring organisms has been identified as a fundamental barrier to the optimisation of applications in microbial fuel cell technology and bioremediation. In the IBN laboratory this issue is being tackled by integrating structural, thermodynamic and kinetic data on the proteins and enzymes of these bioenergetic networks in order to understand at the molecular level their functional properties. NMR spectroscopy is uniquely suited for collecting structural and dynamic information from the proteins under study because in recent years the size and complexity of biological macromolecules that can be studied in detail by this technique has increased considerably. It is combined with other spectroscopic methods, fast transient kinetics methods and electrochemical methods to provide the experimental characterization of the target proteins. This reductionist approach forms the basis for the progressive assembly of a systemic description of the complex network of redox proteins that ensures controlled electron exchange with the cell exterior in a way that is coupled to ATP generation.
Our ultimate goal is to apply this knowledge for the optimization of microbial fuel cells capable of improved energy generation form renewable sources, and for the enhancement of bioremediation processes of sites contaminated with metals and radionuclides.
- Catarina Paquete, Post Doc
- Luis Rosa, Post Doc
- Bruno Fonseca, PhD student
- Ivo Saraiva, PhD student
- Alexandra Alves, PhD student
- Sonia Neto Graduate student
- Nazua Costa Graduate student
- Nelson Pestana Masters student
- Isabel Pacheco, Technician
- Fonseca BM, Paquete CM, Neto SE, Pacheco I, Soares CM, Louro RO, Mind the gap: cytochrome interactions reveal electron pathways across the periplasm of Shewanella oneidensis MR-1, Biochem J (2012) 10.1042/BJ20121467
- Saraiva IH, Newman DK, Louro RO, Functional characterization of the FoxE iron oxidoreductase from the photoferrotroph Rhodobacter ferrooxidans SW2, J Biol Chem, 287: 25541-25548 (2012)
- Fonseca BM, Tien M, Rivera M, Shi L, Louro RO, Efficient and selective isotopic labeling of hemes to facilitate the study of multiheme proteins, BioTechniques Rapid Dispatches (2012) DOI:10.2144/000113859
For further information please visit the laboratory's website
No grupo de Bioquímica Inorgânica e RMN estudamos organismos que vivem à custa de minérios metálicos e as proteínas que lhes conferem a capacidade desse modo de vida único. Muitas dessas proteínas são vermelhas e são semelhantes à hemoglobina do sangue mas transportam electrões em vez de oxigénio. Chamam-se citocromos e a estrutura e modo de funcionamento da maioria destes não são ainda conhecidos. O método de Ressonância Magnética Nuclear em conjunto com outros métodos biofísicos proporciona a possibilidade de elucidar as características estruturais e funcionais destas proteínas e enzimas. Deste modo poderemos determinar como as diferentes proteínas interactuam entre si para realizar a sua função fisiológica. Este conhecimento vai permitir optimizar o desempenho de pilhas que utilizam estes organismos para produzir electricidade, chamadas pilhas de combustível microbianas, e desenhar métodos mais eficientes de bioremediação de locais contaminados com metais pesados ou radioactivos.