http://hdl.handle.net/10362/3396 Tue, 21 May 2013 21:20:08 GMT 2013-05-21T21:20:08Z http://hdl.handle.net/10362/5160 Title: Energy transduction by respiratory complex I Authors: Batista, Ana P. Abstract: The aim of the work presented in this dissertation was to provide a contribution to the understanding of the energy transducing mechanism of respiratory complex I. This enzyme is present in most bacteria and in all mitochondrial systems and it is characterized by its large number of subunits, its prosthetic groups (flavin and iron-sulfur centers), and its NADH:quinone oxidoreductase activity sensitive to specific inhibitors and coupled with charge translocation across the membrane.(...) Description: Dissertation presented to obtain a PhD degree in Biochemistry at the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Wed, 01 Sep 2010 00:00:00 GMT http://hdl.handle.net/10362/5160 2010-09-01T00:00:00Z http://hdl.handle.net/10362/5159 Title: The alternative complex III from Rhodothermus marinus - a prototype of a new family of quinol: electron acceptor oxidoreductase Authors: Refojo, Patrícia N. Abstract: The aim of the work presented in this thesis was the characterization of a complex with quinol: electron carrier oxidodoreductase activity present in the membranes of the thermohalophilic bacterium Rhodothermus (R.) marinus. The complexes involved in the R. marinus respiratory chain have been extensively studied in the past few years. Specifically, the purification and characterization of a complex I (NADH: quinone oxidoreductase), a complex II (succinate:quinone oxidoreductase) and of three different oxygen reductases from the heme-copper oxygen reductases superfamily have been performed. Since those oxygen reductases are unable to receive electrons from quinol molecules, the presence of a complex linking complexes I and II to the oxygen reductases was needed. In fact, a complex with quinol: HiPIP oxidoreductase activity was purified and partially characterized. The absence of the Rieske protein indicated that the complex isolated from R. marinus has a different composition when compared with the typical cytochrome bc1 complex.(...) Description: Dissertation presented to obtain a PhD degree in Biochemistry at the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Thu, 01 Jul 2010 00:00:00 GMT http://hdl.handle.net/10362/5159 2010-07-01T00:00:00Z