INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
Stability, Redox Parameters and Electrocatalytic Activity of a Cytochrome Domain from a New Subfamily
MARÍA FLORENCIA MOLINAS; LEANDRO BENAVIDES; MARIA ANA CASTRO; DANIEL H. MURGIDA
ELSEVIER SCIENCE SA
Lugar: Amsterdam; Año: 2015 vol. 105 p. 25 - 25
We report a spectroscopic, electrochemical and spectroelectrochemical characterization of the soluble cytochrome c domain (Cyt-D) from the Rhodothermus marinus caa3 terminal oxygen reductase and its putative electron donor, a high potential [4Fe-4S] protein (HiPIP). Cyt-D exhibits superior stability, particularly at the level of the heme pocket, compared to archetypical cytochromes in terms of thermal and chemical denaturation, alkaline transition and oxidative bleaching of the heme, which is further increased upon adsorption on biomimetic electrodes. Therefore, this protein is proposed as a suitable building block for electrochemical biosensing. As a proof of concept, we show that the immobilized Cyt-D exhibits good electrocatalytic activity towards H2O2 reduction. Relevant thermodynamic and kinetic electron transfer parameters for Cyt-D and HiPIP are also reported, including reorganization energies of 0.33 eV and 0.42 eV, respectively.