Artículo
Correlated electric field modulation of electron transfer parameters and the access to alternative conformations of multifunctional cytochrome c
Oviedo Rouco, Santiago
; Spedalieri, Ana Cecilia
; Scocozza, Magali Franca
; Tomasina, Florencia; Tórtora, Verónica; Radi, Rafael; Murgida, Daniel Horacio
Fecha de publicación:
02/2022
Editorial:
Elsevier Science SA
Revista:
Bioelectrochemistry
ISSN:
1567-5394
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Cytochrome c (Cyt c) is a multifunctional protein that, in its native conformation, shuttles electrons in the mitochondrial respiratory chain. Conformational transitions that involve replacement of the heme distal ligand lead to the gain of alternative peroxidase activity, which is crucial for membrane permeabilization during apoptosis. Using a time-resolved SERR spectroelectrochemical approach, we found that the key physicochemical parameters that characterize the electron transfer (ET) canonic function and those that determine the transition to alternative conformations are strongly correlated and are modulated by local electric fields (LEF) of biologically meaningful magnitude. The electron shuttling function is optimized at moderate LEFs of around 1 V nm−1. A decrease of the LEF is detrimental for ET as it rises the reorganization energy. Moreover, LEF values below and above the optimal for ET favor alternative conformations with peroxidase activity and downshifted reduction potentials. The underlying proposed mechanism is the LEF modulation of the flexibility of crucial protein segments, which produces a differential effect on the kinetic ET and conformational parameters of Cyt c. These findings might be related to variations in the mitochondrial membrane potential during apoptosis, as the basis for the switch between canonic and alternative functions of Cyt c. Moreover, they highlight the possible role of variable LEFs in determining the function of other moonlighting proteins through modulation of the protein dynamics.
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Articulos(INQUIMAE)
Articulos de INST.D/QUIM FIS D/L MATERIALES MEDIOAMB Y ENERGIA
Articulos de INST.D/QUIM FIS D/L MATERIALES MEDIOAMB Y ENERGIA
Citación
Oviedo Rouco, Santiago; Spedalieri, Ana Cecilia; Scocozza, Magali Franca; Tomasina, Florencia; Tórtora, Verónica; et al.; Correlated electric field modulation of electron transfer parameters and the access to alternative conformations of multifunctional cytochrome c; Elsevier Science SA; Bioelectrochemistry; 143; 2-2022; 1-10
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