The role of protein dynamics and thermal fluctuations in regulating cytochrome c/cytochrome c oxidase electron transfer

• Published in: Biochimica et biophysica acta 2014-07, Vol.1837 (7), p.1196-1207
• Main Authors: Alvarez-Paggi, Damian, Zitare, Ulises, Murgida, Daniel H.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Bioelectrochemistry; CuA; Cytochrome c; Cytochromes c - chemistry; Cytochromes c - metabolism; Electron transfer; Electron Transport; Electron Transport Complex IV - chemistry; Electron Transport Complex IV - metabolism; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Sequence Data; Raman spectroelectrochemistry
• ISSN: 0005-2728; 0006-3002; 1879-2650
• DOI: 10.1016/j.bbabio.2014.01.019

In this overview we present recent combined electrochemical, spectroelectrochemical, spectroscopic and computational studies from our group on the electron transfer reactions of cytochrome c and of the primary electron acceptor of cytochrome c oxidase, the CuA site, in biomimetic complexes. Based on these results, we discuss how protein dynamics and thermal fluctuations may impact on protein ET reactions, comment on the possible physiological relevance of these results, and finally propose a regulatory mechanism that may operate in the Cyt/CcO electron transfer reaction in vivo. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. [Display omitted] •A regulatory mechanism of Cyt/CcO electron transfer reaction is proposed.•The mechanism relies upon reshaping of potential energy surfaces by electrostatics.•Electric fields tune the electronic coupling and reorganization energy of Cyt.•CuA alternates between two different ground states for electron entry and exit.