Surface‐enhanced vibrational spectroscopy for probing transient interactions of proteins with biomimetic interfaces: electric field effects on structure, dynamics and function of cytochrome c

Abstract

Most of the biochemical and biophysical processes of proteins take place at membranes, and are thus under the influence of strong local electric fields, which are likely to affect the structure as well as the reaction mechanism and dynamics. To analyse such electric field effects, biomimetic interfaces may be employed that consist of membrane models deposited on nanostructured metal electrodes. For such devices, surface‐enhanced resonance Raman and IR absorption spectroscopy are powerful techniques to disentangle the complex interfacial processes of proteins in terms of rotational diffusion, electron transfer, and protein and cofactor structural changes. The present article reviews the results obtained for the haem protein cytochrome c, which is widely used as a model protein for studying the various reaction steps of interfacial redox processes in general. In addition, it is shown that electric field effects may be functional for the natural redox processes of cytochrome c in the respiratory chain, as well as for the switch from the redox to the peroxidase function, one of the key events preceding apoptosis.

Vibrational Stark Effect of the Electric-Field Reporter 4-Mercaptobenzonitrile as a Tool for Investigating Electrostatics at Electrode/SAM/Solution Interfaces

“…The more significant deviations in the case of Ag/MBN may either be related to the approximations and simplifications in the present model or to the uncertainty in the tilt angle value taken from the literature. The present electric field analysis for mixed MHA/MBN is consistent with previous results for pure MHA, thus indicating that MBN may be used as a reporter group for in situ monitoring of local electric field in SAMs that are used for binding biomolecules such as redox proteins and enzymes [11,42,43]. …”

On the possible role of protein vibrations in information processing in the brain: three Russian dolls

“…In a review of the role of global and local vibrational modes in the dynamic allostery of protein Hawkins and McLeish ( 2006 ) state “It is now clear that dynamics plays an important role in protein function. For example, there is growing evidence for a dynamic contribution to allosteric signaling within protein molecules.” Furthermore the electric fields produced in folded proteins influence nearly every aspect of protein function (Suydam et al, 2006 ; Stafford et al, 2010 ; Ly et al, 2011 ; Fafarman et al, 2012 ; Schkolnik et al, 2012 ; Ritchie and Webb, 2013 ; Walker et al, 2013 ).…”

Proteomic tools for the analysis of transient interactions between metalloproteins

“…Such a new function is modulated by post‐translational modifications of the metalloprotein [14,15] and by binding to cardiolipin‐enriched membranes or biomimetic interfaces, as suggested by Khoa Ly et al. [16].…”