Electron-Transfer Processes of Cytochrome c at Interfaces. New Insights by Surface-Enhanced Resonance Raman Spectroscopy

Abstract

The heme protein cytochrome c acts as an electron carrier at the mitochondrial-membrane interface and thus exerts its function under the influence of strong electric fields. To assess possible consequences of electric fields on the redox processes of cytochrome c, the protein can be immobilized to self-assembled monolayers on electrodes and studied by surface-enhanced resonance Raman spectroscopy. Such model systems may mimic some essential features of biological interfaces including local electric field strengths. It is shown that physiologically relevant electric field strengths can effectively modulate the electron-transfer dynamics and induce conformational transitions.

Evidence for heme release in layer-by-layer assemblies of myoglobin and polystyrenesulfonate on pyrolitic graphite

“…This could be related to either a change in the heme environment of the protein or a local electric field, as has been reported for cytochrome c immobilized on carboxylic acid terminated self-assembled monolayers [32][33][34][35]. To obtain more insight into the effect of the immobilization, we determined the midpoint potential over a broad pH range and compared it with that of Mb in solution (Fig.…”

Functionalized Ag nanoparticles with tunable optical properties for selective protein analysis

“…The optical properties of the AgNPs were tuned such that their plasmonic resonance matches the Soret transition of the Cyt c heme cofactor at 410 nm. 7 First, citrate-capped AgNPs were prepared by borohydride reduction of Ag + ions in the presence of citrate (Fig. S1, ESIz).…”

Tailored silica coated Ag nanoparticles for non-invasive surface enhanced Raman spectroscopy of biomolecular targets

“…It is therefore expected to interact also with the OH groups that exist at the SiO 2 surface. Cyt c has seen detailed characterisation in the past with SERRS 16,17 and is therefore also used in this work as a Raman marker and model protein. …”