Impact of Self-Assembly Composition on the Alternate Interfacial Electron Transfer for Electrostatically Immobilized Cytochrome C
Articolo
Data di Pubblicazione:
2007
Citazione:
Impact of Self-Assembly Composition on the Alternate Interfacial Electron Transfer for Electrostatically Immobilized Cytochrome C / T.D. Dolidze, S. Rondinini, A. Vertova, D.H. Waldeck, D.E. Khoshtariya. - In: BIOPOLYMERS. - ISSN 0006-3525. - 87:1(2007 Sep), pp. 68-73.
Abstract:
We report on the effects of self-assembled monolayer (SAM) dilution and thickness on the electron transfer (ET) event for cytochrome c (CytC) electrostatically
immobilized on carboxyl terminated groups. We observed biphasic kinetic behavior for a logarithmic dependence of the rate constant on the SAM carbon number (ET distance) within the series of mixed SAMs of C5COOH/
C2OH, C10COOH/C6OH, and C15COOH/C11OH that is
in overall similar to that found earlier for the undiluted SAM assemblies. However, in the case of C15COOH/C11OH and C10COOH/C6OH mixed SAMs a notable increase of the ET standard rate constant was observed, in
comparison with the corresponding unicomponent (x–COOH) SAMs. In the case of the C5COOH/C2OH composite SAM a decrease of the rate constant versus the unicomponent analogue was observed. The value of the
reorganization free energy deduced through the Marcuslike data analysis did not change throughout the series;this fact along with the other observations indicates
uncomplicated rate-determining unimolecular ET in all cases. Our results are consistent with a model that considers a changeover between the alternate, tunneling and adiabatic intrinsic ET mechanisms. The physical mechanism behind the observed fine kinetic effects in terms of the protein-rigidifying x–COOH/CytC interactions arising in the case of mixed SAMs are also discussed.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
cytochrome c; electron transfer; intrinsic mechanisms; self-assembled monolayers; bioelectrochemical nanodevices; mimicking protein–protein interactions; cyclic voltammetry
Elenco autori:
T.D. Dolidze, S. Rondinini, A. Vertova, D.H. Waldeck, D.E. Khoshtariya
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