Spectroelectrochemical investigation of a flavoprotein with a flavin-modified gold electrod
| Jazyk: | English |
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| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dd1c0f69b04800ae66c4d9cb22b13960 http://hdl.handle.net/10281/2347 |
| Rights: | CLOSED |
| Přírůstkové číslo: | edsair.doi.dedup.....dd1c0f69b04800ae66c4d9cb22b13960 |
| Autor: | Jannette Carey, Thomas Schödl, Jörg Daub, Günter Hauska, Erika Kozma, Gilbert Nöll, Rita Grandori |
| Přispěvatelé: | Nöll, G, Kozma, E, Grandori, R, Carey, J, Schödl, T, Hauska, G, Daub, J |
| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: |
Semiquinone
Surface Properties Stereochemistry Flavoprotein Flavin mononucleotide Flavin group Photochemistry Redox chemistry.chemical_compound Electron transfer Coated Materials Biocompatible Flavins Flavoproteins adsorption electrochemistry hopping mechanism electron transfer flavin mononucleotide Electrochemistry General Materials Science Electrodes Spectroscopy Flavoproteins biology Escherichia coli Proteins Surfaces and Interfaces Hydrogen-Ion Concentration Condensed Matter Physics DNA-Binding Proteins Repressor Proteins chemistry Covalent bond Electrode biology.protein Adsorption Gold |
| Popis: | A flavin-modified gold electrode was developed in order to catalyze the electrochemical oxidoreduction of flavoproteins. Surface modification was carried out by a two-step procedure. In the first step a mixed self-assembled monolayer obtained by adsorption of activated and nonactivated 3,3'-dithiopropionic acid (free acid and N-succinimidyl ester) was formed, followed by the covalent attachment of a N(10)-hexylamino-alkylated flavin derivative via an amide bond in the second step. The electrochemical properties of the flavin-modified electrode are presented and discussed. The redox potential of the attached flavin was measured at various pH values and the electron-transfer rate constant between electrode and flavin was determined as k0 = 5 s(-1) independent of pH. The flavin-modified electrode was successfully applied to the electrochemical and spectroelectrochemical investigation of the flavoprotein WrbA from Escherichia coli that shows some structural similarities to flavodoxins. It is concluded that the electron transfer "electrode --> flavin --> flavoprotein" occurs by a two-step hopping mechanism where the first step is rate determining. Kinetic details are discussed. Furthermore, it turned out that, in contrast to flavodoxins, where the semiquinone state is stabilized, WrbA rapidly takes up two electrons, directly leading to the fully reduced form. The presented electrode surface modification may generally lend itself for spectroelectrochemical investigations of flavoproteins. |
| Databáze: | OpenAIRE |
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