Electrochemical switching of the flavoprotein dodecin at gold surfaces modified by flavin-DNA hybrid linkers

Martin Grininger, Gilbert Nöll, Sibylle Trawoeger, Eva-Kathrin Sinner, Dieter Oesterhelt

Research output: Contribution to journalArticlepeer-review

Abstract

Dodecin from Halobacterium salinarum is a dodecameric, hollow-spherical protein, which unspecifically adopts flavin molecules. Reduction of flavin dodecin holocomplexes induces dissociation into apododecin and free flavin. Unspecific binding and dissociation upon reduction were used as key properties to construct an electrochemically switchable surface, which was able to bind and release dodecin apoprotein depending on the applied potential. A flavin modified electrode surface (electrode-DNA-flavin) was generated by direct adsorption of double stranded DNA (ds-DNA) equipped with flavin and disulfide modifications at opposite ends. While the disulfide functionality enabled anchoring the ds-DNA at the gold surface, the flavin exposed at the surface served as the redox-active dodecin docking site. The structures of protein and flavin-DNA hybrid ligands were optimized and characterized by x-ray structural analysis of the holocomplexes. By surface plasmon resonance (SPR) spectroscopy, the adsorption of flavin modified DNA as well as the binding and the electrochemically induced release of dodecin apoprotein could be shown. When the surface immobilization protocol was changed from direct immobilization of the modified ds-DNA to a protocol, which included the hybridization of flavin and thiol modified DNA at the surface, the resulting monolayer was electrochemically inactive. A possible explanation for the strong influence of the surface immobilization protocol on addressing dodecin by the applied potential is that electron transfer is rather mediated by defects in the monolayer than modified ds-DNA. (C) 2008 American Vacuum Society. [DOI: 10.1116/1.2965134]
Original languageEnglish
Pages (from-to)51-58
JournalBiointerphases
Volume3
Issue number3
DOIs
Publication statusPublished - 2008

Bibliographical note

The information about affiliations in this record was updated in December 2015.
The record was previously connected to the following departments: Analytical Chemistry (S/LTH) (011001004)

Subject classification (UKÄ)

  • Analytical Chemistry

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