Direct Binding of a Redox Protein for Single‐Molecule Electron Transfer Measurements

Pia, Eduardo Antonio Della; MacDonald, John Emyr; Elliott, Martin; Jones, D. Dafydd

doi:10.1002/smll.201102416

Cited by 24 publications

(41 citation statements)

References 70 publications

(52 reference statements)

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“…PEGylation) [33], fluorescence (for tracking) [34] and cell-targeted delivery (via DNA aptamers) [35]. The resulting conjugates have widespread uses from drug delivery and medical diagnostics [40] to facilitating single molecule studies and the creation of bio-electronics [37,38,41]. Proteins have been attached to a range of materials from carbon nanotubes [37] to gold [38] to liposomes [39].…”

Section: Azide Reactivity and Post-translational Protein Modificationmentioning

confidence: 99%

Genetically encoding phenyl azide chemistry: new uses and ideas for classical biochemistry

Reddington

Watson

Rizkallah

et al. 2013

Biochemical Society Transactions

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Introducing new physicochemical properties into proteins through genetically encoded Uaa (unnatural amino acid) incorporation can lead to the generation of proteins with novel properties not normally accessible with the 20 natural amino acids. Phenyl azide chemistry represents one such useful addition to the protein repertoire. Classically used in biochemistry as a non-specific photochemical protein cross-linker, genetically encoding phenyl azide chemistry at selected residues provides more powerful routes to post-translationally modify protein function in situ. The two main routes are modulation by light (optogenetics) and site-specific bio-orthogonal modification (bioconjugation) via Click chemistry. In the present article, we discuss both approaches and their influence on protein function.

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Section: Azide Reactivity and Post-translational Protein Modificationmentioning

confidence: 99%

Genetically encoding phenyl azide chemistry: new uses and ideas for classical biochemistry

Reddington

Watson

Rizkallah

et al. 2013

Biochemical Society Transactions

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“…The STM studies by Ulstrup (130, 131), Facci (132) and coworkers on electron transfer by metalloproteins, and by Cannistraro (133) and coworkers on electron conduction and recognition by metalloproteins have been reviewed by these researchers. Wingginton (134), Jones (135), and coworkers have used STM to measure tunneling currents through single cytochrome molecules. AFM was used to manipulate metalloproteins mechanically (i.e., by force).…”

Section: Related Single-molecule Bioinorganic Workmentioning

confidence: 99%

Single-Molecule Dynamics and Mechanisms of Metalloregulators and Metallochaperones

et al. 2013

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Understanding how cells regulate and transport metal ions is an important goal in the field of bioinorganic chemistry, a frontier research area that resides at the interfaces of chemistry and biology. This Current Topics article reviews recent advances from the authors' group in using single-molecule fluorescence imaging techniques to identify the mechanisms of metal homeostatic proteins, including metalloregulators and metallochaperones. It emphasizes the novel mechanistic insights into how dynamic protein–DNA and protein–protein interactions offer efficient pathways for MerR-family metalloregulators and copper chaperones to fulfill their functions. The article also summarizes other related single-molecule studies of bioinorganic systems, and gives an outlook toward single-molecule imaging of metalloprotein functions in living cells.

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“…[16][17][18][19][20][21][22][23][24][25][26] Conductance measurements on proteins by scanning probe techniques have nearly all involved a tunnelling barrier between tip and molecule, [20][21][22][23][24][25][26] or the application of mechanical force to improve the electrical contact between tip and molecule. 23 But recently, we have been able to measure STM conductance of protein molecules in air, 27,28 contacted to two metallic electrodes via chemical anchoring groups. In the present study we show the first single-molecule electrochemical-STM conductance measurements of a heme protein, cytochrome b 562 (cyt b 562 ), of controlled orientation, and contacted directly via two thiol anchoring groups.…”

Section: 4mentioning

confidence: 99%

Fast electron transfer through a single molecule natively structured redox protein

et al. 2012

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The electron transfer properties of proteins are normally measured as molecularly averaged ensembles. Through these and related measurements, proteins are widely regarded as macroscopically insulating materials. Using scanning tunnelling microscopy (STM), we present new measurements of the conductance through single-molecules of the electron transfer protein cytochrome b 562 in its native conformation, under pseudo-physiological conditions. This is achieved by thiol (SH) linker pairs at opposite ends of the molecule through protein engineering, resulting in defined covalent contact between a gold surface and a platinum-iridium STM tip. Two different orientations of the linkers were examined: a long-axis configuration (SH-LA) and a short-axis configuration (SH-SA). In each case, the molecular conductance could be 'gated' through electrochemical control of the heme redox state. Reproducible and remarkably high conductance was observed in this relatively complex electron transfer system, with single-molecule conductance values peaking around 18 nS and 12 nS for the SH-SA and SH-LA cytochrome b 562 molecules near zero electrochemical overpotential. This strongly points to the important role of the heme co-factor bound to the natively structured protein. We suggest that the two-step model of protein electron transfer in the STM geometry requires a multi-electron transfer to explain such a high conductance. The model also yields a low value for the reorganisation energy, implying that solvent reorganisation is largely absent.

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Direct Binding of a Redox Protein for Single‐Molecule Electron Transfer Measurements

Cited by 24 publications

References 70 publications

Genetically encoding phenyl azide chemistry: new uses and ideas for classical biochemistry

Genetically encoding phenyl azide chemistry: new uses and ideas for classical biochemistry

Single-Molecule Dynamics and Mechanisms of Metalloregulators and Metallochaperones

Fast electron transfer through a single molecule natively structured redox protein

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