Genetic modulation of metalloprotein electron transfer at bare gold

Davis, Jason J.; Bruce, Delphine; Canters, Gerard W.; Crozier, John; Hill, H. Allen O.

doi:10.1039/b211246a

Cited by 41 publications

(46 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The properties of metalloprotein assemblies can be studied by a variety of methods, including those based on electrochemistry (Gaigalas and Niaura, 1997;Chi et al, 2001;Davis et al, 2003;Armstrong et al, 1997), photochemistry (Pascher et al, 1996;Gray, 2003) and scanning probe microscopy, SPM (Colton et al, 1997;Davis et al, 2000;Davis and Hill, 2002;Zhang et al, 2002). Scanning probe analyses (including scanning tunnelling microscopy, STM, and atomic force microscopy, AFM) are interesting because they allow us to study molecules individually, without the averaging inherent in most other forms of analysis ( Fig.…”

Section: Introductionmentioning

confidence: 99%

The tunnelling conductance of molecularly ordered metalloprotein arrays

Davis

Wrathmell

Zhao

et al. 2004

J of Molecular Recognition

View full text Add to dashboard Cite

Metalloproteins can be self-assembled in molecularly ordered, electrochemically addressable arrays. We report here on a study of the transport characteristics of the blue copper protein, azurin, from Pseudomonas aeruginosa, by a combination of electrochemical and scanning probe techniques (scanning tunnelling microscopy and conducting atomic force microscopy). Redox-switchable chemisorbed molecular arrays can be formed from both wild-type and mutant proteins using the strong affinity of cysteine residue thiolates for pristine gold surfaces. The molecular transconductance of single protein molecules within these arrays has been studied under controllable conditions where it has been additionally possible to resolve the effects of protein mechanical perturbation. Although tunnelling appears to be non-resonant and adequately explained through the use of a square barrier model, under some conditions the contribution of the redox-active copper centre to conductance is resolvable.

show abstract

Section: Introductionmentioning

confidence: 99%

The tunnelling conductance of molecularly ordered metalloprotein arrays

Davis

Wrathmell

Zhao

et al. 2004

J of Molecular Recognition

View full text Add to dashboard Cite

show abstract

“…Specifically, site-directed mutagenesis studies have implicated the involvement of four lysines on pseudoazurin (in a ring around the type-I Cu centre) and glutamate/aspartate residues on NiR (around the type-I centre) in docking. [23,24] Though recent work has demonstrated that azurin and its mutants can be self-assembled on gold electrodes in orientation-specific electrochemically addressable arrays [8,9,25] we have sought here to maintain maximum orientational flexibility (in the first instance) by carrying out voltammetric studies in the fluid (diffusive) phase. As mentioned, many important developments have been made in generating "biocompatible" electrode interfaces at which metalloprotein voltammetry can be robustly observed.…”

Section: Introductionmentioning

confidence: 99%

“…Though the protein surface itself can be chemically or genetically modified in order to facilitate electron exchange at "bare electrodes" [8,9] in general, it is the electrode surface which is modified. Specifically, an attempt must be made to chemically generate a "biocompatible interface" with which the protein is able to reversibly and nondestructively interact.…”

Section: Introductionmentioning

confidence: 99%

Sensing Nitrite through a Pseudoazurin–Nitrite Reductase Electron Transfer Relay

et al. 2005

Self Cite

View full text Add to dashboard Cite

Nitrite is converted to nitric oxide by haem or copper-containing enzymes in denitrifying bacteria during the process of denitrification. In designing an efficient biosensor, this enzymic turnover must be quantitatively assessed. The enzyme nitrite reductase from Alcaligenes faecalis contains a redox-active blue copper centre and a nonblue enzyme-active copper centre. It can be covalently tethered to modified gold-electrode surfaces in configurations in which direct electron transfer is possible. A surface cysteine mutant of the enzyme can be similarly immobilised on bare electroactive gold substrates. Under such circumstances, however, electron transfer cannot be effectively coupled with substrate catalytic turnover. In using either the natural redox partner, pseudoazurin, or ruthenium hexammine as an "electron-shuttle" or "conduit" between enzyme and a peptide-modified electrode surface, the coupling of electron transfer to catalysis can be utilised in the development of an amperometric nitrite sensor.

show abstract

“…Site-directed mutagenesis has been used to introduce cysteine residues on the surface of blue copper proteins (azurin and plastocyanin), thus facilitating protein chemisorption on unmodified gold. [212][213][214][215] When this strategy was used to promote direct ET to a surface cysteine mutant of Alcaligenes faecalis copper-containing nitrite reductase, only poor catalytic activity could be detected (although some noncatalytic signals were observed); 216 pyrolytic graphite edge eventually proved to be a better choice for studying this enzyme. 167,185 In contrast, cytochrome c nitrite reductase (ccNiR) retains activity when it is immobilized onto an unmodified Au(111) surface.…”

mentioning

confidence: 99%