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Effect of pH on direct electron transfer in the system gold electrode-recombinant horseradish peroxidase

Ferapontova, Elena LU and Gorton, Lo LU (2002) In Bioelectrochemistry 55. p.83-87
Abstract
The effect of pH on the kinetics of the bioelectrocatalytic reduction of H2O2 catalysed by horseradish peroxidase (HRP) has been studied at –50 mV vs. AgjAgCl on HRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Native HRP (nHRP) and a

nonglycosylated recombinant form containing a six-histidine tag at the C-terminus, CHisrHRP, produced by genetic engineering of nonglycosylated recombinant HRP using an E. coli expression system, have been used for adsorptive modification of Au electrodes. A favourable adsorption of CHisrHRP on preoxidised Au from a protein solution at pH 6.0 provided a high and stable current response to H2O2

due to its bioelectrocatalytic reduction based on direct... (More)
The effect of pH on the kinetics of the bioelectrocatalytic reduction of H2O2 catalysed by horseradish peroxidase (HRP) has been studied at –50 mV vs. AgjAgCl on HRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Native HRP (nHRP) and a

nonglycosylated recombinant form containing a six-histidine tag at the C-terminus, CHisrHRP, produced by genetic engineering of nonglycosylated recombinant HRP using an E. coli expression system, have been used for adsorptive modification of Au electrodes. A favourable adsorption of CHisrHRP on preoxidised Au from a protein solution at pH 6.0 provided a high and stable current response to H2O2

due to its bioelectrocatalytic reduction based on direct (mediatorless) electron transfer (ET) between Au and the active site of HRP. The heterogeneous ET rate constant, ks, calculated from experimental data on direct ET, on mediated ET in the presence of catechol as well as from microbalance data, increased more than 30 times when changing from nHRP to CHisrHRP. For both forms of HRP, the increasing

efficiency of bioelectrocatalysis with increasing [H3O+ ] was observed. The values of the apparent ks between CHisrHRP and Au changed from a value of 12F2 s 1 in PBS at pH 8.0 to a value of 434F62 s 1 at pH 6.0; a similar ks–pH dependence was also observed for nHRP, providing the possibility to consider the reaction mechanism involving the participation of a proton in the rate-determining step of the charge transfer. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Recombinant horseradish peroxidase, Heterogeneous direct electron transfer, Bioelectrocatalysis, Au electrode, Proton transfer
in
Bioelectrochemistry
volume
55
pages
83 - 87
publisher
Elsevier
external identifiers
  • wos:000176715500022
  • pmid:11786347
  • scopus:0036148399
ISSN
1878-562X
DOI
10.1016/S1567-5394(01)00158-X
language
English
LU publication?
yes
id
bde1a8d9-300e-4f44-928d-418114d53658 (old id 119259)
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http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6W72-44CXRXC-N-K&_cdi=6614&_orig=search&_coverDate=01%2F31%2F2002&_qd=1&_sk=999449998&view=c&wchp=dGLbVtb-zSkWW&_acct=C000041498&_version=1&_userid=745831&md5=bd4af9b00164aef20aaf2bd740a6ddc7&ie=f.p
date added to LUP
2007-06-26 14:47:46
date last changed
2017-09-10 04:46:00
@article{bde1a8d9-300e-4f44-928d-418114d53658,
  abstract     = {The effect of pH on the kinetics of the bioelectrocatalytic reduction of H2O2 catalysed by horseradish peroxidase (HRP) has been studied at –50 mV vs. AgjAgCl on HRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Native HRP (nHRP) and a<br/><br>
nonglycosylated recombinant form containing a six-histidine tag at the C-terminus, CHisrHRP, produced by genetic engineering of nonglycosylated recombinant HRP using an E. coli expression system, have been used for adsorptive modification of Au electrodes. A favourable adsorption of CHisrHRP on preoxidised Au from a protein solution at pH 6.0 provided a high and stable current response to H2O2<br/><br>
due to its bioelectrocatalytic reduction based on direct (mediatorless) electron transfer (ET) between Au and the active site of HRP. The heterogeneous ET rate constant, ks, calculated from experimental data on direct ET, on mediated ET in the presence of catechol as well as from microbalance data, increased more than 30 times when changing from nHRP to CHisrHRP. For both forms of HRP, the increasing<br/><br>
efficiency of bioelectrocatalysis with increasing [H3O+ ] was observed. The values of the apparent ks between CHisrHRP and Au changed from a value of 12F2 s 1 in PBS at pH 8.0 to a value of 434F62 s 1 at pH 6.0; a similar ks–pH dependence was also observed for nHRP, providing the possibility to consider the reaction mechanism involving the participation of a proton in the rate-determining step of the charge transfer.},
  author       = {Ferapontova, Elena and Gorton, Lo},
  issn         = {1878-562X},
  keyword      = {Recombinant horseradish peroxidase,Heterogeneous direct electron transfer,Bioelectrocatalysis,Au electrode,Proton transfer},
  language     = {eng},
  pages        = {83--87},
  publisher    = {Elsevier},
  series       = {Bioelectrochemistry},
  title        = {Effect of pH on direct electron transfer in the system gold electrode-recombinant horseradish peroxidase},
  url          = {http://dx.doi.org/10.1016/S1567-5394(01)00158-X},
  volume       = {55},
  year         = {2002},
}