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Effect of cysteine mutations on direct electron transfer of horseradish peroxidase on gold

Ferapontova, Elena LU ; Schmengler, K; Borchers, T; Ruzgas, Tautgirdas LU and Gorton, Lo LU (2002) In Biosensors & Bioelectronics 17(11-12). p.953-963
Abstract
Surface exposed cysteines were genetically engineered in the structure of recombinant horseradish peroxidase (rHRP). Recombinant forms of HRP with either a His-tag or a Strep-tag at the C-terminus were produced, which additionally had cysteines at positions 57, 189 or 309 (C-terminus) of the polypeptide chain. An E coli expression system was exploited. The effect of these mutations on the direct electron transfer (ET) between An and the enzyme was studied in the reaction of the bioelectrocatalytic reduction of H2O2, at -50 mV versus AgAgCl, on rHRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Adsorptive immobilisation of rHRPs on pre-oxidised Au from the protein solution at pH 6.0 provided a high and... (More)
Surface exposed cysteines were genetically engineered in the structure of recombinant horseradish peroxidase (rHRP). Recombinant forms of HRP with either a His-tag or a Strep-tag at the C-terminus were produced, which additionally had cysteines at positions 57, 189 or 309 (C-terminus) of the polypeptide chain. An E coli expression system was exploited. The effect of these mutations on the direct electron transfer (ET) between An and the enzyme was studied in the reaction of the bioelectrocatalytic reduction of H2O2, at -50 mV versus AgAgCl, on rHRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Adsorptive immobilisation of rHRPs on pre-oxidised Au from the protein solution at pH 6.0 provided a high and stable current response to H2O2 due to its bioelectrocatalytic reduction based on direct (mediatoriess) ET between Au and the active site of the rHRPs. Comparative analysis of the direct ET rate constants, estimated from the amperometric data on direct and mediated ET in the presence of catechol at pH 7.4 and 6.0, gave evidence that the introduction of the His-tag or cysteine in the C-terminal area of the enzyme resulted in an increased efficiency of direct ET due to a favourable coupled electron and proton transfer pathway. Due to the high efficiency of direct ET, the sensitivity was independent on the addition of the mediator or change of pH indicating that the response to H2O2 is determined solely by the mass transfer of the analyte to the active site of HRP. The sensitivities obtained for the Au electrodes modified with rHRPs (2.0 +/- 0.1 A M-1 cm(-2)) and the low detection limit for H2O2 (10 nM) paves the way to develop the P-chip (peroxidase chip) - a biosensors system of a microscopic size for a mediatorless detection of H2O2 based on direct ET between Au and the recombinant forms of HRP. (C) 2002 Elsevier Science B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
electrodes, gold, bioelectrocatalysis, recombinant horseradish peroxidase, heterogeneous direct electron transfer, P-chip
in
Biosensors & Bioelectronics
volume
17
issue
11-12
pages
953 - 963
publisher
Elsevier
external identifiers
  • pmid:12392944
  • wos:000178791900007
  • scopus:0036883691
ISSN
1873-4235
DOI
10.1016/S0956-5663(02)00087-8
language
English
LU publication?
yes
id
dfebb7bd-3dbe-40a5-b15a-5580d80d0105 (old id 324835)
date added to LUP
2007-08-17 12:22:01
date last changed
2017-04-30 13:50:13
@article{dfebb7bd-3dbe-40a5-b15a-5580d80d0105,
  abstract     = {Surface exposed cysteines were genetically engineered in the structure of recombinant horseradish peroxidase (rHRP). Recombinant forms of HRP with either a His-tag or a Strep-tag at the C-terminus were produced, which additionally had cysteines at positions 57, 189 or 309 (C-terminus) of the polypeptide chain. An E coli expression system was exploited. The effect of these mutations on the direct electron transfer (ET) between An and the enzyme was studied in the reaction of the bioelectrocatalytic reduction of H2O2, at -50 mV versus AgAgCl, on rHRP-modified Au electrodes placed in a wall-jet flow-through electrochemical cell. Adsorptive immobilisation of rHRPs on pre-oxidised Au from the protein solution at pH 6.0 provided a high and stable current response to H2O2 due to its bioelectrocatalytic reduction based on direct (mediatoriess) ET between Au and the active site of the rHRPs. Comparative analysis of the direct ET rate constants, estimated from the amperometric data on direct and mediated ET in the presence of catechol at pH 7.4 and 6.0, gave evidence that the introduction of the His-tag or cysteine in the C-terminal area of the enzyme resulted in an increased efficiency of direct ET due to a favourable coupled electron and proton transfer pathway. Due to the high efficiency of direct ET, the sensitivity was independent on the addition of the mediator or change of pH indicating that the response to H2O2 is determined solely by the mass transfer of the analyte to the active site of HRP. The sensitivities obtained for the Au electrodes modified with rHRPs (2.0 +/- 0.1 A M-1 cm(-2)) and the low detection limit for H2O2 (10 nM) paves the way to develop the P-chip (peroxidase chip) - a biosensors system of a microscopic size for a mediatorless detection of H2O2 based on direct ET between Au and the recombinant forms of HRP. (C) 2002 Elsevier Science B.V. All rights reserved.},
  author       = {Ferapontova, Elena and Schmengler, K and Borchers, T and Ruzgas, Tautgirdas and Gorton, Lo},
  issn         = {1873-4235},
  keyword      = {electrodes,gold,bioelectrocatalysis,recombinant horseradish peroxidase,heterogeneous direct electron transfer,P-chip},
  language     = {eng},
  number       = {11-12},
  pages        = {953--963},
  publisher    = {Elsevier},
  series       = {Biosensors & Bioelectronics},
  title        = {Effect of cysteine mutations on direct electron transfer of horseradish peroxidase on gold},
  url          = {http://dx.doi.org/10.1016/S0956-5663(02)00087-8},
  volume       = {17},
  year         = {2002},
}