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Influence of tryptophan mutation on the direct electron transfer of immobilized tobacco peroxidase

Olloqui-Sariego, José Luis ; Zakharova, Galina S. ; Poloznikov, Andrey A. ; Calvente, Juan José ; Hushpulian, Dmitry M. ; Gorton, Lo LU and Andreu, Rafael (2020) In Electrochimica Acta 351.
Abstract

A major challenge in the design of electrochemical biodevices is to achieve fast rates of electron exchange between proteins and electrodes. In this work, we show that a significant increase in the direct electron transfer rate between a graphite electrode and Tobacco Peroxidase takes place when a surface exposed leucine, located in the vicinity of the heme pocket, is replaced by tryptophan. The analysis of the Fe(III)/Fe(II) voltammetric responses of native and mutated proteins, as a function of solution pH and temperature, leads to similar values of the reduction entropy and reorganization energy, but to a higher electronic coupling in the case of the mutant. In addition, the mutated and native proteins are shown to display similar... (More)

A major challenge in the design of electrochemical biodevices is to achieve fast rates of electron exchange between proteins and electrodes. In this work, we show that a significant increase in the direct electron transfer rate between a graphite electrode and Tobacco Peroxidase takes place when a surface exposed leucine, located in the vicinity of the heme pocket, is replaced by tryptophan. The analysis of the Fe(III)/Fe(II) voltammetric responses of native and mutated proteins, as a function of solution pH and temperature, leads to similar values of the reduction entropy and reorganization energy, but to a higher electronic coupling in the case of the mutant. In addition, the mutated and native proteins are shown to display similar electrocatalytic activities to reduce hydrogen peroxide at positive potentials, indicating that the molecular structure of the heme pocket is largely unaffected by the mutation.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Direct electron transfer, Mutations, Tobacco peroxidase, Tryptophan
in
Electrochimica Acta
volume
351
article number
136465
publisher
Pergamon Press Ltd.
external identifiers
  • scopus:85085236336
ISSN
0013-4686
DOI
10.1016/j.electacta.2020.136465
language
English
LU publication?
yes
id
0c13e0a1-6e7c-4256-a9a7-d216f38c0573
date added to LUP
2020-06-08 15:30:24
date last changed
2022-04-18 22:43:42
@article{0c13e0a1-6e7c-4256-a9a7-d216f38c0573,
  abstract     = {{<p>A major challenge in the design of electrochemical biodevices is to achieve fast rates of electron exchange between proteins and electrodes. In this work, we show that a significant increase in the direct electron transfer rate between a graphite electrode and Tobacco Peroxidase takes place when a surface exposed leucine, located in the vicinity of the heme pocket, is replaced by tryptophan. The analysis of the Fe(III)/Fe(II) voltammetric responses of native and mutated proteins, as a function of solution pH and temperature, leads to similar values of the reduction entropy and reorganization energy, but to a higher electronic coupling in the case of the mutant. In addition, the mutated and native proteins are shown to display similar electrocatalytic activities to reduce hydrogen peroxide at positive potentials, indicating that the molecular structure of the heme pocket is largely unaffected by the mutation.</p>}},
  author       = {{Olloqui-Sariego, José Luis and Zakharova, Galina S. and Poloznikov, Andrey A. and Calvente, Juan José and Hushpulian, Dmitry M. and Gorton, Lo and Andreu, Rafael}},
  issn         = {{0013-4686}},
  keywords     = {{Direct electron transfer; Mutations; Tobacco peroxidase; Tryptophan}},
  language     = {{eng}},
  publisher    = {{Pergamon Press Ltd.}},
  series       = {{Electrochimica Acta}},
  title        = {{Influence of tryptophan mutation on the direct electron transfer of immobilized tobacco peroxidase}},
  url          = {{http://dx.doi.org/10.1016/j.electacta.2020.136465}},
  doi          = {{10.1016/j.electacta.2020.136465}},
  volume       = {{351}},
  year         = {{2020}},
}