Direct electrochemistry and Os-polymer-mediated bioelectrocatalysis of NADH oxidation by Escherichia coil flavohemoglobin at graphite electrodes
(2013) In Biosensors & Bioelectronics 42. p.219-224- Abstract
- Escherichia coli flavohemoglobin (HMP), which contains one heme and one FAD as prosthetic groups and is capable of reducing O-2 by its heme at the expense of NADH oxidized at its FAD site, was electrochemically studied at graphite (Gr) electrodes. Two signals were observed in voltammograms of HMP adsorbed on Gr, at -477 and -171 mV vs. Ag vertical bar AgCl, at pH 7.4, correlating with electrochemical responses from the FAD and heme domains, respectively. The electron transfer rate constant for ET reaction between FAD of HMP and the electrode was estimated to be 83 s(-1). Direct bioelectrocatalytic oxidation of NADH by HMP was not observed, presumably due to impeded substrate access to HMP orientated on Gr through the FAD-domain and/or... (More)
- Escherichia coli flavohemoglobin (HMP), which contains one heme and one FAD as prosthetic groups and is capable of reducing O-2 by its heme at the expense of NADH oxidized at its FAD site, was electrochemically studied at graphite (Gr) electrodes. Two signals were observed in voltammograms of HMP adsorbed on Gr, at -477 and -171 mV vs. Ag vertical bar AgCl, at pH 7.4, correlating with electrochemical responses from the FAD and heme domains, respectively. The electron transfer rate constant for ET reaction between FAD of HMP and the electrode was estimated to be 83 s(-1). Direct bioelectrocatalytic oxidation of NADH by HMP was not observed, presumably due to impeded substrate access to HMP orientated on Gr through the FAD-domain and/or partial denaturation of HMP. Bioelectrocatalysis was achieved when HMP was wired to Gr by the Os redox polymers, with the onset of NADH oxidation at the formal potential of the particular Os complex (+140 mV or -195 mV). Apparent Michaelis constants K-M(app) and j(max) were determined, showing bioelectrocatalytic efficiency of NADH oxidation by HMP exceeding the one earlier shown with diaphorase, which makes HMP very attractive as a component of bioanalytical and bioenergetic devices. (C) 2012 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3930416
- author
- Sosna, Maciej ; Bonamore, Alessandra ; Gorton, Lo LU ; Boffi, Alberto and Ferapontova, Elena E.
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Escherichia coli flavohemoglobin, NADH, Os-complex redox polymers, Bioelectrocatalysis
- in
- Biosensors & Bioelectronics
- volume
- 42
- pages
- 219 - 224
- publisher
- Elsevier
- external identifiers
-
- wos:000319951700036
- scopus:84871666727
- pmid:23208089
- ISSN
- 1873-4235
- DOI
- 10.1016/j.bios.2012.10.094
- language
- English
- LU publication?
- yes
- id
- e42ce0fd-41e9-474f-9042-df8f88f33c74 (old id 3930416)
- date added to LUP
- 2016-04-01 13:23:36
- date last changed
- 2023-09-02 23:17:17
@article{e42ce0fd-41e9-474f-9042-df8f88f33c74,
abstract = {{Escherichia coli flavohemoglobin (HMP), which contains one heme and one FAD as prosthetic groups and is capable of reducing O-2 by its heme at the expense of NADH oxidized at its FAD site, was electrochemically studied at graphite (Gr) electrodes. Two signals were observed in voltammograms of HMP adsorbed on Gr, at -477 and -171 mV vs. Ag vertical bar AgCl, at pH 7.4, correlating with electrochemical responses from the FAD and heme domains, respectively. The electron transfer rate constant for ET reaction between FAD of HMP and the electrode was estimated to be 83 s(-1). Direct bioelectrocatalytic oxidation of NADH by HMP was not observed, presumably due to impeded substrate access to HMP orientated on Gr through the FAD-domain and/or partial denaturation of HMP. Bioelectrocatalysis was achieved when HMP was wired to Gr by the Os redox polymers, with the onset of NADH oxidation at the formal potential of the particular Os complex (+140 mV or -195 mV). Apparent Michaelis constants K-M(app) and j(max) were determined, showing bioelectrocatalytic efficiency of NADH oxidation by HMP exceeding the one earlier shown with diaphorase, which makes HMP very attractive as a component of bioanalytical and bioenergetic devices. (C) 2012 Elsevier B.V. All rights reserved.}},
author = {{Sosna, Maciej and Bonamore, Alessandra and Gorton, Lo and Boffi, Alberto and Ferapontova, Elena E.}},
issn = {{1873-4235}},
keywords = {{Escherichia coli flavohemoglobin; NADH; Os-complex redox polymers; Bioelectrocatalysis}},
language = {{eng}},
pages = {{219--224}},
publisher = {{Elsevier}},
series = {{Biosensors & Bioelectronics}},
title = {{Direct electrochemistry and Os-polymer-mediated bioelectrocatalysis of NADH oxidation by Escherichia coil flavohemoglobin at graphite electrodes}},
url = {{http://dx.doi.org/10.1016/j.bios.2012.10.094}},
doi = {{10.1016/j.bios.2012.10.094}},
volume = {{42}},
year = {{2013}},
}