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An investigation of the peroxidase activity of Vitreoscilla hemoglobin

Kvist, Malin LU ; Ryabova, Ekaterina LU ; Nordlander, Ebbe LU and Bülow, Leif LU (2007) In Journal of Biological Inorganic Chemistry 12(3). p.324-334
Abstract
In order to investigate the ability of the Vitreoscilla hemoglobin (VHb) to act as a peroxidase, the protein was overexpressed in Escerichia coli and purified using a 6xHis-tag. The peroxidase activity of VHb was studied using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferrocene carboxylic acid (FcCOOH) dopamine and L-dopa as substrates. The effects of external agents such as pH, salt concentration/ionic strength, and the thermal stability of VHb on the catalytic activity were assessed. The optimum pH for VHb using ABTS as a substrate was estimated to be 6-7. The VHb protein proved to be stable up to 80 degrees C, as judged by its peroxidase activity. Furthermore, NaCl concentrations up to 100 mM did not exert any... (More)
In order to investigate the ability of the Vitreoscilla hemoglobin (VHb) to act as a peroxidase, the protein was overexpressed in Escerichia coli and purified using a 6xHis-tag. The peroxidase activity of VHb was studied using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferrocene carboxylic acid (FcCOOH) dopamine and L-dopa as substrates. The effects of external agents such as pH, salt concentration/ionic strength, and the thermal stability of VHb on the catalytic activity were assessed. The optimum pH for VHb using ABTS as a substrate was estimated to be 6-7. The VHb protein proved to be stable up to 80 degrees C, as judged by its peroxidase activity. Furthermore, NaCl concentrations up to 100 mM did not exert any significant effect on the activity. The catalytic activity against ABTS and FcCOOH was similar to that measured for horseradish peroxidase, whereas in the case of the phenolic substrates dopamine and L-dopa the activity was several orders of magnitude lower. The Michaelis constants, K-m(H2O2), were in good agreement with the data for human and bovine hemoglobin. No activity could be detected for the negative controls lacking VHb. These results demonstrate that VHb exhibits peroxidase activity, a finding in line with the hypothesis that VHb has cellular functions beyond the role as an oxygen carrier. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
peptide, peroxidase, protopoporphyrin IX, catalysis
in
Journal of Biological Inorganic Chemistry
volume
12
issue
3
pages
324 - 334
publisher
Springer
external identifiers
  • wos:000245457700005
  • scopus:34147115160
ISSN
1432-1327
DOI
10.1007/s00775-006-0190-x
language
English
LU publication?
yes
id
f50da43e-4895-401b-a036-7e7a01327765 (old id 667512)
date added to LUP
2007-12-13 18:04:05
date last changed
2017-07-30 03:53:32
@article{f50da43e-4895-401b-a036-7e7a01327765,
  abstract     = {In order to investigate the ability of the Vitreoscilla hemoglobin (VHb) to act as a peroxidase, the protein was overexpressed in Escerichia coli and purified using a 6xHis-tag. The peroxidase activity of VHb was studied using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferrocene carboxylic acid (FcCOOH) dopamine and L-dopa as substrates. The effects of external agents such as pH, salt concentration/ionic strength, and the thermal stability of VHb on the catalytic activity were assessed. The optimum pH for VHb using ABTS as a substrate was estimated to be 6-7. The VHb protein proved to be stable up to 80 degrees C, as judged by its peroxidase activity. Furthermore, NaCl concentrations up to 100 mM did not exert any significant effect on the activity. The catalytic activity against ABTS and FcCOOH was similar to that measured for horseradish peroxidase, whereas in the case of the phenolic substrates dopamine and L-dopa the activity was several orders of magnitude lower. The Michaelis constants, K-m(H2O2), were in good agreement with the data for human and bovine hemoglobin. No activity could be detected for the negative controls lacking VHb. These results demonstrate that VHb exhibits peroxidase activity, a finding in line with the hypothesis that VHb has cellular functions beyond the role as an oxygen carrier.},
  author       = {Kvist, Malin and Ryabova, Ekaterina and Nordlander, Ebbe and Bülow, Leif},
  issn         = {1432-1327},
  keyword      = {peptide,peroxidase,protopoporphyrin IX,catalysis},
  language     = {eng},
  number       = {3},
  pages        = {324--334},
  publisher    = {Springer},
  series       = {Journal of Biological Inorganic Chemistry},
  title        = {An investigation of the peroxidase activity of Vitreoscilla hemoglobin},
  url          = {http://dx.doi.org/10.1007/s00775-006-0190-x},
  volume       = {12},
  year         = {2007},
}