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Biochemical and Cellular Investigation of Vitreoscilla Hemoglobin (VHb) Variants Possessing Efficient Peroxidase Activity

Isarankura-Na-Ayudhya, Chartchalerm; Tansila, Natta; Worachartcheewan, Apilak; Bülow, Leif LU and Prachayasittikul, Virapong (2010) In Journal of Microbiology and Biotechnology 20(3). p.532-541
Abstract
Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in the distal pocket of peroxidases have successfully been introduced into that of the VHb. A 15-fold increase in catalytic constant (k(cat)) was obtained in P54R variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of the distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either H2O2 or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring the T29H mutation apparently demonstrated a spectral shift in both ferric and ferrous forms... (More)
Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in the distal pocket of peroxidases have successfully been introduced into that of the VHb. A 15-fold increase in catalytic constant (k(cat)) was obtained in P54R variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of the distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either H2O2 or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring the T29H mutation apparently demonstrated a spectral shift in both ferric and ferrous forms (406-408 to 411 nm, and 432 to 424-425 nm, respectively). All VHb proteins in the ferrous state had a lambda(soret) peak at 419 nm following the carbon monoxide (CO) binding. Expression of the P54R mutant mediated the downregulation of iron superoxide dismutase (FeSOD) as identified by two-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived H2O2, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of the Fe2+-ferric uptake regulator protein (Fe2+-Fur), an inducer of FeSOD expression. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
proteomic analysis, catalytic constant, enzyme kinetics, Vitreoscilla hemoglobin, peroxidase-like activity, iron superoxide dismutase
in
Journal of Microbiology and Biotechnology
volume
20
issue
3
pages
532 - 541
publisher
Korean Society for Microbiology and Biotechnology
external identifiers
  • wos:000276194000014
  • scopus:77954279964
ISSN
1017-7825
DOI
10.4014/jmb.0908.08038
language
English
LU publication?
yes
id
ff55bd37-a87f-4578-8672-6b0206b5483b (old id 1586996)
date added to LUP
2010-04-27 11:00:22
date last changed
2018-05-29 09:59:05
@article{ff55bd37-a87f-4578-8672-6b0206b5483b,
  abstract     = {Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in the distal pocket of peroxidases have successfully been introduced into that of the VHb. A 15-fold increase in catalytic constant (k(cat)) was obtained in P54R variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of the distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either H2O2 or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring the T29H mutation apparently demonstrated a spectral shift in both ferric and ferrous forms (406-408 to 411 nm, and 432 to 424-425 nm, respectively). All VHb proteins in the ferrous state had a lambda(soret) peak at 419 nm following the carbon monoxide (CO) binding. Expression of the P54R mutant mediated the downregulation of iron superoxide dismutase (FeSOD) as identified by two-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived H2O2, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of the Fe2+-ferric uptake regulator protein (Fe2+-Fur), an inducer of FeSOD expression.},
  author       = {Isarankura-Na-Ayudhya, Chartchalerm and Tansila, Natta and Worachartcheewan, Apilak and Bülow, Leif and Prachayasittikul, Virapong},
  issn         = {1017-7825},
  keyword      = {proteomic analysis,catalytic constant,enzyme kinetics,Vitreoscilla hemoglobin,peroxidase-like activity,iron superoxide dismutase},
  language     = {eng},
  number       = {3},
  pages        = {532--541},
  publisher    = {Korean Society for Microbiology and Biotechnology},
  series       = {Journal of Microbiology and Biotechnology},
  title        = {Biochemical and Cellular Investigation of Vitreoscilla Hemoglobin (VHb) Variants Possessing Efficient Peroxidase Activity},
  url          = {http://dx.doi.org/10.4014/jmb.0908.08038},
  volume       = {20},
  year         = {2010},
}