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Synthesis and reactivity studies of a manganese microperoxidase containing b-type heme

Ryabova, Ekaterina LU and Nordlander, Ebbe LU (2005) In Dalton Transactions p.1228-1233
Abstract
Mn(III) protoporphyrin IX-6(7)-gly-gly-his methyl ester (MnGGH) has been prepared by condensation of glycyl-glycyl-L-histidine methyl ester with the propionic side chains of Mn(III) protoporphyrin IX. It was characterised by mass spectrometry and UV/VIS spectroscopy. Stopped-flow spectrophotometry was used to study the reaction of the Mn microperoxidase with hydrogen peroxide. The formation of active intermediates analogous to previously described metal-hydroperoxo (compound 0) and metal oxo (compound I) intermediates of the natural Fe(III) microperoxidase-8 and Mn(III) microperoxidase-8 was observed. The rate of formation of the MnGGH-based compound I analogue was found to increase dramatically with increasing pH. A steady-state kinetic... (More)
Mn(III) protoporphyrin IX-6(7)-gly-gly-his methyl ester (MnGGH) has been prepared by condensation of glycyl-glycyl-L-histidine methyl ester with the propionic side chains of Mn(III) protoporphyrin IX. It was characterised by mass spectrometry and UV/VIS spectroscopy. Stopped-flow spectrophotometry was used to study the reaction of the Mn microperoxidase with hydrogen peroxide. The formation of active intermediates analogous to previously described metal-hydroperoxo (compound 0) and metal oxo (compound I) intermediates of the natural Fe(III) microperoxidase-8 and Mn(III) microperoxidase-8 was observed. The rate of formation of the MnGGH-based compound I analogue was found to increase dramatically with increasing pH. A steady-state kinetic analysis of the catalytic peroxidase activity of MnGGH towards K-4[Fe(CN)(6)], L-tyrosine methyl ester, o-dianisidine, o-methoxyphenol and ascorbic acid showed that the peroxidase reaction proceeds via the formation of a microperoxidase substrate complex followed by electron transfer from the substrate to the metal. The reactivity of MnGGH depends on the size and hydrophobicity of the substrate, and these properties appear to influence the rate of the electron transfer, which is the rate-limiting step for the whole process. MnGGH showed higher reactivity towards reducing substrates than its Fe(III) analogue. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Dalton Transactions
issue
7
pages
1228 - 1233
publisher
Royal Society of Chemistry
external identifiers
  • wos:000227792200012
  • scopus:17144426408
ISSN
1477-9234
DOI
10.1039/b417331g
language
English
LU publication?
yes
id
3ab223f5-7daf-4588-8be1-391a7765b44d (old id 248019)
date added to LUP
2007-10-05 13:34:40
date last changed
2017-01-01 05:00:33
@article{3ab223f5-7daf-4588-8be1-391a7765b44d,
  abstract     = {Mn(III) protoporphyrin IX-6(7)-gly-gly-his methyl ester (MnGGH) has been prepared by condensation of glycyl-glycyl-L-histidine methyl ester with the propionic side chains of Mn(III) protoporphyrin IX. It was characterised by mass spectrometry and UV/VIS spectroscopy. Stopped-flow spectrophotometry was used to study the reaction of the Mn microperoxidase with hydrogen peroxide. The formation of active intermediates analogous to previously described metal-hydroperoxo (compound 0) and metal oxo (compound I) intermediates of the natural Fe(III) microperoxidase-8 and Mn(III) microperoxidase-8 was observed. The rate of formation of the MnGGH-based compound I analogue was found to increase dramatically with increasing pH. A steady-state kinetic analysis of the catalytic peroxidase activity of MnGGH towards K-4[Fe(CN)(6)], L-tyrosine methyl ester, o-dianisidine, o-methoxyphenol and ascorbic acid showed that the peroxidase reaction proceeds via the formation of a microperoxidase substrate complex followed by electron transfer from the substrate to the metal. The reactivity of MnGGH depends on the size and hydrophobicity of the substrate, and these properties appear to influence the rate of the electron transfer, which is the rate-limiting step for the whole process. MnGGH showed higher reactivity towards reducing substrates than its Fe(III) analogue.},
  author       = {Ryabova, Ekaterina and Nordlander, Ebbe},
  issn         = {1477-9234},
  language     = {eng},
  number       = {7},
  pages        = {1228--1233},
  publisher    = {Royal Society of Chemistry},
  series       = {Dalton Transactions},
  title        = {Synthesis and reactivity studies of a manganese microperoxidase containing b-type heme},
  url          = {http://dx.doi.org/10.1039/b417331g},
  year         = {2005},
}