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Gewählte Publikation:

Brogioni, S; Stampler, J; Furtmüller, PG; Feis, A; Obinger, C; Smulevich, G.
(2008): The role of the sulfonium linkage in the stabilization of the ferrous form of myeloperoxidase: a comparison with lactoperoxidase.
Biochim Biophys Acta. 2008; 1784(5):843-849 FullText FullText_BOKU

Abstract:
In all mammalian peroxidases, the heme is covalently attached to the protein via two ester linkages between conserved aspartate (Asp94) and glutamate residues (Glu242) and modified methyl groups on pyrrole rings A and C. Only myeloperoxidase has an additional sulfonium ion linkage between the Sulfur atom of the conserved methionine 243 and the beta-carbon of the vinyl group on pyrrole ring A. Upon reduction from Fe(III) to Fe(II), lactoperoxidase (LPO) but not myeloperoxidase (MPO) is shown to adopt three distinct active site coformations which depend on pH and time. Comparative spectroscopic analysis (UV-Vis absorption and resonance Raman) of the ferrous forms of LPO, wild-type MPO and the variants Asp94Val, Glu242GIn, Met243Thr and Met243Val clearly demonstrate that a single, stable ferrous form of MPO is present only in those proteins which retain an intact sulfonium linkage. By contrast, both ferrous Met243Thr and Met243Val can assume two conformations. They resemble ferrous LPO, being five-coordinated high-spin species that are distinguished by the strength of the proximal Fe-histidine bond. This bond weakens with time or decreasing pH, as indicated by the Fe-histidine stretching bands. (c) 2008 Elsevier B.V. All rights reserved.
Autor*innen der BOKU Wien:
Furtmüller Paul Georg
Obinger Christian
Stampler Johanna Maria
BOKU Gendermonitor:

Find related publications in this database (using NML MeSH Indexing)
Animals -
Binding Sites -
CHO Cells -
Cattle -
Cricetinae -
Cricetulus -
Enzyme Stability -
Humans -
Iron - metabolism
Lactoperoxidase - metabolism
Mutant Proteins - metabolism
Peroxidase - chemistry
Protein Conformation -
Spectrum Analysis, Raman -
Sulfonium Compounds - metabolism

Find related publications in this database (Keywords)
myeloperoxidase
lactoperoxidase
ferrous form
heme to protein linkage
resonance Raman spectroscopy
Fe-Im stretching frequency
electronic absorption
site-directed mutagenesis


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