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Role of K+ Binding Residues in Stabilization of Heme Spin state of Leishmania Major Peroxidase

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Title Role of K+ Binding Residues in Stabilization of Heme Spin state of
Leishmania Major Peroxidase
 
Creator Pal, Swati
Yadav, Rajesh K
Adak, Subrata
 
Subject Structural Biology & Bioinformatics
 
Description The endogenous cation in peroxidases may contribute to the type of heme coordination. Here a series of ferric
and ferrous derivatives of wild-type Leishmania major peroxidase (LmP) and of engineered K+ site mutants of
LmP, lacking potassium cation binding site, has been examined by electronic absorption spectroscopy at
25 °C. Using UV–visible spectrophotometry, we show that the removal of K+ binding site causes substantial
changes in spin states of both the ferric and ferrous forms. The spectral changes are interpreted to be, most
likely, due to the formation of a bis-histidine coordination structure in both the ferric and ferrous oxidation
states at neutral pH 7.0. Stopped flow spectrophotometric techniques revealed that characteristics of Compound
I were not observed in the K+ site double mutants in the presence of H2O2. Similarly electron donor
oxidation rate was two orders less for the K+ site double mutants compared to the wild type. These data
show that K+ functions in preserving the protein structure in the heme surroundings as well as the spin
state of the heme iron, in favor of the enzymatically active form of LmP
 
Publisher Elsevier
 
Date 2012
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://www.eprints.iicb.res.in/1663/1/BBA_2012.pdf
Pal, Swati and Yadav, Rajesh K and Adak, Subrata (2012) Role of K+ Binding Residues in Stabilization of Heme Spin state of Leishmania Major Peroxidase. BBA - Biochimica et Biophysica Acta, 1824. pp. 1002-1007.
 
Relation http://dx.doi.org/10.1016/j.bbapap.2012.05.007
http://www.eprints.iicb.res.in/1663/