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Oxidation of histidine residues in copper-zinc superoxide dismutase by bicarbonate-stimulated peroxidase and thiol oxidase activities: pulse EPR and NMR studies. Biochemistry 2010 Dec 21;49(50):10616-22

Date

11/03/2010

Pubmed ID

21038859

Pubmed Central ID

PMC3501376

DOI

10.1021/bi1010305

Scopus ID

2-s2.0-78650389551   12 Citations

Abstract

In this work, we investigated the oxidative modification of histidine residues induced by peroxidase and thiol oxidase activities of bovine copper-zinc superoxide dismutase (Cu-ZnSOD) using NMR and pulse EPR spectroscopy. 1D NMR and 2D-NOESY were used to determine the oxidative damage at the Zn(II) and Cu(II) active sites as well as at distant histidines. Results indicate that during treatment of SOD with hydrogen peroxide (H(2)O(2)) or cysteine in the absence of bicarbonate anion (HCO(3)(-)), both exchangeable and nonexchangeable protons were affected. Both His-44 and His-46 in the Cu(II) active site were oxidized based on the disappearance of NOESY cross-peaks between CH and NH resonances of the imidazole rings. In the Zn(II) site, only His-69, which is closer to His-44, was oxidatively modified. However, addition of HCO(3)(-) protected the active site His residues. Instead, resonances assigned to the His-41 residue, 11 Å away from the Cu(II) site, were completely abolished during both HCO(3)(-)-stimulated peroxidase activity and thiol oxidase activity in the presence of HCO(3)(-) . Additionally, ESEEM/HYSCORE and ENDOR studies of SOD treated with peroxide/Cys in the absence of HCO(3)(-) revealed that hyperfine couplings to the distal and directly coordinated nitrogens of the His-44 and His-46 ligands at the Cu(II) active site were modified. In the presence of HCO(3)(-), these modifications were absent. HCO(3)(-)-mediated, selective oxidative modification of histidines in SOD may be relevant to understanding the molecular mechanism of SOD peroxidase and thiol oxidase activities.

Author List

Chandran K, McCracken J, Peterson FC, Antholine WE, Volkman BF, Kalyanaraman B

Authors

Balaraman Kalyanaraman PhD Chair, Professor in the Biophysics department at Medical College of Wisconsin
Francis C. Peterson PhD Professor in the Biochemistry department at Medical College of Wisconsin
Brian F. Volkman PhD Professor in the Biochemistry department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Bicarbonates
Cattle
Electron Spin Resonance Spectroscopy
Enzyme Activation
Histidine
Magnetic Resonance Spectroscopy
Oxidation-Reduction
Oxidoreductases Acting on Sulfur Group Donors
Peroxidases
Superoxide Dismutase
jenkins-FCD Prod-444 eb4ebd1a08581aba961d3befd3b851a3c3ec6b46