Kinetic study of the reaction of ebselen with peroxynitrite.
The second-order rate constant for the reaction of ebselen with peroxynitrite (ONOO-) is (2.0+/-0.1) X 10(6) M(-1) s(-1) at pH > or = 8 and 25 degrees C, 3-4 orders of magnitude higher than the rate constants observed for cysteine, ascorbate, or methionine. The activation energy is relatively low, 12.8 kJ/mol. This is the fastest reaction of peroxynitrite observed so far. It may allow Se-containing compounds to play a novel role in the defense against peroxynitrite, one of the important reactive species generated during inflammatory processes.
Masumoto
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Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf, Germany.
Kissner
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Koppenol
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WH
Sies
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H
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism*; D001393:Azoles / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D054833:Isoindoles; D007700:Kinetics; D009566:Nitrates / Q000378:metabolism*; D016566:Organoselenium Compounds / Q000378:metabolism*; D010084:Oxidation-Reduction; D013696:Temperature
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001393:Azoles; D054833:Isoindoles; D009566:Nitrates; D016566:Organoselenium Compounds; C039642:peroxynitric acid; C042986:ebselen