Kinetics of reaction of peroxynitrite with selenium- and sulfur-containing compounds: Absolute rate constants and assessment of biological significance.

Abstract

Peroxynitrite (the physiological mixture of ONOOH and its anion, ONOO(-)) is a powerful biologically-relevant oxidant capable of oxidizing and damaging a range of important targets including sulfides, thiols, lipids, proteins, carbohydrates and nucleic acids. Excessive production of peroxynitrite is associated with several human pathologies including cardiovascular disease, ischemic-reperfusion injury, circulatory shock, inflammation and neurodegeneration. This study demonstrates that low-molecular-mass selenols (RSeH), selenides (RSeR') and to a lesser extent diselenides (RSeSeR') react with peroxynitrite with high rate constants. Low molecular mass selenols react particularly rapidly with peroxynitrite, with second order rate constants k2 in the range 5.1 × 10(5)-1.9 × 10(6)M(-1)s(-1), and 250-830 fold faster than the corresponding thiols (RSH) and many other endogenous biological targets. Reactions of peroxynitrite with selenides, including selenosugars are approximately 15-fold faster than their sulfur homologs with k2 approximately 2.5 × 10(3)M(-1)s(-1). The rate constants for diselenides and sulfides were slower with k2 0.72-1.3 × 10(3)M(-1)s(-1) and approximately 2.1 × 10(2)M(-1)s(-1) respectively. These studies demonstrate that both endogenous and exogenous selenium-containing compounds may modulate peroxynitrite-mediated damage at sites of acute and chronic inflammation, with this being of particular relevance at extracellular sites where the thiol pool is limited.

• Authors: Corin Storkey, David I Pattison, Marta T Ignasiak, Carl H Schiesser, Michael J Davies
• Journal: Free radical biology & medicine (Free Radic Biol Med) Vol. 89 Pg. 1049-56 (Dec 2015) ISSN: 1873-4596 [Electronic] United States
• PMID: 26524402 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• Oxidants
• Selenium Compounds
• Sulfur Compounds
• Peroxynitrous Acid

Topics

• Humans
• Kinetics
• Oxidants (chemistry, metabolism)
• Peroxynitrous Acid (chemistry, metabolism)
• Selenium Compounds (chemistry, metabolism)
• Sulfur Compounds (chemistry, metabolism)