Product distribution of peroxynitrite decay as a function of pH, temperature, and concentration.
The decay of peroxynitrite [O=NOO(-), oxoperoxonitrate(1-)] was examined as a function of concentration (0.050-2.5 mM), temperature (5-45 degrees C), and pH (2.2-10.0). Below 5 degrees C and pH 7, little amounts of the decomposition products nitrite and dioxygen are formed, even when the peroxynitrite concentration is high (2.5 mM). Instead, approximately > or =90% isomerizes to nitrate. At higher pH, decomposition increases at the expense of isomerization, up to nearly 80% at pH 10.0 at 5 degrees C and 90% at 45 degrees C. Much less nitrite and dioxygen per peroxynitrite are formed when the peroxynitrite concentration is lower; at 50 microM and pH 10.2, < or =40% decomposes. In contrast to two other reports (Pfeiffer, S.; Gorren, A. C. F.; Schmidt, K.; Werner, E. R.; Hansert, B.; Bohle, D. S.; Mayer, B. J. Biol. Chem. 1997, 272, 3465-3470, and Coddington, J. W.; Hurst, J. K.; Lymar, S. V. J. Am. Chem. Soc. 1999, 121, 2438-2443), we find that the extent of decomposition is dependent on the peroxynitrite concentration.
Kissner
Reinhard
R
Contribution from the Laboratorium für Anorganische Chemie, Eidgenössische Technische Hochschule Hönggerberg, CH-8093 Zürich, Switzerland.
Koppenol
Willem H
WH
D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism; D009573:Nitrites / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
D009566:Nitrates; D009573:Nitrites; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; D010100:Oxygen