Biophysical Studies Evaluating the Potential Physiological Relevance of the Hemoglobin Associated Nitrite Anhydrase Reaction as a Pathway to Generate S-Nitrosothiols from Low Levels of NO and Nitrite

Hemoglobin (Hb) has been implicated in nitrite-mediated mechanisms that generate bioactive forms of nitric oxide by the reaction of deoxy Hb with nitrite to produce NO (Nitrite Reductase) is viewed as part of the mechanism since the generated NO is readily scavenged, raising questions as to how free NO could escape from the red blood cell. A proposed nitrite anhydrase reaction (NA) between met-Hb and both nitrite and NO to yield N2O3, a potent S-nitrosating agent capable of generating longer lived S-nitrosothiols, could address this limitation.