Myeloperoxidase (MPO) is a major neutrophil protein and may be involved in the nitration of
tyrosine residues observed in a wide range of inflammatory diseases that involve
neutrophils and macrophage activation. In order to clarify if nitrite could be a physiological
substrate of myeloperoxidase, we investigated the reactions of the ferric enzyme and its
redox intermediates, compound I and compound II, with nitrite under pre-steady state
conditions by using sequential mixing stopped-flow analysis in the pH range 4–8. At 15° C …