The Reaction between Oxymyoglobin and Hydroperoxides

Abstract

The O-O spliting of t-butyl hydroperoxide by oxymyoglobin is associated with hemoprotein destruction, and organic hydroperoxide- and oxygen consumption. In addition, electronically excited states -detected by low-level chemiluminescence- are formed in a side reaction. The excited states probably originate from the interaction of free radical products generated during the decomposition of t-butyl hydroperoxide by oxymyoglobin. This is indicated by the effect of the free radical scavenger, (+)-cyanidanol-3, which inhibits chemiluminescence, prevents hemoprotein destruction, and enhances t-butyl hydroperoxide and oxygen utilization.

The oxidative character of the reaction between organic hydroperoxide and oxymyoglobin is pointed out by its capacity to peroxidize polyunsaturated fatty acids. This process gives rise to a new chemiluminescence pathway -mainly that involving the mechanism(s) of lipid peroxidation- as shown by a shift toward shorter wavelengths in the spectral distribution of emission.

The excited states generated during the interaction between oxymyoglobin and organic hydroperoxide might contribute to the spectrum of oxidants mediating ischemia/reperfusion cardiac injury as well as in oxidative damage to red cells.