Direct detection of peroxyl radicals formed in the reactions of metmyoglobin and methaemoglobin with t-butyl hydroperoxide.
The reaction of metmyoglobin and methaemoglobin with t-butyl hydroperoxide has been investigated using stopped-flow e.s.r. spectroscopy. The major species observed immediately after mixing has been identified as the basis of its g value (2.014) and line width as being due to a peroxyl radical. The detection of this species under anaerobic conditions suggests that this species is the t-butyl peroxyl radical rather than a secondary species. The immediate observation of this species on mixing suggests that this species is arising via a reaction involving the intact haem moiety rather than via 'free iron' produced via oxidative damage. Detection of a second, oxygen-dependent, species, which is formed at a slower rate, in the metmyoglobin reaction suggests that the initial peroxyl radical subsequently reacts with the protein to give a protein-derived radical.
Davies
M J
MJ
Department of Chemistry, University of York, Heslington, U.K.
D055598:Chemical Phenomena; D002621:Chemistry; D004578:Electron Spin Resonance Spectroscopy; D006418:Heme / Q000032:analysis; D006420:Hemeproteins / Q000032:analysis*; D008706:Methemoglobin / Q000032:analysis*; D008786:Metmyoglobin / Q000032:analysis*; D010545:Peroxides / Q000032:analysis*; D011190:Potassium Cyanide; D020122:tert-Butylhydroperoxide
D006420:Hemeproteins; D010545:Peroxides; D008786:Metmyoglobin; D006418:Heme; D008706:Methemoglobin; D020122:tert-Butylhydroperoxide; D011190:Potassium Cyanide