One electron reduction of metmyoglobin and methemoglobin and the reaction of the reduced molecule with oxygen. Progress report, September 1, 1975--July 1, 1976

We have used the pulse-radiolysis technique to reduce one Fe(III) in methemoglobin and metmyoglobin. We have followed the reaction of the reduced proteins with O2 and found k/sub reduced methemoglobin + O2/ = 2.6 +- 0.6 x 107 M-1 sec-1 and k/sub myoglobin + O2/ = 1.8 +- 0.2 x 107 M-1 sec-1. The spectra of the reduced and oxygenated forms were measured and it was found that e-/sub aq/ did not react with hemin groups quantitatively, and probably part of e-/sub aq/ reacted with the globin moiety. We were also able to follow slight changes in the spectra of both the reduced and oxygenated forms in the microseconds time-scale, and we attribute these changes to conformational changes