Hp attenuates heme loss while allowing oxidation of ferrous Hb.

<p>Spectrum of OxyHb (5 µM) was recorded. H₂O₂ (to yield 6 µM) was added and the mixture was incubated in 37°C and the spectrum recorded again. Experiment was repeated in presence of Hp1-1 (6 µM) 1: time zero (with or without Hp); 2: following 30 min in absence of Hp; 3: following 30 min in presence of Hp. Representative spectra of 3 independent experiments are shown.