The Deoxygenation of Dilute Oxyhemoglobin by Sodium Dithionite

Abstract

The reaction of purified ascaris hemoglobin (Hb) (the A2 fraction) with Na2S2O4 was studied for its reaction pathways, as follows: at pH 7.0, HbO2 (412 m[mu]) [forward arrow] met-Hb (405 m[mu]) [forward arrow] Hb (431 m[mu]), where the 1st step reaction proceeded rapidly in acidic soln; at pH 8 in the presence of 0.33 M KCN, HbO2 [forward arrow] Met-Hb-CN(?) (417 m[mu]) [forward arrow] Hb-CN (428 m[mu]); the above product of Hb (431 m[mu]) was converted at pH below 6.0 to a stable, unidentified Hb derivative (417 m[mu]), which was, however, different from Met-Hb-CN. The rate of 417 m[mu]- compound formation from Met-Hb was independent of the Na2S2O4 concentration.