PREPARATION AND PROPERTIES OF ISOLATED ALPHA AND BETA CHAINS OF HUMAN HEMOGLOBIN IN FERRI STATE - INVESTIGATION OF OXIDATION-REDUCTION EQUILIBRIA

The ferric derivatives of isolated α and β chains of human hemoglobin, known to be rapidly denatured under ordinary conditions, have been prepared in stable form through the choice of an appropriate solvent (1 m-glycine). Preparations in 1 m 1-glycine have been used to study the oxidation-reduction equilibria of the chains. The redox equilibria of the isolated chains are different in the pH range studied (pH 6 to 8), the electron affinity of the β chain being higher (Em7 = + 0.113v) than that of the α chain (Em7 = + 0.052 v); furthermore, the β chains possess an additional oxidation-linked ionization (pK′ ~ 7) not revealed in chain α. The results are discussed in the context of human hemoglobin; they lend support to the idea of intrinsic non-equivalence of sites in the oxidation-reduction equilibrium of the latter. © 1969.