OXYGEN EQUILIBRIA OF HUMAN HEMOGLOBIN VALENCY HYBRIDS - DISCUSSION ON INTRINSIC PROPERTIES OF ALPHA AND BETA CHAINS IN NATIVE PROTEIN

The preparation and some properties of valency hybrids derived from human hemoglobin are described. These derivatives (α23+ β22+ and α22+ β23+), containing both the chains of a given type (α or β) in the ferri state, are obtained through association of isolated partner chains, each in the desired valency state. The hybrids are stable and are tetramers in the normal pH range. The oxygenation behavior of the hybrids has been studied at different pH values; the two complementary valency hybrids are found to be different from each other with respect to oxygen affinity and Bohr ionizations. Since oxygen-binding is accomplished in these cases exclusively by chains of a given type in their natural oligomeric environment, the observed differences favor the view that the intrinsic functional properties of a and β chains of human hemoglobin are not equivalent. © 1969.