Hemoglobin Andrew-Minneapolis α^A₂β^{144 Lys → Asn}₂: A New High-Oxygen-Affinity Mutant Human Hemoglobin

The functional properties and primary structure of a new β-chain mutant of human hemoglobin are described. The mutant was transmitted as an autosomal dominant characteristic. Affected members of the kindred exhibited marked erythrocytosis due to the high oxygen affinity of the resultant hemoglobin. The abnormality is associated with a substitution of an asparaginyl residue for lysine in the 144 position of the β-chain, α^A₂β^144Lys→Asn₂, presumably due to an AAA/G to AAA/U transversion. The mutant hemoglobin displayed a profound increase in oxygen affinity, with a P₅₀ of the fresh whole blood of 14 mm Hg. The isolated mutant hemoglobin exhibited near normal heme—heme interaction, a half-normal Bohr effect, and normal reactivity with 2,3-diphosphoglycerate.