Hemoglobin Saverne: A New Variant with Elongated β Chains: Structural and Functional Properties

A 26-year-old French woman born in Saverne (France) was found to have Heinz body hemolytic anemia. Isoelectrofocusing showed the presence of an abnormal band amounting to 35% of the total hemoglobin concentration, suggesting a β variant. Structural analysis of the abnormal β chain showed an elongated C-terminal segment. Histidine 143 is replaced by a proline and the C-terminal sequence is identical to the corresponding segment of Hb Cranston. This new variant, named Hb Saverne, has β chains composed of 156 amino acid residues. Studies of its functional properties showed that Hb Saverne is an unstable, high affinity variant with low cooperativity.