HB Godavari [α95(G2)PROTHR]: A Neutral Amino Acid Substitution in the α1β2 Interface That Modifies the Electrophoretic Mobility of Hemoglobin

Abstract

Hb Godavari [α95(G2)ProThr] was characterized independently in two families of different ethnic origin. The first case, found in the Netherlands, involved an Indian patient. The second one was identified a few months later in an African family from Mali, living in France. Hb Godavari is the fourth example of a substitution involving neutral residues at position α95(G2). In all these variants the electrophoretic pattern suggested that the structural modification unmasks a charged residue buried in the α1β2 contact area. The oxygen affinity of this abnormal hemoglobin was approximately 10% higher than that of Hb A; in the absence of 2,3-diphosphoglycerate, its cooperativity was moderately decreased, suggesting a slightly unstable T state.