Chemical Characterization of Three Hemoglobins G

Three abnormal hemoglobins identified as G by their electrophoretic mobility and performance on resin chromatography have been discovered in three healthy unrelated Negro individuals in Texas. These three G hemoglobins have been shown to belong to the same molecular species and to have a substitution in the 43rd residue of the β chain. Glutamic acid, which is present in this position in hemoglobin A, has been replaced by alanine in hemoglobin G. According to the recent suggestions on nomenclature of abnormal hemoglobins, hemoglobin G_Galveston may be formulated as α₂⁴β₂^{43 Glu→ ala}. Moreover, it has been shown that the following hemoglobins belong to the same molecular species: hemoglobin G_Galveston, hemoglobin G_{Port Arthur}, and hemoglobin G_Texas. This alteration is the first to be described in the fifth tryptic peptide of the β chain of human hemoglobin and differs from all abnormal hemoglobins previously reported.