HB Melusine [α114(GH2)PRO→SER]: A New Neutral Hemoglobin Variant

Hb Melusine [α114(GH2)Pro→Ser] was found in an Algerian patient during a systematic screening for hemoglobinopathies performed in Luxembourg. The abnormal hemoglobin was suspected when a thickening of the Hb A band was observed by isoelectrofocusing. The mutant hemoglobin was silent in all other electrophoretic methods used for presumptive diagnosis with the exception of globin electrophoresis in the presence of Triton X-100. This technique revealed an α chain considerably more hydrophobic than normal. The structural abnormality of Hb Melusine concerns position α114(GH2) that belongs to a cluster of hydrophobic residues localized in the N-terminal half of the αT-12b tryptic peptide. It has been shown in the case of another variant of that position (Hb Nouakchott), that the replacement of the Pro GH2 by a Leu was responsible for a dramatic increase in the retention time of the a polypeptide chain during reversed phase high performance liquid chromatography, much higher than that reported for similar substi...