Hemoglobin S Travis: a Sickling Hemoglobin with Two Amino Acid Substitutions [β6(A3)Glutamic Acid → Valine and β 142(H20) Alanine → Valine]

Abstract
The .beta.6 Glu .fwdarw. Val mutation imparts to Hb S Travis the characteristic properties of sickling Hb, namely its association with erythrocyte sickling, the insolubility of the Hb in the reduced form, and a minimum gelling concentration value identical to Hb S. Unlike Hb S, Hb S Travis exhibits an increased O2 affinity and a decreased affinity for 2,3-bisphosphoglycerate and inositol hexakisphosphate. In addition, the variant Hb tendency to autoxidize and its mechanical precipitability suggest that there are conformational differences between Hb S and Hb S Travis.