Effect of Some physical Features and of Amino acid Substitutions on the Mechanical Precipitation of Hemoglobin

Abstract
Following mechanical shaking, oxy-Hb S was previously demonstrated by Asakura to be much less stable than oxy-Hb A. The mechanical stability of Hb Creteil (.beta.89 Ser .fwdarw. Asn), Hb Hope (.beta.136 Gly .fwdarw. Asp), Hb Strasbourg (.beta.23 Val .fwdarw. Asp) and the hybrid Hb S/Stanleyville-II (.beta.6 Glu .fwdarw. Val; .alpha.78 Asn .fwdarw. Lys) was studied by the method of Roth et al. Hb Creteil, Hb Hope and Hb S/St-II were sensitive to mechanical shaking, while Hb Strasbourg was more stable than Hb A, a previously undescribed finding. The precise mechanisms responsible for this precipitation are not known. Standard methods for isolation of Hb modify its mechanical stability. Alpha mutation increases the mechanical stability of Hb S in the hybrid Hb S/St-II. Some mutations produce a more stable Hb than Hb A.