Stabilities of human hemoglobins to defined perturbations.

(A) Mechanical stability. The stabilities of the human hemoglobins exposed to mechanical stress were determined as described in “Materials and methods.” The percentage soluble hemoglobin is plotted as a function of time. Early time points are displayed on an expanded scale (inset). (B) Chemical stability. The stabilities of the human hemoglobins exposed to 17% isopropanol are illustrated. Bars represent the average of duplicate determinations using independently prepared isopropanol solutions. Symbols are the same as in panel A. (C) Thermal stability. The relative stabilities of the human hemoglobins incubated at 50°C were determined and plotted as a function of precipitated hemoglobin. Symbols are the same as in panel A.