Effect of 2, 3-diphosphoglycerate on the solubility of deoxy-sickle hemoglobin.
We have examined the effect of 2, 3-diphosphoglycerate (DPG) on the solubility of deoxy-sickle hemoglobin (deoxy-Hb S) under conditions such that concentration, pH, and osmolarity of deoxy-Hb S solutions approached physiological. The range of DPG/Hb molar ratios encompassed the extremes found for this ratio in erythrocytes from individuals with sickle cell anemia. After monomer-polyer equilibrium had been established, the phases were separated by centrifugation and assayed for concentrations of Hb and DPG. DPG had no effect on the solubility of deoxy-Hb S. Furthermore, at DPG/Hb molar ratios less than one, there was no preferential incorporation of deoxy-Hb S containing bound DPG into polymers. At DPG/Hb molar ratios greater than one, concentrations of free DPG in monomer and polymer phases were virtually identical. Thus, under the specified equilibrium conditions, DPG is not a determining factor in the polymerization of deoxy-Hb S.
D000755:Anemia, Sickle Cell / Q000097:blood; D004163:Diphosphoglyceric Acids / Q000494:pharmacology*; D006451:Hemoglobin, Sickle / Q000378:metabolism*; D006801:Humans; D011108:Polymers; D012995:Solubility
D004163:Diphosphoglyceric Acids; D006451:Hemoglobin, Sickle; D011108:Polymers