Hemoglobin α4 and Hemoglobin β4

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Abstract
Reconstruction of human Hb(hemoglobin) from [alpha]- and [beta]-chains were demonstrated. Hb was treated with N/200 HC1, and the isolated globin was fractionated to globins [alpha] and [beta] by precipitation with 75-90% and 50-70% acetone, respectively. Globins a and [beta] were incubated separately with hematin at pH 8 to yield hemiglobins alpha and [beta], respectively, which followed by Na2S2O4-reduction and spontaneous dimerization to Hb [alpha]2 and Hb [beta]2, respectively. Hb [alpha]2 and Hb [beta]2 were easily polymerized to Hb [alpha]4 or Hb [alpha]4, respectively, at pH 8.2, but admixture of Hb [alpha]2 and Hb [beta]2 at an equimolar ratio at pH 8.2 led to the formation of Hb [alpha] 2[beta]2, which was approximately identical with original human Hb in their spectro-scopic properties. Hb [alpha]4 and Hb [beta]4 showed higher affinity towards O2 and lesser stability than Hb [alpha]2[beta]2. Isoelectric pH of Hb [alpha]4 and Hb [beta]4 were determined as 8.2 and 6.5, respectively. Admixture of Hb [alpha]4 and Hb [beta]4 slowly produced Hb [alpha]2[beta]2 at pH 8.2.
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