Purity: > 90% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 0.1M NaCl, 20% glycerol, 2M urea, 2mM DTT. Hemoglobin subunit alpha, also known as HBA2, belongs to the globin family. HBA2 is involved in oxygen transport from the lung to the various peripheral tissues. The alpha-2(HBA2) and alpha-1 (HBA1) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin. Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also been reported. Recombinant human HBA2 protein, fused to His-tag at N-terminus, was expressed in E.coli.