Involved in oxygen transport from the lung to the various peripheral tissues. Heterotetramer of two alpha chains and two beta chains. Different alleles are known. The alpha-A allelic variant contains Gly-16. Adult sheep and other mammalian species produce unequal amounts of alpha-globin from their non-allelic loci. The alpha-1 sequence is shown. Sheep insoluble core region (positions 101-140) contains 1 more Gly, one more Glu, and two fewer Ser than the corresponding region shown (PubMed:6033754). According to PubMed:5658545 it contains one more Thr and one less Ser. Belongs to the globin family.