[Primary structures of the alpha and beta chains from the major hemoglobin component of the ostrich (Struthio camelus) and American rhea (Rhea americana) (Struthioformes). Aspects of respiratory physiology and taxonomy].

The primary structures of the alpha A- und beta-chains from the major hemoglobin component of the Ostrich (Struthio camelus) and American Rhea (Rhea americana) are given. The minor component with the alpha D-chains was detected in Ostrich in several concentrations, in American Rhea as in chicken and pheasant (about 40%). By homologous comparison, Greylag Goose (Anser anser) hemoglobin and Ostrich alpha A-chains differ by 15 amino acids or 16 nucleotide (1 two-point mutation) exchanges, beta-chains by 4 exchanges. Four substitutions modify alpha 1 beta 1-contacts and one phosphate contact. American Rhea and Greylag Goose hemoglobin alpha A-chains differ by 20 amino acids or 23 nucleotides (3 two-point mutations), beta-chains by 4 exchanges. Two substitutions modify alpha 1 beta 1-contacts, one phosphate contact and one heme contact. Oxygen affinity of three hemoglobin components of Ostrich are measured and the results are discussed. Systematic and evolution of Ostrich and American Rhea are discussed.