Hemoglobin of the adult white stork (Ciconia ciconia, ciconiiformes). The primary structure of alpha A- and beta-chains from the only present hemoglobin component.

Abstract

The hemolysate obtained from erythrocytes of the adult White Stork (Ciconia ciconia) contains only one hemoglobin component, identified to be HbA. The complete primary structures of alpha A- and beta-chains are presented. The minor hemoglobin component HbD with alpha D-chains usually present in adult avian species was not detected by the White Stork. The sequence was determined by automatic Edman degradation of tryptic peptides and in the case of beta-chains additionally of the C-terminal peptide obtained by chemical cleavage at the Asp-Pro bond. Homologous comparison with the Greylag Goose (Anser anser) hemoglobin showed that the alpha A-chains differ by 23 amino-acid exchanges, the beta-chains by 17. Four of the substitutions in the alpha A-chains are in the alpha 1 beta 1-contact points, one in the alpha 1 beta 2-contacts and one in the amino acids near the heme. The amino-acid substitutions of the White Stork hemoglobin as compared to the other avian hemoglobins are discussed. We suggest that alpha D-chain is persistence of an embryonic gene.