Structural adaptation of bird hemoglobins to high-altitude respiration and the primary sequences of black-headed gull (Larus ridibundus, Charadriiformes) alpha A- and beta/beta'-chains.
Two hemoglobin components HbA (alpha A2 beta 2) and (alpha D2 beta 2) have been detected by analytical electrophoresis in the lysed erythrocytes of the adult Black-Headed Gull (Larus ridibundus). We report the complete primary structure of the alpha A- and beta-chains of the major hemoglobin component HbA. Following the chain separation and isolation of the tryptic peptides by RP-HPLC, the amino-acid sequence was established by automatic Edman degradation in spinning cup and gas-phase sequencers. The primary structures of alpha A- and beta-chains from the Black-Headed Gull HbA differ by 11 and by 6 amino-acid residues from the corresponding chains of Greylag Goose. These changes are randomly distributed over both alpha-helical and interhelical regions. The presence of beta/beta'-chains is indicated by the observation of Ile/Leu at position beta 78. An exchange at position beta 55 (D6)Leu-Asn which is known to be involved in the alpha 1 beta 1-interface with alpha 119(H2)Pro has been found. It is suggested that packing contacts in the alpha 1 beta 1-interface are important for high altitude respiration in birds.
Godovac-Zimmermann
J
J
Max-Planck-Institut für Biochemie, Abt. Proteinchemie, Martinsried.
Kösters
J
J
Braunitzer
G
G
Göltenboth
R
R
D000222:Adaptation, Physiological; D000531:Altitude; D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds / Q000097:blood*; D005777:Geese; D006454:Hemoglobins / Q000235:genetics* / Q000378:metabolism; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D012119:Respiration; D013045:Species Specificity; D014357:Trypsin
D006454:Hemoglobins; D046911:Macromolecular Substances; D010446:Peptide Fragments; D014357:Trypsin