The primary structures of the major and minor hemoglobin-components of adult Andean goose (Chloephaga melanoptera, Anatidae): the mutation Leu----Ser in position 55 of the beta-chains.
The primary structures of the hemoglobin components Hb A and Hb D of the adult Andean Goose (Chloephaga melanoptera) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer. The amino-acid sequences were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid- and gas-phase sequenators. The sequences are aligned with those of Greylag Goose (Anser anser) as a biological reference and other sequences of birds. A detailed evaluation of all residues of Andean Goose hemoglobins on the basis of the 12000 known avian globin sequences leads to a molecular pattern for high-altitude respiration of geese. The replacement of functional and structural importance is the unique occurrence of the residue beta 55 Leu----Ser (all other exchanges are functionally neutral), interrupting the same alpha 1 beta 1-interface contact (alpha 119-beta 55) that accounts for high-altitude respiration of the Barheaded Goose (Anser indicus); there the mutation is found on alpha A 119. Loosening the constraints of this interface must be interpreted as a destabilization of the low-affinity T-structure in favour of the high-affinity R-structure. The structural and functional significance of this interface for the molecular biology of high-altitude respiration of the Andean Goose and Barheaded Goose is discussed. Since Hb A consists of alpha A2 beta 2 and Hb D consists of alpha D2 beta 2 the mutation occurring in blood of the Andean Goose affects both hemoglobins whereas in the case of the Barheaded Goose only Hb A is affected. These results show that Hb D can be considered a biological reserve to enlarge situatively the normal hemoglobin function. A general molecular pattern for permanent (selective advantage of high intrinsic oxygen affinity) and transitory (selective advantage of graded oxygen affinities) adaptation to hypoxia is discussed. A survey on the sequence homology of the globin chains of geese (Anserinae) and ducks (Anatinae) is given.
Max-Planck-Institut für Biochemie, Abt. Proteinchemie, Martinsried bei München.
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I
Hiebl
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G
Braunitzer
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D
Schneeganss
D000531:Altitude; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005777:Geese / Q000097:blood*; D005914:Globins / Q000235:genetics; D006454:Hemoglobins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006455:Hemoglobins, Abnormal / Q000378:metabolism; D006868:Hydrolysis; D000860:Hypoxia / Q000097:blood; D008969:Molecular Sequence Data; D009154:Mutation; D010101:Oxygen Consumption; D010455:Peptides / Q000032:analysis; D014357:Trypsin
D000596:Amino Acids; D006454:Hemoglobins; D006455:Hemoglobins, Abnormal; D010455:Peptides; C032001:hemoglobin D; D005914:Globins; D014357:Trypsin