Hemoglobin of tree sparrows (Passer montanus, Passeriformes): Sequence of the major (Hb A) and minor (Hb D) components

Blood of the adult Tree Sparrow (Passer montanus) contains two hemoglobin components, Hb A (ca. 85%), Hb D (ca. 15%). They differ in their alpha-chains (alpha A, alpha D), the beta-chains are identical. The complete primary structures of alpha A-, alpha D- and beta-chains are presented. Comparison with the Greylag Goose (Anser anser) hemoglobin (Hb A) showed that the alpha A-chains differ by 22 amino-acid exchanges, the beta-chains by 16. Comparison with the minor component of the Pheasant (Phasianus colchicus colchicus) hemoglobin (Hb D) showed that the alpha D-chains differ by 34 amino-acid exchanges. Proline is found incorporated in an internal position of an alpha-helix (pos. 124, H7). In comparison to that of the Starling (Sturnus vulgaris) the ratio of amino-acid exchanges for beta: alpha A: alpha D chains is 1 : 7 : 4; in comparison to other birds this ratio is found to be 1 : 2 (1.4-2.2):3 (2.2-4).