The primary structure of the hemoglobin from the lobe-lipped bat (Chalinolobus morio, Microchiroptera).

Abstract

The hemoglobin of the lobe-lipped bat (Chalinolobus morio, Vespertilionidae) is composed of 45% HbI and 55% HbII. Both components show identical alpha-chains but differ at the following three positions of their beta-chains: beta I/beta II 21: Glu/Asp, 70: Ser/Ala, and 135: Gln/Leu. High performance liquid chromatography revealed pure alpha-chains and a mixture of only partly separated beta-chains. Based on this material, the primary structures of all three globin chains could be achieved by automatic Edman degradation of the whole chains and peptides obtained by trypsin hydrolysis. Compared to human hemoglobin, Chalinolobus shows 17 replacements in the alpha-chains and 24/22 in the beta-chains. A sequence comparison of the globin chains from the three vespertilionid bats Chalinolobus morio and Myotis velifer (Vespertilioninae) as well as Antrozous pallidus (Nyctophilinae) supports a close relationship of the former only for the beta-chains. Molecular modeling showed that the replacements involved in three alpha 1/beta 1 and one alpha 1/beta 2 subunit interface contacts do not cause any interruption. All phosphate binding sites and amino acid residues responsible for the Bohr effect are unchanged. Thus normal physiological properties should be expected for Chalinolobus morio hemoglobin.