Complete primary structure of the beta chain from the hemoglobin of a baboon, Papio cynocephalus.

The complete primary structure of the beta chain from the adult hemoglobin of a baboon, Papio cynocephalus, has been determined by automated, Edman degradation of the intact chain and four fragments derived therefrom by specific cleavage reactions. The analysis was facilitated by application of a modified solvent system that permits unambiguous identification, by high-performance liquid chromatography, of the 17 amino acids whose phenylthiohydantoin derivatives are soluble in ethyl acetate. The sequence obtained differs from that of the human beta chain at eight sites, a degree of divergence similar to that observed when human and macaque beta chains are compared. Of the cercopithecoid beta chains whose complete sequences have been determined or inferred from compositions of small peptides, that of P. cynocephalus is most like the beta chain of the gelada baboon, an observation in accord with assessment of a close phylogenetic relationship between the genera Papio and Theropithecus.