Fibrinopeptides A and B of baboons (Papio anubis, Papio hamadryas, and Theropithecus gelada): their amino acid sequences and evolutionary rates and a molecular phylogeny for the baboons.

Amino acid sequences of fibrinopeptides A and B from savanna baboons, Papio anubis and Papio hamadryas, and highland baboon, Theropithecus gelada, were established. The sequences of the fibrinopeptides A from the three baboons were identical: (sequence: see text) The fibrinopeptides B were composed of 9 residues and demonstrated the sequence: (sequence see text) where X3 = Arg in P. anubis, His in P. hamadryas, and Gly in Th. gelada. Position-3 of the B peptides was the only replacement site observed among the 25 amino acid residues in both fibrinopeptides from the baboons. Based on these sequences, a molecular phylogeny for the three species of baboons was deduced. The evolutionary rates of the peptides B of the baboons and macaques were also estimated. It was observed that the fibrinopeptides changed at an uneven rate during the evolution of old-world monkeys, i.e., baboons and macaques.