Abstract
Fibronectin has been purified from baboon plasma by affinity chromatography on immobilized gelatin. Baboon fibronectin has subunit sizes, CNBr and thermolysin peptide patterns and an amino acid composition similar to human fibronectin. In Ouchterlony plates, baboon plasma fibronectin gives an immunological reaction of identity with human fibronectin, and a partial reaction with hamster fibronectin, using a goat antibody to human fibronectin. By radial immunodiffusion and rocket immunoelectrophoresis, using the same antibody, baboon fibronectin gives a dose response pattern similar to human fibronectin. Plasma concentrations of fibronectin in baboons are similar to those in humans. Fibronectin is thus another interesting protein that is closely related to its human counterpart and can be studied in subhuman primates using available antibodies to the human protein.