Summary
A peptide containing the vitamin K dependent Ca2+ binding region of human prothrombin has been isolated by adsorption of the tryptic
digest of the native protein on barium citrate. Its aminoacid composition has been
determined. The N- and C-terminal residues have been characterized. The obtained results
are showing some slight differences with the corresponding bovine peptide. Since they
were not strictly identical for two different preparations, the eventuality of a molecular
heterogeneity is discussed.