Isolation and Characterization of Antithrombin III from Human, Porcine and Rabbit Plasma, and Rat Serum

Abstract

1. Human, porcine, rabbit, and rat antithrombin III have been purified by affuity chromatography using heparin-agarose.The amino acid and carbohydrate compositions, aminoterminal sequence, immunollogical cross-reactivites, and inhibitions of human thrombin were studied. 2. Human, porcine, rabbit, and rat antithrombin III are single-chain glycorpoteins containing hexose, glucosamine, and neuraminic acid. 3. The total carbohydrate contents were 17, 16, 14 and 15% for human, poreine, rabbit, and rat antithrombin III, respectively. 4. Molecular weights estimated form the migration in sodium dodecyl sulfate (SDS)-poly acrylamide gel electrophoresis were 59,000, 58,000, 63,000, and 63,000 for human, porcine rabbit, and rat antithrombin III, respectively. 5. These four proteine have similar amino acid composition, althouth some minor differences were noted. 6. Human, porcine, and rabbit antithrombin III have a histidine residue at the aminoterminus, while rat antithrombin III contains an amino-terminal asparagine residue. 7. The amino-terminal sequences up to the first 17 residues showed high homlogy among the four proteins. 8. Some immunological cross-reactiviy was observed only between human and porcine antithrombin III.9. The apparent dissociation constants (K1)) for the complexes between human thrombin and human porcine, rabbit, and rat antithrombin III were about respectively.