Bothrops jararaca antithrombin: isolation, characterization and comparison with other animal antithrombins.

Antithrombin was purified from Bothrops jararaca plasma by affinity chromatography using HiTrap Heparin HP column, and its molecular weight, amino-terminal sequence, carbohydrate content, isoelectric point, inhibition of bovine thrombin, and immunological properties were studied and compared with previously described antithrombins. B. jararaca antithrombin is a single-chain glycoprotein with a total carbohydrate content of 18%. The molecular weight from SDS-PAGE was 61 kDa and the inhibitor exhibited an acidic isoelectric point (4.5). The amino-terminal sequence has been determined as His-Glu-Ser-Ser-Val-Gln-Asp-Ile-Ile-Thr, which is highly homologous to the terminal sequences of other animal antithrombins, indicating high amino acid conservation among several animals. Immunological cross-reactivity was observed among fish, frog, chicken, human, non-venomous snake and B. jararaca antithrombins. B. jararaca antithrombin showed inhibitory activity upon human and B. jararaca coagulation and amidolytic substrate S-2238.