JPS597694B

PURPOSE:To separate and to purify antithrombin III efficiently, by adsorbing specifically antithrombin III on deactivated thrombin gel from a mixed solution of plasma and protein in affinity chromatography method, followed by eluting it. CONSTITUTION:In affinity chromatography, and elute having a pH of 6-8 and an ionic strength of 0-1, comprising a buffer solution, solution of neutral salt and a mixed solution of plasma and protein is brought into contact with the gel, and antithrombin III is specifically adsorbed on it. A gel obtained by linking chemically modified deactivated thrombin (e.g., antihydrothrombin) as an affinity ligand to a hydrophilic carrier is used as the gel. Antithrombin III is eluted with a solution of neutral salt in a pH of 4.0-5.5 or a substrate analog such as benzamidine, etc., so that it is separated and purified. Antithrombin III is one kind of glycoproteins paticipating in blood clotting.