Anticoagulant activity of heparin octasaccharide.

Porcine intestinal heparin was partially digested with a purified heparinase and an octasaccharide with high-affinity for antithrombin III was isolated from the digest by gel filtration, followed by affinity chromatography on a column of Sepharose 4B coupled with antithrombin III. The anticoagulant activity determined by the activated partial thromboplastin time method of the octasaccharide was 240 units/mg. Fifty percent inactivation activities of the octasaccharide for thrombin and factor Xa in the presence of antithrombin III were 2 and 6.5 times, respectively, higher than those of the initial heparin. These data indicate that the octasaccharide possesses the critical structural integrities required for manifesting these biological activities.