Novel approach for preparation of heparins specific to factor Xa using affinity chromatography coupled with synthetic antithrombin III-related peptides.

In the blood coagulation cascade, heparin activates human plasma antithrombin III (hAT III), resulting in the inhibition of factor Xa. This polysaccharide also exhibits hemorrhagic tendency mediated by the inhibition of thrombin in heparinotherapy. Therefore, attention has focused on the development of low molecular weight heparins (LMW-heparins) that inhibit factor Xa but not thrombin. In this investigation, we examined the biochemical and physicochemical properties of hAT III-derived heparin-binding peptides (HBPs). Of all the tested HBPs, hAT III (123-139) exhibited the highest affinity with heparin and showed an inhibitory effect on the heparin-induced enhancement of hAT III activity toward factor Xa, indicating that hAT III (123-139) specifically interacts with the active region in heparin. We prepared a synthetic hAT III (123-139)-coupled affinity chromatography system, and demonstrated that this novel affinity chromatography is useful for fractionation of highly active moieties in LMW-heparins.