Phosphotungstate as a useful eluent for antithrombin III purification by heparin-agarose affinity chromatography

We have recently found that phosphotungstate (PTA) has a heparin-like anticoagulant effect. In the present paper, we studied whether PTA is useful as an eluent of antithrombin III (ATIII) on heparin-Sepharose affinity chromatography. Human ATIII adsorbed on the heparin-Sepharose gel was eluted with NaCl buffer at the NaCl level of 1M. Whereas, PTA could elute ATIII at the level of less than 1mM and thus obtained ATIII fraction contained less impurities than such a fraction eluted with NaCl. Residual PTA in the eluate was easily decomposed by alkalization, being convenient for subsequent studies.