Aptamer loaded superparamagnetic beads for selective capturing and gentle release of activated protein C.

Activated protein C (APC) is a serine protease with anticoagulant and cytoprotective activities which make it an attractive target for diagnostic and therapeutic applications. In this work, we present one-step activation of APC from a commercial source of protein C (PC, Ceprotin) followed by rapid and efficient purification using an APC-specific aptamer, HS02-52G, loaded on MyOne superparamagnetic beads. Due to the Ca-dependent binding of APC to HS02-52G, an efficient capturing of APC was applied in the presence of Ca ions, while a gentle release of captured APC was achieved in the elution buffer containing low EDTA concentration (5 mM).