Diannexin, an annexin A5 homodimer, binds phosphatidylserine with high affinity and is a potent inhibitor of platelet‐mediated events during thrombus formation

BACKGROUND: Shielding of procoagulant phosphatidylserine (PS) with annexin A5 attenuates thrombosis, but annexin A5 (35.7 kDa) is rapidly cleared from the circulation. In contrast, Diannexin, a 73.1 kDa homodimer of annexin A5, has an extended half-life. OBJECTIVES: To quantify the affinity of Diannexin for PS, examine its interaction with activated platelets and determine its effects on platelet-mediated events during thrombus formation.