Annexin V is a marker of aEUR'

Apoptosis Annexin V assays provides simple and effective method to detect apoptosis at a very early stage. This assay makes advantage of the fact that phosphatidylserine (PS) is translocated from the inner (cytoplasmic) leaflet of the plasma membrane to the outer (cell surface) leaflet soon after the induction of apoptosis and that the annexin V protein has strong specific affinity for phosphatidyl serine. Phosphatidyl serine on the outer leaflet is available to bind labelled annexin V providing the basis for a simple staining assay. All of the annexin proteins share the propey of binding calcium and phospholipids. Annexin V is a cause of syndrome called antiphospholipid antibody syndrome. Annexin V normally forms a shield around ceain phospholipid molecules that blocks their entry into coagulation (clotting) reactions. In the antiphospholipid antibody syndrome; the formation of the shield is disrupted by the abnormal antibodies. Without the shield, there is an increased quantity of phospholipid molecules on cell membranes speeding up coagulation reactions and causing the abnormal blood clotting characteristic of antiphospholipid antibody syndrome.