Activated platelet procoagulant surface

Activated platelet/phospholipid surfaces serve as the essential catalytic platform for the assembly of blood coagulation factor complexes. Upon activation by stimuli such as thrombin or collagen, platelets undergo a loss of membrane asymmetry, exposing negatively charged phospholipids—primarily phosphatidylserine (PS)—on their outer leaflet (Zwaal & Schroit, 1997). This exposed surface provides high-affinity binding sites for the gamma-carboxyglutamic acid (GLA) domains of vitamin K-dependent clotting factors, including Factors II, VII, IX, and X, as well as cofactors V and VIII (Heemskerk et al., 2002). The assembly of the tenase and prothrombinase complexes on these surfaces accelerates thrombin generation by several orders of magnitude compared to reactions in solution, facilitating rapid clot formation. In disease states, these surfaces drive pathological thrombosis, leading to conditions such as myocardial infarction and stroke. Therapeutic agents like Annexin V derivatives target these surfaces by binding to exposed PS, effectively shielding the membrane and preventing the assembly of procoagulant complexes to reduce thrombotic risk (Lentz, 2003).

Other names

Activated platelet/phospholipid surfacesPhosphatidylserine-exposed membraneProcoagulant platelet surfaceActivated platelet membraneProcoagulant phospholipid surface

Masking of exposed phosphatidylserine to prevent the assembly and activation of the tenase and prothrombinase complexes.