Study of the sites of plasminogen molecule which are responsible for inhibitory effect of Lys-plasminogen on platelet aggregation.

Plasminogen/plasmin system is involved in such important processes as thrombosis, inflammation and cancer. Plasmin and plasminogen mediate their action through plasminogen-binding proteins on the cell surface. Lys-plasminogen, but not Glu-plasminogen, shows inhibitory effect on platelet aggregation induced by ADP, collagen and thrombin in preparations of both: platelet-rich plasma and washed platelets.

[THE EFFECTS OF LYS-PLASMINOGEN ON HUMAN PLATELET SECRETION].

The effects of Lys-plasminoge on platelet α-granule secretion were studied. The level of P-selectin exposed on the surface of plasma membranes of washed human platelets was measured by flow cytometry as a market of α-granule secretion. It was shown that Lys-plasminogen facilitates partial release of α-granules, but impedes thrombin-induced platelet exocytosis.