title: Study of the sites of plasminogen molecule which are responsible for inhibitory effect of Lys-plasminogen on platelet aggregation.
abstract: 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. We have shown that the kringle domains of Lys-plasminogen mediate interaction of this proenzyme with platelet- surface proteins. The aim of the work is to study the role of certain kringle domains in the inhibitory effect of Lys-plasminogen and to determine possible plasminogen-binding proteins on the platelet surface. All studied plasminogen fragments (K1-3, K4 and K5) abolished the inhibitory effect of Lys-plasminogen on platelet aggregation. We observed that K5 was more effective than K1-3 and K4. Biotin-labeled Lys-plasminogen, Glu-plasminogen and plasminogen fragment K1-3 possessed the highest affinity for actin, whereas the binding of biotin-labeled mini-plasminogen and K4 to actin was negligible. We have suggested that inhibitory effect of Lys-plasminogen is due to the interaction of kringle domains of this proenzyme with membrane-bound proteins which are exposed on the platelet surface during activation and are involved in thrombus formation.
authors: Y M
authors: YM
authors: Roka-Moya
authors: D D
authors: DD
authors: Zhernossekov
authors: E I
authors: EI
authors: Yusova
authors: L G
authors: LG
authors: Kapustianenko
authors: T V
authors: TV
authors: Grinenko
mesh_terms: D000199:Actins / Q000737:chemistry; D001792:Blood Platelets / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects*; D002478:Cells, Cultured; D005340:Fibrinogen / Q000737:chemistry; D005341:Fibrinolysin / Q000737:chemistry; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D010958:Plasminogen / Q000737:chemistry / Q000494:pharmacology*; D015539:Platelet Activation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D011485:Protein Binding; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D019699:Thrombospondins / Q000737:chemistry
chemical_list: D000199:Actins; D010446:Peptide Fragments; D019699:Thrombospondins; C018998:lysyl-plasminogen; C044190:miniplasminogen; D005340:Fibrinogen; D010958:Plasminogen; D013917:Thrombin; D005341:Fibrinolysin