title: Non-enzymatic activation of prothrombin induced by interaction with fibrin β26-42 region.
abstract: We have discovered that addition of monomeric desAB fibrin to prothrombin leads to appearance of the thrombin-like activity of prothrombin towards S2238 chromogenic substrate. DesA and desABβ(15-42)2 fibrin forms did not cause any activation of prothrombin. From this observation we could suggested that amino acid residues of the 15-42 fragment of BβN-domain presented in desAB fibrin, cleaved in desABβ(15-42)2 fibrin and protected in desA fibrin, play a crucial role in the non-enzymatic activation of prothrombin. To identify the Bβ amino acid residues involved in the fibrin-prothrombin binding we used monoclonal antibodies 1-5G and 2d2a with epitopes in Bβ26-42 and Bβ12-26 fibrin fragments respectively. The thrombin-like activity in the mixture of prothrombin and desAB fibrin was monitored in the presence of each of these monoclonal antibodies. It was found that anti-Bβ12-26 antibody does not exhibit any inhibitory effect on the thombin-like activity of the mixture. In contrast, adding of Bβ26-42 antibody into the mixture of desAB fibrin with prothrombin diminished the thrombin-like activity by 70%. Recombinant dimeric peptides Bβ(15-44)2 and Bβ(15-66)2 that mimic amino acid residues in fibrin were also tested for their ability to activate prothrombin. It was found that both peptides were able to induce non-enzymatic activation of prothrombin. The activation was more evident in the case of Bβ(15-44)2 peptide. From the data obtained we can conclude that desAB fibrin binds to prothrombin through the Bβ26-42 amino acid residues and the formation of such a complex caused a non-enzymatic activation of prothrombin.
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Volodymyr O
authors: VO
authors: Chernyshenko
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Tamara M
authors: TM
authors: Chernyshenko
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Dar'ya S
authors: DS
authors: Korolova
authors: Institute of Molecular Biology and Genetics of NAS of Ukraine, Department of Medicinal Chemistry, Kyiv, Ukraine.
authors: Galyna P
authors: GP
authors: Volynets
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Iryna N
authors: IN
authors: Kolesnikova
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Tetyana M
authors: TM
authors: Platonova
authors: Palladin Biochemistry Institute of NAS of Ukraine Kyiv, Protein Structure and Functions Department, Kyiv, Ukraine.
authors: Eduard V
authors: EV
authors: Lugovskoy
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000911:Antibodies, Monoclonal / Q000737:chemistry; D002384:Catalysis; D003030:Coagulase / Q000737:chemistry; D000939:Epitopes / Q000737:chemistry; D005337:Fibrin / Q000737:chemistry*; D005338:Fibrin Fibrinogen Degradation Products / Q000737:chemistry; D005340:Fibrinogen / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011516:Prothrombin / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D000911:Antibodies, Monoclonal; D003030:Coagulase; D000939:Epitopes; D005338:Fibrin Fibrinogen Degradation Products; D010446:Peptide Fragments; C415348:desA-profibrin; C011468:fibrinmonomer; D011516:Prothrombin; D005337:Fibrin; D005340:Fibrinogen