tailieunhanh - Báo cáo khoa học: Functional role of Bb-chain N-terminal fragment in the fibrin polymerization process

Four mAbs of the IgG1 class to the thrombin-treated N-terminal disulfide knot of fibrin, secreted by various hybridomas, have been selected. Epi-topes for two mAbs, I-3C and III-10d, were situated in human fibrin frag-ment Bb15–26, and those for two other mAbs, I-5G and I-3B, were in fragment Bb26–36. | ễFEBS Journal Functional role of Bp-chain N-terminal fragment in the fibrin polymerization process E. V. Lugovskoy P. G. Gritsenko L. G. Kapustianenko I. N. Kolesnikova V. I. Chernishov and S. V. Komisarenko Palladin Institute of Biochemistry NationalAcademy of Sciences of Ukraine Kyiv Ukraine Keywords fibrin monoclonalantibodies peptides polymerization sites Correspondence E. Lugovskoy Palladin Institute of Biochemistry NationalAcademy of Sciences of Ukraine 9 Leontovicha Street 01601 Kyiv Ukraine Fax 38 044 2796365 Tel 38 044 2343354 E-mail lougovskoy@ Received 15 May 2007 revised 3 July 2007 accepted 10 July 2007 doi Four mAbs of the IgG1 class to the thrombin-treated N-terminal disulfide knot of fibrin secreted by various hybridomas have been selected. Epitopes for two mAbs I-3C and III-10d were situated in human fibrin fragment BP15-26 and those for two other mAbs I-5G and I-3B were in fragment BP26-36. Three of these mAbs I-5G I-3B and III-10D as well as their Fab-fragments decreased the maximum rate of fibrin desAA and desAABB polymerization up to 90-95 at a molar ratio of mAb or Fab-fragment to fibrin of 1 or 2. The fourth mAb I-3C did not influence the fibrin desAABB polymerization and inhibited by 50 the maximum rate of fibrin desAA polymerization. These results suggest that these mAb inhibitors block a longitudinal fibrin polymerization site. As the mAbs retard both fibrin desAABB and fibrin desAA polymerization one can conclude that the polymerization site does not coincide with polymerization site B BP15-17 . To verify this suggestion the polymerization inhibitory activity of synthetic peptides BpSARGHRPLDKKREEA 12-26 BpLDKKREEA 19-26 BpApSLRPaPpPI 26-36 BpAPSLRPAPPPIS GGGYRARPA 26-46 and BpGYRARPA 40-46 which imitate the various sequences in the N-terminal region of the fibrin Bp-chain have been investigated. Peptides Bp 12 26 and Bp26 46. but not Bp40 46 Bp19 26 and Bp26 36 proved to be specific inhibitors of