title: Staphylokinase-annexin XI chimera exhibited efficient in vitro thrombolytic activities.
abstract: Annexins (ANXs) are a family of calcium dependent phospholipid binding proteins. Phospholipids such as phosphatidylserine are rapidly exposed on the surfaces of injured endothelial cells, activated platelets, and apoptotic cells in a large number of disorders. In this study, annexin V and XI (ANXV and ANXXI) were individually fused to the C-terminal of staphylokinase (SAK), a fibrin-selective thrombolytic protein, to form chimeras for evaluation of their in-vitro thrombolytic activities. The two chimeras were found to have plasminogen activation activity of comparable efficiency. When the chimeras were challenged under higher concentrations of plasmin for 1 h, hydrolysis of them into moieties was not seen on SDS-PAGE. In two thrombolytic assays, SAK-ANXXI was found to resolve both platelet rich plasma (PRP) clots and platelet poor plasma (PPP) clots with an efficiency similar to that of SAK. However, SAK-ANXV showed significantly reduced efficiency. With regard to anticoagulation ability, SAK-ANXXI was also found to have a stronger effect on dose-dependent extension of clotting time among the four tested proteins. The unique long N-terminal tail of ANXXI, composed of 202 residues, in contrast to the 16 residues of ANXV, probably served successfully to dispatch two moieties to function properly in a complicated microenvironment. Hence, a new option other than the most committed ANXV for the ANX based chimera without elaboration of linker construction is presented.
authors.affiliation: Cancer Center and Department of Radiation Oncology, Taipei Medical University Hospital, Taipei, Taiwan, ROC.
authors.forename: Jeng-Fong
authors.initials: JF
authors.lastname: Chiou
authors.forename: Ming-Dar
authors.initials: MD
authors.lastname: Woon
authors.forename: Shin-Nan
authors.initials: SN
authors.lastname: Cheng
authors.forename: Chih-Hsueng
authors.initials: CH
authors.lastname: Hsu
authors.forename: Shiou-Chi
authors.initials: SC
authors.lastname: Cherng
authors.forename: Feng-Ken
authors.initials: FK
authors.lastname: Hsieh
authors.forename: Shou-Ming
authors.initials: SM
authors.lastname: Lin
authors.forename: Chia-Yang
authors.initials: CY
authors.lastname: Shiau
mesh_terms: D000595:Amino Acid Sequence; D017302:Annexins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D005343:Fibrinolytic Agents / Q000378:metabolism / Q000494:pharmacology*; D005798:Genes, Bacterial; D006639:Histidine / Q000737:chemistry; D066298:In Vitro Techniques; D007700:Kinetics; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010958:Plasminogen / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013211:Staphylococcus aureus / Q000235:genetics
chemical_list: D017302:Annexins; D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D006639:Histidine; D010958:Plasminogen; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus