Thromb Haemost 2007; 97(06): 890-898
DOI: 10.1160/TH06-08-0458
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Factor XIII activation peptide is released into plasma upon cleavage by thrombin and shows a different structure compared to its bound form

Verena Schroeder
1   Laboratory for Thrombosis Research, Department of Clinical Research, University of Bern, Bern, Switzerland
,
Jean-Marc Vuissoz
2   Pediatric Endocrinology and Metabolism, University Children's Hospital, Inselspital, Bern, Switzerland
,
Amedeo Caflisch
3   Computational Structural Biology, Department of Biochemistry, University of Zurich, Zurich, Switzerland
,
Hans P. Kohler
1   Laboratory for Thrombosis Research, Department of Clinical Research, University of Bern, Bern, Switzerland
› Institutsangaben

Financial support: This work was funded by the Swiss National Science Foundation (Grant No.3200B0–105385).
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Publikationsverlauf

Received 22. August 2006

Accepted after resubmission 30. März 2007

Publikationsdatum:
27. November 2017 (online)

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Summary

The first step of coagulation factor XIII (FXIII) activation involves cleavage of the FXIII activation peptide (FXIII-AP) by thrombin. However, it is not known whether the FXIII-AP is released into plasma upon cleavage or remains attached to activated FXIII. The aim of the present work was to study the structure of free FXIII-AP, develop an assay for FXIII-AP determination in human plasma, and to answer the question whether FXIII-AP is released into plasma. We used ab-initio modeling and molecular dynamics simulations to study the structure of free FXIII-AP. We raised monoclonal and polyclonal antibodies against FXIII-AP and developed a highly sensitive and specific ELISA method for direct detection of FXIII-AP in human plasma. Structural analysis showed a putative different conformation of the free FXIII-AP compared to FXIII-AP bound to the FXIII protein. We concluded that it might be feasible to develop specific antibodies against the free FXIII-AP. Using our new FXIII-AP ELISA, we found high levels of FXIII-AP in in-vitro activated plasma samples and serum. We showed for the first time that FXIIIAP is detached from activated FXIII and is released into plasma, where it can be directly measured. Our findings may be of major clinical interest in regard to a possible new marker in thrombotic disease.