Thromb Haemost 1994; 72(03): 408-414
DOI: 10.1055/s-0038-1648880
Original Article
Schattauer GmbH Stuttgart

Isolation and Characterization of Single-Chain Protein S

Authors

  • Fenny Meijer-Huizinga

    The Department of Blood Coagulation, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam, The Netherlands
  • Koen Mertens

    The Department of Blood Coagulation, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam, The Netherlands
  • Jan A van Mourik

    The Department of Blood Coagulation, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam, The Netherlands
Weitere Informationen

Publikationsverlauf

Received 18. November 1993

Accepted after resubmission 19. Mai 1994

Publikationsdatum:
25. Juli 2018 (online)

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Summary

Protein S is a vitamin K-dependent cofactor of activated protein C in the proteolytic cleavage and concomitant inactivation of the coagulation factors Va and Villa. Protein S is sensitive to proteolysis by thrombin which reduces its functional activity. Uncontrolled proteolytic breakdown, leading to the generation of a two-chain molecule, is commonly encountered during the purification of both human and bovine protein S. In this study we demonstrate that human, single-chain, intact protein S can be isolated from plasma in a single step by affinity chromatography using a monoclonal antibody, CLB PS 52, directed to an epitope located within the thrombin-sensitive region of protein S. The product of purification was readily cleaved by thrombin after Arg49, resulting in a two-chain molecule which demonstrated a lower reactivity towards CLB-PS 52 than the parent single-chain protein. This study for the first time shows that intact protein S can be isolated directly from plasma using a monoclonal antibody selected for its ability to recognize uncleaved protein S.