Characterization of common neoantigenic epitopes generated in plasminogen activator inhibitor‐1 after cleavage of the reactive center loop or after complex formation with various serine proteinases

FEBS Letters

Declerck, Paul J.¹  Debrock, Sophie¹ 

[1] Laboratory for Pharmaceutical Biology and Phytopharmacology, Faculty of Pharmaceutical Sciences, Katholieke Universiteit Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium

关键词: Monoclonal antibody;    Plasminogen activator inhibitor;    PAI-1;    Neoantigenic;    Serpin;    PAI-1;    plasminogen activator inhibitor-1;    t-PA;    tissue-type plasminogen activator;    u-PA;    urokinase-type plasminogen activator;    ELISA;    enzyme linked immunosorbent assay;    PBS;    phosphate buffered saline;    serpin;    serine proteinase inhibitor;    RAM;    rabbit anti-mouse;    HRP;    horseradish peroxidase;   

DOI  :  10.1016/0014-5793(95)01289-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Plasminogen activator inhibitor-1 (PAI-1), an important risk factor for thrombotic diseases, is a member of the superfamily of serine proteinase inhibitors. To define structural rearrangements occurring during interaction between PAI-1 and its target proteinases we have raised monoclonal antibodies against the PAI-1/t-PA complex. Thirteen out of 401 monoclonal antibodies reacted preferentially with the PAI-1/t-PA complex as compared to free PAI-1 or free t-PA. Detailed characterization revealed the presence of two non-overlapping neoantigenic epitopes in the PAI-1/t-PA complex. Both neoantigenic epitopes were also exposed after complex formation between PAI-1 and either urokinase-type plasminogen activator, plasmin or thrombin as well as after cleavage of the reactive site loop of non-inhibitory substrate type PAI-1 variants. Thus, we have identified two neoantigenic epitopes, localized entirely in PAI-1, and commonly exposed after complex formation of active PAI-1 with various proteinases or after cleavage of substrate PAI-1. These monoclonal antibodies should facilitate further studies on the mechanism of interaction between various PAI-1 forms and its target proteinases.

【 授权许可】

Unknown