Monoclonal antibodies detect receptor-induced binding sites in Glu-plasminogen.
Blood
; 118(6): 1653-62, 2011 Aug 11.
Article
en En
| MEDLINE
| ID: mdl-21680799
ABSTRACT
When Glu-plasminogen binds to cells, its activation to plasmin is markedly enhanced compared with the reaction in solution, suggesting that Glu-plasminogen on cell surfaces adopts a conformation distinct from that in solution. However, direct evidence for such conformational changes has not been obtained. Therefore, we developed anti-plasminogen mAbs to test the hypothesis that Glu-plasminogen undergoes conformational changes on its interaction with cells. Six anti-plasminogen mAbs (recognizing 3 distinct epitopes) that preferentially recognized receptor-induced binding sites (RIBS) in Glu-plasminogen were obtained. The mAbs also preferentially recognized Glu-plasminogen bound to the C-terminal peptide of the plasminogen receptor, Plg-R(KT), and to fibrin, plasmin-treated fibrinogen, and Matrigel. We used trypsin proteolysis, immunoaffinity chromatography, and tandem mass spectrometry and identified Glu-plasminogen sequences containing epitopes recognized by the anti-plasminogen-RIBS mAbs a linear epitope within a domain linking kringles 1 and 2; a nonlinear epitope contained within the kringle 5 domain and the latent protease domain; and a nonlinear epitope contained within the N-terminal peptide of Glu-plasminogen and the latent protease domain. Our results identify neoepitopes latent in soluble Glu-plasminogen that become available when Glu-plasminogen binds to cells and demonstrate that binding of Glu-plasminogen to cells induces a conformational change in Glu-plasminogen distinct from that of Lys-Pg.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Plasminógeno
/
Receptores de Superficie Celular
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Anticuerpos Monoclonales
/
Epítopos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Blood
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos