The activation peptide cleft exposed by thrombin cleavage of FXIII-A(2) contains a recognition site for the fibrinogen α chain.
Blood
; 121(11): 2117-26, 2013 Mar 14.
Article
em En
| MEDLINE
| ID: mdl-23303819
ABSTRACT
Formation of a stable fibrin clot is dependent on interactions between factor XIII and fibrin. We have previously identified a key residue on the αC of fibrin(ogen) (Glu396) involved in binding activated factor XIII-A(2) (FXIII-A(2)*); however, the functional role of this interaction and binding site(s) on FXIII-A(2)* remains unknown. Here we (1) characterized the functional implications of this interaction; (2) identified by liquid-chromatography-tandem mass spectrometry the interacting residues on FXIII-A(2)* following chemical cross-linking of fibrin(ogen) αC389-402 peptides to FXIII-A(2)*; and (3) carried out molecular modeling of the FXIII-A(2)*/peptide complex to identify contact site(s) involved. Results demonstrated that inhibition of the FXIII-A(2)*/αC interaction using αC389-402 peptide (Pep1) significantly decreased incorporation of biotinamido-pentylamine and α2-antiplasmin to fibrin, and fibrin cross-linking, in contrast to Pep1-E396A and scrambled peptide controls. Pep1 did not inhibit transglutaminase-2 activity, and incorporation of biotinyl-TVQQEL to fibrin was only weakly inhibited. Molecular modeling predicted that Pep1 binds the activation peptide cleft (AP-cleft) within the ß-sandwich domain of FXIII-A(2)* localizing αC cross-linking Q366 to the FXIII-A(2)* active site. Our findings demonstrate that binding of fibrin αC389-402 to the AP-cleft is fundamental to clot stabilization and presents this region of FXIII-A(2)* as a potential site involved in glutamine-donor substrate recognition.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Fator XIII
/
Fibrinogênio
/
Trombina
/
Domínio Catalítico
/
Domínios e Motivos de Interação entre Proteínas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Blood
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Reino Unido