Conformation of factor Xa in solution revealed by single-molecule spectroscopy.
J Thromb Haemost
; 2024 Jul 11.
Article
en En
| MEDLINE
| ID: mdl-39002733
ABSTRACT
BACKGROUND:
All current X-ray structures of factor (F)Xa are devoid of the γ-carboxyglutamate (Gla) domain and fail to reveal the overall conformation of the free protein. The recent cryogenic electron microscopy (cryo-EM) structure of FXa in the prothrombinase complex is the only structure of full-length FXa and shows that the Gla domain is positioned at an angle relative to the epidermal growth factor 1 domain.OBJECTIVES:
Establish if the curved conformation of FXa revealed by cryo-EM is also present in solution.METHODS:
The conformation of FXa in solution was studied by single-molecule Förster resonance energy transfer.RESULTS:
The conformation of full-length FXa in solution is resolved for the first time. The conformation is curved and extremely sensitive to Ca2+. It does not differ significantly from its zymogen form or from that present in the prothrombinase complex free or bound to the physiologic substrates prothrombin and meizothrombin.CONCLUSION:
Measurements by single-molecule Förster resonance energy transfer reveal that FXa has a curved conformation in solution, free or bound to physiologic ligands, and validate the recent cryo-EM structures of prothrombinase. The drastic conformational changes observed in the absence of Ca2+ suggest that the structural architecture of FXa changes upon administration of vitamin K antagonists that perturb the interaction of the Gla domain with divalent cations.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Thromb Haemost
Asunto de la revista:
HEMATOLOGIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido