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Conformation of factor Xa in solution revealed by single-molecule spectroscopy.
- Source :
-
Journal of thrombosis and haemostasis : JTH [J Thromb Haemost] 2024 Jul 11. Date of Electronic Publication: 2024 Jul 11. - Publication Year :
- 2024
- Publisher :
- Ahead of Print
-
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.<br />Objectives: Establish if the curved conformation of FXa revealed by cryo-EM is also present in solution.<br />Methods: The conformation of FXa in solution was studied by single-molecule Förster resonance energy transfer.<br />Results: The conformation of full-length FXa in solution is resolved for the first time. The conformation is curved and extremely sensitive to Ca <superscript>2+</superscript> . 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.<br />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 Ca <superscript>2+</superscript> 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.<br />Competing Interests: Declaration of competing interests There are no competing interests to disclose.<br /> (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
Details
- Language :
- English
- ISSN :
- 1538-7836
- Database :
- MEDLINE
- Journal :
- Journal of thrombosis and haemostasis : JTH
- Publication Type :
- Academic Journal
- Accession number :
- 39002733
- Full Text :
- https://doi.org/10.1016/j.jtha.2024.07.003