A hydrophobic patch (PLVIVG; 1481–1486) in the B-domain of factor V-short is crucial for its synergistic TFPIα-cofactor activity with protein S and for the formation of the FXa-inhibitory complex comprising FV-short, TFPIα, and protein S
(2022) In Journal of Thrombosis and Haemostasis 20(5). p.1146-1157- Abstract
Background: Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)–cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493–1537) in the B domain binds TFPIα. The preAR2 (1458–1492) is crucial for the synergistic TFPIα–cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα. Objective: To identify which part of preAR2 is required for the synergistic TFPIα–cofactor activity between FV-short and protein S. Methods: A FXa-inhibition assay was used to test the synergistic TFPIα cofactor activity between protein S and new FV-short variants... (More)
Background: Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)–cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493–1537) in the B domain binds TFPIα. The preAR2 (1458–1492) is crucial for the synergistic TFPIα–cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα. Objective: To identify which part of preAR2 is required for the synergistic TFPIα–cofactor activity between FV-short and protein S. Methods: A FXa-inhibition assay was used to test the synergistic TFPIα cofactor activity between protein S and new FV-short variants FV709-1476, FV712-1478, FV712-1481, FV712-1484, FV712-1487, and FV712-1490. A microtiter-based assay analyzed binding among FV-short variants, protein S, and TFPIα. Results: FV709-1476, FV712-1478, and FV712-1481 were fully active as synergistic TFPIα cofactors with protein S; FV712-1484 showed intermediate activity; and FV712-1487 and FV712-1490 were inactive. TFPIα interacted with all variants in the absence of protein S but FV712-1478 and FV712-1481 bound TFPIα with highest affinity. None of the FV-short variants bound directly to protein S in the absence of TFPIα. In the presence of TFPIα, efficient cooperative binding was demonstrated between protein S, TFPIα, and FV709-1476, FV712-1478, or FV712-1481. In contrast, no cooperativity among TFPIα, protein S, and FV712-1484, FV712-1487, or FV712-1490 was seen. Conclusion: A short hydrophobic patch in preAR2 (PLVIVG, 1481–1486) in FV-short is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for the assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα.
(Less)
- author
- Dahlbäck, Björn LU and Tran, Sinh LU
- organization
- publishing date
- 2022-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- blood coagulation, factor V, factor Xa, protein S, tissue factor pathway inhibitor
- in
- Journal of Thrombosis and Haemostasis
- volume
- 20
- issue
- 5
- pages
- 12 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:35247027
- scopus:85126288599
- ISSN
- 1538-7933
- DOI
- 10.1111/jth.15690
- language
- English
- LU publication?
- yes
- id
- 77440dae-e929-4795-9d81-95f2a8795456
- date added to LUP
- 2022-05-03 16:29:12
- date last changed
- 2024-05-03 07:59:18
@article{77440dae-e929-4795-9d81-95f2a8795456,
abstract = {{<p>Background: Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)–cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493–1537) in the B domain binds TFPIα. The preAR2 (1458–1492) is crucial for the synergistic TFPIα–cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα. Objective: To identify which part of preAR2 is required for the synergistic TFPIα–cofactor activity between FV-short and protein S. Methods: A FXa-inhibition assay was used to test the synergistic TFPIα cofactor activity between protein S and new FV-short variants FV709-1476, FV712-1478, FV712-1481, FV712-1484, FV712-1487, and FV712-1490. A microtiter-based assay analyzed binding among FV-short variants, protein S, and TFPIα. Results: FV709-1476, FV712-1478, and FV712-1481 were fully active as synergistic TFPIα cofactors with protein S; FV712-1484 showed intermediate activity; and FV712-1487 and FV712-1490 were inactive. TFPIα interacted with all variants in the absence of protein S but FV712-1478 and FV712-1481 bound TFPIα with highest affinity. None of the FV-short variants bound directly to protein S in the absence of TFPIα. In the presence of TFPIα, efficient cooperative binding was demonstrated between protein S, TFPIα, and FV709-1476, FV712-1478, or FV712-1481. In contrast, no cooperativity among TFPIα, protein S, and FV712-1484, FV712-1487, or FV712-1490 was seen. Conclusion: A short hydrophobic patch in preAR2 (PLVIVG, 1481–1486) in FV-short is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for the assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα.</p>}},
author = {{Dahlbäck, Björn and Tran, Sinh}},
issn = {{1538-7933}},
keywords = {{blood coagulation; factor V; factor Xa; protein S; tissue factor pathway inhibitor}},
language = {{eng}},
number = {{5}},
pages = {{1146--1157}},
publisher = {{Wiley-Blackwell}},
series = {{Journal of Thrombosis and Haemostasis}},
title = {{A hydrophobic patch (PLVIVG; 1481–1486) in the B-domain of factor V-short is crucial for its synergistic TFPIα-cofactor activity with protein S and for the formation of the FXa-inhibitory complex comprising FV-short, TFPIα, and protein S}},
url = {{http://dx.doi.org/10.1111/jth.15690}},
doi = {{10.1111/jth.15690}},
volume = {{20}},
year = {{2022}},
}