Evidence map›Paper›PMID 33829620›Full record

ArticleJournal of thrombosis and haemostasis : JTH2021

Structure-function of anticoagulant TIX-5, the inhibitor of factor Xa-mediated FV activation.

Anja Maag, Priyanka Sharma, Tim J Schuijt, Wil F Kopatz, Daniëlle Kruijswijk, J Arnoud Marquart, Tom van der Poll, Tilman M Hackeng, Gerry A F Nicolaes, Joost C M Meijers and 2 more

Open access · hybridAbstract read
In one paragraph

Article in Journal of thrombosis and haemostasis : JTH, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.1field-weighted citation impact, top 56% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 1 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors at 5 institutions in 1 country.

Anja MaagAmsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection and Immunity Institute, Amsterdam, The Netherlands.ORCID 0000-0002-9398-9094
Priyanka SharmaAmsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection and Immunity Institute, Amsterdam, The Netherlands.
Tim J SchuijtHospital Gelderse Vallei Ede, Clinical Chemistry and Hematology Laboratory, Ede, The Netherlands.
Wil F KopatzDepartment of Experimental Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
Daniëlle KruijswijkAmsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection and Immunity Institute, Amsterdam, The Netherlands.
J Arnoud MarquartDepartment of Molecular and Cellular Hemostasis, Sanquin Research, Amsterdam, The Netherlands.
Tom van der PollAmsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection and Immunity Institute, Amsterdam, The Netherlands.
Tilman M HackengDepartment of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM) Maastricht University, Maastricht, The Netherlands.
Gerry A F NicolaesDepartment of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM) Maastricht University, Maastricht, The Netherlands.
Joost C M MeijersDepartment of Experimental Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
Mettine H A BosDivision of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, The Netherlands.
Cornelis van 't VeerAmsterdam UMC, University of Amsterdam, Center for Experimental and Molecular Medicine, Amsterdam Infection and Immunity Institute, Amsterdam, The Netherlands.
Amsterdam University Medical Centers · NLLeiden University Medical Center · NLMaastricht University · NLSanquin · NLZiekenhuis Gelderse Vallei · NL

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe prothrombinase complex consists of factors Xa (FXa) and Va (FVa) on an anionic phospholipid surface and converts prothrombin into thrombin. Both coagulation factors require activation before complex assembly. We recently identified TIX-5, a unique anticoagulant tick protein that specifically inhibits FXa-mediated activation of FV. Because TIX-5 inhibited thrombin generation in blood plasma, it was concluded that FV activation by FXa contributes importantly to coagulation.

objectiveWe aimed to unravel the structure-function relationships of TIX-5.

methodWe used a structure model generated based on homology with the allergen Der F7.

resultsTick inhibitor of factor Xa toward FV was predicted to consist of a single rod formed by several beta sheets wrapped around a central C-terminal alpha helix. By mutagenesis we could show that two hydrophobic loops at one end of the rod mediate the phospholipid binding of TIX-5. On the other end of the rod an FV interaction region was identified on one side, whereas on the other side an EGK sequence was identified that could potentially form a pseudosubstrate of FXa. All three interaction sites were important for the anticoagulant properties of TIX-5 in a tissue factor-initiated thrombin generation assay as well as in the inhibition of FV activation by FXa in a purified system.

conclusionThe structure-function properties of TIX-5 are in perfect agreement with a protein that inhibits the FXa-mediated activation on a phospholipid surface. The present elucidation of the mechanism of action of TIX-5 will aid in deciphering the processes involved in the initiation phase of blood coagulation.

Indexed as

AnticoagulantsFactor Xa InhibitorsBlood CoagulationFactor VFactor VaFactor XaHumansProthrombinThrombinThromboplastinAnticoagulantsFactor VFactor VaFactor XaFactor Xa InhibitorsProthrombinThrombinThromboplastinanticoagulantfactor Vfactor XaHemorrhagethrombin

Identifiers

PMID33829620
PMCPMC8360041
OpenAlexW3147341461

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.