Open Access
CC BY 4.0 · TH Open 2024; 08(01): e96-e105
DOI: 10.1055/a-2247-9438
Original Article

Development of the Integrated Computer Simulation Model of the Intracellular, Transmembrane, and Extracellular Domain of Platelet Integrin αIIbβ3 (Platelet Membrane Glycoprotein: GPIIb–IIIa)

Masamitsu Nakayama
1   Department of Medicine (Cardiology), Tokai University School of Medicine, Isehara, Japan
,
1   Department of Medicine (Cardiology), Tokai University School of Medicine, Isehara, Japan
,
1   Department of Medicine (Cardiology), Tokai University School of Medicine, Isehara, Japan
› Author Affiliations

Funding This work was funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan Society for the Promotion of Science, Kakenhi19H03661.


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Abstract

Background The structure and functions of the extracellular domain of platelet integrin αIIbβ3 (platelet membrane glycoprotein: GPIIb–IIIa) change substantially upon platelet activation. However, the stability of the integrated model of extracellular/transmembrane/intracellular domains of integrin αIIbβ3 with the inactive state of the extracellular domain has not been clarified.

Methods The integrated model of integrin αIIbβ3 was developed by combining the extracellular domain adopted from the crystal structure and the transmembrane and intracellular domain obtained by Nuclear Magnetic Resonace (NMR). The transmembrane domain was settled into the phosphatidylcholine (2-oleoyl-1-palmitoyl-sn-glycerol-3-phosphocholine (POPC)) lipid bilayer model. The position coordinates and velocity vectors of all atoms and water molecules around them were calculated by molecular dynamic (MD) simulation with the use of Chemistry at Harvard Macromolecular Mechanics force field in every 2 × 10−15 seconds.

Results The root-mean-square deviations (RMSDs) of atoms constructing the integrated αIIbβ3 model apparently stabilized at approximately 23 Å after 200 ns of calculation. However, minor fluctuation persisted during the entire calculation period of 650 ns. The RMSDs of both αIIb and β3 showed similar trends before 200 ns. The RMSD of β3 apparently stabilized approximately at 15 Å at 400 ns with persisting minor fluctuation afterward, while the structural fluctuation in αIIb persisted throughout the 650 ns calculation period.

Conclusion In conclusion, the integrated model of the intracellular, transmembrane, and extracellular domain of integrin αIIbβ3 suggested persisting fluctuation even after convergence of MD calculation.

* The contribution of Shinichi Goto on this paper is equal to Masamitsu Nakayama.




Publication History

Received: 11 May 2023

Accepted: 04 January 2024

Accepted Manuscript online:
17 January 2024

Article published online:
29 February 2024

© 2024. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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