Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3

Roy R. Hantgan, Douglas S. Lyles, T. Conn Mallett, Mattia Rocco, Chandrasekaran Nagaswami, John W. Weisel

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Integrin αIIbβ3 clusters on the platelet surface after binding adhesive proteins in a process that regulates signal transduction. However, the intermolecular forces driving integrin self-association are poorly understood. This work provides new insights into integrin clustering mechanisms by demonstrating how temperature and ligand binding interact to affect the oligomeric state of αIIbβ3. The ligand-free receptor, solubilized in thermostable octyl glucoside micelles, exhibited a cooperative transition at ∼43°C, monitored by changes in intrinsic fluorescence and circular dichroism. Both signals changed in a direction opposite to that for global unfolding, and both were diminished upon binding the fibrinogen γ-chain ligand-mimetic peptide cHArGD. Free and bound receptors also exhibited differential sensitivity to temperature-enhanced oligomerization, as measured by dynamic light scattering, sedimentation velocity, and sedimentation equilibrium. Van't Hoff analyses of dimerization constants for αIIbβ3 complexed with cHArGD, cRGD, or eptifibatide yielded large, favorable entropy changes partly offset by unfavorable enthalpy changes. Transmission electron microscopy showed that ligand binding and 37°C incubation enhanced assembly of integrin dimers and larger oligomers linked by tail-to-tail contacts. Interpretation of these images was aided by threading models for αIIbβ3 protomers and dimers based on the ectodomain structure of αvβ3. We propose that entropy-favorable nonpolar interactions drive ligand-induced integrin clustering and outside-in signaling.

Original languageEnglish
Pages (from-to)3417-3426
Number of pages10
JournalJournal of Biological Chemistry
Volume278
Issue number5
DOIs
Publication statusPublished - Jan 31 2003

Fingerprint

Oligomerization
Entropy
Integrins
Ligands
Sedimentation
Dimers
Cluster Analysis
Signal transduction
Temperature
Dimerization
Protein Subunits
Micelles
Dynamic light scattering
Circular Dichroism
Platelets
Transmission Electron Microscopy
Oligomers
Adhesives
Fibrinogen
Enthalpy

ASJC Scopus subject areas

  • Biochemistry

Cite this

Hantgan, R. R., Lyles, D. S., Mallett, T. C., Rocco, M., Nagaswami, C., & Weisel, J. W. (2003). Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3 . Journal of Biological Chemistry, 278(5), 3417-3426. https://doi.org/10.1074/jbc.M208869200

Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3 . / Hantgan, Roy R.; Lyles, Douglas S.; Mallett, T. Conn; Rocco, Mattia; Nagaswami, Chandrasekaran; Weisel, John W.

In: Journal of Biological Chemistry, Vol. 278, No. 5, 31.01.2003, p. 3417-3426.

Research output: Contribution to journalArticle

Hantgan, RR, Lyles, DS, Mallett, TC, Rocco, M, Nagaswami, C & Weisel, JW 2003, 'Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3 ', Journal of Biological Chemistry, vol. 278, no. 5, pp. 3417-3426. https://doi.org/10.1074/jbc.M208869200
Hantgan RR, Lyles DS, Mallett TC, Rocco M, Nagaswami C, Weisel JW. Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3 . Journal of Biological Chemistry. 2003 Jan 31;278(5):3417-3426. https://doi.org/10.1074/jbc.M208869200
Hantgan, Roy R. ; Lyles, Douglas S. ; Mallett, T. Conn ; Rocco, Mattia ; Nagaswami, Chandrasekaran ; Weisel, John W. / Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3 . In: Journal of Biological Chemistry. 2003 ; Vol. 278, No. 5. pp. 3417-3426.
@article{23aff234bd5a4f738482555e82b67395,
title = "Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3",
abstract = "Integrin αIIbβ3 clusters on the platelet surface after binding adhesive proteins in a process that regulates signal transduction. However, the intermolecular forces driving integrin self-association are poorly understood. This work provides new insights into integrin clustering mechanisms by demonstrating how temperature and ligand binding interact to affect the oligomeric state of αIIbβ3. The ligand-free receptor, solubilized in thermostable octyl glucoside micelles, exhibited a cooperative transition at ∼43°C, monitored by changes in intrinsic fluorescence and circular dichroism. Both signals changed in a direction opposite to that for global unfolding, and both were diminished upon binding the fibrinogen γ-chain ligand-mimetic peptide cHArGD. Free and bound receptors also exhibited differential sensitivity to temperature-enhanced oligomerization, as measured by dynamic light scattering, sedimentation velocity, and sedimentation equilibrium. Van't Hoff analyses of dimerization constants for αIIbβ3 complexed with cHArGD, cRGD, or eptifibatide yielded large, favorable entropy changes partly offset by unfavorable enthalpy changes. Transmission electron microscopy showed that ligand binding and 37°C incubation enhanced assembly of integrin dimers and larger oligomers linked by tail-to-tail contacts. Interpretation of these images was aided by threading models for αIIbβ3 protomers and dimers based on the ectodomain structure of αvβ3. We propose that entropy-favorable nonpolar interactions drive ligand-induced integrin clustering and outside-in signaling.",
author = "Hantgan, {Roy R.} and Lyles, {Douglas S.} and Mallett, {T. Conn} and Mattia Rocco and Chandrasekaran Nagaswami and Weisel, {John W.}",
year = "2003",
month = "1",
day = "31",
doi = "10.1074/jbc.M208869200",
language = "English",
volume = "278",
pages = "3417--3426",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "5",

}

TY - JOUR

T1 - Ligand binding promotes the entropy-driven oligomerization of integrin αIIbβ3

AU - Hantgan, Roy R.

AU - Lyles, Douglas S.

AU - Mallett, T. Conn

AU - Rocco, Mattia

AU - Nagaswami, Chandrasekaran

AU - Weisel, John W.

PY - 2003/1/31

Y1 - 2003/1/31

N2 - Integrin αIIbβ3 clusters on the platelet surface after binding adhesive proteins in a process that regulates signal transduction. However, the intermolecular forces driving integrin self-association are poorly understood. This work provides new insights into integrin clustering mechanisms by demonstrating how temperature and ligand binding interact to affect the oligomeric state of αIIbβ3. The ligand-free receptor, solubilized in thermostable octyl glucoside micelles, exhibited a cooperative transition at ∼43°C, monitored by changes in intrinsic fluorescence and circular dichroism. Both signals changed in a direction opposite to that for global unfolding, and both were diminished upon binding the fibrinogen γ-chain ligand-mimetic peptide cHArGD. Free and bound receptors also exhibited differential sensitivity to temperature-enhanced oligomerization, as measured by dynamic light scattering, sedimentation velocity, and sedimentation equilibrium. Van't Hoff analyses of dimerization constants for αIIbβ3 complexed with cHArGD, cRGD, or eptifibatide yielded large, favorable entropy changes partly offset by unfavorable enthalpy changes. Transmission electron microscopy showed that ligand binding and 37°C incubation enhanced assembly of integrin dimers and larger oligomers linked by tail-to-tail contacts. Interpretation of these images was aided by threading models for αIIbβ3 protomers and dimers based on the ectodomain structure of αvβ3. We propose that entropy-favorable nonpolar interactions drive ligand-induced integrin clustering and outside-in signaling.

AB - Integrin αIIbβ3 clusters on the platelet surface after binding adhesive proteins in a process that regulates signal transduction. However, the intermolecular forces driving integrin self-association are poorly understood. This work provides new insights into integrin clustering mechanisms by demonstrating how temperature and ligand binding interact to affect the oligomeric state of αIIbβ3. The ligand-free receptor, solubilized in thermostable octyl glucoside micelles, exhibited a cooperative transition at ∼43°C, monitored by changes in intrinsic fluorescence and circular dichroism. Both signals changed in a direction opposite to that for global unfolding, and both were diminished upon binding the fibrinogen γ-chain ligand-mimetic peptide cHArGD. Free and bound receptors also exhibited differential sensitivity to temperature-enhanced oligomerization, as measured by dynamic light scattering, sedimentation velocity, and sedimentation equilibrium. Van't Hoff analyses of dimerization constants for αIIbβ3 complexed with cHArGD, cRGD, or eptifibatide yielded large, favorable entropy changes partly offset by unfavorable enthalpy changes. Transmission electron microscopy showed that ligand binding and 37°C incubation enhanced assembly of integrin dimers and larger oligomers linked by tail-to-tail contacts. Interpretation of these images was aided by threading models for αIIbβ3 protomers and dimers based on the ectodomain structure of αvβ3. We propose that entropy-favorable nonpolar interactions drive ligand-induced integrin clustering and outside-in signaling.

UR - http://www.scopus.com/inward/record.url?scp=0037474302&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037474302&partnerID=8YFLogxK

U2 - 10.1074/jbc.M208869200

DO - 10.1074/jbc.M208869200

M3 - Article

C2 - 12426312

AN - SCOPUS:0037474302

VL - 278

SP - 3417

EP - 3426

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 5

ER -