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Open data
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Basic information
| Entry | Database: PDB / ID: 9dax | ||||||||||||||||||||||||
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| Title | The structure of AlphaIIbbeta3 in apo state | ||||||||||||||||||||||||
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Keywords | BLOOD CLOTTING / alphaIIbbeta3 integrin / platelet aggregation / clot retraction | ||||||||||||||||||||||||
| Function / homology | Function and homology informationregulation of serotonin uptake / positive regulation of adenylate cyclase-inhibiting opioid receptor signaling pathway / tube development / alpha9-beta1 integrin-ADAM8 complex / regulation of trophoblast cell migration / integrin alphaIIb-beta3 complex / regulation of postsynaptic neurotransmitter receptor diffusion trapping / alphav-beta3 integrin-vitronectin complex / maintenance of postsynaptic specialization structure / regulation of extracellular matrix organization ...regulation of serotonin uptake / positive regulation of adenylate cyclase-inhibiting opioid receptor signaling pathway / tube development / alpha9-beta1 integrin-ADAM8 complex / regulation of trophoblast cell migration / integrin alphaIIb-beta3 complex / regulation of postsynaptic neurotransmitter receptor diffusion trapping / alphav-beta3 integrin-vitronectin complex / maintenance of postsynaptic specialization structure / regulation of extracellular matrix organization / platelet alpha granule membrane / integrin alphav-beta3 complex / negative regulation of lipoprotein metabolic process / positive regulation of glomerular mesangial cell proliferation / alphav-beta3 integrin-PKCalpha complex / fibrinogen binding / alphav-beta3 integrin-HMGB1 complex / vascular endothelial growth factor receptor 2 binding / negative regulation of lipid transport / positive regulation of vascular endothelial growth factor signaling pathway / Elastic fibre formation / cell-substrate junction assembly / alphav-beta3 integrin-IGF-1-IGF1R complex / positive regulation of bone resorption / platelet-derived growth factor receptor binding / mesodermal cell differentiation / glycinergic synapse / extracellular matrix binding / filopodium membrane / regulation of release of sequestered calcium ion into cytosol / positive regulation of vascular endothelial growth factor receptor signaling pathway / positive regulation of cell adhesion mediated by integrin / apolipoprotein A-I-mediated signaling pathway / negative regulation of low-density lipoprotein particle clearance / regulation of bone resorption / angiogenesis involved in wound healing / positive regulation of leukocyte migration / wound healing, spreading of epidermal cells / apoptotic cell clearance / positive regulation of fibroblast migration / integrin complex / cell adhesion mediated by integrin / smooth muscle cell migration / heterotypic cell-cell adhesion / Molecules associated with elastic fibres / positive regulation of smooth muscle cell migration / negative chemotaxis / Mechanical load activates signaling by PIEZO1 and integrins in osteocytes / positive regulation of cell-matrix adhesion / Syndecan interactions / p130Cas linkage to MAPK signaling for integrins / regulation of postsynaptic neurotransmitter receptor internalization / cellular response to insulin-like growth factor stimulus / positive regulation of osteoblast proliferation / protein disulfide isomerase activity / microvillus membrane / cell-substrate adhesion / platelet-derived growth factor receptor signaling pathway / PECAM1 interactions / GRB2:SOS provides linkage to MAPK signaling for Integrins / TGF-beta receptor signaling activates SMADs / fibronectin binding / lamellipodium membrane / negative regulation of macrophage derived foam cell differentiation / negative regulation of lipid storage / blood coagulation, fibrin clot formation / ECM proteoglycans / Integrin cell surface interactions / negative regulation of endothelial cell apoptotic process / positive regulation of T cell migration / coreceptor activity / cellular response to platelet-derived growth factor stimulus / Integrin signaling / positive regulation of endothelial cell proliferation / positive regulation of substrate adhesion-dependent cell spreading / substrate adhesion-dependent cell spreading / embryo implantation / cell adhesion molecule binding / positive regulation of endothelial cell migration / positive regulation of smooth muscle cell proliferation / Turbulent (oscillatory, disturbed) flow shear stress activates signaling by PIEZO1 and integrins in endothelial cells / protein kinase C binding / cell-matrix adhesion / response to activity / Signal transduction by L1 / integrin-mediated signaling pathway / regulation of actin cytoskeleton organization / wound healing / cellular response to mechanical stimulus / Signaling by high-kinase activity BRAF mutants / MAP2K and MAPK activation / RUNX1 regulates genes involved in megakaryocyte differentiation and platelet function / cell-cell adhesion / platelet activation / VEGFA-VEGFR2 Pathway / platelet aggregation / integrin binding / cellular response to xenobiotic stimulus / positive regulation of fibroblast proliferation / ruffle membrane Similarity search - Function | ||||||||||||||||||||||||
| Biological species | Homo sapiens (human) | ||||||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å | ||||||||||||||||||||||||
Authors | Walz, T. / Coller, B.S. / Wang, J.L. / Buitrago, L. / Wang, L. / Li, J.H. | ||||||||||||||||||||||||
| Funding support | United States, 1items
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Citation | Journal: Blood Adv / Year: 2025Title: An αIIbβ3 ligand-mimetic murine monoclonal antibody that produces platelet activation by engaging the FcγIIa receptor. Authors: Jialing Wang / Lorena Buitrago / Lu Wang / Jihong Li / Thomas Walz / Barry S Coller / ![]() Abstract: To produce a murine monoclonal antibody (mAb) that binds to glycoprotein IIb/IIIa (αIIbβ3) and inhibits clot retraction (CR), we immunized mice with human platelets and tested hybridoma ...To produce a murine monoclonal antibody (mAb) that binds to glycoprotein IIb/IIIa (αIIbβ3) and inhibits clot retraction (CR), we immunized mice with human platelets and tested hybridoma supernatants for their ability to bind to αIIbβ3 and inhibit CR. The immunoglobulin G1 (IgG1) mAb R6H8 completely inhibited CR at 20 μg/mL. Paradoxically, at 5 μg/mL, R6H8 initiated platelet aggregation and induced P-selectin expression, fibrinogen binding, and PAC-1 binding. At 20 μg/mL, however, R6H8 completely inhibited aggregation induced by thrombin PAR-1 receptor activating peptide SFLLRN (T6; 25 μg/mL) and T6-induced fibrinogen and PAC-1 binding to platelets. Platelet aggregation induced by R6H8 was inhibited by mAb IV.3, which blocks the FcγIIa receptor (FcγRIIa), and the Fab fragment of R6H8 did not induce platelet aggregation, suggesting that R6H8 binds to both αIIbβ3 and FcγRIIa. Cryogenic electron microscopy analysis of the R6H8 Fab-αIIbβ3 complex revealed that R6H8 (1) binds to the αIIbβ3 RGD binding pocket via an Arg-Tyr-Asp (RYD) sequence in its heavy chain complementarity-determining region 3; (2) interacts with β3 Asp126, producing a reorientation of Asp126 and loss of the adjacent to metal ion-dependent adhesion site Ca2+; and (3) initiates swing-out of the β3 hybrid domain. We conclude that R6H8 is an αIIbβ3 ligand-mimetic mAb that activates platelets via FcγRIIa at low concentrations and potently inhibits platelet aggregation and CR at high concentrations. R6H8 simulates the actions of a number of pathological antibodies, including platelet-activating antibodies developed after therapy with αIIbβ3 inhibitors and platelet-activating antibodies in heparin-induced thrombocytopenia and vaccine-induced immune thrombotic thrombocytopenia. As such, it may be a valuable reagent for better understanding these disorders and identifying potential therapies. | ||||||||||||||||||||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 9dax.cif.gz | 193.6 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9dax.ent.gz | 138.4 KB | Display | PDB format |
| PDBx/mmJSON format | 9dax.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/da/9dax ftp://data.pdbj.org/pub/pdb/validation_reports/da/9dax | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 46701MC ![]() 9daoC C: citing same article ( M: map data used to model this data |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
| #1: Protein | Mass: 110106.391 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P08514 | ||||||||
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| #2: Protein | Mass: 84478.500 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P05106 | ||||||||
| #3: Chemical | ChemComp-CA / #4: Chemical | ChemComp-MG / | #5: Water | ChemComp-HOH / | Has ligand of interest | Y | Has protein modification | Y | |
-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
| Component | Name: AlphaIIbbeta3 integrin in apo state / Type: COMPLEX / Details: AlphaIIbbeta3 is platelet-derived / Entity ID: #1-#2 / Source: NATURAL | ||||||||||||||||
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| Molecular weight |
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| Source (natural) | Organism: Homo sapiens (human) | ||||||||||||||||
| Buffer solution | pH: 7.4 | ||||||||||||||||
| Specimen | Conc.: 0.012 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | ||||||||||||||||
| Specimen support | Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: Quantifoil R1.2/1.3 | ||||||||||||||||
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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| Microscopy | Model: FEI TITAN KRIOS |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2500 nm / Nominal defocus min: 1200 nm |
| Image recording | Electron dose: 54 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
| EM software | Name: PHENIX / Category: model refinement | ||||||||||||||||||||||||
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| CTF correction | Type: NONE | ||||||||||||||||||||||||
| 3D reconstruction | Resolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 146339 / Symmetry type: POINT | ||||||||||||||||||||||||
| Atomic model building | Protocol: RIGID BODY FIT | ||||||||||||||||||||||||
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About Yorodumi




Homo sapiens (human)
United States, 1items
Citation


PDBj
















FIELD EMISSION GUN