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Open data
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Basic information
Entry | Database: PDB / ID: 9b9k | ||||||||||||
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Title | Integrin alpha-5 beta-1 in complex with MINT1526A Fab | ||||||||||||
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![]() | SIGNALING PROTEIN / Integrin / Antibody Fab / Inhibitory | ||||||||||||
Function / homology | ![]() integrin alpha8-beta1 complex / : / integrin alpha3-beta1 complex / integrin alpha5-beta1 complex / integrin alpha6-beta1 complex / integrin alpha7-beta1 complex / integrin alpha10-beta1 complex / integrin alpha11-beta1 complex / positive regulation of glutamate uptake involved in transmission of nerve impulse / myoblast fate specification ...integrin alpha8-beta1 complex / : / integrin alpha3-beta1 complex / integrin alpha5-beta1 complex / integrin alpha6-beta1 complex / integrin alpha7-beta1 complex / integrin alpha10-beta1 complex / integrin alpha11-beta1 complex / positive regulation of glutamate uptake involved in transmission of nerve impulse / myoblast fate specification / integrin alpha9-beta1 complex / regulation of collagen catabolic process / cardiac cell fate specification / integrin binding involved in cell-matrix adhesion / integrin alpha4-beta1 complex / cell-cell adhesion mediated by integrin / integrin alpha1-beta1 complex / collagen binding involved in cell-matrix adhesion / Localization of the PINCH-ILK-PARVIN complex to focal adhesions / integrin alpha2-beta1 complex / reactive gliosis / formation of radial glial scaffolds / Other semaphorin interactions / cerebellar climbing fiber to Purkinje cell synapse / Formation of the ureteric bud / positive regulation of fibroblast growth factor receptor signaling pathway / CD40 signaling pathway / Fibronectin matrix formation / calcium-independent cell-matrix adhesion / basement membrane organization / regulation of synapse pruning / integrin alphav-beta1 complex / myelin sheath abaxonal region / CHL1 interactions / RUNX2 regulates genes involved in cell migration / cardiac muscle cell myoblast differentiation / alphav-beta3 integrin-vitronectin complex / MET interacts with TNS proteins / Laminin interactions / leukocyte tethering or rolling / cardiac muscle cell differentiation / germ cell migration / cell projection organization / Platelet Adhesion to exposed collagen / vascular endothelial growth factor receptor 2 binding / myoblast fusion / positive regulation of vascular endothelial growth factor signaling pathway / Elastic fibre formation / mesodermal cell differentiation / cell-substrate junction assembly / platelet-derived growth factor receptor binding / axon extension / myoblast differentiation / cell migration involved in sprouting angiogenesis / Differentiation of Keratinocytes in Interfollicular Epidermis in Mammalian Skin / positive regulation of fibroblast migration / positive regulation of vascular endothelial growth factor receptor signaling pathway / positive regulation of cell-substrate adhesion / wound healing, spreading of epidermal cells / integrin complex / heterophilic cell-cell adhesion via plasma membrane cell adhesion molecules / heterotypic cell-cell adhesion / regulation of spontaneous synaptic transmission / epidermal growth factor receptor binding / lamellipodium assembly / dendrite morphogenesis / sarcomere organization / Molecules associated with elastic fibres / MET activates PTK2 signaling / Basigin interactions / Mechanical load activates signaling by PIEZO1 and integrins in osteocytes / negative regulation of vasoconstriction / leukocyte cell-cell adhesion / cell adhesion mediated by integrin / positive regulation of wound healing / muscle organ development / Syndecan interactions / response to muscle activity / positive regulation of neuroblast proliferation / maintenance of blood-brain barrier / negative regulation of Rho protein signal transduction / positive regulation of sprouting angiogenesis / cell-substrate adhesion / endodermal cell differentiation / homophilic cell adhesion via plasma membrane adhesion molecules / TGF-beta receptor signaling activates SMADs / establishment of mitotic spindle orientation / cleavage furrow / fibronectin binding / negative regulation of anoikis / cellular response to low-density lipoprotein particle stimulus / RHOG GTPase cycle / glial cell projection / intercalated disc / neuroblast proliferation / negative regulation of neuron differentiation / RAC2 GTPase cycle / ECM proteoglycans / RAC3 GTPase cycle / Integrin cell surface interactions Similarity search - Function | ||||||||||||
Biological species | ![]() unidentified (others) | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.7 Å | ||||||||||||
![]() | Nguyen, A. / Azumaya, C.M. / Campbell, M.G. | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Structural and functional characterization of integrin α5-targeting antibodies for anti-angiogenic therapy. Authors: Adam Nguyen / Joel B Heim / Gabriele Cordara / Matthew C Chan / Hedda Johannesen / Cristine Charlesworth / Ming Li / Caleigh M Azumaya / Benjamin Madden / Ute Krengel / Alexander Meves / Melody G Campbell / ![]() ![]() Abstract: Integrins are a large family of heterodimeric receptors important for cell adhesion and signaling. Integrin α5β1, also known as the fibronectin receptor, is a key mediator of angiogenesis and its ...Integrins are a large family of heterodimeric receptors important for cell adhesion and signaling. Integrin α5β1, also known as the fibronectin receptor, is a key mediator of angiogenesis and its dysregulation is associated with tumor proliferation, progression, and metastasis. Despite numerous efforts, α5β1-targeting therapeutics have been unsuccessful in large part due to efficacy and off-target effects. To mediate activation and signaling, integrins undergo drastic conformational changes. However, how therapeutics influence or are affected by integrin conformation remains incompletely characterized. Using cell biology, biophysics, and electron microscopy, we shed light on these relationships by characterizing two potentially therapeutic anti-α5β1 antibodies, BIIG2 and MINT1526A. We show that both antibodies bind α5β1 with nanomolar affinity and reduce angiogenesis . We demonstrate BIIG2 reduces tumor growth in two human xenograft mouse models and exhibits a strong specificity for connective tissue-resident fibroblasts and melanoma cells. Using electron microscopy, we map out the molecular interfaces mediating the integrin-antibody interactions and reveal that although both antibodies have overlapping epitopes and block fibronectin binding via steric hindrance, the effect on the conformational equilibrium is drastically different. While MINT1526A constricts α5β1's range of flexibility, BIIG2 binds without restricting the available conformational states. These mechanistic insights, coupled with the functional analysis, guide which aspects should be prioritized to avoid off-target effects or partial agonism in the design of future integrin-targeted therapeutics. | ||||||||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 425.8 KB | Display | ![]() |
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PDB format | ![]() | 338.4 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 44387MC ![]() 8r38C ![]() 9b9jC C: citing same article ( M: map data used to model this data |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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1 |
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Components
-Protein , 2 types, 2 molecules AB
#1: Protein | Mass: 108693.734 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Details: Integrin alpha-5 ectodomain with cleaved linker, HRV 3C cute site, acid coil and Strep-Tag II. Source: (gene. exp.) ![]() ![]() ![]() |
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#2: Protein | Mass: 80653.781 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Details: Integrin beta-1 ectodomain with cleaved linker, HRV 3C cut site, base coil, and 6x His-tag. Source: (gene. exp.) ![]() ![]() ![]() |
-Antibody , 2 types, 2 molecules HL
#3: Antibody | Mass: 13398.053 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) unidentified (others) |
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#4: Antibody | Mass: 11978.021 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) unidentified (others) |
-Sugars , 5 types, 11 molecules 
#5: Polysaccharide | beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta- ...beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose Source method: isolated from a genetically manipulated source #6: Polysaccharide | alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-6)-[alpha-D- ...alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose | Source method: isolated from a genetically manipulated source #7: Polysaccharide | alpha-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1- ...alpha-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose | Source method: isolated from a genetically manipulated source #8: Polysaccharide | 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose Source method: isolated from a genetically manipulated source #10: Sugar | ChemComp-NAG / | |
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-Non-polymers , 1 types, 7 molecules 
#9: Chemical | ChemComp-CA / |
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-Details
Has ligand of interest | N |
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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: Protein complex of integrin alpha-5 beta-1 with MINT1526A Fab Type: COMPLEX / Entity ID: #1-#4 / Source: RECOMBINANT | ||||||||||||||||||||
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Molecular weight | Experimental value: NO | ||||||||||||||||||||
Source (natural) | Organism: ![]() | ||||||||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | ||||||||||||||||||||
Buffer solution | pH: 7.4 | ||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 0.1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | ||||||||||||||||||||
Specimen support | Grid material: GOLD / Grid mesh size: 300 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
Microscopy | Model: TFS GLACIOS |
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Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 36000 X / Nominal defocus max: 1800 nm / Nominal defocus min: 1400 nm / Cs: 2.7 mm |
Specimen holder | Cryogen: NITROGEN |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) / Num. of grids imaged: 1 / Num. of real images: 3079 |
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Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 1339328 | ||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.7 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 342608 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 106.4 / Protocol: RIGID BODY FIT / Space: REAL / Target criteria: Cross-correlation coefficient Details: Initial local fitting was done using ChimeraX and then Phenix, ISOLDE and COOT for flexible fitting and modeling. | ||||||||||||||||||||||||||||||||||||
Atomic model building | 3D fitting-ID: 1 / Accession code: 7NXD / Initial refinement model-ID: 1 / PDB-ID: 7NXD / Source name: PDB / Type: experimental model
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Refinement | Highest resolution: 2.7 Å |