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Abstract
The formation of membrane-bound complexes between specific coagulation factors at different cell surfaces is required for effective blood clotting. The most important of these complexes, the intrinsic Tenase and Prothrombinase complexes, are formed on the activated platelet surface during the propagation phase of coagulation. These two complexes are highly specific in their assembly mechanism and function modulated by anionic membranes, thus offering desirable targets for pharmaceutical interventions. Factor V (FV) and factor VIII (FVIII) are highly homologous non-enzymatic proteins. In their active state, FVa and FVIIIa serve as cofactors for the respective serine proteases factor Xa (FXa) and factor IXa (FIXa), significantly increasing their catalytic activity. This is achieved by forming well organized membrane-bound complexes at the phosphatidylserine rich activated platelet membrane in the presence of Ca2+ ions. The tenase (FVIIIa/FIXa) complex, catalyzes the proteolytic conversion of FX to FXa. Subsequently the prothrombinase (FVa/FXa) complex catalyzes the conversion of prothrombin to thrombin, required for efficient blood clotting. Although significant knowledge of FV and FVIII biochemistry and regulation has been achieved, the molecular mechanisms of their function are yet to be defined. Understanding the geometric assembly of the tenase and prothrombinase complexes is paramount in defining the structural basis of bleeding and thrombotic disorders. Such knowledge will enable the design of efficient pro- and anticoagulant therapies critical for regulating abnormal hemostasis. In this chapter, we will summarize the findings to date, showing our achievement in the field and outlining the future findings required to grasp the complexity of these proteins.
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Affiliation(s)
- Svetla Stoilova-McPhie
- Center for Nanoscale Systems (CNS), Laboratory For Integrated Sciences and Engineering (LISE), Faculty of Art and Sciences (FAS), Harvard University, 11 Oxford Street, Cambridge, MA, 02138, England, UK.
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Smith IW, d’Aquino AE, Coyle CW, Fedanov A, Parker ET, Denning G, Spencer HT, Lollar P, Doering CB, Spiegel PC. The 3.2 Å structure of a bioengineered variant of blood coagulation factor VIII indicates two conformations of the C2 domain. J Thromb Haemost 2020; 18:57-69. [PMID: 31454152 PMCID: PMC6940532 DOI: 10.1111/jth.14621] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/23/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Coagulation factor VIII represents one of the oldest protein-based therapeutics, serving as an effective hemophilia A treatment for half a century. Optimal treatment consists of repeated intravenous infusions of blood coagulation factor VIII (FVIII) per week for life. Despite overall treatment success, significant limitations remain, including treatment invasiveness, duration, immunogenicity, and cost. These issues have inspired research into the development of bioengineered FVIII products and gene therapies. OBJECTIVES To structurally characterize a bioengineered construct of FVIII, termed ET3i, which is a human/porcine chimeric B domain-deleted heterodimer with improved expression and slower A2 domain dissociation following proteolytic activation by thrombin. METHODS The structure of ET3i was characterized with X-ray crystallography and tandem mass spectrometry-based glycoproteomics. RESULTS Here, we report the 3.2 Å crystal structure of ET3i and characterize the distribution of N-linked glycans with LC-MS/MS glycoproteomics. This structure shows remarkable conservation with the human FVIII protein and provides a detailed view of the interface between the A2 domain and the remaining FVIII structure. With two FVIII molecules in the crystal, we observe two conformations of the C2 domain relative to the remaining FVIII structure. The improved model and stereochemistry of ET3i served as a scaffold to generate an improved, refined structure of human FVIII. With the original datasets at 3.7 Å and 4.0 Å resolution, this new structure resulted in improved refinement statistics. CONCLUSIONS These improved structures yield a more confident model for next-generation engineering efforts to develop FVIII therapeutics with longer half-lives, higher expression levels, and lower immunogenicity.
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Affiliation(s)
- Ian W. Smith
- Department of Chemistry, Western Washington University, 516 High Street, MS 9150, Bellingham, WA 98225-9150
| | - Anne E. d’Aquino
- Department of Chemistry, Western Washington University, 516 High Street, MS 9150, Bellingham, WA 98225-9150
| | - Christopher W. Coyle
- Graduate Program in Molecular and Systems Pharmacology, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA 30322
| | - Andrew Fedanov
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University, Atlanta, GA 30322
| | - Ernest T. Parker
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University, Atlanta, GA 30322
| | | | - H. Trent Spencer
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University, Atlanta, GA 30322
| | - Pete Lollar
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University, Atlanta, GA 30322
| | - Christopher B. Doering
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University, Atlanta, GA 30322
| | - P. Clint Spiegel
- Department of Chemistry, Western Washington University, 516 High Street, MS 9150, Bellingham, WA 98225-9150
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Dalm D, Galaz-Montoya JG, Miller JL, Grushin K, Villalobos A, Koyfman AY, Schmid MF, Stoilova-McPhie S. Dimeric Organization of Blood Coagulation Factor VIII bound to Lipid Nanotubes. Sci Rep 2015; 5:11212. [PMID: 26082135 PMCID: PMC4469981 DOI: 10.1038/srep11212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/05/2015] [Indexed: 11/09/2022] Open
Abstract
Membrane-bound Factor VIII (FVIII) has a critical function in blood coagulation as the pro-cofactor to the serine-protease Factor IXa (FIXa) in the FVIIIa-FIXa complex assembled on the activated platelet membrane. Defects or deficiency of FVIII cause Hemophilia A, a mild to severe bleeding disorder. Despite existing crystal structures for FVIII, its membrane-bound organization has not been resolved. Here we present the dimeric FVIII membrane-bound structure when bound to lipid nanotubes, as determined by cryo-electron microscopy. By combining the structural information obtained from helical reconstruction and single particle subtomogram averaging at intermediate resolution (15-20 Å), we show unambiguously that FVIII forms dimers on lipid nanotubes. We also demonstrate that the organization of the FVIII membrane-bound domains is consistently different from the crystal structure in solution. The presented results are a critical step towards understanding the mechanism of the FVIIIa-FIXa complex assembly on the activated platelet surface in the propagation phase of blood coagulation.
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Affiliation(s)
- Daniela Dalm
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jesus G Galaz-Montoya
- 1] Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA [2] National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jaimy L Miller
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Kirill Grushin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Alex Villalobos
- School of Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Alexey Y Koyfman
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Michael F Schmid
- 1] Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA [2] National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Svetla Stoilova-McPhie
- 1] Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA [2] Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
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Grushin K, Miller J, Dalm D, Stoilova-McPhie S. Factor VIII organisation on nanodiscs with different lipid composition. Thromb Haemost 2015; 113:741-9. [PMID: 25589466 DOI: 10.1160/th14-09-0725] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/23/2014] [Indexed: 11/05/2022]
Abstract
Nanodiscs (ND) are lipid bilayer membrane patches held by amphiphilic scaffolding proteins (MSP) of ~10 nm in diameter. Nanodiscs have been developed as lipid nanoplatforms for structural and functional studies of membrane and membrane associated proteins. Their size and monodispersity have rendered them unique for electron microscopy (EM) and single particle analysis studies of proteins and complexes either spanning or associated to the ND membrane. Binding of blood coagulation factors and complexes, such as the Factor VIII (FVIII) and the Factor VIIIa - Factor IXa (intrinsic tenase) complex to the negatively charged activated platelet membrane is required for normal haemostasis. In this study we present our work on optimising ND, specifically designed to bind FVIII at close to physiological conditions. The binding of FVIII to the negatively charged ND rich in phosphatidylserine (PS) was followed by electron microscopy at three different PS compositions and two different membrane scaffolding protein (MSP1D1) to lipid ratios. Our results show that the ND with highest PS content (80 %) and lowest MSP1D1 to lipid ratio (1:47) are the most suitable for structure determination of the membrane-bound FVIII by single particle EM. Our preliminary FVIII 3D reconstruction as bound to PS containing ND demonstrates the suitability of the optimised ND for structural studies by EM. Further assembly of the activated FVIII form (FVIIIa) and the whole FVIIIa-FIXa complex on ND, followed by EM and single particle reconstruction will help to identify the protein-protein and protein-membrane interfaces critical for the intrinsic tenase complex assembly and function.
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Affiliation(s)
| | | | | | - Svetla Stoilova-McPhie
- Svetla Stoilova-McPhie, Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA, Tel: +1 979 319 1349, Fax: +1 409 747 2200, E-mail:
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Stoilova-McPhie S, Grushin K, Dalm D, Miller J. Lipid nanotechnologies for structural studies of membrane-associated proteins. Proteins 2014; 82:2902-9. [PMID: 24957666 PMCID: PMC5292012 DOI: 10.1002/prot.24631] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 06/04/2014] [Accepted: 06/08/2014] [Indexed: 11/09/2022]
Abstract
We present a methodology of lipid nanotubes (LNT) and nanodisks technologies optimized in our laboratory for structural studies of membrane-associated proteins at close to physiological conditions. The application of these lipid nanotechnologies for structure determination by cryo-electron microscopy (cryo-EM) is fundamental for understanding and modulating their function. The LNTs in our studies are single bilayer galactosylceramide based nanotubes of ∼20 nm inner diameter and a few microns in length, that self-assemble in aqueous solutions. The lipid nanodisks (NDs) are self-assembled discoid lipid bilayers of ∼10 nm diameter, which are stabilized in aqueous solutions by a belt of amphipathic helical scaffold proteins. By combining LNT and ND technologies, we can examine structurally how the membrane curvature and lipid composition modulates the function of the membrane-associated proteins. As proof of principle, we have engineered these lipid nanotechnologies to mimic the activated platelet's phosphtaidylserine rich membrane and have successfully assembled functional membrane-bound coagulation factor VIII in vitro for structure determination by cryo-EM. The macromolecular organization of the proteins bound to ND and LNT are further defined by fitting the known atomic structures within the calculated three-dimensional maps. The combination of LNT and ND technologies offers a means to control the design and assembly of a wide range of functional membrane-associated proteins and complexes for structural studies by cryo-EM. The presented results confirm the suitability of the developed methodology for studying the functional structure of membrane-associated proteins, such as the coagulation factors, at a close to physiological environment.
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Affiliation(s)
- Svetla Stoilova-McPhie
- Department of Neuroscience and Cell Biology, The University of Texas Medical Branch, 301 University Blvd, Galveston, Texas, 77555; Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, 301 University Blvd, Galveston, Texas, 77555
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Miller J, Dalm D, Koyfman AY, Grushin K, Stoilova-McPhie S. Helical organization of blood coagulation factor VIII on lipid nanotubes. J Vis Exp 2014. [PMID: 24961276 DOI: 10.3791/51254] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cryo-electron microscopy (Cryo-EM)(1) is a powerful approach to investigate the functional structure of proteins and complexes in a hydrated state and membrane environment(2). Coagulation Factor VIII (FVIII)(3) is a multi-domain blood plasma glycoprotein. Defect or deficiency of FVIII is the cause for Hemophilia type A - a severe bleeding disorder. Upon proteolytic activation, FVIII binds to the serine protease Factor IXa on the negatively charged platelet membrane, which is critical for normal blood clotting(4). Despite the pivotal role FVIII plays in coagulation, structural information for its membrane-bound state is incomplete(5). Recombinant FVIII concentrate is the most effective drug against Hemophilia type A and commercially available FVIII can be expressed as human or porcine, both forming functional complexes with human Factor IXa(6,7). In this study we present a combination of Cryo-electron microscopy (Cryo-EM), lipid nanotechnology and structure analysis applied to resolve the membrane-bound structure of two highly homologous FVIII forms: human and porcine. The methodology developed in our laboratory to helically organize the two functional recombinant FVIII forms on negatively charged lipid nanotubes (LNT) is described. The representative results demonstrate that our approach is sufficiently sensitive to define the differences in the helical organization between the two highly homologous in sequence (86% sequence identity) proteins. Detailed protocols for the helical organization, Cryo-EM and electron tomography (ET) data acquisition are given. The two-dimensional (2D) and three-dimensional (3D) structure analysis applied to obtain the 3D reconstructions of human and porcine FVIII-LNT is discussed. The presented human and porcine FVIII-LNT structures show the potential of the proposed methodology to calculate the functional, membrane-bound organization of blood coagulation Factor VIII at high resolution.
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Affiliation(s)
- Jaimy Miller
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch
| | - Daniela Dalm
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch
| | - Alexey Y Koyfman
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch
| | - Kirill Grushin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch
| | - Svetla Stoilova-McPhie
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch;
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van den Ent F, Izoré T, Bharat TA, Johnson CM, Löwe J. Bacterial actin MreB forms antiparallel double filaments. eLife 2014; 3:e02634. [PMID: 24843005 PMCID: PMC4051119 DOI: 10.7554/elife.02634] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 05/02/2014] [Indexed: 12/30/2022] Open
Abstract
Filaments of all actin-like proteins known to date are assembled from pairs of protofilaments that are arranged in a parallel fashion, generating polarity. In this study, we show that the prokaryotic actin homologue MreB forms pairs of protofilaments that adopt an antiparallel arrangement in vitro and in vivo. We provide an atomic view of antiparallel protofilaments of Caulobacter MreB as apparent from crystal structures. We show that a protofilament doublet is essential for MreB's function in cell shape maintenance and demonstrate by in vivo site-specific cross-linking the antiparallel orientation of MreB protofilaments in E. coli. 3D cryo-EM shows that pairs of protofilaments of Caulobacter MreB tightly bind to membranes. Crystal structures of different nucleotide and polymerisation states of Caulobacter MreB reveal conserved conformational changes accompanying antiparallel filament formation. Finally, the antimicrobial agents A22/MP265 are shown to bind close to the bound nucleotide of MreB, presumably preventing nucleotide hydrolysis and destabilising double protofilaments.DOI: http://dx.doi.org/10.7554/eLife.02634.001.
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Affiliation(s)
- Fusinita van den Ent
- Structural Studies Division, Medical Research Council - Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Thierry Izoré
- Structural Studies Division, Medical Research Council - Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Tanmay Am Bharat
- Structural Studies Division, Medical Research Council - Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Christopher M Johnson
- Protein and Nucleic Acid Chemistry Division, Medical Research Council - Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Jan Löwe
- Structural Studies Division, Medical Research Council - Laboratory of Molecular Biology, Cambridge, United Kingdom
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Stoilova-McPhie S, Lynch GC, Ludtke S, Pettitt BM. Domain organization of membrane-bound factor VIII. Biopolymers 2013; 99:448-59. [PMID: 23616213 PMCID: PMC4090243 DOI: 10.1002/bip.22199] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/13/2012] [Accepted: 11/18/2012] [Indexed: 11/07/2022]
Abstract
Factor VIII (FVIII) is the blood coagulation protein which when defective or deficient causes for hemophilia A, a severe hereditary bleeding disorder. Activated FVIII (FVIIIa) is the cofactor to the serine protease factor IXa (FIXa) within the membrane-bound Tenase complex, responsible for amplifying its proteolytic activity more than 100,000 times, necessary for normal clot formation. FVIII is composed of two noncovalently linked peptide chains: a light chain (LC) holding the membrane interaction sites and a heavy chain (HC) holding the main FIXa interaction sites. The interplay between the light and heavy chains (HCs) in the membrane-bound state is critical for the biological efficiency of FVIII. Here, we present our cryo-electron microscopy (EM) and structure analysis studies of human FVIII-LC, when helically assembled onto negatively charged single lipid bilayer nanotubes. The resolved FVIII-LC membrane-bound structure supports aspects of our previously proposed FVIII structure from membrane-bound two-dimensional (2D) crystals, such as only the C2 domain interacts directly with the membrane. The LC is oriented differently in the FVIII membrane-bound helical and 2D crystal structures based on EM data, and the existing X-ray structures. This flexibility of the FVIII-LC domain organization in different states is discussed in the light of the FVIIIa-FIXa complex assembly and function.
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Affiliation(s)
- Svetla Stoilova-McPhie
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, USA.
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KAMETA N, MASUDA M, SHIMIZU T. Liquid-Phase Nanospace Science of Bionanotubes Consisting of Synthetic Lipid Membranes. KOBUNSHI RONBUNSHU 2010. [DOI: 10.1295/koron.67.560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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