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In-Silico Characterization of von Willebrand Factor Bound to FVIII. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Factor VIII belongs to the coagulation cascade and is expressed as a long pre-protein (mature form, 2351 amino acids long). FVIII is deficient or defective in hemophilic A patients, who need to be treated with hemoderivatives or recombinant FVIII substitutes, i.e., biologic drugs. The interaction between FVIII and von Willebrand factor (VWF) influences the pharmacokinetics of FVIII medications. In vivo, full-length FVIII (FL-FVIII) is secreted in a plasma-inactive form, which includes the B domain, which is then proteolyzed by thrombin protease activity, leading to an inactive plasma intermediate. In this work, we analyzed through a computational approach the binding of VWF with two structure models of FVIII (secreted full-length with B domain, and B domain-deleted FVIII). We included in our analysis the atomic model of efanesoctocog alfa, a novel and investigational recombinant FVIII medication, in which the VWF is covalently linked to FVIII. We carried out a structural analysis of VWF/FVIII interfaces by means of protein–protein docking, PISA (Proteins, Interfaces, Structures and Assemblies), and protein contact networks (PCN) analyses. Accordingly, our computational approaches to previously published experimental data demonstrated that the domains A3-C1 of B domain-deleted FVIII (BDD-FVIII) is the preferential binding site for VWF. Overall, our computational approach applied to topological analysis of protein–protein interface can be aimed at the rational design of biologic drugs other than FVIII medications.
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Zerra PE, Parker ET, Baldwin WH, Healey JF, Patel SR, McCoy JW, Cox C, Stowell SR, Meeks SL. Engineering a Therapeutic Protein to Enhance the Study of Anti-Drug Immunity. Biomedicines 2022; 10:1724. [PMID: 35885029 PMCID: PMC9313379 DOI: 10.3390/biomedicines10071724] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/29/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
The development of anti-drug antibodies represents a significant barrier to the utilization of protein-based therapies for a wide variety of diseases. While the rate of antibody formation can vary depending on the therapeutic employed and the target patient population receiving the drug, the antigen-specific immune response underlying the development of anti-drug antibodies often remains difficult to define. This is especially true for patients with hemophilia A who, following exposure, develop antibodies against the coagulation factor, factor VIII (FVIII). Models capable of studying this response in an antigen-specific manner have been lacking. To overcome this challenge, we engineered FVIII to contain a peptide (323-339) from the model antigen ovalbumin (OVA), a very common tool used to study antigen-specific immunity. FVIII with an OVA peptide (FVIII-OVA) retained clotting activity and possessed the ability to activate CD4 T cells specific to OVA323-339 in vitro. When compared to FVIII alone, FVIII-OVA also exhibited a similar level of immunogenicity, suggesting that the presence of OVA323-339 does not substantially alter the anti-FVIII immune response. Intriguingly, while little CD4 T cell response could be observed following exposure to FVIII-OVA alone, inclusion of anti-FVIII antibodies, recently shown to favorably modulate anti-FVIII immune responses, significantly enhanced CD4 T cell activation following FVIII-OVA exposure. These results demonstrate that model antigens can be incorporated into a therapeutic protein to study antigen-specific responses and more specifically that the CD4 T cell response to FVIII-OVA can be augmented by pre-existing anti-FVIII antibodies.
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Affiliation(s)
- Patricia E. Zerra
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University, Atlanta, GA 30322, USA; (P.E.Z.); (J.W.M.)
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Ernest T. Parker
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Wallace Hunter Baldwin
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - John F. Healey
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Seema R. Patel
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - James W. McCoy
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University, Atlanta, GA 30322, USA; (P.E.Z.); (J.W.M.)
| | - Courtney Cox
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Sean R. Stowell
- Joint Program in Transfusion Medicine, Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Shannon L. Meeks
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
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Anzengruber J, Feichtinger M, Bärnthaler P, Haider N, Ilas J, Pruckner N, Benamara K, Scheiflinger F, Reipert BM, Malisauskas M. How Full-Length FVIII Benefits from Its Heterogeneity - Insights into the Role of the B-Domain. Pharm Res 2019; 36:77. [PMID: 30937539 PMCID: PMC6443606 DOI: 10.1007/s11095-019-2599-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/27/2019] [Indexed: 11/19/2022]
Abstract
Purpose To explore how the natural heterogeneity of human coagulation factor VIII (FVIII) and the processing of its B-domain specifically modulate protein aggregation. Methods Recombinant FVIII (rFVIII) molecular species containing 70% or 20% B-domain, and B-domain-deleted rFVIII (BDD-rFVIII), were separated from full-length recombinant FVIII (FL-rFVIII). Purified human plasma-derived FVIII (pdFVIII) was used as a comparator. Heterogeneity and aggregation of the various rFVIII molecular species, FL-rFVIII and pdFVIII were analysed by SDS-PAGE, dynamic light scattering, high-performance size-exclusion chromatography and flow cytometry-based particle analysis. Results FL-rFVIII and pdFVIII were heterogeneous in nature and demonstrated similar resistance to aggregation under physical stress. Differences were observed between these and among rFVIII molecular species. FVIII molecular species exhibited diverging aggregation pathways dependent on B-domain content. The propensity to form aggregates increased with decreasing proportions of B-domain, whereas the opposite was observed for oligomer formation. Development of cross-β sheet-containing aggregates in BDD-rFVIII induced effective homologous seeding and faster aggregation. Naturally heterogeneous FL-rFVIII and pdFVIII displayed the lowest propensity to aggregate in all experiments. Conclusions These results demonstrate that pdFVIII and FL-rFVIII have similar levels of molecular heterogeneity, and suggest that heterogeneity and the B-domain are involved in stabilising FVIII by modulating its aggregation pathway. Electronic supplementary material The online version of this article (10.1007/s11095-019-2599-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julia Anzengruber
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria.
| | - Martin Feichtinger
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Philipp Bärnthaler
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Norbert Haider
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Josenato Ilas
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Nina Pruckner
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Karima Benamara
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | | | - Birgit M Reipert
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Mantas Malisauskas
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
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Baunsgaard D, Nielsen AD, Nielsen PF, Henriksen A, Kristensen AK, Bagger HW, Ezban M. A comparative analysis of heterogeneity in commercially available recombinant factor VIII products. Haemophilia 2018; 24:880-887. [DOI: 10.1111/hae.13497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2018] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - A. Henriksen
- Global Research; Novo Nordisk A/S; Måløv Denmark
| | | | - H. W. Bagger
- Global Research; Novo Nordisk A/S; Måløv Denmark
| | - M. Ezban
- Global Research; Novo Nordisk A/S; Måløv Denmark
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Continuous infusions of B domain-truncated recombinant factor VIII, turoctocog alfa, for orthopedic surgery in severe hemophilia A: first case report. Int J Hematol 2018; 108:199-202. [DOI: 10.1007/s12185-018-2415-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/23/2018] [Accepted: 01/24/2018] [Indexed: 01/08/2023]
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Shestopal SA, Hao JJ, Karnaukhova E, Liang Y, Ovanesov MV, Lin M, Kurasawa JH, Lee TK, Mcvey JH, Sarafanov AG. Expression and characterization of a codon-optimized blood coagulation factor VIII. J Thromb Haemost 2017; 15:709-720. [PMID: 28109042 DOI: 10.1111/jth.13632] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Indexed: 08/31/2023]
Abstract
Essentials Recombinant factor VIII (FVIII) is known to be expressed at a low level in cell culture. To increase expression, we used codon-optimization of a B-domain deleted FVIII (BDD-FVIII). This resulted in 7-fold increase of the expression level in cell culture. The biochemical properties of codon-optimized BDD-FVIII were similar to the wild-type protein. SUMMARY Background Production of recombinant factor VIII (FVIII) is challenging because of its low expression. It was previously shown that codon-optimization of a B-domain-deleted FVIII (BDD-FVIII) cDNA resulted in increased protein expression. However, it is well recognized that synonymous mutations may affect the protein structure and function. Objectives To compare biochemical properties of a BDD-FVIII variants expressed from codon-optimized and wild-type cDNAs (CO and WT, respectively). Methods Each variant of the BDD-FVIII was expressed in several independent Chinese hamster ovary (CHO) cell lines, generated using a lentiviral platform. The proteins were purified by two-step affinity chromatography and analyzed in parallel by PAGE-western blot, mass spectrometry, circular dichroism, surface plasmon resonance, and chromogenic, clotting and thrombin generation assays. Results and conclusion The average yield of the CO was 7-fold higher than WT, whereas both proteins were identical in the amino acid sequences (99% coverage) and very similar in patterns of the molecular fragments (before and after thrombin cleavage), glycosylation and tyrosine sulfation, secondary structures and binding to von Willebrand factor and to a fragment of the low-density lipoprotein receptor-related protein 1. The CO preparations had on average 1.5-fold higher FVIII specific activity (activity normalized to protein mass) than WT preparations, which was attributed to better preservation of the CO structure as a result of considerably higher protein concentrations during the production. We concluded that the codon-optimization of the BDD-FVIII resulted in significant increase of its expression and did not affect the structure-function properties.
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Affiliation(s)
- S A Shestopal
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - J-J Hao
- Poochon Scientific, Frederick, MD, USA
| | - E Karnaukhova
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Y Liang
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - M V Ovanesov
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - M Lin
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - J H Kurasawa
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - T K Lee
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - J H Mcvey
- School of Biosciences and Medicine, University of Surrey, Surrey, UK
| | - A G Sarafanov
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
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Csencsits-Smith K, Grushin K, Stoilova-McPhie S. Binding of Factor VIII to Lipid Nanodiscs Increases its Clotting Function in a Mouse Model of Hemophilia A. ACTA ACUST UNITED AC 2015; 6:325. [PMID: 28936365 PMCID: PMC5603210 DOI: 10.4172/2155-9864.1000325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Background Hemophilia A is a congenital bleeding disorder caused by defective or deficient factor VIII (FVIII). The active form of FVIII is the co-factor for the serine protease factor IXa (FIXa) in the membrane-bound intrinsic tenase (FVIIIa-FIXa) complex. The assembly of the FVIIIa-FIXa complex on the activated platelet surface is critical for successful blood clotting. Objectives To characterize the role of lipid nanodiscs (ND) for on FVIII function in vivo and test the lipid ND as a delivery system for FVIII. To evaluate the potential of binding recombinant FVIII to ND as improved treatment for Hemophilia A. Methods Recombinant porcine FVIII (rpFVIII) was expressed and characterized in solution, and when bound to ND. The rpFVIII, ND and rpFVIII-ND complexes were characterized via transmission electron microscopy. Functional studies were carried out using aPTT tests and time resolved tail snip studies of hemophilic mice. Results Functional rpFVIII was successfully assembled on lipid ND. When injected in hemophilic mice, the rpFVIII-ND complexes showed a pronounced pro-coagulant effect, which was stronger than that of rpFVIII alone. While injection of the ND alone showed a pro-coagulant effect this effect was not additive, implying that the rpFVIII-ND complexes have a synergistic effect on the clotting process in hemophilic mice. Conclusions Binding of rpFVIII to ND prior to its injection in hemophilic mice significantly improves the therapeutic function of the protein. This represents a meaningful step towards a new approach to modulate blood coagulation at the membrane-bound FVIII level and the assembly of the intrinsic tenase complex.
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Affiliation(s)
- Keri Csencsits-Smith
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center, Houston, TX-77030, USA
| | - Krill Grushin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX-77555, USA
| | - Svetla Stoilova-McPhie
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX-77555, USA
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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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Ca2+ concentration-dependent conformational change of FVIII B-domain observed by atomic force microscopy. Anal Bioanal Chem 2015; 407:6051-6. [DOI: 10.1007/s00216-015-8778-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 11/26/2022]
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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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Santagostino E. A new recombinant factor VIII: from genetics to clinical use. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:2507-15. [PMID: 25548513 PMCID: PMC4271724 DOI: 10.2147/dddt.s73241] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Advances in recombinant technology and knowledge about coagulation factor VIII (FVIII) are building a platform for new therapeutic options in patients with hemophilia A. The development of turoctocog alfa, a novel, high-purity, third-generation, B-domain truncated recombinant FVIII, has been produced and formulated without the use of animal-derived or human serum-derived components, in the wake of understanding of the new biochemical characteristics of FVIII, namely its protein structure, and glycosylation and sulfating patterns. Culture conditions and a five-step purification process have been developed to optimize the safety of turoctocog alfa. The results of two pilot clinical trials using turoctocog alfa confirmed high safety levels, with no patient developing inhibitors during the period of observation. The purpose of this review is to describe briefly the molecular and biological properties of turoctocog alfa, together with details of its clinical development, with emphasis on the needs of patients with hemophilia A.
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Affiliation(s)
- Elena Santagostino
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
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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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