1
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Marino M, Zhou L, Rincon MY, Callaerts-Vegh Z, Verhaert J, Wahis J, Creemers E, Yshii L, Wierda K, Saito T, Marneffe C, Voytyuk I, Wouters Y, Dewilde M, Duqué SI, Vincke C, Levites Y, Golde TE, Saido TC, Muyldermans S, Liston A, De Strooper B, Holt MG. AAV-mediated delivery of an anti-BACE1 VHH alleviates pathology in an Alzheimer's disease model. EMBO Mol Med 2022; 14:e09824. [PMID: 35352880 PMCID: PMC8988209 DOI: 10.15252/emmm.201809824] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 01/18/2023] Open
Abstract
Single domain antibodies (VHHs) are potentially disruptive therapeutics, with important biological value for treatment of several diseases, including neurological disorders. However, VHHs have not been widely used in the central nervous system (CNS), largely because of their restricted blood-brain barrier (BBB) penetration. Here, we propose a gene transfer strategy based on BBB-crossing Adeno-associated virus (AAV)-based vectors to deliver VHH directly into the CNS. As a proof-of-concept, we explored the potential of AAV-delivered VHH to inhibit BACE1, a well-characterized target in Alzheimer's disease. First, we generated a panel of VHHs targeting BACE1, one of which, VHH-B9, shows high selectivity for BACE1 and efficacy in lowering BACE1 activity in vitro. We further demonstrate that a single systemic dose of AAV-VHH-B9 produces positive long-term (12 months plus) effects on amyloid load, neuroinflammation, synaptic function, and cognitive performance, in the AppNL-G-F Alzheimer's disease mouse model. These results constitute a novel therapeutic approach forneurodegenerative diseases, which is applicable to a range of CNS disease targets.
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Affiliation(s)
- Marika Marino
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Lujia Zhou
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Melvin Y Rincon
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | | | - Jens Verhaert
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jérôme Wahis
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Eline Creemers
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,Electrophysiology Expertise Unit, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Lidia Yshii
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Keimpe Wierda
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,Electrophysiology Expertise Unit, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Catherine Marneffe
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Iryna Voytyuk
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Yessica Wouters
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Maarten Dewilde
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Sandra I Duqué
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Cécile Vincke
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yona Levites
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Todd E Golde
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Japan
| | - Serge Muyldermans
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Adrian Liston
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Immunology Programme, The Babraham Institute, Cambridge, UK
| | - Bart De Strooper
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,UK Dementia Research institute at UCL, London, UK.,Leuven Brain Institute, Leuven, Belgium
| | - Matthew G Holt
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium.,Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Porto, Portugal
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2
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Joshi PRH, Venereo-Sanchez A, Chahal PS, Kamen AA. Advancements in molecular design and bioprocessing of recombinant adeno-associated virus gene delivery vectors using the insect-cell baculovirus expression platform. Biotechnol J 2021; 16:e2000021. [PMID: 33277815 DOI: 10.1002/biot.202000021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 11/27/2020] [Indexed: 01/23/2023]
Abstract
Despite rapid progress in the field, scalable high-yield production of adeno-associated virus (AAV) is still one of the critical bottlenecks the manufacturing sector is facing. The insect cell-baculovirus expression vector system (IC-BEVS) has emerged as a mainstream platform for the scalable production of recombinant proteins with clinically approved products for human use. In this review, we provide a detailed overview of the advancements in IC-BEVS for rAAV production. Since the first report of baculovirus-induced production of rAAV vector in insect cells in 2002, this platform has undergone significant improvements, including enhanced stability of Bac-vector expression and a reduced number of baculovirus-coinfections. The latter streamlining strategy led to the eventual development of the Two-Bac, One-Bac, and Mono-Bac systems. The one baculovirus system consisting of an inducible packaging insect cell line was further improved to enhance the AAV vector quality and potency. In parallel, the implementation of advanced manufacturing approaches and control of critical processing parameters have demonstrated promising results with process validation in large-scale bioreactor runs. Moreover, optimization of the molecular design of vectors to enable higher cell-specific yields of functional AAV particles combined with bioprocess intensification strategies may also contribute to addressing current and future manufacturing challenges.
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Affiliation(s)
- Pranav R H Joshi
- Department of Bioengineering, McGill University, Montréal, Quebec, Canada
| | | | - Parminder S Chahal
- Human Health Therapeutics Portfolio, National Research Council of Canada, Montréal, Quebec, Canada
| | - Amine A Kamen
- Department of Bioengineering, McGill University, Montréal, Quebec, Canada
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3
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Deshpande CN, Xin V, Lu Y, Savage T, Anderson GJ, Jormakka M. Large scale expression and purification of secreted mouse hephaestin. PLoS One 2017; 12:e0184366. [PMID: 28880952 PMCID: PMC5589216 DOI: 10.1371/journal.pone.0184366] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/22/2017] [Indexed: 01/04/2023] Open
Abstract
Hephaestin is a large membrane-anchored multicopper ferroxidase involved in mammalian iron metabolism. Newly absorbed dietary iron is exported across the enterocyte basolateral membrane by the ferrous iron transporter ferroportin, but hephaestin increases the efficiency of this process by oxidizing the transported iron to its ferric form and promoting its release from ferroportin. Deletion or mutation of the hephaestin gene leads to systemic anemia with iron accumulation in the intestinal epithelium. The crystal structure of human ceruloplasmin, another multicopper ferroxidase with 50% sequence identity to hephaestin, has provided a framework for comparative analysis and modelling. However, detailed structural information for hephaestin is still absent, leaving questions relating to metal coordination and binding sites unanswered. To obtain structural information for hephaestin, a reliable protocol for large-scale purification is required. Here, we present an expression and purification protocol of soluble mouse hephaestin, yielding milligram amounts of enzymatically active, purified protein using the baculovirus/insect cell system.
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Affiliation(s)
- Chandrika N. Deshpande
- Structural Biology Program, Centenary Institute, Sydney, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Vicky Xin
- Structural Biology Program, Centenary Institute, Sydney, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Yan Lu
- Iron Metabolism Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Tom Savage
- School of Geosciences, University of Sydney, Sydney, New South Wales, Australia
| | - Gregory J. Anderson
- Iron Metabolism Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Mika Jormakka
- Structural Biology Program, Centenary Institute, Sydney, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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4
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Lim JH, Lee BR, Park HW, Hong BS, Lim BO, Kim YJ. β-Secretase (BACE1) Purification by Refolding Method and Complex with Hispidin. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2014. [DOI: 10.5012/jkcs.2014.58.6.553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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5
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Wilde M, Klausberger M, Palmberger D, Ernst W, Grabherr R. Tnao38, high five and Sf9--evaluation of host-virus interactions in three different insect cell lines: baculovirus production and recombinant protein expression. Biotechnol Lett 2013; 36:743-9. [PMID: 24375231 PMCID: PMC3955137 DOI: 10.1007/s10529-013-1429-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 12/08/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE OF WORK A comparative analysis of new and established insect cell lines, in regard to process relevant parameters, provide data that can be exploited for designing more robust and effective protein production processes. The baculovirus-insect cell expression system has been efficiently used for the production of heterologous proteins. Three different insect cell lines Tnao38, High Five and Sf9 were compared in terms of virus susceptibility, baculovirus production and product yield of an intra-cellularly (YFP) and extra-cellularly (influenza A virus hemagglutinin)-expressed recombinant protein. The Tnao38 and High Five cell lines exhibited higher (tenfold) susceptibility to baculovirus infection than Sf9 cells, whereas Sf9 cells showed a higher (100-fold) capacity for production of infectious virus particles. Analysis of recombinant protein expression revealed considerably higher product yields in Tnao38 and High Five cells as compared to Sf9 cells, for both model proteins. Overall, the two Trichoplusia ni-derived cell lines, High Five and Tnao38, were significantly more efficient in terms of secreting proteins such as the glycoprotein hemagglutinin of influenza A virus.
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Affiliation(s)
- Monika Wilde
- Vienna Institute of BioTechnology (VIBT), University of Natural Resources and Life Sciences, Muthgasse 11, 1190, Vienna, Austria,
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6
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Kim HS, Youm JW, Moon KB, Ha JH, Kim YH, Joung H, Jeon JH. Expression analysis of human β-secretase in transgenic tomato fruits. Protein Expr Purif 2011; 82:125-31. [PMID: 22178732 DOI: 10.1016/j.pep.2011.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/18/2011] [Accepted: 11/19/2011] [Indexed: 11/16/2022]
Abstract
An emerging strategy in biomanufacturing involves using transgenic plants to express recombinant pharmaceutical and industrial proteins in large quantities. β-Site APP cleaving enzyme 1 (β-secretase 1, BACE1) is an enzyme involved in the abnormal production of Aβ42, the major component of senile plaques in Alzheimer's disease (AD). Thus, BACE1 represents a key target protein in the development of new potential drugs to treat Alzheimer's disease. We aimed to develop a tomato-derived recombinant BACE1 (rBACE1) protein to serve as a vaccine antigen that would promote an immune response. We utilized a plant expression cassette, pE8BACE, to optimize BACE1 expression in tomato fruits. Polyemerase chain reaction and Southern blot analyses verified integration of the BACE1 gene into the plant genome. Northern and Western blot analyses demonstrated successful mRNA and protein expression of rBACE1, respectively; the Sensizyme assay kit estimated the expression level of rBACE1 protein at 136 ± 7 ng mg⁻¹ total soluble protein. The tomato-derived rBACE1 retains its activity for a long storage period at cool or room temperature, and is highly resistant to degradation in conditions such as low acidity. Tomato-derived rBACE1 was severely degraded by heat or boiling. The proteolytic activity of tomato-derived rBACE1, confirmed by fluorescence resonance transfer assay, was similar to that of a commercial sample of Escherichia coli-derived BACE1.
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Affiliation(s)
- H-S Kim
- Plant Systemic Engineering Research Center, KRIBB, Gwahangno 125, Yuseong-gu, Daejeon 305-806, Republic of Korea
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7
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Youm JW, Jeon JH, Kim H, Min SR, Kim MS, Joung H, Jeong WJ, Kim HS. High-level expression of a human β-site APP cleaving enzyme in transgenic tobacco chloroplasts and its immunogenicity in mice. Transgenic Res 2010; 19:1099-108. [PMID: 20229285 PMCID: PMC7089353 DOI: 10.1007/s11248-010-9383-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 03/04/2010] [Indexed: 11/28/2022]
Abstract
Plastid transformation has to date been applied to the expression of heterologous genes involved in agronomic traits and to the production of useful recombinant proteins. Here, we report a feasibility study for producing the human β-site APP cleaving enzyme (BACE) via transformation of tobacco chloroplasts. Stable integration of human BACE into the plastome was confirmed by PCR. Genomic Southern blot analysis detected the presence of the tobacco aadA and human BACE genes between trnI and trnA in the plastome. Northern blot analysis revealed that the aadA and BACE genes were both properly transcribed into a dicistronic transcriptional unit. Human BACE protein expression in transplastomic tobacco was determined by western blot analysis. ELISA analysis revealed that, based on a dilution series of E. coli-derived BACE as a standard, transplastomic lines accumulated BACE to levels of 2.0% of total soluble proteins. When mice were gavaged with the transplastomic tobacco extracts, they showed an immune response against the BACE antigen. The successful production of plastid-based BACE protein has the potential for developing a plant-based vaccine against Alzheimer disease.
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Affiliation(s)
- Jung Won Youm
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Jae Heung Jeon
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Hee Kim
- Digital Biotech Inc., R&D, Ansan City, KyungGiDo, 425-839 Korea
| | - Sung Ran Min
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Mi Sun Kim
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Hyouk Joung
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Won Joong Jeong
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
| | - Hyun Soon Kim
- Plant Systems Engineering Research Center, KRIBB, Daejeon, 305-806 Korea
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8
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Zhu Z, Li C, Wang X, Yang Z, Chen J, Hu L, Jiang H, Shen X. 2,2',4'-trihydroxychalcone from Glycyrrhiza glabra as a new specific BACE1 inhibitor efficiently ameliorates memory impairment in mice. J Neurochem 2010; 114:374-85. [PMID: 20412384 DOI: 10.1111/j.1471-4159.2010.06751.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) characterizes a progressive neurodegenerative disorder of the brain, while AD patients are afflicted with irreversible loss of neurons and further the intellectual abilities including memory and reasoning. One of the typical hallmarks of AD is the deposition of senile plaque that is contributed mainly by amyloid-beta (Abeta), whose production is initiated by beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1). Inhibition of BACE1 is thereby regarded as an attractive strategy for anti-AD drug discovery. Here, we reported that the natural product 2,2',4'-trihydroxychalcone (TDC) from Glycyrrhiza glabra functioned as a specific non-competitive inhibitor against BACE1 enzyme, and potently repressed beta-cleavage of APP and production of Abeta in human embryo kidney cells-APPswe cells. Moreover, the amelioration ability of this compound against the in vivo memory impairment was further evaluated by APP-PS1 double transgenic mice model. It is discovered that treatment of 9 mg/kg/day of TDC could obviously decrease Abeta production and Abeta plaque formation, while efficiently improve the memory impairment based on Morris water maze test. Our findings thus demonstrated that the natural product TDC as a new BACE1 inhibitor could ameliorate memory impairment in mice, and is expected to be potentially used as a lead compound for further anti-AD reagent development.
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Affiliation(s)
- Zhiyuan Zhu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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9
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Baxter EW, Conway KA, Kennis L, Bischoff F, Mercken MH, Winter HLD, Reynolds CH, Tounge BA, Luo C, Scott MK, Huang Y, Braeken M, Pieters SMA, Berthelot DJC, Masure S, Bruinzeel WD, Jordan AD, Parker MH, Boyd RE, Qu J, Alexander RS, Brenneman DE, Reitz AB. 2-Amino-3,4-dihydroquinazolines as Inhibitors of BACE-1 (β-Site APP Cleaving Enzyme): Use of Structure Based Design to Convert a Micromolar Hit into a Nanomolar Lead. J Med Chem 2007; 50:4261-4. [PMID: 17685503 DOI: 10.1021/jm0705408] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new aspartic protease inhibitory chemotype bearing a 2-amino-3,4-dihydroquinazoline ring was identified by high-throughput screening for the inhibition of BACE-1. X-ray crystallography revealed that the exocyclic amino group participated in a hydrogen bonding array with the two catalytic aspartic acids of BACE-1 (Asp(32), Asp(228)). BACE-1 inhibitory potency was increased (0.9 microM to 11 nM K(i)) by substitution into the unoccupied S(1)' pocket.
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Affiliation(s)
- Ellen W Baxter
- Johnson & Johnson Pharmaceutical Research and Development, LLC, Spring House, Pennsylvania 19477, USA.
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10
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Abstract
Integrins are large modular cell-surface receptors that regulate almost every aspect of cellular function through bidirectional signals transmitted across the lipid bilayer. Regulation of integrin activity is accomplished by complex and still incompletely understood biochemical pathways that modify integrin ligand binding, clustering, trafficking, and signaling functions. The dynamic tertiary and quaternary changes required to channel some of these activities have hampered, until recently, the crystal structure determination of these heterodimeric receptors. In this chapter, we review the methods used to purify and characterize these proteins biophysically and functionally, and to derive their three-dimensional structures.
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Affiliation(s)
- Jian-Ping Xiong
- Structural Biology Program, Leukocyte Biology and Inflammation Program, Nephrology Division, Massachusetts General Hospital and Harvard Medical School, Charlestown, USA
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11
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Chang KH, Baek NI, Yang JM, Lee JM, Bo JH, Chung IS. Expression and characterization of recombinant beta-secretase from Trichoplusia ni BTI Tn5B1-4 cells transformed with cDNAs encoding human beta1,4-galactosyltransferase and Gal beta1,4-GlcNAc alpha 2,6-sialytransferase. Protein Expr Purif 2005; 44:87-93. [PMID: 16226891 DOI: 10.1016/j.pep.2005.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 08/13/2005] [Accepted: 08/18/2005] [Indexed: 11/16/2022]
Abstract
Beta-Secretase (betaSEC) was expressed in Trichoplusia ni BTI Tn5B1-4 (Tn5B1-4) cells transformed with cDNAs encoding beta1,4-galactosyltransferase (GalT) and Gal beta1,4-GlcNAc alpha 2,6-sialyltransferase (ST). The apparent molecular weight of recombinant beta-secretase was increased from 57 to 59 k Da. A lectin blot analysis indicated that recombinant beta-secretase from Tn5B1-4 betaSEC/GalT-ST cells (Tn5B1-4 cells co-transformed with cDNAs encoding beta-secretase, glycosyltransferases, GalT, and ST) contained the glycan residues of beta1,4-linked galactose and alpha2,6-linked sialic acid. Two-dimensional electrophoresis revealed that recombinant beta-secretase from Tn5B1-4 beta SEC/GalT-ST cells had a lower isoelectric point than beta-secretase from control Tn5B1-4 betaSEC cells (Tn5B1-4 cells transformed only with beta-secretase cDNA). The enzyme activity of recombinant beta-secretase from Tn5B1-4 betaSEC/GalT-ST cells was enhanced up to 77% compared to control Tn5B1-4 betaSEC cells. The concentrations at half-maximum inhibition (IC(50)) values estimated from inhibition analyses using purified beta-secretases from Tn5B1-4/betaSEC and Tn5B1-4/betaSEC/GalT-ST cells were 32 and 290 nM, respectively.
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Affiliation(s)
- Kyung Hwa Chang
- Department of Genetic Engineering, Kyung Hee University, Suwon 449-701, Republic of Korea
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12
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Chang KH, Yang JM, Chun HOK, Chung IS. Enhanced activity of recombinant beta-secretase from Drosophila melanogaster S2 cells transformed with cDNAs encoding human beta1,4-galactosyltransferase and Galbeta1,4-GlcNAc alpha2,6-sialyltransferase. J Biotechnol 2005; 116:359-67. [PMID: 15748762 DOI: 10.1016/j.jbiotec.2004.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Revised: 12/15/2004] [Accepted: 12/20/2004] [Indexed: 11/26/2022]
Abstract
beta-Secretase (betaSEC) was expressed in Drososphila melanogaster Schneider 2 (S2) cells transformed with cDNAs encoding beta1,4-galactosyltransferase (GalT) and Galbeta1,4-GlcNAc alpha2,6-sialyltransferase (ST). The apparent molecular weight of recombinant beta-secretase was increased from 56kDa to 61kDa. A lectin blot analysis indicated that recombinant beta-secretase from S2betaSEC/GalT-ST cells (S2 cells co-transformed with cDNAs encoding beta-secretase, glycosyltransferases, GalT, and ST) contained the glycan residues of beta1,4-linked galactose and alpha2,6-linked sialic acid. Two dimensional electrophoresis revealed that recombinant beta-secretase from S2betaSEC/GalT-ST cells had a lower isoelectric point compared to beta-secretase from control S2betaSEC cells (S2 cells transformed only with beta-secretase cDNA). Recombinant beta-secretase from transformed S2 cells was also present as heterogeneous forms. The enzyme activity of recombinant beta-secretase from S2betaSEC/GalT-ST cells was enhanced up to 260% compared to control S2betaSEC cells. We have shown that an exogeneous human glycosyltransferases cDNA can be introduced into S2 cells to extend the N-glycan processing capabilities of the insect cell line, and that the extended glycosylation improves the activity of recombinant beta-secretase.
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Affiliation(s)
- Kyung Hwa Chang
- Department of Genetic Engineering and Plant Metabolism Research Center, Kyung Hee University, Suwon 449-701, Republic of Korea
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13
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Sardana V, Xu B, Zugay-Murphy J, Chen Z, Sardana M, Darke PL, Munshi S, Kuo LC. A general procedure for the purification of human beta-secretase expressed in Escherichia coli. Protein Expr Purif 2004; 34:190-6. [PMID: 15003250 DOI: 10.1016/j.pep.2003.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Revised: 12/23/2003] [Indexed: 11/23/2022]
Abstract
Expression and purification of human beta-secretase (BACE1) in bacteria have been plagued with issues concerning solubility, inhomogeneous N-terminus, and lack of enzymic activity. Several forms of the mature human BACE1 have been expressed in Escherichia coli with different N-terminal extensions and without the C-terminus transmembrane domain. Although each of the proteins expresses in inclusion bodies, a generalized protocol has been developed to solubilize, refold, and purify these BACE1 variants. The resultant proteins are homogeneous and monodispersed in solution. Each possesses a unique N-terminus. Activity assays using the peptide substrate 7-methoxycoumarin-4-yl-SEVNLDAEFK-2,4-dinitrophenyl-RR, corresponding to the beta-secretase cleavage sequence in the amyloid precursor protein with the Swedish mutations of N(670)L(671) substituting for the residues K(670)M(671), reveal a kcat and KM of 9.3 min(-1) and 55 microM, respectively.
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Affiliation(s)
- Vinod Sardana
- Department of Structural Biology, Merck Research Laboratories, West Point, PA 19486, USA.
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14
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Patel S, Vuillard L, Cleasby A, Murray CW, Yon J. Apo and inhibitor complex structures of BACE (beta-secretase). J Mol Biol 2004; 343:407-16. [PMID: 15451669 DOI: 10.1016/j.jmb.2004.08.018] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 08/05/2004] [Accepted: 08/09/2004] [Indexed: 12/01/2022]
Abstract
Human BACE, also known as beta-secretase, shows promise as a potential therapeutic target for Alzheimer's disease. We determined the apo structure of BACE to 1.75 A, and a structure of a hydroxyethylamine inhibitor complex derived by soaking. These show significant active-site movements compared to previously described BACE structures. Additionally, the structures reveal two pockets that could be targeted by structure-based drug design.
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Affiliation(s)
- Sahil Patel
- Astex Technology, 436 Cambridge Science Park, Milton Road, CB4 0QA, UK
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Wang W, Reichert P, Beyer BM, Liu JJ, Lee J, Zhang L, Liu YH, Taremi SS, Le HV, Strickland C. Crystallization of glycosylated human BACE protease domain expressed in Trichoplusia ni. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1698:255-9. [PMID: 15134659 DOI: 10.1016/j.bbapap.2003.11.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 11/24/2003] [Accepted: 11/26/2003] [Indexed: 10/26/2022]
Abstract
Human beta-amyloid precursor protein cleaving enzyme (beta-secretase, or BACE) belongs to the aspartyl protease family, and is responsible for generating the N-terminus of beta-amyloid peptide (Abeta). BACE is a type I transmembrane glycoprotein with pre-, pro- and catalytic domains, a short transmembrane helix and a cytoplasmic region. In this study, a truncated form was engineered to produce the authentic catalytic domain of BACE in Trichoplusia ni (High 5) cells. The glycosylated BACE zymogen (proBACE) was secreted into the conditioned medium for facile purification by metal chelate and gel filtration chromatographies. The mature catalytic domain was obtained by a trans cleavage event under acidic conditions and crystallized in the absence of a bound inhibitor. A complete 3.4 A data set was collected on a single orthorhombic crystal with unit cell parameters a=74 A, b=130 A, c=134A. Successful molecular replacement shows two BACE molecules in the asymmetric unit.
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Affiliation(s)
- Wenyan Wang
- Protein Engineering and Biochem.Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA
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Kennedy ME, Wang W, Song L, Lee J, Zhang L, Wong G, Wang L, Parker E. Measuring human beta-secretase (BACE1) activity using homogeneous time-resolved fluorescence. Anal Biochem 2003; 319:49-55. [PMID: 12842106 DOI: 10.1016/s0003-2697(03)00253-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The human beta-secretase enzyme, BACE1, mediates a critical step in the production of A beta(40) and A beta(42) peptides which are responsible for the severe neuronal cell death and insoluble amyloid plaques of Alzheimer's disease (AD). Several lines of evidence suggest that potent BACE1 inhibitors represent an attractive A beta-lowering strategy for AD. We designed a simple homogeneous time-resolved fluorescence (HTRF) assay which utilizes the fluorescence resonance energy transfer (FRET) pair europium and allophycocyanin for measuring BACE1 enzymatic activity in a high-throughput manner. Robust FRET was observed when an 18-amino-acid APP Swedish-synthetic peptide that was N-terminally labeled with europium cryptate and C-terminally biotinylated was incubated with streptavidin-coupled cross-linked allophycocyanin (SA-XL665). Purified BACE1 enzyme caused a time- and concentration-dependent linear change in FRET at low nanomolar enzyme concentrations. This assay was used to compare the autoprocessed "mature" BACE1 enzyme (sautoBACe1) and the soluble proBACE1 for activity and inhibition by selected peptidic BACE inhibitors. sautoBACE1 displayed only a modest increase in activity compared to sproBACE1 and this activity was uninhibited by the BACE1 prodomain peptide. Interestingly, the BACE1 prodomain peptide was able to partially inhibit sproBACE1 activity. IC(50s) for a P10-P4' statine BACE1 inhibitor, OM99-2, and OM-003 determined using the HTRF assay were in good agreement with those reported in the literature. The primary advantages of the HTRF-formatted BACE1 protease assay include appropriate reflection of native BACE1 activity, high sensitivity, low variability, and intrinsic quench correction afforded by ratiometric measurements made between EuK and SA-XL665 fluorophores.
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Affiliation(s)
- Matthew E Kennedy
- CNS/Cardiovascular Research, Schering Plough Research Institute, Kenilworth, NJ 07033, USA.
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