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Chen SY, Zacharias M. An internal docking site stabilizes substrate binding to γ-secretase: Analysis by molecular dynamics simulations. Biophys J 2022; 121:2330-2344. [PMID: 35598043 PMCID: PMC9279352 DOI: 10.1016/j.bpj.2022.05.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/02/2022] Open
Abstract
Amyloid precursor protein (APP) is cleaved and processed sequentially by γ-secretase yielding amyloid β (Aβ) peptides of different lengths. Longer Aβ peptides are associated with the formation of neurotoxic plaques related to Alzheimer's disease. Based on the APP substrate-bound structure of γ-secretase, we investigated the enzyme-substrate interaction using molecular dynamics simulations and generated model structures that represent the sequentially cleaved intermediates during the processing reaction. The simulations indicated an internal docking site providing strong enzyme-substrate packing interaction. In the enzyme-substrate complex, it is located close to the region where the helical conformation of the substrate is interrupted and continues toward the active site in an extended conformation. The internal docking site consists of two non-polar pockets that are preferentially filled by large hydrophobic or aromatic substrate side chains to stabilize binding. Placement of smaller residues such as glycine can trigger a shift in the cleavage pattern during the simulations or results in destabilization of substrate binding. The reduced packing by smaller residues also influences the hydration of the active site and the formation of a catalytically active state. The simulations on processed substrate intermediates and a substrate G33I mutation offer an explanation of the experimentally observed relative increase of short Aβ fragment production for this mutation. In addition, studies on a substrate K28A mutation indicate that the internal docking site opposes the tendency of substrate dissociation due to a hydrophobic mismatch at the membrane boundary caused by K28 during processing and substrate movement toward the enzyme active site. The proposed internal docking site could also be useful for the specific design of new γ-secretase modulators.
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Affiliation(s)
- Shu-Yu Chen
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany
| | - Martin Zacharias
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany.
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2
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Verteporfin is a Substrate-Selective γ-Secretase Inhibitor that Binds the Amyloid Precursor Protein Transmembrane Domain. J Biol Chem 2022; 298:101792. [PMID: 35247387 PMCID: PMC8968665 DOI: 10.1016/j.jbc.2022.101792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/22/2022] [Accepted: 02/26/2022] [Indexed: 11/23/2022] Open
Abstract
This work reports substrate-selective inhibition of a protease with broad substrate specificity based on direct binding of a small molecule inhibitor to the substrate. The target for these studies was γ-secretase protease, which cleaves dozens of different single span membrane protein substrates, including both the C99 domain of the human amyloid precursor protein and the Notch receptor. Substrate-specific inhibition of C99 cleavage is desirable to reduce production of the amyloid-β polypeptide without inhibiting Notch cleavage, a major source of toxicity associated with broad specificity γ-secretase inhibitors. In order to identify a C99-selective inhibitors of the human γ-secretase, we conducted an NMR-based screen of FDA-approved drugs against C99 in model membranes. From this screen, we identified the small molecule verteporfin with these properties. We observed that verteporfin formed a direct 1:1 complex with C99, with a KD of 15-47 μM (depending on the membrane mimetic used), and that it did not bind the transmembrane domain of the Notch-1 receptor. Biochemical assays showed that direct binding of verteporfin to C99 inhibits γ-secretase cleavage of C99 with IC50 values in the range of 15- 164 μM, while Notch-1 cleavage was inhibited only at higher concentrations, and likely via a mechanism that does not involve binding to Notch-1. This work documents a robust NMR-based approach to discovery of small molecule binders to single-span membrane proteins and confirmed that it is possible to inhibit γ-secretase in a substrate-specific manner.
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3
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Svedružić ŽM, Vrbnjak K, Martinović M, Miletić V. Structural Analysis of the Simultaneous Activation and Inhibition of γ-Secretase Activity in the Development of Drugs for Alzheimer's Disease. Pharmaceutics 2021; 13:pharmaceutics13040514. [PMID: 33917979 PMCID: PMC8068388 DOI: 10.3390/pharmaceutics13040514] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/24/2022] Open
Abstract
Significance: The majority of the drugs which target membrane-embedded protease γ-secretase show an unusual biphasic activation–inhibition dose-response in cells, model animals, and humans. Semagacestat and avagacestat are two biphasic drugs that can facilitate cognitive decline in patients with Alzheimer’s disease. Initial mechanistic studies showed that the biphasic drugs, and pathogenic mutations, can produce the same type of changes in γ-secretase activity. Results: DAPT, semagacestat LY-411,575, and avagacestat are four drugs that show different binding constants, and a biphasic activation–inhibition dose-response for amyloid-β-40 products in SH-SY5 cells. Multiscale molecular dynamics studies have shown that all four drugs bind to the most mobile parts in the presenilin structure, at different ends of the 29 Å long active site tunnel. The biphasic dose-response assays are a result of the modulation of γ-secretase activity by the concurrent binding of multiple drug molecules at each end of the active site tunnel. The drugs activate γ-secretase by facilitating the opening of the active site tunnel, when the rate-limiting step is the tunnel opening, and the formation of the enzyme–substrate complex. The drugs inhibit γ-secretase as uncompetitive inhibitors by binding next to the substrate, to dynamic enzyme structures which regulate processive catalysis. The drugs can modulate the production of different amyloid-β catalytic intermediates by penetration into the active site tunnel, to different depths, with different flexibility and different binding affinity. Conclusions: Biphasic drugs and pathogenic mutations can affect the same dynamic protein structures that control processive catalysis. Successful drug-design strategies must incorporate transient changes in the γ-secretase structure in the development of specific modulators of its catalytic activity.
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Affiliation(s)
- Željko M. Svedružić
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia; (K.V.); (M.M.)
- Laboratory for Medical Biochemistry, Psychiatric Hospital Rab, Kampor 224, 51280 Rab, Croatia
- Correspondence:
| | - Katarina Vrbnjak
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia; (K.V.); (M.M.)
- Laboratory for Mechanisms of Cell Transformation (VIB-KU Leuven), ON IV Herestraat—Box 912, 3000 Leuven, Belgium
| | - Manuel Martinović
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia; (K.V.); (M.M.)
| | - Vedran Miletić
- Department of Informatics, University of Rijeka, 51000 Rijeka, Croatia;
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4
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Zhao J, Liu X, Xia W, Zhang Y, Wang C. Targeting Amyloidogenic Processing of APP in Alzheimer's Disease. Front Mol Neurosci 2020; 13:137. [PMID: 32848600 PMCID: PMC7418514 DOI: 10.3389/fnmol.2020.00137] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is the most common type of senile dementia, characterized by neurofibrillary tangle and amyloid plaque in brain pathology. Major efforts in AD drug were devoted to the interference with the production and accumulation of amyloid-β peptide (Aβ), which plays a causal role in the pathogenesis of AD. Aβ is generated from amyloid precursor protein (APP), by consecutive cleavage by β-secretase and γ-secretase. Therefore, β-secretase and γ-secretase inhibition have been the focus for AD drug discovery efforts for amyloid reduction. Here, we review β-secretase inhibitors and γ-secretase inhibitors/modulators, and their efficacies in clinical trials. In addition, we discussed the novel concept of specifically targeting the γ-secretase substrate APP. Targeting amyloidogenic processing of APP is still a fundamentally sound strategy to develop disease-modifying AD therapies and recent advance in γ-secretase/APP complex structure provides new opportunities in designing selective inhibitors/modulators for AD.
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Affiliation(s)
- Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Xinyue Liu
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Weiming Xia
- Geriatric Research Education Clinical Center, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, United States
- Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, NY, United States
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States
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5
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Zhao J, Xiao Y, Liu X, Kim S, Wu X, Barros M, Zhuang R, Hou X, Zhang Y, Robakis NK, Li YM, Dordick JS, Ubarretxena-Belandia I, Wang C. Substrate interaction inhibits γ-secretase production of amyloid-β peptides. Chem Commun (Camb) 2020; 56:2578-2581. [PMID: 32016207 PMCID: PMC8219260 DOI: 10.1039/c9cc09170j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Combining NMR, mass spectrometry, AlphaLISA and cell assays, we discovered a compound C1 that binds C-terminal juxtamembrane lysines at the transmembrane domain of the amyloid precursor protein (APPTM) and inhibits γ-secretase production of amyloid-β with μM IC50. Our work suggests that targeting APPTM is a novel and viable strategy in AD drug discovery.
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Affiliation(s)
- Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Yuanyuan Xiao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Xinyue Liu
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Soohyun Kim
- Center for Molecular Biology and Genetics of Neurodegeneration, Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xianzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Marilia Barros
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ran Zhuang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Xuben Hou
- Department of Medicinal Chemistry and Key Laboratory of Chemical Biology of Natural Products (MOE), School of Pharmacy, Shandong University, Jinan, Shandong 250012, China
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, NY 10003, USA
| | - Nikolaos K Robakis
- Center for Molecular Biology and Genetics of Neurodegeneration, Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jonathan S Dordick
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. and Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Iban Ubarretxena-Belandia
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA and Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, E-48940, Leioa, Spain and Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. and Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA and Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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6
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Deatherage CL, Lu Z, Kroncke BM, Ma S, Smith JA, Voehler MW, McFeeters RL, Sanders CR. Structural and biochemical differences between the Notch and the amyloid precursor protein transmembrane domains. SCIENCE ADVANCES 2017; 3:e1602794. [PMID: 28439555 PMCID: PMC5389784 DOI: 10.1126/sciadv.1602794] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/13/2017] [Indexed: 05/11/2023]
Abstract
γ-Secretase cleavage of the Notch receptor transmembrane domain is a critical signaling event for various cellular processes. Efforts to develop inhibitors of γ-secretase cleavage of the amyloid-β precursor C99 protein as potential Alzheimer's disease therapeutics have been confounded by toxicity resulting from the inhibition of normal cleavage of Notch. We present biochemical and structural data for the combined transmembrane and juxtamembrane Notch domains (Notch-TMD) that illuminate Notch signaling and that can be compared and contrasted with the corresponding traits of C99. The Notch-TMD and C99 have very different conformations, adapt differently to changes in model membrane hydrophobic span, and exhibit different cholesterol-binding properties. These differences may be exploited in the design of agents that inhibit cleavage of C99 while allowing Notch cleavage.
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Affiliation(s)
- Catherine L. Deatherage
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Zhenwei Lu
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Brett M. Kroncke
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Sirui Ma
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Jarrod A. Smith
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Markus W. Voehler
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Robert L. McFeeters
- Department of Chemistry, University of Alabama in Huntsville, Huntsville, AL 35899, USA
| | - Charles R. Sanders
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
- Center for Structural Biology and Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Corresponding author.
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7
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High-efficient production and biophysical characterisation of nicastrin and its interaction with APPC100. Sci Rep 2017; 7:44297. [PMID: 28276527 PMCID: PMC5343570 DOI: 10.1038/srep44297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/06/2017] [Indexed: 01/06/2023] Open
Abstract
Nicastrin, the largest member among the four components of the γ-secretase complex, has been identified to be the substrate recognizer for the proteolytic activity of the complex. Here we report that full-length human nicastrin (hNCT) can be obtained by heterologous expression in E. coli. Milligram quantities of the target protein are purified in a two-step purification protocol using affinity chromatography followed by SEC. The FOS-choline 14 purified tetrameric hNCT exhibits a proper folding with 31% α-helix and 23% β-sheet content. Thermal stability studies reveal stable secondary and tertiary structure of the detergent purified hNCT. A physical interaction between nicastrin and the γ-secretase substrate APPC100 confirmed the functionality of hNCT as a substrate recognizer.
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8
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Dormán G, Nakamura H, Pulsipher A, Prestwich GD. The Life of Pi Star: Exploring the Exciting and Forbidden Worlds of the Benzophenone Photophore. Chem Rev 2016; 116:15284-15398. [PMID: 27983805 DOI: 10.1021/acs.chemrev.6b00342] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The widespread applications of benzophenone (BP) photochemistry in biological chemistry, bioorganic chemistry, and material science have been prominent in both academic and industrial research. BP photophores have unique photochemical properties: upon n-π* excitation at 365 nm, a biradicaloid triplet state is formed reversibly, which can abstract a hydrogen atom from accessible C-H bonds; the radicals subsequently recombine, creating a stable covalent C-C bond. This light-directed covalent attachment process is exploited in many different ways: (i) binding/contact site mapping of ligand (or protein)-protein interactions; (ii) identification of molecular targets and interactome mapping; (iii) proteome profiling; (iv) bioconjugation and site-directed modification of biopolymers; (v) surface grafting and immobilization. BP photochemistry also has many practical advantages, including low reactivity toward water, stability in ambient light, and the convenient excitation at 365 nm. In addition, several BP-containing building blocks and reagents are commercially available. In this review, we explore the "forbidden" (transitions) and excitation-activated world of photoinduced covalent attachment of BP photophores by touring a colorful palette of recent examples. In this exploration, we will see the pros and cons of using BP photophores, and we hope that both novice and expert photolabelers will enjoy and be inspired by the breadth and depth of possibilities.
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Affiliation(s)
- György Dormán
- Targetex llc , Dunakeszi H-2120, Hungary.,Faculty of Pharmacy, University of Szeged , Szeged H-6720, Hungary
| | - Hiroyuki Nakamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Abigail Pulsipher
- GlycoMira Therapeutics, Inc. , Salt Lake City, Utah 84108, United States.,Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
| | - Glenn D Prestwich
- Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
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9
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BIIB042, a novel γ-secretase modulator, reduces amyloidogenic Aβ isoforms in primates and rodents and plaque pathology in a mouse model of Alzheimer's disease. Neuropharmacology 2016; 103:57-68. [DOI: 10.1016/j.neuropharm.2015.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/16/2015] [Accepted: 12/09/2015] [Indexed: 12/16/2022]
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10
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Prade E, Barucker C, Sarkar R, Althoff-Ospelt G, Lopez del Amo JM, Hossain S, Zhong Y, Multhaup G, Reif B. Sulindac Sulfide Induces the Formation of Large Oligomeric Aggregates of the Alzheimer's Disease Amyloid-β Peptide Which Exhibit Reduced Neurotoxicity. Biochemistry 2016; 55:1839-49. [PMID: 26900939 DOI: 10.1021/acs.biochem.5b01272] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease is characterized by deposition of the amyloid β-peptide (Aβ) in brain tissue of affected individuals. In recent years, many potential lead structures have been suggested that can potentially be used for diagnosis and therapy. However, the mode of action of these compounds is so far not understood. Among these small molecules, the nonsteroidal anti-inflammatory drug (NSAID) sulindac sulfide received a lot of attention. In this manuscript, we characterize the interaction between the monomeric Aβ peptide and the NSAID sulindac sulfide. We find that sulindac sulfide efficiently depletes the pool of toxic oligomers by enhancing the rate of fibril formation. In vitro, sulindac sulfide forms colloidal particles which catalyze the formation of fibrils. Aggregation is immediate, presumably by perturbing the supersaturated Aβ solution. We find that sulindac sulfide induced Aβ aggregates are structurally homogeneous. The C-terminal part of the peptide adopts a β-sheet structure, whereas the N-terminus is disordered. The salt bridge between D23 and K28 is present, similar as in wild type fibril structures. (13)C-(19)F transferred echo double resonance experiments suggest that sulindac sulfide colocalizes with the Aβ peptide in the aggregate.
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Affiliation(s)
- Elke Prade
- Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Christian Barucker
- Department of Pharmacology & Therapeutics, McGill University , 3655 Promenade Sir-William-Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Riddhiman Sarkar
- Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany
| | | | - Juan Miguel Lopez del Amo
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Shireen Hossain
- Department of Pharmacology & Therapeutics, McGill University , 3655 Promenade Sir-William-Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Yifei Zhong
- Department of Pharmacology & Therapeutics, McGill University , 3655 Promenade Sir-William-Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Gerd Multhaup
- Department of Pharmacology & Therapeutics, McGill University , 3655 Promenade Sir-William-Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Bernd Reif
- Munich Center for Integrated Protein Science (CIPS-M) at Department Chemie, Technische Universität München (TUM) , Lichtenbergstrasse 4, 85747 Garching, Germany.,Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
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11
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Prade E, Bittner HJ, Sarkar R, Lopez Del Amo JM, Althoff-Ospelt G, Multhaup G, Hildebrand PW, Reif B. Structural Mechanism of the Interaction of Alzheimer Disease Aβ Fibrils with the Non-steroidal Anti-inflammatory Drug (NSAID) Sulindac Sulfide. J Biol Chem 2015; 290:28737-45. [PMID: 26416887 PMCID: PMC4661391 DOI: 10.1074/jbc.m115.675215] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 09/14/2015] [Indexed: 01/12/2023] Open
Abstract
Alzheimer disease is the most severe neurodegenerative disease worldwide. In the past years, a plethora of small molecules interfering with amyloid-β (Aβ) aggregation has been reported. However, their mode of interaction with amyloid fibers is not understood. Non-steroidal anti-inflammatory drugs (NSAIDs) are known γ-secretase modulators; they influence Aβ populations. It has been suggested that NSAIDs are pleiotrophic and can interact with more than one pathomechanism. Here we present a magic angle spinning solid-state NMR study demonstrating that the NSAID sulindac sulfide interacts specifically with Alzheimer disease Aβ fibrils. We find that sulindac sulfide does not induce drastic architectural changes in the fibrillar structure but intercalates between the two β-strands of the amyloid fibril and binds to hydrophobic cavities, which are found consistently in all analyzed structures. The characteristic Asp(23)-Lys(28) salt bridge is not affected upon interacting with sulindac sulfide. The primary binding site is located in the vicinity of residue Gly(33), a residue involved in Met(35) oxidation. The results presented here will assist the search for pharmacologically active molecules that can potentially be employed as lead structures to guide the design of small molecules for the treatment of Alzheimer disease.
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Affiliation(s)
- Elke Prade
- From the Munich Center for Integrated Protein Science at Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Heiko J Bittner
- Molecular Modeling, Institute of Medical Physics and Biophysics, Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Riddhiman Sarkar
- From the Munich Center for Integrated Protein Science at Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | | | | | - Gerd Multhaup
- the Department of Pharmacology and Therapeutics, McGill University, Montreal Quebec H3G 1Y6, Canada, and
| | - Peter W Hildebrand
- Molecular Modeling, Institute of Medical Physics and Biophysics, Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Bernd Reif
- From the Munich Center for Integrated Protein Science at Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany, the Helmholtz-Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landtstr. 1, 85764 Neuherberg, Germany
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12
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Uversky VN, Davé V, Iakoucheva LM, Malaney P, Metallo SJ, Pathak RR, Joerger AC. Pathological unfoldomics of uncontrolled chaos: intrinsically disordered proteins and human diseases. Chem Rev 2014; 114:6844-79. [PMID: 24830552 PMCID: PMC4100540 DOI: 10.1021/cr400713r] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 22254, Saudi Arabia
| | - Vrushank Davé
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, United States
| | - Lilia M. Iakoucheva
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
| | - Prerna Malaney
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Steven J. Metallo
- Department of Chemistry, Georgetown University, Washington, District of Columbia 20057, United States
| | - Ravi Ramesh Pathak
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Andreas C. Joerger
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
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13
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Karran E, Hardy J. A critique of the drug discovery and phase 3 clinical programs targeting the amyloid hypothesis for Alzheimer disease. Ann Neurol 2014; 76:185-205. [PMID: 24853080 PMCID: PMC4204160 DOI: 10.1002/ana.24188] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Eric Karran
- Alzheimer's Research UK, Cambridge; Reta Lila Weston Laboratories, London; Department of Molecular Neuroscience, University College London, London, United Kingdom
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14
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Ohki Y, Shimada N, Tominaga A, Osawa S, Higo T, Yokoshima S, Fukuyama T, Tomita T, Iwatsubo T. Binding of longer Aβ to transmembrane domain 1 of presenilin 1 impacts on Aβ42 generation. Mol Neurodegener 2014; 9:7. [PMID: 24410857 PMCID: PMC3896738 DOI: 10.1186/1750-1326-9-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/10/2014] [Indexed: 11/18/2022] Open
Abstract
Background Amyloid-β peptide ending at 42nd residue (Aβ42) is believed as a pathogenic peptide for Alzheimer disease. Although γ-secretase is a responsible protease to generate Aβ through a processive cleavage, the proteolytic mechanism of γ-secretase at molecular level is poorly understood. Results We found that the transmembrane domain (TMD) 1 of presenilin (PS) 1, a catalytic subunit for the γ-secretase, as a key modulatory domain for Aβ42 production. Aβ42-lowering and -raising γ-secretase modulators (GSMs) directly targeted TMD1 of PS1 and affected its structure. A point mutation in TMD1 caused an aberrant secretion of longer Aβ species including Aβ45 that are the precursor of Aβ42. We further found that the helical surface of TMD1 is involved in the binding of Aβ45/48 and that the binding was altered by GSMs as well as TMD1 mutation. Conclusions Binding between PS1 TMD1 and longer Aβ is critical for Aβ42 production.
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Affiliation(s)
| | | | | | | | | | | | | | - Taisuke Tomita
- Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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15
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Song Y, Hustedt EJ, Brandon S, Sanders CR. Competition between homodimerization and cholesterol binding to the C99 domain of the amyloid precursor protein. Biochemistry 2013; 52:5051-64. [PMID: 23865807 DOI: 10.1021/bi400735x] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The 99-residue transmembrane C-terminal domain (C99, also known as β-CTF) of the amyloid precursor protein (APP) is the product of the β-secretase cleavage of the full-length APP and is the substrate for γ-secretase cleavage. The latter cleavage releases the amyloid-β polypeptides that are closely associated with Alzheimer's disease. C99 is thought to form homodimers; however, the free energy in favor of dimerization has not previously been quantitated. It was also recently documented that cholesterol forms a 1:1 complex with monomeric C99 in bicelles. Here, the affinities for both homodimerization and cholesterol binding to C99 were measured in bilayered lipid vesicles using both electron paramagnetic resonance (EPR) and Förster resonance energy transfer (FRET) methods. Homodimerization and cholesterol binding were seen to be competitive processes that center on the transmembrane G₇₀₀XXXG₇₀₄XXXG₇₀₈ glycine-zipper motif and adjacent Gly709. On one hand, the observed Kd for cholesterol binding (Kd = 2.7 ± 0.3 mol %) is on the low end of the physiological cholesterol concentration range in mammalian cell membranes. On the other hand, the observed K(d) for homodimerization (K(d) = 0.47 ± 0.15 mol %) likely exceeds the physiological concentration range for C99. These results suggest that the 1:1 cholesterol/C99 complex will be more highly populated than C99 homodimers under most physiological conditions. These observations are of relevance for understanding the γ-secretase cleavage of C99.
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Affiliation(s)
- Yuanli Song
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
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16
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Crump CJ, Johnson DS, Li YM. Development and mechanism of γ-secretase modulators for Alzheimer's disease. Biochemistry 2013; 52:3197-216. [PMID: 23614767 DOI: 10.1021/bi400377p] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
γ-Secretase is an aspartyl intramembranal protease composed of presenilin, Nicastrin, Aph1, and Pen2 with 19 transmembrane domains. γ-Secretase cleaves the amyloid precursor proteins (APP) to release Aβ peptides that likely play a causative role in the pathogenesis of Alzheimer's disease (AD). In addition, γ-secretase cleaves Notch and other type I membrane proteins. γ-Secretase inhibitors (GSIs) have been developed and used for clinical studies. However, clinical trials have shown adverse effects of GSIs that are potentially linked with nondiscriminatory inhibition of Notch signaling, overall APP processing, and other substrate cleavages. Therefore, these findings call for the development of disease-modifying agents that target γ-secretase activity to lower levels of Aβ42 production without blocking the overall processing of γ-secretase substrates. γ-Secretase modulators (GSMs) originally derived from nonsteroidal anti-inflammatory drugs (NSAIDs) display such characteristics and are the focus of this review. However, first-generation GSMs have limited potential because of the low potency and undesired neuropharmacokinetic properties. This generation of GSMs has been suggested to interact with the APP substrate, γ-secretase, or both. To improve the potency and brain availability, second-generation GSMs, including NSAID-derived carboxylic acid and non-NSAID-derived heterocyclic chemotypes, as well as natural product-derived GSMs have been developed. Animal studies of this generation of GSMs have shown encouraging preclinical profiles. Moreover, using potent GSM photoaffinity probes, multiple studies unambiguously have showed that both carboxylic acid and heterocyclic GSMs specifically target presenilin, the catalytic subunit of γ-secretase. In addition, two types of GSMs have distinct binding sites within the γ-secretase complex and exhibit different Aβ profiles. GSMs induce a conformational change of γ-secretase to achieve modulation. Various models are proposed and discussed. Despite the progress of GSM research, many outstanding issues remain to be investigated to achieve the ultimate goal of developing GSMs as effective AD therapies.
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Affiliation(s)
- Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center , 1275 York Avenue, New York, New York 10065, United States
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17
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Barrett PJ, Chen J, Cho MK, Kim JH, Lu Z, Mathew S, Peng D, Song Y, Van Horn WD, Zhuang T, Sönnichsen FD, Sanders CR. The quiet renaissance of protein nuclear magnetic resonance. Biochemistry 2013; 52:1303-20. [PMID: 23368985 DOI: 10.1021/bi4000436] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
From roughly 1985 through the start of the new millennium, the cutting edge of solution protein nuclear magnetic resonance (NMR) spectroscopy was to a significant extent driven by the aspiration to determine structures. Here we survey recent advances in protein NMR that herald a renaissance in which a number of its most important applications reflect the broad problem-solving capability displayed by this method during its classical era during the 1970s and early 1980s.
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Affiliation(s)
- Paul J Barrett
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232-8725, United States
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18
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Svedružić ŽM, Popović K, Šendula-Jengić V. Modulators of γ-secretase activity can facilitate the toxic side-effects and pathogenesis of Alzheimer's disease. PLoS One 2013; 8:e50759. [PMID: 23308095 PMCID: PMC3538728 DOI: 10.1371/journal.pone.0050759] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 10/25/2012] [Indexed: 11/18/2022] Open
Abstract
Background Selective modulation of different Aβ products of an intramembrane protease γ-secretase, could be the most promising strategy for development of effective therapies for Alzheimer's disease. We describe how different drug-candidates can modulate γ-secretase activity in cells, by studying how DAPT affects changes in γ-secretase activity caused by gradual increase in Aβ metabolism. Results Aβ 1–40 secretion in the presence of DAPT shows biphasic activation-inhibition dose-response curves. The biphasic mechanism is a result of modulation of γ-secretase activity by multiple substrate and inhibitor molecules that can bind to the enzyme simultaneously. The activation is due to an increase in γ-secretase's kinetic affinity for its substrate, which can make the enzyme increasingly more saturated with otherwise sub-saturating substrate. The noncompetitive inhibition that prevails at the saturating substrate can decrease the maximal activity. The synergistic activation-inhibition effects can drastically reduce γ-secretase's capacity to process its physiological substrates. This reduction makes the biphasic inhibitors exceptionally prone to the toxic side-effects and potentially pathogenic. Without the modulation, γ-secretase activity on it physiological substrate in cells is only 14% of its maximal activity, and far below the saturation. Significance Presented mechanism can explain why moderate inhibition of γ-secretase cannot lead to effective therapies, the pharmacodynamics of Aβ-rebound phenomenon, and recent failures of the major drug-candidates such as semagacestat. Novel improved drug-candidates can be prepared from competitive inhibitors that can bind to different sites on γ-secretase simultaneously. Our quantitative analysis of the catalytic capacity can facilitate the future studies of the therapeutic potential of γ-secretase and the pathogenic changes in Aβ metabolism.
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Affiliation(s)
- Željko M Svedružić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia.
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19
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Synthesis of a potent photoreactive acidic γ-secretase modulator for target identification in cells. Bioorg Med Chem 2012; 20:6523-32. [PMID: 23000293 DOI: 10.1016/j.bmc.2012.08.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/23/2012] [Accepted: 08/08/2012] [Indexed: 11/24/2022]
Abstract
Supramolecular self-assembly of amyloidogenic peptides is closely associated with numerous pathological conditions. For instance, Alzheimer´s disease (AD) is characterized by abundant amyloid plaques originating from the proteolytic cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. Compounds named γ-secretase modulators (GSMs) can shift the substrate cleavage specificity of γ-secretase toward the production of non-amyloidogenic, shorter Aβ fragments. Herein, we describe the synthesis of highly potent acidic GSMs, equipped with a photoreactive diazirine moiety for photoaffinity labeling. The probes labeled the N-terminal fragment of presenilin (the catalytic subunit of γ-secretase), supporting a mode of action involving binding to γ-secretase. This fundamental step toward the elucidation of the molecular mechanism governing the GSM-induced shift in γ-secretase proteolytic specificity should pave the way for the development of improved drugs against AD.
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20
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Bulic B, Ness J, Hahn S, Rennhack A, Jumpertz T, Weggen S. Chemical Biology, Molecular Mechanism and Clinical Perspective of γ-Secretase Modulators in Alzheimer's Disease. Curr Neuropharmacol 2012; 9:598-622. [PMID: 22798753 PMCID: PMC3391656 DOI: 10.2174/157015911798376352] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 10/25/2010] [Accepted: 11/01/2010] [Indexed: 12/25/2022] Open
Abstract
Comprehensive evidence supports that oligomerization and accumulation of amyloidogenic Aβ42 peptides in brain is crucial in the pathogenesis of both familial and sporadic forms of Alzheimer's disease. Imaging studies indicate that the buildup of Aβ begins many years before the onset of clinical symptoms, and that subsequent neurodegeneration and cognitive decline may proceed independently of Aβ. This implies the necessity for early intervention in cognitively normal individuals with therapeutic strategies that prioritize safety. The aspartyl protease γ-secretase catalyses the last step in the cellular generation of Aβ42 peptides, and is a principal target for anti-amyloidogenic intervention strategies. Due to the essential role of γ-secretase in the NOTCH signaling pathway, overt mechanism-based toxicity has been observed with the first generation of γ-secretase inhibitors, and safety of this approach has been questioned. However, two new classes of small molecules, γ-secretase modulators (GSMs) and NOTCH-sparing γ-secretase inhibitors, have revitalized γ-secretase as a drug target in AD. GSMs are small molecules that cause a product shift from Aβ42 towards shorter and less toxic Ab peptides. Importantly, GSMs spare other physiologically important substrates of the γ-secretase complex like NOTCH. Recently, GSMs with nanomolar potency and favorable in vivo properties have been described. In this review, we summarize the knowledge about the unusual proteolytic activity of γ-secretase, and the chemical biology, molecular mechanisms and clinical perspective of compounds that target the γ-secretase complex, with a particular focus on GSMs.
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Affiliation(s)
- Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, D-53175 Bonn, Germany
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21
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Wanngren J, Ottervald J, Parpal S, Portelius E, Strömberg K, Borgegård T, Klintenberg R, Juréus A, Blomqvist J, Blennow K, Zetterberg H, Lundkvist J, Rosqvist S, Karlström H. Second generation γ-secretase modulators exhibit different modulation of Notch β and Aβ production. J Biol Chem 2012; 287:32640-50. [PMID: 22851182 DOI: 10.1074/jbc.m112.376541] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The γ-secretase complex is an appealing drug target when the therapeutic strategy is to alter amyloid-β peptide (Aβ) aggregation in Alzheimer disease. γ-Secretase is directly involved in Aβ formation and determines the pathogenic potential of Aβ by generating the aggregation-prone Aβ42 peptide. Because γ-secretase mediates cleavage of many substrates involved in cell signaling, such as the Notch receptor, it is crucial to sustain these pathways while altering the Aβ secretion. A way of avoiding interference with the physiological function of γ-secretase is to use γ-secretase modulators (GSMs) instead of inhibitors of the enzyme. GSMs modify the Aβ formation from producing the amyloid-prone Aβ42 variant to shorter and less amyloidogenic Aβ species. The modes of action of GSMs are not fully understood, and even though the pharmacology of GSMs has been thoroughly studied regarding Aβ generation, knowledge is lacking about their effects on other substrates, such as Notch. Here, using immunoprecipitation followed by MALDI-TOF MS analysis, we found that two novel, second generation GSMs modulate both Notch β and Aβ production. Moreover, by correlating S3-specific Val-1744 cleavage of Notch intracellular domain (Notch intracellular domain) to total Notch intracellular domain levels using immunocytochemistry, we also demonstrated that Notch intracellular domain is not modulated by the compounds. Interestingly, two well characterized, nonsteroidal anti-inflammatory drugs (nonsteroidal anti-inflammatory drug), R-flurbiprofen and sulindac sulfide, affect only Aβ and not Notch β formation, indicating that second generation GSMs and nonsteroidal anti-inflammatory drug-based GSMs have different modes of action regarding Notch processing.
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Affiliation(s)
- Johanna Wanngren
- Department of Neurobiology, Care Sciences and society, KI-Alzheimer's Disease Research Center, Karolinska Institutet, 14157 Stockholm, Sweden
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22
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Rezaei-Ghaleh N, Blackledge M, Zweckstetter M. Intrinsically Disordered Proteins: From Sequence and Conformational Properties toward Drug Discovery. Chembiochem 2012; 13:930-50. [DOI: 10.1002/cbic.201200093] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Indexed: 01/31/2023]
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23
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Jumpertz T, Rennhack A, Ness J, Baches S, Pietrzik CU, Bulic B, Weggen S. Presenilin is the molecular target of acidic γ-secretase modulators in living cells. PLoS One 2012; 7:e30484. [PMID: 22238696 PMCID: PMC3253113 DOI: 10.1371/journal.pone.0030484] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 12/16/2011] [Indexed: 01/19/2023] Open
Abstract
The intramembrane-cleaving protease γ-secretase catalyzes the last step in the generation of toxic amyloid-β (Aβ) peptides and is a principal therapeutic target in Alzheimer's disease. Both preclinical and clinical studies have demonstrated that inhibition of γ-secretase is associated with prohibitive side effects due to suppression of Notch processing and signaling. Potentially safer are γ-secretase modulators (GSMs), which are small molecules that selectively lower generation of the highly amyloidogenic Aβ42 peptides but spare Notch processing. GSMs with nanomolar potency and favorable pharmacological properties have been described, but the molecular mechanism of GSMs remains uncertain and both the substrate amyloid precursor protein (APP) and subunits of the γ-secretase complex have been proposed as the molecular target of GSMs. We have generated a potent photo-probe based on an acidic GSM that lowers Aβ42 generation with an IC50 of 290 nM in cellular assays. By combining in vivo photo-crosslinking with affinity purification, we demonstrated that this probe binds the N-terminal fragment of presenilin (PSEN), the catalytic subunit of the γ-secretase complex, in living cells. Labeling was not observed for APP or any of the other γ-secretase subunits. Binding was readily competed by structurally divergent acidic and non-acidic GSMs suggesting a shared mode of action. These findings indicate that potent acidic GSMs target presenilin to modulate the enzymatic activity of the γ-secretase complex.
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Affiliation(s)
- Thorsten Jumpertz
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Andreas Rennhack
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, Bonn, Germany
| | - Julia Ness
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Sandra Baches
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Claus U. Pietrzik
- Molecular Neurodegeneration Group, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, Bonn, Germany
- * E-mail: (BB); (SW)
| | - Sascha Weggen
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
- * E-mail: (BB); (SW)
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24
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Crump CJ, Fish BA, Castro SV, Chau DM, Gertsik N, Ahn K, Stiff C, Pozdnyakov N, Bales KR, Johnson DS, Li YM. Piperidine acetic acid based γ-secretase modulators directly bind to Presenilin-1. ACS Chem Neurosci 2011; 2:705-710. [PMID: 22229075 DOI: 10.1021/cn200098p] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Aβ42 is believed to play a causative role in Alzheimer's disease (AD) pathogenesis. γ-Secretase modulators (GSMs) are actively being pursued as potential AD therapeutics because they selectively alter the cleavage site of the amyloid precursor protein (APP) to reduce the formation of Aβ42. However, the binding partner of acid based GSMs was unresolved until now. We have developed clickable photoaffinity probes based on piperidine acetic acid GSM-1 and identified PS1 as the target within the γ-secretase complex. Furthermore, we provide evidence that allosteric interaction of GSMs with PS1 results in a conformational change in the active site of the γ-secretase complex leading to the observed modulation of γ-secretase activity.
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Affiliation(s)
- Christina J. Crump
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Benjamin A. Fish
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Suita V. Castro
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - De-Ming Chau
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Natalya Gertsik
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Kwangwook Ahn
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Cory Stiff
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Nikolay Pozdnyakov
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Kelly R. Bales
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Douglas S. Johnson
- Pfizer Worldwide Research and Development, Groton, Connecticut 06340,
United States
| | - Yue-Ming Li
- Molecular Pharmacology
and Chemistry
Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
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25
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Barrett PJ, Sanders CR, Kaufman SA, Michelsen K, Jordan JB. NSAID-based γ-secretase modulators do not bind to the amyloid-β polypeptide. Biochemistry 2011; 50:10328-42. [PMID: 21995415 DOI: 10.1021/bi201371j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
γ-Secretase modulators (GSMs) have received much attention as potential therapeutic agents for Alzheimer's disease (AD). GSMs increase the ratio between short and long forms of the amyloid-β (Aβ) polypeptides produced by γ-secretase and thereby decrease the amount of the toxic amyloid species. However, the mechanism of action of these agents is still poorly understood. One recent paper [Richter et al. (2010) Proc. Natl. Acad. Sci. U. S. A.107, 14597-14602] presented data that were interpreted to support direct binding of the GSM sulindac sulfide to Aβ(42), supporting the notion that GSM action is linked to direct binding of these compounds to the Aβ domain of its immediate precursor, the 99-residue C-terminal domain of the amyloid precursor protein (C99, also known as the β-CTF). Here, contrasting results are presented that indicate there is no interaction between monomeric sulindac sulfide and monomeric forms of Aβ42. Instead, it was observed that sulindac sulfide is itself prone to form aggregates that can bind nonspecifically to Aβ42 and trigger its aggregation. This observation, combined with data from previous work [Beel et al. (2009) Biochemistry48, 11837-11839], suggests both that the poor behavior of some NSAID-based GSMs in solution may obscure results of binding assays and that NSAID-based GSMs do not function by directly targeting C99. It was also observed that another GSM, flurbiprofen, fails to bind to monomeric Aβ42 or to C99 reconstituted into bilayered lipid vesicles. These results disfavor the hypothesis that these NSAID-based GSMs exert their modulatory effect by directly targeting a site located in the Aβ42 domain of free C99.
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Affiliation(s)
- Paul J Barrett
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232-8725, United States
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26
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Ohki Y, Higo T, Uemura K, Shimada N, Osawa S, Berezovska O, Yokoshima S, Fukuyama T, Tomita T, Iwatsubo T. Phenylpiperidine-type γ-secretase modulators target the transmembrane domain 1 of presenilin 1. EMBO J 2011; 30:4815-24. [PMID: 22002539 DOI: 10.1038/emboj.2011.372] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 09/21/2011] [Indexed: 01/30/2023] Open
Abstract
Amyloid-β peptide ending at the 42nd residue (Aβ42) is implicated in the pathogenesis of Alzheimer's disease (AD). Small compounds that exhibit selective lowering effects on Aβ42 production are termed γ-secretase modulators (GSMs) and are deemed as promising therapeutic agents against AD, although the molecular target as well as the mechanism of action remains controversial. Here, we show that a phenylpiperidine-type compound GSM-1 directly targets the transmembrane domain (TMD) 1 of presenilin 1 (PS1) by photoaffinity labelling experiments combined with limited digestion. Binding of GSM-1 affected the structure of the initial substrate binding and the catalytic sites of the γ-secretase, thereby decreasing production of Aβ42, possibly by enhancing its conversion to Aβ38. These data indicate an allosteric action of GSM-1 by directly binding to the TMD1 of PS1, pinpointing the target structure of the phenylpiperidine-type GSMs.
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Affiliation(s)
- Yu Ohki
- Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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27
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Abstract
The growth of new blood vessels (angiogenesis) is critical for tumor growth and progression. The highly conserved Notch signaling pathway is involved in a variety of cell fate decisions and regulates many cellular biological processes, including angiogenesis. Aberrant Notch signaling has also been implicated in tumorigenesis. Notch ligands and receptors are expressed on many different cell types present within the tumor, including tumor cells and the stromal compartment. This article highlights in particular the various mechanisms by which Notch signaling can mediate tumor angiogenesis. The most studied Notch ligands, Delta-like 4 and Jagged1, competitively regulate tumor angiogenesis. Studies have demonstrated that Delta-like 4 functions as a negative regulator of tumor angiogenesis, whereas Jagged1 promotes angiogenesis. Understanding the implications of Notch signaling in various tumor backgrounds will enable the effects of specific Notch signaling inhibition on tumor angiogenesis and growth to be evaluated as a potential for a novel antiangiogenic therapy in the clinic.
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Affiliation(s)
- Esther Bridges
- Molecular Oncology Laboratories, University Department of Medical Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
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28
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Ebke A, Luebbers T, Fukumori A, Shirotani K, Haass C, Baumann K, Steiner H. Novel γ-secretase enzyme modulators directly target presenilin protein. J Biol Chem 2011; 286:37181-6. [PMID: 21896486 DOI: 10.1074/jbc.c111.276972] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
γ-Secretase is essential for the generation of the neurotoxic 42-amino acid amyloid β-peptide (Aβ(42)). The aggregation-prone hydrophobic peptide, which is deposited in Alzheimer disease (AD) patient brain, is generated from a C-terminal fragment of the β-amyloid precursor protein by an intramembrane cleavage of γ-secretase. Because Aβ(42) is widely believed to trigger AD pathogenesis, γ-secretase is a key AD drug target. Unlike inhibitors of the enzyme, γ-secretase modulators (GSMs) selectively lower Aβ(42) without interfering with the physiological function of γ-secretase. The molecular target(s) of GSMs and hence the mechanism of GSM action are not established. Here we demonstrate by using a biotinylated photocross-linkable derivative of highly potent novel second generation GSMs that γ-secretase is a direct target of GSMs. The GSM photoprobe specifically bound to the N-terminal fragment of presenilin, the catalytic subunit of γ-secretase, but not to other γ-secretase subunits. Binding was differentially competed by GSMs of diverse structural classes, indicating the existence of overlapping/multiple GSM binding sites or allosteric alteration of the photoprobe binding site. The β-amyloid precursor protein C-terminal fragment previously implicated as the GSM binding site was not targeted by the compound. The identification of presenilin as the molecular target of GSMs directly establishes allosteric modulation of enzyme activity as a mechanism of GSM action and may contribute to the development of therapeutically active GSMs for the treatment of AD.
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Affiliation(s)
- Amelie Ebke
- Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, 80336 Munich, Germany
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29
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Kretner B, Fukumori A, Gutsmiedl A, Page RM, Luebbers T, Galley G, Baumann K, Haass C, Steiner H. Attenuated Abeta42 responses to low potency gamma-secretase modulators can be overcome for many pathogenic presenilin mutants by second-generation compounds. J Biol Chem 2011; 286:15240-51. [PMID: 21357415 DOI: 10.1074/jbc.m110.213587] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Sequential processing of the β-amyloid precursor protein by β- and γ-secretase generates the amyloid β-peptide (Aβ), which is widely believed to play a causative role in Alzheimer disease. Selective lowering of the pathogenic 42-amino acid variant of Aβ by γ-secretase modulators (GSMs) is a promising therapeutic strategy. Here we report that mutations in presenilin (PS), the catalytic subunit of γ-secretase, display differential responses to non-steroidal anti-inflammatory drug (NSAID)-type GSMs and more potent second-generation compounds. Although many pathogenic PS mutations resisted lowering of Aβ(42) generation by the NSAID sulindac sulfide, the potent NSAID-like second-generation compound GSM-1 was capable of lowering Aβ(42) for many but not all mutants. We further found that mutations at homologous positions in PS1 and PS2 can elicit differential Aβ(42) responses to GSM-1, suggesting that a positive GSM-1 response depends on the spatial environment in γ-secretase. The aggressive pathogenic PS1 L166P mutation was one of the few pathogenic mutations that resisted GSM-1, and Leu-166 was identified as a critical residue with respect to the Aβ(42)-lowering response of GSM-1. Finally, we found that GSM-1-responsive and -resistant PS mutants behave very similarly toward other potent second-generation compounds of different structural classes than GSM-1. Taken together, our data show that a positive Aβ(42) response for PS mutants depends both on the particular mutation and the GSM used and that attenuated Aβ(42) responses to low potency GSMs can be overcome for many PS mutants by second generation GSMs.
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Affiliation(s)
- Benedikt Kretner
- DZNE-German Center for Neurodegenerative Diseases, Ludwig-Maximilians-University, 80336 Munich, Germany
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Pettersson M, Kauffman GW, am Ende CW, Patel NC, Stiff C, Tran TP, Johnson DS. Novel γ-secretase modulators: a review of patents from 2008 to 2010. Expert Opin Ther Pat 2011; 21:205-26. [PMID: 21231889 DOI: 10.1517/13543776.2011.547479] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The amyloid precursor protein is first cleaved by β-secretase to generate a 99-residue membrane-bound CTF (C99 or β-CTF), which is subsequently cleaved by γ-secretase to generate amyloid β (Aβ) peptides and the APP intracellular domain. The amyloidogenic Aβ42 has attracted considerable attention because it is thought to be the most pathogenic species associated with Alzheimer's disease progression. New classes of compounds, called γ-secretase modulators (GSMs), have been shown to selectively lower Aβ42 production without shutting down key γ-secretase-dependent signaling pathways. This has become an important therapeutic strategy aimed at modulating Aβ production. AREAS COVERED The progress on the clinical development of γ-secretase inhibitors is briefly covered in this review, followed by a discussion of the potential differentiating attributes of GSMs. Then, the patent literature covering novel GSMs is reviewed, focusing on patents from 2008 to 2010. EXPERT OPINION Much progress has been made in the past 2 years on developing GSMs with improved potency for lowering the production of Aβ42. However, many of these chemotypes are in a challenging chemical space and generally possess higher lipophilicity than most CNS drugs. It will be important to gain a better understanding of the specific target(s) that these GSMs interact with in order to facilitate future drug design efforts.
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Affiliation(s)
- Martin Pettersson
- Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry, Eastern Point Road, Groton, CT 06340, USA
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Botev A, Munter LM, Wenzel R, Richter L, Althoff V, Ismer J, Gerling U, Weise C, Koksch B, Hildebrand PW, Bittl R, Multhaup G. The amyloid precursor protein C-terminal fragment C100 occurs in monomeric and dimeric stable conformations and binds γ-secretase modulators. Biochemistry 2011; 50:828-35. [PMID: 21186781 DOI: 10.1021/bi1014002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The amyloid-β (Aβ) peptide is contained within the C-terminal fragment (β-CTF) of the amyloid precursor protein (APP) and is intimately linked to Alzheimer's disease. In vivo, Aβ is generated by sequential cleavage of β-CTF within the γ-secretase module. To investigate γ-secretase function, in vitro assays are in widespread use which require a recombinant β-CTF substrate expressed in bacteria and purified from inclusion bodies, termed C100. So far, little is known about the conformation of C100 under different conditions of purification and refolding. Since C100 dimerization influences the efficiency and specificity of γ-secretase cleavage, it is also of great interest to determine the secondary structure and the oligomeric state of the synthetic substrate as well as the binding properties of small molecules named γ-secretase modulators (GSMs) which we could previously show to modulate APP transmembrane sequence interactions [Richter et al. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 14597-14602]. Here, we use circular dichroism and continuous-wave electron spin resonance measurements to show that C100 purified in a buffer containing SDS at micelle-forming concentrations adopts a highly stable α-helical conformation, in which it shows little tendency to aggregate or to form higher oligomers than dimers. By surface plasmon resonance analysis and molecular modeling we show that the GSM sulindac sulfide binds to C100 and has a preference for C100 dimers.
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Affiliation(s)
- Anne Botev
- Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
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Oehlrich D, Berthelot DJC, Gijsen HJM. γ-Secretase modulators as potential disease modifying anti-Alzheimer's drugs. J Med Chem 2010; 54:669-98. [PMID: 21141968 DOI: 10.1021/jm101168r] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Daniel Oehlrich
- Medicinal Chemistry, Janssen Research and Development, a Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340 Beerse, Belgium.
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Uemura K, Farner KC, Hashimoto T, Nasser-Ghodsi N, Wolfe MS, Koo EH, Hyman BT, Berezovska O. Substrate docking to γ-secretase allows access of γ-secretase modulators to an allosteric site. Nat Commun 2010; 1:130. [PMID: 21119643 PMCID: PMC3060602 DOI: 10.1038/ncomms1129] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 11/02/2010] [Indexed: 01/24/2023] Open
Abstract
γ-Secretase generates the peptides of Alzheimer's disease, Aβ40 and Aβ42, by cleaving the amyloid precursor protein within its transmembrane domain. γ-Secretase also cleaves numerous other substrates, raising concerns about γ-secretase inhibitor off-target effects. Another important class of drugs, γ-secretase modulators, alter the cleavage site of γ-secretase on amyloid precursor protein, changing the Aβ42/Aβ40 ratio, and are thus a promising therapeutic approach for Alzheimer's disease. However, the target for γ-secretase modulators is uncertain, with some data suggesting that they function on γ-secretase, whereas others support their binding to the amyloid precursor. In this paper we address this controversy by using a fluorescence resonance energy transfer-based assay to examine whether γ-secretase modulators alter Presenilin-1/γ-secretase conformation in intact cells in the absence of its natural substrates such as amyloid precursor protein and Notch. We report that the γ-secretase allosteric site is located within the γ-secretase complex, but substrate docking is needed for γ-secretase modulators to access this site. γ-Secretase modulators have promise in the treatment of Alzheimer's disease, but their molecular target is uncertain. Here, fluorescence resonance energy transfer is used to determine that the γ-secretase allosteric site is within the γ-secretase complex and that substrate docking is required for modulators to access the site.
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Affiliation(s)
- Kengo Uemura
- 1] Alzheimer Research Unit, MassGeneral Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA. [2]
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Zettl H, Weggen S, Schneider P, Schneider G. Exploring the chemical space of γ-secretase modulators. Trends Pharmacol Sci 2010; 31:402-10. [DOI: 10.1016/j.tips.2010.05.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 05/24/2010] [Accepted: 05/26/2010] [Indexed: 11/29/2022]
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Amyloid beta 42 peptide (Abeta42)-lowering compounds directly bind to Abeta and interfere with amyloid precursor protein (APP) transmembrane dimerization. Proc Natl Acad Sci U S A 2010; 107:14597-602. [PMID: 20679249 DOI: 10.1073/pnas.1003026107] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Following ectodomain shedding by beta-secretase, successive proteolytic cleavages within the transmembrane sequence (TMS) of the amyloid precursor protein (APP) catalyzed by gamma-secretase result in the release of amyloid-beta (Abeta) peptides of variable length. Abeta peptides with 42 amino acids appear to be the key pathogenic species in Alzheimer's disease, as they are believed to initiate neuronal degeneration. Sulindac sulfide, which is known as a potent gamma-secretase modulator (GSM), selectively reduces Abeta42 production in favor of shorter Abeta species, such as Abeta38. By studying APP-TMS dimerization we previously showed that an attenuated interaction similarly decreased Abeta42 levels and concomitantly increased Abeta38 levels. However, the precise molecular mechanism by which GSMs modulate Abeta production is still unclear. In this study, using a reporter gene-based dimerization assay, we found that APP-TMS dimers are destabilized by sulindac sulfide and related Abeta42-lowering compounds in a concentration-dependent manner. By surface plasmon resonance analysis and NMR spectroscopy, we show that sulindac sulfide and novel sulindac-derived compounds directly bind to the Abeta sequence. Strikingly, the attenuated APP-TMS interaction by GSMs correlated strongly with Abeta42-lowering activity and binding strength to the Abeta sequence. Molecular docking analyses suggest that certain GSMs bind to the GxxxG dimerization motif in the APP-TMS. We conclude that these GSMs decrease Abeta42 levels by modulating APP-TMS interactions. This effect specifically emphasizes the importance of the dimeric APP-TMS as a promising drug target in Alzheimer's disease.
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Page RM, Gutsmiedl A, Fukumori A, Winkler E, Haass C, Steiner H. Beta-amyloid precursor protein mutants respond to gamma-secretase modulators. J Biol Chem 2010; 285:17798-810. [PMID: 20348104 DOI: 10.1074/jbc.m110.103283] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogenic generation of the 42-amino acid variant of the amyloid beta-peptide (Abeta) by beta- and gamma-secretase cleavage of the beta-amyloid precursor protein (APP) is believed to be causative for Alzheimer disease (AD). Lowering of Abeta(42) production by gamma-secretase modulators (GSMs) is a hopeful approach toward AD treatment. The mechanism of GSM action is not fully understood. Moreover, whether GSMs target the Abeta domain is controversial. To further our understanding of the mode of action of GSMs and the cleavage mechanism of gamma-secretase, we analyzed mutations located at different positions of the APP transmembrane domain around or within the Abeta domain regarding their response to GSMs. We found that Abeta(42)-increasing familial AD mutations of the gamma-secretase cleavage site domain responded robustly to Abeta(42)-lowering GSMs, especially to the potent compound GSM-1, irrespective of the amount of Abeta(42) produced. We thus expect that familial AD patients carrying mutations at the gamma-secretase cleavage sites of APP should respond to GSM-based therapeutic approaches. Systematic phenylalanine-scanning mutagenesis of this region revealed a high permissiveness to GSM-1 and demonstrated a complex mechanism of GSM action as other Abeta species (Abeta(41), Abeta(39)) could also be lowered besides Abeta(42). Moreover, certain mutations simultaneously increased Abeta(42) and the shorter peptide Abeta(38), arguing that the proposed precursor-product relationship of these Abeta species is not general. Finally, mutations of residues in the proposed GSM-binding site implicated in Abeta(42) generation (Gly-29, Gly-33) and potentially in GSM-binding (Lys-28) were also responsive to GSMs, a finding that may question APP substrate targeting of GSMs.
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Affiliation(s)
- Richard M Page
- German Center for Neurodegenerative Diseases DZNE)and Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, 80336 Munich, Germany
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Beel AJ, Sakakura M, Barrett PJ, Sanders CR. Direct binding of cholesterol to the amyloid precursor protein: An important interaction in lipid-Alzheimer's disease relationships? Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:975-82. [PMID: 20304095 DOI: 10.1016/j.bbalip.2010.03.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 03/10/2010] [Accepted: 03/10/2010] [Indexed: 12/21/2022]
Abstract
It is generally believed that cholesterol homoeostasis in the brain is both linked to and impacted by Alzheimer's disease (AD). For example, elevated levels of cholesterol in neuronal plasma and endosome membranes appear to be a pro-amyloidogenic factor. The recent observation that the C-terminal transmembrane domain (C99, also known as the beta-C-terminal fragment, or beta-CTF) of the amyloid precursor protein (APP) specifically binds cholesterol helps to tie together previously loose ends in the web of our understanding of Alzheimer's-cholesterol relationships. In particular, binding of cholesterol to C99 appears to favor the amyloidogenic pathway in cells by promoting localization of C99 in lipid rafts. In turn, the products of this pathway-amyloid-beta and the intracellular domain of the APP (AICD)-may down-regulate ApoE-mediated cholesterol uptake and cholesterol biosynthesis. If confirmed, this negative-feedback loop for membrane cholesterol levels has implications for understanding the function of the APP and for devising anti-amyloidogenic preventive strategies for AD.
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Affiliation(s)
- Andrew J Beel
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-8725, USA
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