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Misra P, Tischer A, Lampe L, Pierluissi-Ruiz V, Dick CJ, Bragantini B, Kormshchikov N, Auton M, Ramirez-Alvarado M. Biophysical characterization of human-cell-expressed, full-length κI O18/O8, AL-09, λ6a, and Wil immunoglobulin light chains. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2024; 1872:140993. [PMID: 38169170 PMCID: PMC10939777 DOI: 10.1016/j.bbapap.2023.140993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/12/2023] [Accepted: 12/29/2023] [Indexed: 01/05/2024]
Abstract
Immunoglobulin light chain (AL) amyloidosis involves the deposition of insoluble monoclonal AL protein fibrils in the extracellular space of different organs leading to dysfunction and death. Development of methods to efficiently express and purify AL proteins with acceptable standards of homogeneity and structural integrity has become critical to understand the in vitro and in vivo aspects of AL protein aggregation, and thus the disease progression. In this study, we report the biophysical characterization of His-tagged and untagged versions of AL full-length (FL) κI and λ6 subgroup proteins and their mutants expressed from the Expi293F human cell line. We used an array of biophysical and biochemical methods to analyze the structure and stability of the monomers, oligomerization states, and thermodynamic characteristics of the purified FL proteins and how they compare with the bacterially expressed FL proteins. Our results demonstrate that the tagged and untagged versions of FL proteins have comparable stability to proteins expressed in bacterial cells but exhibit multiple unfolding transitions and reversibility. Non-reducing SDS-PAGE and analytical ultracentrifugation analysis showed presence of monomers and dimers, with an insignificant amount of higher-order oligomers, in the purified fraction of all proteins. Overall, the FL proteins were expressed with sufficient yields for biophysical studies and can replace bacterial expression systems.
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Affiliation(s)
- Pinaki Misra
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
| | - Alexander Tischer
- Department of Hematology, Mayo Clinic, 200 First St SW, Rochester, MN, USA.
| | - Lindsey Lampe
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
| | - Valeria Pierluissi-Ruiz
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
| | - Christopher J Dick
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
| | - Benoit Bragantini
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
| | - Nikita Kormshchikov
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
| | - Matthew Auton
- Department of Hematology, Mayo Clinic, 200 First St SW, Rochester, MN, USA
| | - Marina Ramirez-Alvarado
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA; Department of Immunology, Mayo Clinic, 200 First St SW, Rochester, MN, USA.
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2
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Lavatelli F, Natalello A, Marchese L, Ami D, Corazza A, Raimondi S, Mimmi MC, Malinverni S, Mangione PP, Palmer MT, Lampis A, Concardi M, Verona G, Canetti D, Arbustini E, Bellotti V, Giorgetti S. Truncation of the constant domain drives amyloid formation by immunoglobulin light chains. J Biol Chem 2024; 300:107174. [PMID: 38499153 PMCID: PMC11016911 DOI: 10.1016/j.jbc.2024.107174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/20/2024] Open
Abstract
AL amyloidosis is a life-threatening disease caused by deposition of immunoglobulin light chains. While the mechanisms underlying light chains amyloidogenesis in vivo remain unclear, several studies have highlighted the role that tissue environment and structural amyloidogenicity of individual light chains have in the disease pathogenesis. AL natural deposits contain both full-length light chains and fragments encompassing the variable domain (VL) as well as different length segments of the constant region (CL), thus highlighting the relevance that proteolysis may have in the fibrillogenesis pathway. Here, we investigate the role of major truncated species of the disease-associated AL55 light chain that were previously identified in natural deposits. Specifically, we study structure, molecular dynamics, thermal stability, and capacity to form fibrils of a fragment containing both the VL and part of the CL (133-AL55), in comparison with the full-length protein and its variable domain alone, under shear stress and physiological conditions. Whereas the full-length light chain forms exclusively amorphous aggregates, both fragments generate fibrils, although, with different kinetics, aggregate structure, and interplay with the unfragmented protein. More specifically, the VL-CL 133-AL55 fragment entirely converts into amyloid fibrils microscopically and spectroscopically similar to their ex vivo counterpart and increases the amorphous aggregation of full-length AL55. Overall, our data support the idea that light chain structure and proteolysis are both relevant for amyloidogenesis in vivo and provide a novel biocompatible model of light chain fibrillogenesis suitable for future mechanistic studies.
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Affiliation(s)
- Francesca Lavatelli
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy; Research Area, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
| | - Loredana Marchese
- Pathology Unit, Fondazione IRCSS Policlinico San Matteo, Pavia, Italy
| | - Diletta Ami
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Alessandra Corazza
- Department of Medicine (DAME), University of Udine, Udine, Italy; Istituto Nazionale Biostrutture e Biosistemi, Roma, Italy
| | - Sara Raimondi
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | - Maria Chiara Mimmi
- Transplant Research Area and Centre for Inherited Cardiovascular Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Silvia Malinverni
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | - P Patrizia Mangione
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy; Research Area, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Manel Terrones Palmer
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Alessio Lampis
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | - Monica Concardi
- Transplant Research Area and Centre for Inherited Cardiovascular Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Guglielmo Verona
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy; Centre for Amyloidosis, Division of Medicine, University College London, London, UK
| | - Diana Canetti
- Centre for Amyloidosis, Division of Medicine, University College London, London, UK
| | - Eloisa Arbustini
- Transplant Research Area and Centre for Inherited Cardiovascular Diseases, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Vittorio Bellotti
- Research Area, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Sofia Giorgetti
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy; Research Area, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
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3
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Klimtchuk ES, Peterle D, Bullitt EA, Connors LH, Engen JR, Gursky O. Role of complementarity-determining regions 1 and 3 in pathologic amyloid formation by human immunoglobulin κ1 light chains. Amyloid 2023; 30:364-378. [PMID: 37216473 PMCID: PMC10663386 DOI: 10.1080/13506129.2023.2212397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/24/2023] [Accepted: 05/04/2023] [Indexed: 05/24/2023]
Abstract
BACKGROUND Immunoglobulin light chain (LC) amyloidosis is a life-threatening disease complicated by vast numbers of patient-specific mutations. We explored 14 patient-derived and engineered proteins related to κ1-family germline genes IGKVLD-33*01 and IGKVLD-39*01. METHODS Hydrogen-deuterium exchange mass spectrometry analysis of conformational dynamics in recombinant LCs and their fragments was integrated with studies of thermal stability, proteolytic susceptibility, amyloid formation and amyloidogenic sequence propensity. The results were mapped on the structures of native and fibrillary proteins. RESULTS Proteins from two κ1 subfamilies showed unexpected differences. Compared to their germline counterparts, amyloid LC related to IGKVLD-33*01 was less stable and formed amyloid faster, whereas amyloid LC related to IGKVLD-39*01 had similar stability and formed amyloid slower, suggesting different major factors influencing amyloidogenesis. In 33*01-related amyloid LC, these factors involved destabilization of the native structure and probable stabilization of amyloid. The atypical behavior of 39*01-related amyloid LC stemmed from increased dynamics/exposure of amyloidogenic segments in βC'V and βEV that could initiate aggregation and decreased dynamics/exposure near the Cys23-Cys88 disulfide. CONCLUSIONS The results suggest distinct amyloidogenic pathways for closely related LCs and point to the complementarity-defining regions CDR1 and CDR3, linked via the conserved internal disulfide, as key factors in amyloid formation.
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Affiliation(s)
- Elena S. Klimtchuk
- Amyloidosis Center, Boston University Chobanian and Avedisian School of Medicine, Boston MA 02118, United States
| | - Daniele Peterle
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, United States
| | - Esther A. Bullitt
- Department of Physiology & Biophysics, Boston University Chobanian and Avedisian School of Medicine, W302, 700 Albany Street, Boston, MA, 02118, United States
| | - Lawreen H. Connors
- Amyloidosis Center, Boston University Chobanian and Avedisian School of Medicine, Boston MA 02118, United States
| | - John R. Engen
- Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, United States
| | - Olga Gursky
- Amyloidosis Center, Boston University Chobanian and Avedisian School of Medicine, Boston MA 02118, United States
- Department of Physiology & Biophysics, Boston University Chobanian and Avedisian School of Medicine, W302, 700 Albany Street, Boston, MA, 02118, United States
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4
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Yan NL, Morgan GJ, Petrassi HM, Wilson IA, Kelly JW. Pharmacological stabilization of the native state of full-length immunoglobulin light chains to treat light chain amyloidosis. Curr Opin Chem Biol 2023; 75:102319. [PMID: 37279624 PMCID: PMC10523890 DOI: 10.1016/j.cbpa.2023.102319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/03/2023] [Accepted: 04/14/2023] [Indexed: 06/08/2023]
Abstract
Immunoglobulin light chain amyloidosis (AL) is a cancer of plasma cells that secrete unstable full-length immunoglobulin light chains. These light chains misfold and aggregate, often with aberrant endoproteolysis, leading to organ toxicity. AL is currently treated by pharmacological elimination of the clonal plasma cells. Since it remains difficult to completely kill these cells in the majority of patients, we seek a complementary drug that inhibits light chain aggregation, which should diminish organ toxicity. We discovered a small-molecule binding site on full-length immunoglobulin light chains by structurally characterizing hit stabilizers emerging from a high-throughput screen seeking small molecules that protect full-length light chains from conformational excursion-linked endoproteolysis. The x-ray crystallographic characterization of 7 structurally distinct hit native-state stabilizers provided a structure-based blueprint, reviewed herein, to design more potent stabilizers. This approach enabled us to transform hits with micromolar affinity into stabilizers with nanomolar dissociation constants that potently prevent light chain aggregation.
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Affiliation(s)
- Nicholas L Yan
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Gareth J Morgan
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA
| | - H Michael Petrassi
- Protego Biopharma, 10945 Vista Sorrento Parkway, San Diego, CA 92130, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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5
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Sizova DV, Raiker S, Lakheram D, Rao V, Proffitt A, Jmeian Y, Voegtli W, Batonick M. Producing amyloid fibrils in vitro: A tool for studying AL amyloidosis. Biochem Biophys Rep 2023; 34:101442. [PMID: 36875796 PMCID: PMC9982448 DOI: 10.1016/j.bbrep.2023.101442] [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: 12/14/2022] [Revised: 02/03/2023] [Accepted: 02/16/2023] [Indexed: 02/27/2023] Open
Abstract
Amyloid light-chain (AL) amyloidosis is the second most common form of systemic amyloidosis which is characterized by a high level of mortality and no effective treatment to remove fibril deposition. This disorder is caused by malfunctioning of B-cells resulting in production of abnormal protein fibrils composed of immunoglobulin light chain fragments that tend to deposit on various organs and tissues. AL amyloidosis is set apart from other forms of amyloidosis in that no specific sequences have been identified in the immunoglobulin light chains that are amyloid fibril formation causative and patient specific. This unusual feature hinders the therapeutic progress and requires either direct access to patient samples (which is not always possible) or a source of in vitro produced fibrils. While isolated reports of successful AL amyloid fibril formation from various patient-specific protein sequences can be found in literature, no systematic research on this topic was performed since 1999. In the present study we have developed a generalized approach to in vitro fibril production from various types of previously reported [[1], [2], [3]] amyloidogenic immunoglobulin light chains and their fragments. We describe the procedure from selection and generation of starting material, through finding of optimal assay conditions, to applying a panel of methods to confirm successful fibril formation. Procedure details are discussed in the light of the most recent findings and theories on amyloid fibril formation. The reported protocol produces high quality AL amyloid fibrils that can subsequently be used in the development of the much-needed amyloid-targeting diagnostic and therapeutic approaches.
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6
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Absmeier RM, Rottenaicher GJ, Svilenov HL, Kazman P, Buchner J. Antibodies gone bad - the molecular mechanism of light chain amyloidosis. FEBS J 2023; 290:1398-1419. [PMID: 35122394 DOI: 10.1111/febs.16390] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/19/2022] [Accepted: 02/03/2022] [Indexed: 12/19/2022]
Abstract
Light chain amyloidosis (AL) is a systemic disease in which abnormally proliferating plasma cells secrete large amounts of mutated antibody light chains (LCs) that eventually form fibrils. The fibrils are deposited in various organs, most often in the heart and kidney, and impair their function. The prognosis for patients diagnosed with AL is generally poor. The disease is set apart from other amyloidoses by the huge number of patient-specific mutations in the disease-causing and fibril-forming protein. The molecular mechanisms that drive the aggregation of mutated LCs into fibrils have been enigmatic, which hindered the development of efficient diagnostics and therapies. In this review, we summarize our current knowledge on AL amyloidosis and discuss open issues.
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Affiliation(s)
- Ramona M Absmeier
- Center for Functional Protein Assemblies and Department of Chemistry, Technische Universität München, Garching, Germany
| | - Georg J Rottenaicher
- Center for Functional Protein Assemblies and Department of Chemistry, Technische Universität München, Garching, Germany
| | - Hristo L Svilenov
- Center for Functional Protein Assemblies and Department of Chemistry, Technische Universität München, Garching, Germany
| | - Pamina Kazman
- Center for Functional Protein Assemblies and Department of Chemistry, Technische Universität München, Garching, Germany
| | - Johannes Buchner
- Center for Functional Protein Assemblies and Department of Chemistry, Technische Universität München, Garching, Germany
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7
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Rottenaicher GJ, Absmeier RM, Meier L, Zacharias M, Buchner J. A constant domain mutation in a patient-derived antibody light chain reveals principles of AL amyloidosis. Commun Biol 2023; 6:209. [PMID: 36823438 PMCID: PMC9950467 DOI: 10.1038/s42003-023-04574-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/09/2023] [Indexed: 02/25/2023] Open
Abstract
Light chain (AL) amyloidosis is a debilitating disease in which mutant antibody light chains (LC), secreted by aberrant plasma cell clones, misfold and form insoluble fibrils, which can be deposited in various organs. In the majority of cases, the fibrillar deposits consist of LC variable domains (VL) containing destabilizing mutations compared to their germline counterparts. This is also true for the patient LC FOR005. However, this pathogenic LC sequence contains an additional mutation in the constant domain (CL). The mechanistic impact of CL mutations is not yet understood in the context of AL amyloidosis. Our analysis reveals that the FOR005 CL mutation influences the amyloid pathway in specific ways: (1) folding and stability of the patient CL domain are strongly impaired; (2) the mutation disrupts the LC dimer interface and weakens dimerization; (3) the CL mutation promotes proteolytic cleavage of the LC monomers resulting in an isolated, amyloidogenic VL domain while dimeric LCs are not cleaved. The enhanced proteolysis rates and the inability of full-length LCs to form amyloid fibrils even in the presence of a destabilized CL domain support a model for AL amyloidosis in which the CL domain plays a protective role and in which proteolytic cleavage precedes amyloid formation.
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Affiliation(s)
- Georg J Rottenaicher
- Center for Functional Protein Assemblies, Technical University Munich, Ernst-Otto-Fischer-Str. 8, 85748, Garching, Germany
- Department of Biosciences, TUM School of Natural Sciences, Technical University Munich, Boltzmannstr. 10, 85748, Garching, Germany
| | - Ramona M Absmeier
- Center for Functional Protein Assemblies, Technical University Munich, Ernst-Otto-Fischer-Str. 8, 85748, Garching, Germany
- Department of Biosciences, TUM School of Natural Sciences, Technical University Munich, Boltzmannstr. 10, 85748, Garching, Germany
| | - Laura Meier
- Center for Functional Protein Assemblies, Technical University Munich, Ernst-Otto-Fischer-Str. 8, 85748, Garching, Germany
- Department of Biosciences, TUM School of Natural Sciences, Technical University Munich, Boltzmannstr. 10, 85748, Garching, Germany
| | - Martin Zacharias
- Center for Functional Protein Assemblies, Technical University Munich, Ernst-Otto-Fischer-Str. 8, 85748, Garching, Germany
- Department of Biosciences, TUM School of Natural Sciences, Technical University Munich, Boltzmannstr. 10, 85748, Garching, Germany
| | - Johannes Buchner
- Center for Functional Protein Assemblies, Technical University Munich, Ernst-Otto-Fischer-Str. 8, 85748, Garching, Germany.
- Department of Biosciences, TUM School of Natural Sciences, Technical University Munich, Boltzmannstr. 10, 85748, Garching, Germany.
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8
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Klimtchuk ES, Peterle D, Bullitt EA, Connors LH, Engen JR, Gursky O. Role of Complementarity-Determining Regions 1 and 3 in Pathologic Amyloid Formation by Human Immunoglobulin κ1 Light Chains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526662. [PMID: 36778378 PMCID: PMC9915687 DOI: 10.1101/2023.02.01.526662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Immunoglobulin light chain (LC) amyloidosis is a life-threatening disease whose understanding and treatment is complicated by vast numbers of patient-specific mutations. To address molecular origins of the disease, we explored 14 patient-derived and engineered proteins related to κ1-family germline genes IGKVLD-33*01 and IGKVLD-39*01. Hydrogen-deuterium exchange mass spectrometry analysis of local conformational dynamics in full-length recombinant LCs and their fragments was integrated with studies of thermal stability, proteolytic susceptibility, amyloid formation, and amyloidogenic sequence propensities using spectroscopic, electron microscopic and bioinformatics tools. The results were mapped on the atomic structures of native and fibrillary proteins. Proteins from two κ1 subfamilies showed unexpected differences. Compared to their germline counterparts, amyloid LC related to IGKVLD-33*01 was less stable and formed amyloid faster, whereas amyloid LC related to IGKVLD-39*01 had similar stability and formed amyloid slower. These and other differences suggest different major factors influencing amyloid formation. In 33*01-related amyloid LC, these factors involved mutation-induced destabilization of the native structure and probable stabilization of amyloid. The atypical behaviour of 39*01-related amyloid LC tracked back to increased dynamics/exposure of amyloidogenic segments in βC' V and βE V that could initiate aggregation, combined with decreased dynamics/exposure near the Cys23-Cys88 disulfide whose rearrangement is rate-limiting to amyloidogenesis. The results suggest distinct amyloidogenic pathways for closely related LCs and point to the antigen-binding, complementarity-determining regions CDR1 and CDR3, which are linked via the conserved internal disulfide, as key factors in amyloid formation by various LCs.
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9
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Martinez-Rivas G, Bender S, Sirac C. Understanding AL amyloidosis with a little help from in vivo models. Front Immunol 2022; 13:1008449. [PMID: 36458006 PMCID: PMC9707859 DOI: 10.3389/fimmu.2022.1008449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 10/27/2022] [Indexed: 08/01/2023] Open
Abstract
Monoclonal immunoglobulin (Ig) light chain amyloidosis (AL) is a rare but severe disease that may occur when a B or plasma cell clone secretes an excess of free Ig light chains (LCs). Some of these LCs tend to aggregate into organized fibrils with a β-sheet structure, the so-called amyloid fibrils, and deposit into the extracellular compartment of organs, such as the heart or kidneys, causing their dysfunction. Recent findings have confirmed that the core of the amyloid fibrils is constituted by the variable (V) domain of the LCs, but the mechanisms underlying the unfolding and aggregation of this fragment and its deposition are still unclear. Moreover, in addition to the mechanical constraints exerted by the massive accumulation of amyloid fibrils in organs, the direct toxicity of these variable domain LCs, full-length light chains, or primary amyloid precursors (oligomers) seems to play a role in the pathogenesis of the disease. Many in vitro studies have focused on these topics, but the variability of this disease, in which each LC presents unique properties, and the extent and complexity of affected organs make its study in vivo very difficult. Accordingly, several groups have focused on the development of animal models for years, with some encouraging but mostly disappointing results. In this review, we discuss the experimental models that have been used to better understand the unknowns of this pathology with an emphasis on in vivo approaches. We also focus on why reliable AL amyloidosis animal models remain so difficult to obtain and what this tells us about the pathophysiology of the disease.
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10
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An N-glycosylation hotspot in immunoglobulin κ light chains is associated with AL amyloidosis. Leukemia 2022; 36:2076-2085. [PMID: 35610346 DOI: 10.1038/s41375-022-01599-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 12/24/2022]
Abstract
Immunoglobulin light chain (AL) amyloidosis is caused by a small, minimally proliferating B-cell/plasma-cell clone secreting a patient-unique, aggregation-prone, toxic light chain (LC). The pathogenicity of LCs is encrypted in their sequence, yet molecular determinants of amyloidogenesis are poorly understood. Higher rates of N-glycosylation among clonal κ LCs from patients with AL amyloidosis compared to other monoclonal gammopathies indicate that this post-translational modification is associated with a higher risk of developing AL amyloidosis. Here, we exploited LC sequence information from previously published amyloidogenic and control clonal LCs and from a series of 220 patients with AL amyloidosis or multiple myeloma followed at our Institutions to define sequence and spatial features of N-glycosylation, combining bioinformatics, biochemical, proteomics, structural and genetic analyses. We found peculiar sequence and spatial pattern of N-glycosylation in amyloidogenic κ LCs, with most of the N-glycosylation sites laying in the framework region 3, particularly within the E strand, and consisting mainly of the NFT sequon, setting them apart with respect to non-amyloidogenic clonal LCs. Our data further support a potential role of N-glycosylation in determining the pathogenic behavior of a subset of amyloidogenic LCs and may help refine current N-glycosylation-based prognostic assessments for patients with monoclonal gammopathies.
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11
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Morgan GJ. Transient disorder along pathways to amyloid. Biophys Chem 2021; 281:106711. [PMID: 34839162 DOI: 10.1016/j.bpc.2021.106711] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/15/2023]
Abstract
High-resolution structures of amyloid fibrils formed from normally-folded proteins have revealed non-native conformations of the polypeptide chains. Attaining these conformations apparently requires transition from the native state via a highly disordered conformation, in contrast to earlier models that posited a role for assembly of partially folded proteins. Modifications or interactions that extend the lifetime or constrain the conformations of these disordered states could act to enhance or suppress amyloid formation. Understanding how the properties of both the folded and transiently disordered structural ensembles influence the process of amyloid formation is a substantial challenge, but research into the properties of intrinsically disordered proteins will deliver important insights.
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Affiliation(s)
- Gareth J Morgan
- The Amyloidosis Center and Section of Hematology and Medical Oncology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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12
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Morgan GJ, Buxbaum JN, Kelly JW. Light Chain Stabilization: A Therapeutic Approach to Ameliorate AL Amyloidosis. HEMATO 2021; 2:645-659. [PMID: 35757512 PMCID: PMC9218996 DOI: 10.3390/hemato2040042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Non-native immunoglobulin light chain conformations, including aggregates, appear to cause light chain amyloidosis pathology. Despite significant progress in pharmacological eradication of the neoplastic plasma cells that secrete these light chains, in many patients impaired organ function remains. The impairment is apparently due to a subset of resistant plasma cells that continue to secrete misfolding-prone light chains. These light chains are susceptible to the proteolytic cleavage that may enable light chain aggregation. We propose that small molecules that preferentially bind to the natively folded state of full-length light chains could act as pharmacological kinetic stabilizers, protecting light chains against unfolding, proteolysis and aggregation. Although the sequence of the pathological light chain is unique to each patient, fortunately light chains have highly conserved residues that form binding sites for small molecule kinetic stabilizers. We envision that such stabilizers could complement existing and emerging therapies to benefit light chain amyloidosis patients.
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Affiliation(s)
- Gareth J. Morgan
- Section of Hematology and Medical Oncology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- The Amyloidosis Center, Boston University School of Medicine, Boston, MA 02118, USA
- Correspondence:
| | - Joel N. Buxbaum
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffery W. Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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13
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Mazzini G, Ricagno S, Caminito S, Rognoni P, Milani P, Nuvolone M, Basset M, Foli A, Russo R, Merlini G, Palladini G, Lavatelli F. Protease-sensitive regions in amyloid light chains: what a common pattern of fragmentation across organs suggests about aggregation. FEBS J 2021; 289:494-506. [PMID: 34482629 PMCID: PMC9292950 DOI: 10.1111/febs.16182] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/26/2021] [Accepted: 09/03/2021] [Indexed: 01/31/2023]
Abstract
Light‐chain (AL) amyloidosis is characterized by deposition of immunoglobulin light chains (LC) as fibrils in target organs. Alongside the full‐length protein, abundant LC fragments are always present in AL deposits. Herein, by combining gel‐based and mass spectrometry analyses, we identified and compared the fragmentation sites of amyloid LCs from multiple organs of an AL λ amyloidosis patient (AL‐55). The positions pinpointed here in kidney and subcutaneous fat, alongside those previously detected in heart of the same patient, were aligned and mapped on the LC’s dimeric and fibrillar states. All tissues contain fragmented LCs along with the full‐length protein; the fragment pattern is coincident across organs, although microheterogeneity exists. Multiple cleavage positions were detected; some are shared, whereas some are organ‐specific, likely due to a complex of proteases. Cleavage sites are concentrated in ‘proteolysis‐prone’ regions, common to all tissues. Several proteolytic sites are not accessible on native dimers, while they are compatible with fibrils. Overall, data suggest that the heterogeneous ensemble of LC fragments originates in tissues and is consistent with digestion of preformed fibrils, or with the hypothesis that initial proteolytic cleavage of the constant domain triggers the amyloidogenic potential of LCs, followed by subsequent proteolytic degradation. This work provides a unique set of molecular data on proteolysis from ex vivo amyloid, which allows discussing hypotheses on role and timing of proteolytic events occurring along amyloid formation and accumulation in AL patients.
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Affiliation(s)
- Giulia Mazzini
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università Degli Studi di Milano, Italy
| | - Serena Caminito
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Paola Rognoni
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Paolo Milani
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Mario Nuvolone
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Marco Basset
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Andrea Foli
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e Dei Trapianti, Università Degli Studi di Milano, Italy
| | - Giampaolo Merlini
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Giovanni Palladini
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
| | - Francesca Lavatelli
- Amyloidosis Treatment and Research Center, Fondazione IRCCS Policlinico San Matteo and Università Degli Studi di Pavia, Italy
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14
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Yan NL, Santos-Martins D, Nair R, Chu A, Wilson IA, Johnson KA, Forli S, Morgan GJ, Petrassi HM, Kelly JW. Discovery of Potent Coumarin-Based Kinetic Stabilizers of Amyloidogenic Immunoglobulin Light Chains Using Structure-Based Design. J Med Chem 2021; 64:6273-6299. [PMID: 33939422 DOI: 10.1021/acs.jmedchem.1c00339] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In immunoglobulin light-chain (LC) amyloidosis, transient unfolding or unfolding and proteolysis enable aggregation of LC proteins, causing potentially fatal organ damage. A drug that kinetically stabilizes LCs could suppress aggregation; however, LC sequences are variable and have no natural ligands, hindering drug development efforts. We previously identified high-throughput screening hits that bind to a site at the interface between the two variable domains of the LC homodimer. We hypothesized that extending the stabilizers beyond this initially characterized binding site would improve affinity. Here, using protease sensitivity assays, we identified stabilizers that can be divided into four substructures. Some stabilizers exhibit nanomolar EC50 values, a 3000-fold enhancement over the screening hits. Crystal structures reveal a key π-π stacking interaction with a conserved tyrosine residue that was not utilized by the screening hits. These data provide a foundation for developing LC stabilizers with improved binding selectivity and enhanced physicochemical properties.
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Affiliation(s)
- Nicholas L Yan
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Diogo Santos-Martins
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Reji Nair
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Alan Chu
- California Institute for Biomedical Research, 11119 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Kristen A Johnson
- California Institute for Biomedical Research, 11119 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Stefano Forli
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Gareth J Morgan
- Section of Hematology and Medical Oncology, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, United States.,The Amyloidosis Center, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - H Michael Petrassi
- California Institute for Biomedical Research, 11119 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States.,The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
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15
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Inherent Biophysical Properties Modulate the Toxicity of Soluble Amyloidogenic Light Chains. J Mol Biol 2019; 432:845-860. [PMID: 31874151 DOI: 10.1016/j.jmb.2019.12.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 01/20/2023]
Abstract
In light chain amyloidosis (AL), fibrillar deposition of monoclonal immunoglobulin light chains (LCs) in vital organs, such as heart, is associated with their severe dysfunction. In addition to the cellular damage caused by fibril deposition, direct toxicity of soluble prefibrillar amyloidogenic proteins has been reported, in particular, for cardiotoxicity. However, the molecular bases of proteotoxicity by soluble LCs have not been clarified. Here, to address this issue, we rationally engineered the amino acid sequence of the highly cardiotoxic LC H6 by introducing three residue mutations, designed to reduce the dynamics of its native state. The resulting mutant (mH6) is less toxic than its parent H6 to human cardiac fibroblasts and C. elegans. The high sequence and structural similarity, together with the different toxicity, make H6 and its non-toxic designed variant mH6 a test case to shed light on the molecular properties underlying soluble toxicity. Our comparative structural and biochemical study of H6 and mH6 shows closely matching crystal structures, whereas spectroscopic data and limited proteolysis indicate that H6 displays poorly cooperative fold, higher flexibility, and kinetic instability, and a higher dynamic state in its native fold. Taken together, the results of this study show a strong correlation between the overall conformational properties of the native fold and the proteotoxicity of cardiotropic LCs.
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16
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Rennella E, Morgan GJ, Yan N, Kelly JW, Kay LE. The Role of Protein Thermodynamics and Primary Structure in Fibrillogenesis of Variable Domains from Immunoglobulin Light Chains. J Am Chem Soc 2019; 141:13562-13571. [PMID: 31364359 DOI: 10.1021/jacs.9b05499] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Immunoglobulin light-chain amyloidosis is a protein aggregation disease that leads to proteinaceous deposits in a variety of organs in the body and, if untreated, ultimately results in death. The mechanisms by which light-chain aggregation occurs are not well understood. Here we have used solution NMR spectroscopy and biophysical studies to probe immunoglobulin variable domain λV6-57 VL aggregation, a process that appears to drive the degenerative phenotypes in amyloidosis patients. Our results establish that aggregation proceeds via the unfolded state. We identify, through NMR relaxation experiments recorded on the unfolded domain ensemble, a series of hotspots that could be involved in the initial phases of aggregate formation. Mutational analysis of these hotspots reveals that the region that includes K16-R24 is particularly aggregation prone. Notably, this region includes the site of the R24G substitution, a mutation that is found in variable domains of λ light-chain deposits in 25% of patients. The R24G λV6-57 VL domain aggregates more rapidly than would be expected on the basis of thermodynamic stability alone, while substitutions in many of the aggregation-prone regions significantly slow down fibril formation.
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Affiliation(s)
- Enrico Rennella
- Departments of Molecular Genetics, Biochemistry and Chemistry , The University of Toronto , Toronto , Ontario , Canada M5S1A8
| | - Gareth J Morgan
- Departments of Molecular Medicine and Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States.,Department of Medicine , Boston University School of Medicine , Boston , Massachusetts 02118 , United States
| | - Nicholas Yan
- Departments of Molecular Medicine and Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Jeffery W Kelly
- Departments of Molecular Medicine and Chemistry , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry , The University of Toronto , Toronto , Ontario , Canada M5S1A8.,The Hospital for Sick Children , Program in Molecular Medicine , 555 University Avenue , Toronto , Ontario , Canada M5G1X8
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17
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Stabilization of amyloidogenic immunoglobulin light chains by small molecules. Proc Natl Acad Sci U S A 2019; 116:8360-8369. [PMID: 30971495 DOI: 10.1073/pnas.1817567116] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In Ig light-chain (LC) amyloidosis (AL), the unique antibody LC protein that is secreted by monoclonal plasma cells in each patient misfolds and/or aggregates, a process leading to organ degeneration. As a step toward developing treatments for AL patients with substantial cardiac involvement who have difficulty tolerating existing chemotherapy regimens, we introduce small-molecule kinetic stabilizers of the native dimeric structure of full-length LCs, which can slow or stop the amyloidogenicity cascade at its origin. A protease-coupled fluorescence polarization-based high-throughput screen was employed to identify small molecules that kinetically stabilize LCs. NMR and X-ray crystallographic data demonstrate that at least one structural family of hits bind at the LC-LC dimerization interface within full-length LCs, utilizing variable-domain residues that are highly conserved in most AL patients. Stopping the amyloidogenesis cascade at the beginning is a proven strategy to ameliorate postmitotic tissue degeneration.
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18
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Swuec P, Lavatelli F, Tasaki M, Paissoni C, Rognoni P, Maritan M, Brambilla F, Milani P, Mauri P, Camilloni C, Palladini G, Merlini G, Ricagno S, Bolognesi M. Cryo-EM structure of cardiac amyloid fibrils from an immunoglobulin light chain AL amyloidosis patient. Nat Commun 2019; 10:1269. [PMID: 30894521 PMCID: PMC6427027 DOI: 10.1038/s41467-019-09133-w] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 02/15/2019] [Indexed: 11/09/2022] Open
Abstract
Systemic light chain amyloidosis (AL) is a life-threatening disease caused by aggregation and deposition of monoclonal immunoglobulin light chains (LC) in target organs. Severity of heart involvement is the most important factor determining prognosis. Here, we report the 4.0 Å resolution cryo-electron microscopy map and molecular model of amyloid fibrils extracted from the heart of an AL amyloidosis patient with severe amyloid cardiomyopathy. The helical fibrils are composed of a single protofilament, showing typical 4.9 Å stacking and cross-β architecture. Two distinct polypeptide stretches (total of 77 residues) from the LC variable domain (Vl) fit the fibril density. Despite Vl high sequence variability, residues stabilizing the fibril core are conserved through different cardiotoxic Vl, highlighting structural motifs that may be common to misfolding-prone LCs. Our data shed light on the architecture of LC amyloids, correlate amino acid sequences with fibril assembly, providing the grounds for development of innovative medicines.
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Affiliation(s)
- Paolo Swuec
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.,Centro di Ricerca Pediatrica Romeo ed Enrica Invernizzi, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Francesca Lavatelli
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy
| | - Masayoshi Tasaki
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy.,Department of Morphological and Physiological Sciences, Graduate School of Health Sciences,, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, 862-0976, Japan.,Department of Neurology, Graduate School of Medical Sciences, 1-1-1, Honjo, Kumamoto, 860-0811, Japan
| | - Cristina Paissoni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Paola Rognoni
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy
| | - Martina Maritan
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Francesca Brambilla
- Institute for Biomedical Technologies-CNR, Via Fratelli Cervi 93, 20090, Segrate, Italy
| | - Paolo Milani
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy
| | - Pierluigi Mauri
- Institute for Biomedical Technologies-CNR, Via Fratelli Cervi 93, 20090, Segrate, Italy
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Giovanni Palladini
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy
| | - Giampaolo Merlini
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, P.le Golgi 19, 27100, Pavia, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
| | - Martino Bolognesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy. .,Centro di Ricerca Pediatrica Romeo ed Enrica Invernizzi, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
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19
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Role of domain interactions in the aggregation of full-length immunoglobulin light chains. Proc Natl Acad Sci U S A 2018; 116:854-863. [PMID: 30598439 DOI: 10.1073/pnas.1817538116] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Amyloid light-chain (LC) amyloidosis is a protein misfolding disease in which the aggregation of an overexpressed antibody LC from a clonal plasma cell leads to organ toxicity and patient death if left untreated. While the overall dimeric architecture of LC molecules is established, with each LC composed of variable (VL) and constant (CL) domains, the relative contributions of LC domain-domain interfaces and intrinsic domain stabilities to protection against LC aggregation are not well understood. To address these topics we have engineered a number of domain-destabilized LC mutants and used solution NMR spectroscopy to characterize their structural properties and intrinsic stabilities. Moreover, we used fluorescence spectroscopy to assay their aggregation propensities. Our results point to the importance of both dimerization strength and intrinsic monomer stability in stabilizing VL domains against aggregation. Notably, in all cases considered VL domains aggregate at least 10-fold faster than full-length LCs, establishing the important protective role of CL domains. A strong protective coupling is found between VL-VL and CL-CL dimer interfaces, with destabilization of one interface adversely affecting the stability of the other. Fibril formation is observed when either the VL or CL domain in the full-length protein is severely destabilized (i.e., where domain unfolding free energies are less than 2 kcal/mol). The important role of CL domains in preventing aggregation highlights the potential of the CL-CL interface as a target for the development of drugs to stabilize the dimeric LC structure and hence prevent LC amyloidosis.
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20
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Weber B, Hora M, Kazman P, Göbl C, Camilloni C, Reif B, Buchner J. The Antibody Light-Chain Linker Regulates Domain Orientation and Amyloidogenicity. J Mol Biol 2018; 430:4925-4940. [PMID: 30414962 DOI: 10.1016/j.jmb.2018.10.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/04/2018] [Accepted: 10/28/2018] [Indexed: 12/21/2022]
Abstract
The antibody light chain (LC) consists of two domains and is essential for antigen binding in mature immunoglobulins. The two domains are connected by a highly conserved linker that comprises the structurally important Arg108 residue. In antibody light chain (AL) amyloidosis, a severe protein amyloid disease, the LC and its N-terminal variable domain (VL) convert to fibrils deposited in the tissues causing organ failure. Understanding the factors shaping the architecture of the LC is important for basic science, biotechnology and for deciphering the principles that lead to fibril formation. In this study, we examined the structure and properties of LC variants with a mutated or extended linker. We show that under destabilizing conditions, the linker modulates the amyloidogenicity of the LC. The fibril formation propensity of LC linker variants and their susceptibility to proteolysis directly correlate implying an interplay between the two LC domains. Using NMR and residual dipolar coupling-based simulations, we found that the linker residue Arg108 is a key factor regulating the relative orientation of the VL and CL domains, keeping them in a bent and dense, but still flexible conformation. Thus, inter-domain contacts and the relative orientation of VL and CL to each other are of major importance for maintaining the structural integrity of the full-length LC.
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Affiliation(s)
- Benedikt Weber
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany
| | - Manuel Hora
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany
| | - Pamina Kazman
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany
| | - Christoph Göbl
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany; Helmholtz Zentrum München, Institute of Structural Biology, Ingolstädter Landstr, 1, 85764 Neuherberg, Germany
| | - Carlo Camilloni
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milan, Italy
| | - Bernd Reif
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Lichtenbergstr, 4, 85748 Garching, Germany.
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21
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Marinelli P, Navarro S, Baño-Polo M, Morel B, Graña-Montes R, Sabe A, Canals F, Fernandez MR, Conejero-Lara F, Ventura S. Global Protein Stabilization Does Not Suffice to Prevent Amyloid Fibril Formation. ACS Chem Biol 2018; 13:2094-2105. [PMID: 29966079 DOI: 10.1021/acschembio.8b00607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mutations or cellular conditions that destabilize the native protein conformation promote the population of partially unfolded conformations, which in many cases assemble into insoluble amyloid fibrils, a process associated with multiple human pathologies. Therefore, stabilization of protein structures is seen as an efficient way to prevent misfolding and subsequent aggregation. This has been suggested to be the underlying reason why proteins living in harsh environments, such as the extracellular space, have evolved disulfide bonds. The effect of protein disulfides on the thermodynamics and kinetics of folding has been extensively studied, but much less is known on its effect on aggregation reactions. Here, we designed a single point mutation that introduces a disulfide bond in the all-α FF domain, a protein that, despite being devoid of preformed β-sheets, forms β-sheet-rich amyloid fibrils. The novel and unique covalent bond in the FF domain dramatically increases its thermodynamic stability and folding speed. Nevertheless, these optimized properties cannot counteract the inherent aggregation propensity of the protein, thus indicating that a high global protein stabilization does not suffice to prevent amyloid formation unless it contributes to hide from exposure the specific regions that nucleate the aggregation reaction.
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Affiliation(s)
- Patrizia Marinelli
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Susanna Navarro
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Manuel Baño-Polo
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Bertrand Morel
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Ricardo Graña-Montes
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Anna Sabe
- Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron University Hospital, 08135 Barcelona, Spain
| | - Francesc Canals
- Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron University Hospital, 08135 Barcelona, Spain
| | - Maria Rosario Fernandez
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
| | - Francisco Conejero-Lara
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
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22
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Ruiz-Guerrero L, Barriales-Villa R. Storage diseases with hypertrophic cardiomyopathy phenotype. Glob Cardiol Sci Pract 2018; 2018:28. [PMID: 30393640 PMCID: PMC6209457 DOI: 10.21542/gcsp.2018.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Never judge a book by its cover, nor assume hypertrophic cardiomyopathy (HCM) as sarcomeric, as appearances can deceive. HCM phenocopies account for a 5–10% of the cases, mainly represented by storage diseases, flagged by the increasing prevalence of senile cardiac amyloid in developing countries. Multisystemic and heterogeneous presentation of these entities is a challenge for clinicians, and time delay in diagnosis is a major concern. Promising drugs and gene-specific tailored therapies are under development, therefore, more than ever, appropriate understanding of these conditions is mandatory for adequate early treatment and counselling. In this review, storage disorders will be classified as extracellular and intracellular deposit storage diseases, focusing our attention on the most prevalent conditions from the cardiologist’s perspective.
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Affiliation(s)
- Luis Ruiz-Guerrero
- Cardiology Service, Hospital Universitario Marqués de Valdecilla, Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Spain
| | - Roberto Barriales-Villa
- Inherited Cardiovascular Diseases Unit, Cardiology Service, Complexo Hospitalario Universitario de A Coruña, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), Universidade da Coruña, A Coruña, Spain.,Centro de Investigación Biomédica en Red. Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
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