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Long-range allostery mediates the regulation of plasminogen activator inhibitor-1 by cell adhesion factor vitronectin. J Biol Chem 2022; 298:102652. [PMID: 36444882 PMCID: PMC9731859 DOI: 10.1016/j.jbc.2022.102652] [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: 07/20/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/05/2022] Open
Abstract
The serpin plasminogen activator inhibitor 1 (PAI-1) spontaneously undergoes a massive structural change from a metastable and active conformation, with a solvent-accessible reactive center loop (RCL), to a stable, inactive, or latent conformation, with the RCL inserted into the central β-sheet. Physiologically, conversion to the latent state is regulated by the binding of vitronectin, which hinders the latency transition rate approximately twofold. The molecular mechanisms leading to this rate change are unclear. Here, we investigated the effects of vitronectin on the PAI-1 latency transition using all-atom path sampling simulations in explicit solvent. In simulated latency transitions of free PAI-1, the RCL is quite mobile as is the gate, the region that impedes RCL access to the central β-sheet. This mobility allows the formation of a transient salt bridge that facilitates the transition; this finding rationalizes existing mutagenesis results. Vitronectin binding reduces RCL and gate mobility by allosterically rigidifying structural elements over 40 Å away from the binding site, thus blocking transition to the latent conformation. The effects of vitronectin are propagated by a network of dynamically correlated residues including a number of conserved sites that were previously identified as important for PAI-1 stability. Simulations also revealed a transient pocket populated only in the vitronectin-bound state, corresponding to a cryptic drug-binding site identified by crystallography. Overall, these results shed new light on PAI-1 latency transition regulation by vitronectin and illustrate the potential of path sampling simulations for understanding functional protein conformational changes and for facilitating drug discovery.
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2
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A Review of Alpha-1 Antitrypsin Binding Partners for Immune Regulation and Potential Therapeutic Application. Int J Mol Sci 2022; 23:ijms23052441. [PMID: 35269582 PMCID: PMC8910375 DOI: 10.3390/ijms23052441] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 02/06/2023] Open
Abstract
Alpha-1 antitrypsin (AAT) is the canonical serine protease inhibitor of neutrophil-derived proteases and can modulate innate immune mechanisms through its anti-inflammatory activities mediated by a broad spectrum of protein, cytokine, and cell surface interactions. AAT contains a reactive methionine residue that is critical for its protease-specific binding capacity, whereby AAT entraps the protease on cleavage of its reactive centre loop, neutralises its activity by key changes in its tertiary structure, and permits removal of the AAT-protease complex from the circulation. Recently, however, the immunomodulatory role of AAT has come increasingly to the fore with several prominent studies focused on lipid or protein-protein interactions that are predominantly mediated through electrostatic, glycan, or hydrophobic potential binding sites. The aim of this review was to investigate the spectrum of AAT molecular interactions, with newer studies supporting a potential therapeutic paradigm for AAT augmentation therapy in disorders in which a chronic immune response is strongly linked.
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The Serpin Superfamily and Their Role in the Regulation and Dysfunction of Serine Protease Activity in COPD and Other Chronic Lung Diseases. Int J Mol Sci 2021; 22:ijms22126351. [PMID: 34198546 PMCID: PMC8231800 DOI: 10.3390/ijms22126351] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 12/21/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a debilitating heterogeneous disease characterised by unregulated proteolytic destruction of lung tissue mediated via a protease-antiprotease imbalance. In COPD, the relationship between the neutrophil serine protease, neutrophil elastase, and its endogenous inhibitor, alpha-1-antitrypsin (AAT) is the best characterised. AAT belongs to a superfamily of serine protease inhibitors known as serpins. Advances in screening technologies have, however, resulted in many members of the serpin superfamily being identified as having differential expression across a multitude of chronic lung diseases compared to healthy individuals. Serpins exhibit a unique suicide-substrate mechanism of inhibition during which they undergo a dramatic conformational change to a more stable form. A limitation is that this also renders them susceptible to disease-causing mutations. Identification of the extent of their physiological/pathological role in the airways would allow further expansion of knowledge regarding the complexity of protease regulation in the lung and may provide wider opportunity for their use as therapeutics to aid the management of COPD and other chronic airways diseases.
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Ansari S, Ray A, Ali MF, Bano S, Jairajpuri MA. Contrasting conformational dynamics of β-sheet A and helix F with implications in neuroserpin inhibition and aggregation. Int J Biol Macromol 2021; 176:117-125. [PMID: 33516851 DOI: 10.1016/j.ijbiomac.2021.01.171] [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: 12/23/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 11/25/2022]
Abstract
Neuroserpin (NS) is an inhibitory protein of serpin super family, its shutter region variants have high propensity to aggregate leading to pathological disorders like familial encephalopathy with NS inclusion bodies (FENIB). Helix F and β-sheet A of NS participate in the tissue plasminogen activator (tPA) inhibition but the mechanism is not yet completely understood. A microsecond (μs) molecular dynamics simulation of the helix F and strand 3A variants showed predominant fluctuations in the loop connecting the strands of β-sheet A. Therefore to understand the role of helix F and strand 3A of β-sheet A, cysteine was incorporated at the position N182 in stand 3A (N182C) and position W154 (W154C) in the helix F using site-directed mutagenesis. Purified variants were further labeled with Alexa Fluor488 C5 maleimide dye. Temperature dependent study using non-denaturing PAGE showed the formation of large aggregates of helix F variant W154C but not the strand 3A N182C variant. Interestingly tPA inhibition was found to be decreased in the labeled N182C with decreased tPA-complex formation as compared to labeled W154C NS variant. The fluorescence emission intensity of the labeled helix F variant W154C decreased in the presence of an increasing concentration of tPA, whereas an increase in emission intensity was observed in labeled strand 3A variant N182C, indicating more exposure of strand 3A and shielding of helix F. Taken together the data shows that helix F has a predominant role in the aggregation but a minor role in the inhibition mechanism.
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Affiliation(s)
- Shoyab Ansari
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi 110020, India
| | - Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Shadabi Bano
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India.
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Ronzoni R, Heyer‐Chauhan N, Fra A, Pearce AC, Rüdiger M, Miranda E, Irving JA, Lomas DA. The molecular species responsible for α 1 -antitrypsin deficiency are suppressed by a small molecule chaperone. FEBS J 2021; 288:2222-2237. [PMID: 33058391 PMCID: PMC8436759 DOI: 10.1111/febs.15597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/28/2020] [Accepted: 10/12/2020] [Indexed: 12/16/2022]
Abstract
The formation of ordered Z (Glu342Lys) α1 -antitrypsin polymers in hepatocytes is central to liver disease in α1 -antitrypsin deficiency. In vitro experiments have identified an intermediate conformational state (M*) that precedes polymer formation, but this has yet to be identified in vivo. Moreover, the mechanism of polymer formation and their fate in cells have been incompletely characterised. We have used cell models of disease in conjunction with conformation-selective monoclonal antibodies and a small molecule inhibitor of polymerisation to define the dynamics of polymer formation, accumulation and secretion. Pulse-chase experiments demonstrate that Z α1 -antitrypsin accumulates as short-chain polymers that partition with soluble cellular components and are partially secreted by cells. These precede the formation of larger, insoluble polymers with a longer half-life (10.9 ± 1.7 h and 20.9 ± 7.4 h for soluble and insoluble polymers, respectively). The M* intermediate (or a by-product thereof) was identified in the cells by a conformation-specific monoclonal antibody. This was completely abrogated by treatment with the small molecule, which also blocked the formation of intracellular polymers. These data allow us to conclude that the M* conformation is central to polymerisation of Z α1 -antitrypsin in vivo; preventing its accumulation represents a tractable approach for pharmacological treatment of this condition; polymers are partially secreted; and polymers exist as two distinct populations in cells whose different dynamics have likely consequences for the aetiology of the disease.
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Affiliation(s)
| | | | - Annamaria Fra
- Department of Molecular and Translational MedicineUniversity of BresciaItaly
| | | | | | - Elena Miranda
- Department of Biology and Biotechnologies‘Charles Darwin’ and Pasteur Institute – Cenci‐Bolognetti FoundationSapienza University of RomeItaly
| | - James A. Irving
- UCL RespiratoryDivision of MedicineUniversity College LondonUK
| | - David A. Lomas
- UCL RespiratoryDivision of MedicineUniversity College LondonUK
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6
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Lomas DA, Irving JA, Arico‐Muendel C, Belyanskaya S, Brewster A, Brown M, Chung C, Dave H, Denis A, Dodic N, Dossang A, Eddershaw P, Klimaszewska D, Haq I, Holmes DS, Hutchinson JP, Jagger AM, Jakhria T, Jigorel E, Liddle J, Lind K, Marciniak SJ, Messer J, Neu M, Olszewski A, Ordonez A, Ronzoni R, Rowedder J, Rüdiger M, Skinner S, Smith KJ, Terry R, Trottet L, Uings I, Wilson S, Zhu Z, Pearce AC. Development of a small molecule that corrects misfolding and increases secretion of Z α 1 -antitrypsin. EMBO Mol Med 2021; 13:e13167. [PMID: 33512066 PMCID: PMC7933930 DOI: 10.15252/emmm.202013167] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 01/23/2023] Open
Abstract
Severe α1 -antitrypsin deficiency results from the Z allele (Glu342Lys) that causes the accumulation of homopolymers of mutant α1 -antitrypsin within the endoplasmic reticulum of hepatocytes in association with liver disease. We have used a DNA-encoded chemical library to undertake a high-throughput screen to identify small molecules that bind to, and stabilise Z α1 -antitrypsin. The lead compound blocks Z α1 -antitrypsin polymerisation in vitro, reduces intracellular polymerisation and increases the secretion of Z α1 -antitrypsin threefold in an iPSC model of disease. Crystallographic and biophysical analyses demonstrate that GSK716 and related molecules bind to a cryptic binding pocket, negate the local effects of the Z mutation and stabilise the bound state against progression along the polymerisation pathway. Oral dosing of transgenic mice at 100 mg/kg three times a day for 20 days increased the secretion of Z α1 -antitrypsin into the plasma by sevenfold. There was no observable clearance of hepatic inclusions with respect to controls over the same time period. This study provides proof of principle that "mutation ameliorating" small molecules can block the aberrant polymerisation that underlies Z α1 -antitrypsin deficiency.
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Affiliation(s)
- David A Lomas
- UCL RespiratoryRayne InstituteUniversity College LondonLondonUK
| | - James A Irving
- UCL RespiratoryRayne InstituteUniversity College LondonLondonUK
| | | | | | | | | | | | | | | | | | | | | | | | - Imran Haq
- UCL RespiratoryRayne InstituteUniversity College LondonLondonUK
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7
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Li S, Luo J, Zhou X, Li X, Wang F, Liu Y. Identification of characteristic proteins of wheat varieties used to commercially produce dried noodles by electrophoresis and proteomics analysis. J Food Compost Anal 2021. [DOI: 10.1016/j.jfca.2020.103685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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8
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Jagger AM, Waudby CA, Irving JA, Christodoulou J, Lomas DA. High-resolution ex vivo NMR spectroscopy of human Z α 1-antitrypsin. Nat Commun 2020; 11:6371. [PMID: 33311470 PMCID: PMC7732992 DOI: 10.1038/s41467-020-20147-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 11/15/2020] [Indexed: 01/18/2023] Open
Abstract
Genetic mutations predispose the serine protease inhibitor α1-antitrypsin to misfolding and polymerisation within hepatocytes, causing liver disease and chronic obstructive pulmonary disease. This misfolding occurs via a transiently populated intermediate state, but our structural understanding of this process is limited by the instability of recombinant α1-antitrypsin variants in solution. Here we apply NMR spectroscopy to patient-derived samples of α1-antitrypsin at natural isotopic abundance to investigate the consequences of disease-causing mutations, and observe widespread chemical shift perturbations for methyl groups in Z AAT (E342K). By comparison with perturbations induced by binding of a small-molecule inhibitor of misfolding we conclude that they arise from rapid exchange between the native conformation and a well-populated intermediate state. The observation that this intermediate is stabilised by inhibitor binding suggests a paradoxical approach to the targeted treatment of protein misfolding disorders, wherein the stabilisation of disease-associated states provides selectivity while inhibiting further transitions along misfolding pathways.
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Affiliation(s)
- Alistair M Jagger
- UCL Respiratory, Rayne Institute, University College London, London, WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London and School of Crystallography, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK
| | - Christopher A Waudby
- Institute of Structural and Molecular Biology, University College London and School of Crystallography, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK
| | - James A Irving
- UCL Respiratory, Rayne Institute, University College London, London, WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London and School of Crystallography, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK.
| | - John Christodoulou
- Institute of Structural and Molecular Biology, University College London and School of Crystallography, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK.
| | - David A Lomas
- UCL Respiratory, Rayne Institute, University College London, London, WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London and School of Crystallography, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK.
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Kellici TF, Pilka ES, Bodkin MJ. Small-molecule modulators of serine protease inhibitor proteins (serpins). Drug Discov Today 2020; 26:442-454. [PMID: 33259801 DOI: 10.1016/j.drudis.2020.11.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/11/2020] [Accepted: 11/10/2020] [Indexed: 02/06/2023]
Abstract
Serine protease inhibitors (serpins) are a large family of proteins that regulate and control crucial physiological processes, such as inflammation, coagulation, thrombosis and thrombolysis, and immune responses. The extraordinary impact that these proteins have on numerous crucial pathways makes them an attractive target for drug discovery. In this review, we discuss recent advances in research on small-molecule modulators of serpins, examine their mode of action, analyse the structural data from crystallised protein-ligand complexes, and highlight the potential obstacles and possible therapeutic perspectives. The application of in silico methods for rational drug discovery is also summarised. In addition, we stress the need for continued research in this field.
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10
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Rare Loss-of-Function Mutation in SERPINA3 in Generalized Pustular Psoriasis. J Invest Dermatol 2020; 140:1451-1455.e13. [PMID: 31945348 DOI: 10.1016/j.jid.2019.11.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 02/06/2023]
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11
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Wang X, Appels R, Zhang X, Bekes F, Diepeveen D, Ma W, Hu X, Islam S. Solubility variation of wheat dough proteins: A practical way to track protein behaviors in dough processing. Food Chem 2019; 312:126038. [PMID: 31896458 DOI: 10.1016/j.foodchem.2019.126038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/05/2019] [Accepted: 12/06/2019] [Indexed: 01/22/2023]
Abstract
To understand wheat dough protein behavior under dual mixing and thermal treatment, solubility of Mixolab-dough proteins were investigated using nine extraction buffers of different dissociation capacities. Size exclusion high performance liquid chromatography (SE-HPLC) and two-dimensional gel electrophoresis (2-DGE) demonstrated that overall changes of protein fractions and dynamic responses of specific proteins during dough processing were well reflected by their solubility variations. After starch pasting, the abundance of 0.5 M NaCl extractable proteins were decreased except for six protein groups including α-amylase inhibitors and superoxide dismutase (SOD). The solubility loss of glutenin proteins at C3 (32 min; 80 ℃) was mainly ascribed to the un-extractable HMW-GSs, LMW-GSs, globulin and triticin, while the extract yield of α-, β-, γ-gliadins and avenin-like proteins (ALPs) increased after starch pasting. Differential responses of dough proteins to extraction systems provides the basis for further exploring wheat protein dynamics in processing.
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Affiliation(s)
- Xiaolong Wang
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China; Australia China Centre for Wheat Improvement, College of Science Health Engineering and Education, Murdoch University, 90, South Street, Murdoch, WA 6150, Australia
| | - Rudi Appels
- School of Bio Sciences, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Xiaoke Zhang
- College of Agronomy, Northwest A & F University, Yangling, Shaanxi 712100, China
| | | | - Dean Diepeveen
- Australia China Centre for Wheat Improvement, College of Science Health Engineering and Education, Murdoch University, 90, South Street, Murdoch, WA 6150, Australia; Department of Primary Industries and Regional Development, Western Australia, 3 Baron-Hay Court, South Perth, WA 6151, Australia
| | - Wujun Ma
- Australia China Centre for Wheat Improvement, College of Science Health Engineering and Education, Murdoch University, 90, South Street, Murdoch, WA 6150, Australia
| | - Xinzhong Hu
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China
| | - Shahidul Islam
- Australia China Centre for Wheat Improvement, College of Science Health Engineering and Education, Murdoch University, 90, South Street, Murdoch, WA 6150, Australia.
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12
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Affiliation(s)
- Mehwish Saba Aslam
- Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, China
| | - Liudi Yuan
- Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, China
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13
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Trinh HN, Jang SH, Lee C. Functional characterization of a SNP (F51S) found in human alpha 1-antitrypsin. Mol Genet Genomic Med 2019; 7:e819. [PMID: 31251477 PMCID: PMC6687665 DOI: 10.1002/mgg3.819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/16/2019] [Accepted: 05/29/2019] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Alpha 1-antitrypsin (A1AT) deficiency is related to lung and liver diseases, including pulmonary emphysema and liver cirrhosis in humans. Genetic variations including single nucleotide polymorphisms (SNPs) of SERPINA1 are responsible for A1AT deficiency, but the characteristics of the SNPs are not well-understood. Here, we investigated the features of a rare SNP (F51S) of A1AT, which introduces an additional N-glycosylation site in the N-terminal region of A1AT. METHODS We evaluated the F51S variant compared with the wild-type (WT) A1AT with regard to expression in CHO-K1 cells, trypsin inhibitory activity, polymerization, and thermal stability. RESULTS The recombinant F51S protein expressed in CHO-K1 cells was mostly retained inside cells. The F51S variant had trypsin inhibitory activity, but reduced thermal stability compared with the WT A1AT. The native acrylamide gel data showed that F51S tended to prevent polymerization of A1AT. CONCLUSION The results of this study indicate that Phe51 and the surrounding hydrophobic residue cluster plays an important role in the conformation and secretion of A1AT and suggest the harmful effects of a rare F51S SNP in human health.
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Affiliation(s)
- Hong-Nhung Trinh
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - Sei-Heon Jang
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - ChangWoo Lee
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
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14
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Speevak M, DeMarco M, Wiebe N, Chapman K. An unusual case of alpha-1-antitrypsin deficiency: SZ/Z. Clin Biochem 2019; 64:49-52. [DOI: 10.1016/j.clinbiochem.2018.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/19/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022]
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15
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Methods for Determining and Understanding Serpin Structure and Function: X-Ray Crystallography. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2018; 1826:9-39. [PMID: 30194591 DOI: 10.1007/978-1-4939-8645-3_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Deciphering the X-ray crystal structures of serine protease inhibitors (serpins) and serpin complexes has been an integral part of understanding serpin function and inhibitory mechanisms. In addition, high-resolution structural information of serpins derived from the three domains of life (bacteria, archaea, and eukaryotic) and viruses has provided valuable insights into the hereditary and evolutionary history of this unique superfamily of proteins. This chapter will provide an overview of the predominant biophysical method that has yielded this information, X-ray crystallography. In addition, details of up-and-coming methods, such as neutron crystallography, cryo-electron microscopy, and small- and wide-angle solution scattering, and their potential applications to serpin structural biology will be briefly discussed. As serpins remain important both biologically and medicinally, the information provided in this chapter will aid in future experiments to expand our knowledge of this family of proteins.
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Lomas DA. New Therapeutic Targets for Alpha-1 Antitrypsin Deficiency. CHRONIC OBSTRUCTIVE PULMONARY DISEASES-JOURNAL OF THE COPD FOUNDATION 2018; 5:233-243. [PMID: 30723781 DOI: 10.15326/jcopdf.5.4.2017.0165] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alpha-1antitrypsin deficiency (AATD) results from the intracellular polymerization and retention of mutant alpha-1antitrypsin (AAT) within the endoplasmic reticulum of hepatocytes. This causes cirrhosis whilst the deficiency of circulating AAT predisposes to early onset emphysema. This is an exciting time for researchers in the field with the development of novel therapies based on understanding the pathobiology of disease. I review here augmentation therapy to prevent the progression of lung disease and a range of approaches to treat the liver disease associated with the accumulation of mutant AAT: modifying proteostasis networks that are activated by Z AAT polymers, stimulating autophagy, small interfering RNA and small molecules to block intracellular polymerization, and stem cell technology to correct the genetic defect that underlies AATD.
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Affiliation(s)
- David A Lomas
- UCL Respiratory, Division of Medicine, University College London, United Kingdom
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17
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Protein interactions during flour mixing using wheat flour with altered starch. Food Chem 2017; 231:247-257. [DOI: 10.1016/j.foodchem.2017.03.115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/20/2017] [Accepted: 03/22/2017] [Indexed: 01/06/2023]
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18
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Jendroszek A, Sønnichsen MS, Muñoz AC, Leyman K, Christensen A, Petersen SV, Wang T, Bendixen C, Panitz F, Andreasen PA, Jensen JK. Latency transition of plasminogen activator inhibitor type 1 is evolutionarily conserved. Thromb Haemost 2017; 117:1688-1699. [PMID: 28771275 DOI: 10.1160/th17-02-0102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/11/2017] [Indexed: 02/04/2023]
Abstract
Plasminogen activator inhibitor type 1 (PAI-1) is a central regulator of fibrinolysis and tissue remodelling. PAI-1 belongs to the serpin superfamily and unlike other inhibitory serpins undergoes a spontaneous inactivation process under physiological conditions, termed latency transition. During latency transition the solvent exposed reactive centre loop is inserted into the central β-sheet A of the molecule, and is no longer accessible to reaction with the protease. More than three decades of research on mammalian PAI-1 has not been able to clarify the evolutionary advantage and physiological relevance of latency transition. In order to study the origin of PAI-1 latency transition, we produced PAI-1 from Spiny dogfish shark (Squalus acanthias) and African lungfish (Protopterus sp.), which represent central species in the evolution of vertebrates. Although human PAI-1 and the non-mammalian PAI-1 variants share only approximately 50 % sequence identity, our results showed that all tested PAI-1 variants undergo latency transition with a similar rate. Since the functional stability of PAI-1 can be greatly increased by substitution of few amino acid residues, we conclude that the ability to undergo latency transition must have been a specific selection criterion for the evolution of PAI-1. It appears that all PAI-1 molecules must harbour latency transition to fulfil their physiological function, stressing the importance to further pursue a complete understanding of this molecular phenomenon with possible implication to pharmacological intervention. Our results provide the next step in understanding how the complete role of this important protease inhibitor evolved along with the fibrinolytic system.
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Petersen M, Madsen JB, Jørgensen TJD, Trelle MB. Conformational preludes to the latency transition in PAI-1 as determined by atomistic computer simulations and hydrogen/deuterium-exchange mass spectrometry. Sci Rep 2017; 7:6636. [PMID: 28747729 PMCID: PMC5529462 DOI: 10.1038/s41598-017-06290-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/12/2017] [Indexed: 11/25/2022] Open
Abstract
Both function and dysfunction of serine protease inhibitors (serpins) involve massive conformational change in their tertiary structure but the dynamics facilitating these events remain poorly understood. We have studied the dynamic preludes to conformational change in the serpin plasminogen activator inhibitor 1 (PAI-1). We report the first multi-microsecond atomistic molecular dynamics simulations of PAI-1 and compare the data with experimental hydrogen/deuterium-exchange data (HDXMS). The simulations reveal notable conformational flexibility of helices D, E and F and major fluctuations are observed in the W86-loop which occasionally leads to progressive detachment of β-strand 2 A from β-strand 3 A. An interesting correlation between Cα-RMSD values from simulations and experimental HDXMS data is observed. Helices D, E and F are known to be important for the overall stability of active PAI-1 as ligand binding in this region can accelerate or decelerate the conformational inactivation. Plasticity in this region may thus be mechanistically linked to the conformational change, possibly through facilitation of further unfolding of the hydrophobic core, as previously reported. This study provides a promising example of how computer simulations can help tether out mechanisms of serpin function and dysfunction at a spatial and temporal resolution that is far beyond the reach of any experiment.
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Affiliation(s)
- Michael Petersen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230, Odense, M, Denmark
| | - Jeppe B Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230, Odense, M, Denmark
| | - Thomas J D Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230, Odense, M, Denmark
| | - Morten B Trelle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230, Odense, M, Denmark.
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20
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Vincenz-Donnelly L, Hipp MS. The endoplasmic reticulum: A hub of protein quality control in health and disease. Free Radic Biol Med 2017; 108:383-393. [PMID: 28363604 DOI: 10.1016/j.freeradbiomed.2017.03.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 01/03/2023]
Abstract
One third of the eukaryotic proteome is synthesized at the endoplasmic reticulum (ER), whose unique properties provide a folding environment substantially different from the cytosol. A healthy, balanced proteome in the ER is maintained by a network of factors referred to as the ER quality control (ERQC) machinery. This network consists of various protein folding chaperones and modifying enzymes, and is regulated by stress response pathways that prevent the build-up as well as the secretion of potentially toxic and aggregation-prone misfolded protein species. Here, we describe the components of the ERQC machinery, investigate their response to different forms of stress, and discuss the consequences of ERQC break-down.
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Affiliation(s)
- Lisa Vincenz-Donnelly
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, 82152 Martinsried, Germany
| | - Mark S Hipp
- Max Planck Institute of Biochemistry, Department of Cellular Biochemistry, 82152 Martinsried, Germany
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21
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Inhibitory serpins. New insights into their folding, polymerization, regulation and clearance. Biochem J 2017; 473:2273-93. [PMID: 27470592 DOI: 10.1042/bcj20160014] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/31/2016] [Indexed: 12/20/2022]
Abstract
Serpins are a widely distributed family of high molecular mass protein proteinase inhibitors that can inhibit both serine and cysteine proteinases by a remarkable mechanism-based kinetic trapping of an acyl or thioacyl enzyme intermediate that involves massive conformational transformation. The trapping is based on distortion of the proteinase in the complex, with energy derived from the unique metastability of the active serpin. Serpins are the favoured inhibitors for regulation of proteinases in complex proteolytic cascades, such as are involved in blood coagulation, fibrinolysis and complement activation, by virtue of the ability to modulate their specificity and reactivity. Given their prominence as inhibitors, much work has been carried out to understand not only the mechanism of inhibition, but how it is fine-tuned, both spatially and temporally. The metastability of the active state raises the question of how serpins fold, whereas the misfolding of some serpin variants that leads to polymerization and pathologies of liver disease, emphysema and dementia makes it clinically important to understand how such polymerization might occur. Finally, since binding of serpins and their proteinase complexes, particularly plasminogen activator inhibitor-1 (PAI-1), to the clearance and signalling receptor LRP1 (low density lipoprotein receptor-related protein 1), may affect pathways linked to cell migration, angiogenesis, and tumour progression, it is important to understand the nature and specificity of binding. The current state of understanding of these areas is addressed here.
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22
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Ali MF, Kaushik A, Kapil C, Gupta D, Jairajpuri MA. A hydrophobic patch surrounding Trp154 in human neuroserpin controls the helix F dynamics with implications in inhibition and aggregation. Sci Rep 2017; 7:42987. [PMID: 28230174 PMCID: PMC5322333 DOI: 10.1038/srep42987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 01/17/2017] [Indexed: 01/23/2023] Open
Abstract
Neuroserpin (NS) mediated inhibition of tissue-type plasminogen activator (tPA) is important for brain development, synapse formation and memory. Aberrations in helix F and β-sheet A movement during inhibition can directly lead to epilepsy or dementia. Conserved W154 residue in a hydrophobic patch between helix F and β-sheet A is ideally placed to control their movement during inhibition. Molecular Dynamics (MD) simulation on wild type (WT) NS and its two variants (W154A and W154P) demonstrated partial deformation in helix F and conformational differences in strands 1A and 2A only in W154P. A fluorescence and Circular Dichroism (CD) analysis with purified W154 variants revealed a significant red-shift and an increase in α-helical content in W154P as compared to W154A and WT NS. Kinetics of tPA inhibition showed a decline in association rates (ka) for W154A as compared to WT NS with indication of complex formation. Appearance of cleaved without complex formation in W154P indicates that the variant acts as substrate due to conformational misfolding around helix F. Both the variants however showed increased rate of aggregation as compared to WT NS. The hydrophobic patch identified in this study may have importance in helix F dynamics of NS.
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Affiliation(s)
- Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
| | - Abhinav Kaushik
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Charu Kapil
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
| | - Dinesh Gupta
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
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23
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Andersen OJ, Risør MW, Poulsen EC, Nielsen NC, Miao Y, Enghild JJ, Schiøtt B. Reactive Center Loop Insertion in α-1-Antitrypsin Captured by Accelerated Molecular Dynamics Simulation. Biochemistry 2017; 56:634-646. [PMID: 27995800 DOI: 10.1021/acs.biochem.6b00839] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protease inhibition by metastable serine protease inhibitors (serpins) is mediated by one of the largest functional intradomain conformational changes known in biology. In this extensive structural rearrangement, protease-serpin complex formation triggers cleavage of the serpin reactive center loop (RCL), its subsequent insertion into central β-sheet A, and covalent trapping of the target protease. In this study, we present the first detailed accelerated molecular dynamics simulation of the insertion of the fully cleaved RCL in α-1-antitrypsin (α1AT), the archetypal member of the family of human serpins. Our results reveal internal water pathways that allow the initial incorporation of side chains of RCL residues into the protein interior. We observed structural plasticity of the helix F (hF) element that blocks the RCL path in the native state, which is in excellent agreement with previous experimental reports. Furthermore, the simulation suggested a novel role of hF and the connected turn (thFs3A) as chaperones that support the insertion process by reducing the conformational space available to the RCL. Transient electrostatic interactions of RCL residues potentially fine-tune the serpin inhibitory activity. On the basis of our simulation, we generated the α1AT mutants K168E, E346K, and K168E/E346K and analyzed their inhibitory activity along with their intrinsic stability and heat-induced polymerization. Remarkably, the E346K mutation exhibited enhanced inhibitory activity along with an increased rate of premature structural collapse (polymerization), suggesting a significant role of E346 in the gatekeeping of the strain in the metastable native state.
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Affiliation(s)
- Ole Juul Andersen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
| | - Michael Wulff Risør
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Emil Christian Poulsen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Niels Chr Nielsen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
| | - Yinglong Miao
- Howard Hughes Medical Institute and Department of Pharmacology, University of California at San Diego , La Jolla, California 92093, United States
| | - Jan J Enghild
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Birgit Schiøtt
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
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24
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Pippel J, Kuettner EB, Ulbricht D, Daberger J, Schultz S, Heiker JT, Sträter N. Crystal structure of cleaved vaspin (serpinA12). Biol Chem 2016; 397:111-23. [PMID: 26529565 DOI: 10.1515/hsz-2015-0229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/28/2015] [Indexed: 11/15/2022]
Abstract
The adipokine vaspin (serpinA12) is mainly expressed in white adipose tissue and exhibits various beneficial effects on obesity-related processes. Kallikrein 7 is the only known target protease of vaspin and is inhibited by the classical serpin inhibitory mechanism involving a cleavage of the reactive center loop between P1 (M378) and P1' (E379). Here, we present the X-ray structure of vaspin, cleaved between M378 and E379. We provide a comprehensive analysis of differences between the uncleaved and cleaved forms in the shutter, breach, and hinge regions with relation to common molecular features underlying the serpin inhibitory mode. Furthermore, we point out differences towards other serpins and provide novel data underlining the remarkable stability of vaspin. We speculate that the previously reported FKGx1Wx2x3 motif in the breach region may play a decisive role in determining the reactive center loop configuration in the native vaspin state and might contribute to the high thermostability of vaspin. Thus, this structure may provide a basis for future mutational studies.
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25
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Motamedi-Shad N, Jagger AM, Liedtke M, Faull SV, Nanda AS, Salvadori E, Wort JL, Kay CW, Heyer-Chauhan N, Miranda E, Perez J, Ordóñez A, Haq I, Irving JA, Lomas DA. An antibody that prevents serpin polymerisation acts by inducing a novel allosteric behaviour. Biochem J 2016; 473:3269-90. [PMID: 27407165 PMCID: PMC5264506 DOI: 10.1042/bcj20160159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 11/30/2022]
Abstract
Serpins are important regulators of proteolytic pathways with an antiprotease activity that involves a conformational transition from a metastable to a hyperstable state. Certain mutations permit the transition to occur in the absence of a protease; when associated with an intermolecular interaction, this yields linear polymers of hyperstable serpin molecules, which accumulate at the site of synthesis. This is the basis of many pathologies termed the serpinopathies. We have previously identified a monoclonal antibody (mAb4B12) that, in single-chain form, blocks α1-antitrypsin (α1-AT) polymerisation in cells. Here, we describe the structural basis for this activity. The mAb4B12 epitope was found to encompass residues Glu32, Glu39 and His43 on helix A and Leu306 on helix I. This is not a region typically associated with the serpin mechanism of conformational change, and correspondingly the epitope was present in all tested structural forms of the protein. Antibody binding rendered β-sheet A - on the opposite face of the molecule - more liable to adopt an 'open' state, mediated by changes distal to the breach region and proximal to helix F. The allosteric propagation of induced changes through the molecule was evidenced by an increased rate of peptide incorporation and destabilisation of a preformed serpin-enzyme complex following mAb4B12 binding. These data suggest that prematurely shifting the β-sheet A equilibrium towards the 'open' state out of sequence with other changes suppresses polymer formation. This work identifies a region potentially exploitable for a rational design of ligands that is able to dynamically influence α1-AT polymerisation.
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Affiliation(s)
- Neda Motamedi-Shad
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Alistair M. Jagger
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Maximilian Liedtke
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
| | - Sarah V. Faull
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Arjun Scott Nanda
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Enrico Salvadori
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Joshua L. Wort
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Christopher W.M. Kay
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K
| | - Narinder Heyer-Chauhan
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Elena Miranda
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, Rome 00185, Italy
| | - Juan Perez
- Departamento de Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Campus Teatinos, Universidad de Malaga, Malaga 29071, Spain
| | - Adriana Ordóñez
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Imran Haq
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - James A. Irving
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - David A. Lomas
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
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26
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Porebski BT, Keleher S, Hollins JJ, Nickson AA, Marijanovic EM, Borg NA, Costa MGS, Pearce MA, Dai W, Zhu L, Irving JA, Hoke DE, Kass I, Whisstock JC, Bottomley SP, Webb GI, McGowan S, Buckle AM. Smoothing a rugged protein folding landscape by sequence-based redesign. Sci Rep 2016; 6:33958. [PMID: 27667094 PMCID: PMC5036219 DOI: 10.1038/srep33958] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/01/2016] [Indexed: 11/09/2022] Open
Abstract
The rugged folding landscapes of functional proteins puts them at risk of misfolding and aggregation. Serine protease inhibitors, or serpins, are paradigms for this delicate balance between function and misfolding. Serpins exist in a metastable state that undergoes a major conformational change in order to inhibit proteases. However, conformational labiality of the native serpin fold renders them susceptible to misfolding, which underlies misfolding diseases such as α1-antitrypsin deficiency. To investigate how serpins balance function and folding, we used consensus design to create conserpin, a synthetic serpin that folds reversibly, is functional, thermostable, and polymerization resistant. Characterization of its structure, folding and dynamics suggest that consensus design has remodeled the folding landscape to reconcile competing requirements for stability and function. This approach may offer general benefits for engineering functional proteins that have risky folding landscapes, including the removal of aggregation-prone intermediates, and modifying scaffolds for use as protein therapeutics.
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Affiliation(s)
- Benjamin T Porebski
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, United Kingdom
| | - Shani Keleher
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Jeffrey J Hollins
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Adrian A Nickson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Emilia M Marijanovic
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Natalie A Borg
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Mauricio G S Costa
- Programa de Computação Científica, Fundação Oswaldo Cruz, 21949900 Rio de Janeiro, Brazil
| | - Mary A Pearce
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Weiwen Dai
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Liguang Zhu
- Faculty of Information Technology, Monash University, Clayton, Victoria 3800, Australia
| | - James A Irving
- Wolfson Institute for Biomedical Research, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - David E Hoke
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Itamar Kass
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - James C Whisstock
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Stephen P Bottomley
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Geoffrey I Webb
- Faculty of Information Technology, Monash University, Clayton, Victoria 3800, Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Ashley M Buckle
- Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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27
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Lomas DA, Hurst JR, Gooptu B. Update on alpha-1 antitrypsin deficiency: New therapies. J Hepatol 2016; 65:413-24. [PMID: 27034252 DOI: 10.1016/j.jhep.2016.03.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/16/2016] [Accepted: 03/20/2016] [Indexed: 02/07/2023]
Abstract
α1-Antitrypsin deficiency is characterised by the misfolding and intracellular polymerisation of mutant α1-antitrypsin within the endoplasmic reticulum of hepatocytes. The retention of mutant protein causes hepatic damage and cirrhosis whilst the lack of an important circulating protease inhibitor predisposes the individuals with severe α1-antitrypsin deficiency to early onset emphysema. Our work over the past 25years has led to new paradigms for the liver and lung disease associated with α1-antitrypsin deficiency. We review here the molecular pathology of the cirrhosis and emphysema associated with α1-antitrypsin deficiency and show how an understanding of this condition provided the paradigm for a wider group of disorders that we have termed the serpinopathies. The detailed understanding of the pathobiology of α1-antitrypsin deficiency has identified important disease mechanisms to target. As a result, several novel parallel and complementary therapeutic approaches are in development with some now in clinical trials. We provide an overview of these new therapies for the liver and lung disease associated with α1-antitrypsin deficiency.
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Affiliation(s)
- David A Lomas
- UCL Respiratory, Division of Medicine, Rayne Building, University College London, UK; The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK; Institute of Structural and Molecular Biology, UCL/Birkbeck College, University of London, London WC1E 7HX, UK.
| | - John R Hurst
- UCL Respiratory, Division of Medicine, Rayne Building, University College London, UK; The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK
| | - Bibek Gooptu
- The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK; Institute of Structural and Molecular Biology, UCL/Birkbeck College, University of London, London WC1E 7HX, UK; Division of Asthma, Allergy and Lung Biology, King's College London, Guy's Hospital, 5th Floor, Tower Wing, London, UK
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28
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Madsen JB, Andersen LM, Dupont DM, Trelle MB, Johansen JS, Jensen JK, Jørgensen TJD, Andreasen PA. An RNA Aptamer Inhibits a Mutation-Induced Inactivating Misfolding of a Serpin. Cell Chem Biol 2016; 23:700-8. [PMID: 27265748 DOI: 10.1016/j.chembiol.2016.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 12/17/2022]
Abstract
Most serpins are fast and specific inhibitors of extracellular serine proteases controlling biological processes such as blood coagulation, fibrinolysis, tissue remodeling, and inflammation. The inhibitory activity of serpins is based on a conserved metastable structure and their conversion to a more stable state during reaction with the target protease. However, the metastable state also makes serpins vulnerable to mutations, resulting in disease caused by inactive and misfolded monomeric or polymeric forms ("serpinopathy"). Misfolding can occur either intracellularly (type-I serpinopathies) or extracellularly (type-II serpinopathies). We have isolated a 2'-fluoropyrimidine-modified RNA aptamer, which inhibits a mutation-induced inactivating misfolding of the serpin α1-antichymotrypsin. It is the first agent able to stabilize a type-II mutation of a serpin without interfering with the inhibitory mechanism, thereby presenting a solution for the long-standing challenge of preventing pathogenic misfolding without compromising the inhibitory function.
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Affiliation(s)
- Jeppe B Madsen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Lisbeth M Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Daniel M Dupont
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Morten B Trelle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper S Johansen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Jan K Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Thomas J D Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Peter A Andreasen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark.
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29
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Huang X, Zheng Y, Zhang F, Wei Z, Wang Y, Carrell RW, Read RJ, Chen GQ, Zhou A. Molecular Mechanism of Z α1-Antitrypsin Deficiency. J Biol Chem 2016; 291:15674-86. [PMID: 27246852 PMCID: PMC4957051 DOI: 10.1074/jbc.m116.727826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Indexed: 12/14/2022] Open
Abstract
The Z mutation (E342K) of α1-antitrypsin (α1-AT), carried by 4% of Northern Europeans, predisposes to early onset of emphysema due to decreased functional α1-AT in the lung and to liver cirrhosis due to accumulation of polymers in hepatocytes. However, it remains unclear why the Z mutation causes intracellular polymerization of nascent Z α1-AT and why 15% of the expressed Z α1-AT is secreted into circulation as functional, but polymerogenic, monomers. Here, we solve the crystal structure of the Z-monomer and have engineered replacements to assess the conformational role of residue Glu-342 in α1-AT. The results reveal that Z α1-AT has a labile strand 5 of the central β-sheet A (s5A) with a consequent equilibrium between a native inhibitory conformation, as in its crystal structure here, and an aberrant conformation with s5A only partially incorporated into the central β-sheet. This aberrant conformation, induced by the loss of interactions from the Glu-342 side chain, explains why Z α1-AT is prone to polymerization and readily binds to a 6-mer peptide, and it supports that annealing of s5A into the central β-sheet is a crucial step in the serpins' metastable conformational formation. The demonstration that the aberrant conformation can be rectified through stabilization of the labile s5A by binding of a small molecule opens a potential therapeutic approach for Z α1-AT deficiency.
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Affiliation(s)
- Xin Huang
- From the Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine and University of Chinese Academy of Sciences, Shanghai 200025, China
| | - Ying Zheng
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Fei Zhang
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Zhenquan Wei
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Yugang Wang
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Robin W Carrell
- the Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Randy J Read
- the Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Guo-Qiang Chen
- From the Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine and University of Chinese Academy of Sciences, Shanghai 200025, China, the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Aiwu Zhou
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
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30
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Caccia S, Ricagno S, Bolognesi M. Molecular bases of neuroserpin function and pathology. Biomol Concepts 2015; 1:117-30. [PMID: 25961991 DOI: 10.1515/bmc.2010.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Serpins build a large and evolutionary widespread protein superfamily, hosting members that are mainly Ser-protease inhibitors. Typically, serpins display a conserved core domain composed of three main β-sheets and 9-10 α-helices, for a total of approximately 350 amino acids. Neuroserpin (NS) is mostly expressed in neurons and in the central and peripheral nervous systems, where it targets tissue-type plasminogen activator. NS activity is relevant for axogenesis, synaptogenesis and synaptic plasticity. Five (single amino acid) NS mutations are associated with severe neurodegenerative disease in man, leading to early onset dementia, epilepsy and neuronal death. The functional aspects of NS protease inhibition are linked to the presence of a long exposed loop (reactive center loop, RCL) that acts as bait for the incoming partner protease. Large NS conformational changes, associated with the cleavage of the RCL, trap the protease in an acyl-enzyme complex. Contrary to other serpins, this complex has a half-life of approximately 10 min. Conformational flexibility is held to be at the bases of NS polymerization leading to Collins bodies intracellular deposition and neuronal damage in the pathological NS variants. Two main general mechanisms of serpin polymerization are currently discussed. Both models require the swapping of the RCL among neighboring serpin molecules. Specific differences in the size of swapped regions, as well as differences in the folding stage at which polymerization can occur, distinguish the two models. The results provided by recent crystallographic and biophysical studies allow rationalization of the functional and pathological roles played by NS based on the analysis of four three-dimensional structures.
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31
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Berthelier V, Harris JB, Estenson KN, Baudry J. Discovery of an inhibitor of Z-alpha1 antitrypsin polymerization. PLoS One 2015; 10:e0126256. [PMID: 25961288 PMCID: PMC4427445 DOI: 10.1371/journal.pone.0126256] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/31/2015] [Indexed: 11/25/2022] Open
Abstract
Polymerization of the Z variant alpha-1-antitrypsin (Z-α1AT) results in the most common and severe form of α1AT deficiency (α1ATD), a debilitating genetic disorder whose clinical manifestations range from asymptomatic to fatal liver and/or lung disease. As the altered conformation of Z-α1AT and its attendant aggregation are responsible for pathogenesis, the polymerization process per se has become a major target for the development of therapeutics. Based on the ability of Z-α1AT to aggregate by recruiting the reactive center loop (RCL) of another Z-α1AT into its s4A cavity, we developed a high-throughput screening assay that uses a modified 6-mer peptide mimicking the RCL to screen for inhibitors of Z-α1AT polymer growth. A subset of compounds from the Library of Pharmacologically Active Compounds (LOPAC) with molecular weights ranging from 300 to 700 Da, was used to evaluate the assay's capabilities. The inhibitor S-(4-nitrobenzyl)-6-thioguanosine was identified as a lead compound and its ability to prevent Z-α1AT polymerization confirmed by secondary assays. To further investigate the binding location of S-(4-nitrobenzyl)-6-thioguanosine, an in silico strategy was pursued and the intermediate α1AT M* state modeled to allow molecular docking simulations and explore various potential binding sites. Docking results predict that S-(4-nitrobenzyl)-6-thioguanosine can bind at the s4A cavity and at the edge of β-sheet A. The former binding site would directly block RCL insertion whereas the latter site would prevent β-sheet A from expanding between s3A/s5A, and thus indirectly impede RCL insertion. Altogether, our investigations have revealed a novel compound that inhibits the formation of Z-α1AT polymers, as well as in vitro and in silico strategies for identifying and characterizing additional blocking molecules of Z-α1AT polymerization.
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Affiliation(s)
- Valerie Berthelier
- Department of Medicine, University of Tennessee Health Science Center—Graduate School of Medicine, Knoxville, Tennessee, United States of America
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jason Brett Harris
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- UT-ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Kasey Noel Estenson
- Department of Medicine, University of Tennessee Health Science Center—Graduate School of Medicine, Knoxville, Tennessee, United States of America
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jerome Baudry
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
- UT-ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
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32
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Noto R, Santangelo MG, Levantino M, Cupane A, Mangione MR, Parisi D, Ricagno S, Bolognesi M, Manno M, Martorana V. Functional and dysfunctional conformers of human neuroserpin characterized by optical spectroscopies and Molecular Dynamics. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1854:110-7. [PMID: 25450507 PMCID: PMC4332418 DOI: 10.1016/j.bbapap.2014.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/04/2014] [Accepted: 10/03/2014] [Indexed: 12/12/2022]
Abstract
Neuroserpin (NS) is a serine protease inhibitor (SERPIN) involved in different neurological pathologies, including the Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), related to the aberrant polymerization of NS mutants. Here we present an in vitro and in silico characterization of native neuroserpin and its dysfunctional conformation isoforms: the proteolytically cleaved conformer, the inactive latent conformer, and the polymeric species. Based on circular dichroism and fluorescence spectroscopy, we present an experimental validation of the latent model and highlight the main structural features of the different conformers. In particular, emission spectra of aromatic residues yield distinct conformational fingerprints, that provide a novel and simple spectroscopic tool for selecting serpin conformers in vitro. Based on the structural relationship between cleaved and latent serpins, we propose a structural model for latent NS, for which an experimental crystallographic structure is lacking. Molecular Dynamics simulations suggest that NS conformational stability and flexibility arise from a spatial distribution of intramolecular salt-bridges and hydrogen bonds.
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Affiliation(s)
- Rosina Noto
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | | | - Matteo Levantino
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
| | - Antonio Cupane
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
| | | | - Daniele Parisi
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy; Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Stefano Ricagno
- Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Martino Bolognesi
- Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy.
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
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33
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Duvoix A, Roussel B, Lomas D. Molecular pathogenesis of alpha-1-antitrypsin deficiency. Rev Mal Respir 2014; 31:992-1002. [DOI: 10.1016/j.rmr.2014.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/14/2014] [Indexed: 11/24/2022]
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34
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Tan L, Perez J, Mela M, Miranda E, Burling KA, Rouhani FN, DeMeo DL, Haq I, Irving JA, Ordóñez A, Dickens JA, Brantly M, Marciniak SJ, Alexander GJM, Gooptu B, Lomas DA. Characterising the association of latency with α(1)-antitrypsin polymerisation using a novel monoclonal antibody. Int J Biochem Cell Biol 2014; 58:81-91. [PMID: 25462157 PMCID: PMC4305080 DOI: 10.1016/j.biocel.2014.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 10/13/2014] [Accepted: 11/04/2014] [Indexed: 11/27/2022]
Abstract
α1-Antitrypsin is primarily synthesised in the liver, circulates to the lung and protects pulmonary tissues from proteolytic damage. The Z mutant (Glu342Lys) undergoes inactivating conformational change and polymerises. Polymers are retained within the hepatocyte endoplasmic reticulum (ER) in homozygous (PiZZ) individuals, predisposing the individuals to hepatic cirrhosis and emphysema. Latency is an analogous process of inactivating, intra-molecular conformational change and may co-occur with polymerisation. However, the relationship between latency and polymerisation remained unexplored in the absence of a suitable probe. We have developed a novel monoclonal antibody specific for latent α1-antitrypsin and used it in combination with a polymer-specific antibody, to assess the association of both conformers in vitro, in disease and during augmentation therapy. In vitro kinetics analysis showed polymerisation dominated the pathway but latency could be promoted by stabilising monomeric α1-antitrypsin. Polymers were extensively produced in hepatocytes and a cell line expressing Z α1-antitrypsin but the latent protein was not detected despite manipulation of the secretory pathway. However, α1-antitrypsin augmentation therapy contains latent α1-antitrypsin, as did the plasma of 63/274 PiZZ individuals treated with augmentation therapy but 0/264 who were not receiving this medication (p<10(-14)). We conclude that latent α1-antitrypsin is a by-product of the polymerisation pathway, that the intracellular folding environment is resistant to formation of the latent conformer but that augmentation therapy introduces latent α1-antitrypsin into the circulation. A suite of monoclonal antibodies and methodologies developed in this study can characterise α1-antitrypsin folding and conformational transitions, and screen methods to improve augmentation therapy.
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Affiliation(s)
- Lu Tan
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Juan Perez
- Department of Cell Biology, Genetics and Physiology, University of Málaga, Málaga, Spain
| | - Marianna Mela
- Division of Gastroenterology & Hepatology, University Department of Medicine, Cambridge University Hospitals, Cambridge, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies Charles Darwin and Pasteur Institute-Cenci Bolognetti Foundation-University of Rome La Sapienza, Rome, Italy
| | - Keith A Burling
- Core Biochemical Assay Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Farshid N Rouhani
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Dawn L DeMeo
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Imran Haq
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - James A Irving
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Adriana Ordóñez
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Jennifer A Dickens
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Mark Brantly
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Stefan J Marciniak
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Graeme J M Alexander
- Division of Gastroenterology & Hepatology, University Department of Medicine, Cambridge University Hospitals, Cambridge, UK
| | - Bibek Gooptu
- Division of Asthma, Allergy and Lung Biology, King's College London, Guy's Hospital, 5th Floor, Tower Wing, London, UK.
| | - David A Lomas
- Wolfson Institute for Biomedical Research, University College London, London, UK.
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35
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Gomes S, Marques PI, Matthiesen R, Seixas S. Adaptive evolution and divergence of SERPINB3: a young duplicate in great Apes. PLoS One 2014; 9:e104935. [PMID: 25133778 PMCID: PMC4136820 DOI: 10.1371/journal.pone.0104935] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/14/2014] [Indexed: 11/23/2022] Open
Abstract
A series of duplication events led to an expansion of clade B Serine Protease Inhibitors (SERPIN), currently displaying a large repertoire of functions in vertebrates. Accordingly, the recent duplicates SERPINB3 and B4 located in human 18q21.3 SERPIN cluster control the activity of different cysteine and serine proteases, respectively. Here, we aim to assess SERPINB3 and B4 coevolution with their target proteases in order to understand the evolutionary forces shaping the accelerated divergence of these duplicates. Phylogenetic analysis of primate sequences placed the duplication event in a Hominoidae ancestor (∼30 Mya) and the emergence of SERPINB3 in Homininae (∼9 Mya). We detected evidence of strong positive selection throughout SERPINB4/B3 primate tree and target proteases, cathepsin L2 (CTSL2) and G (CTSG) and chymase (CMA1). Specifically, in the Homininae clade a perfect match was observed between the adaptive evolution of SERPINB3 and cathepsin S (CTSS) and most of sites under positive selection were located at the inhibitor/protease interface. Altogether our results seem to favour a coevolution hypothesis for SERPINB3, CTSS and CTSL2 and for SERPINB4 and CTSG and CMA1. A scenario of an accelerated evolution driven by host-pathogen interactions is also possible since SERPINB3/B4 are potent inhibitors of exogenous proteases, released by infectious agents. Finally, similar patterns of expression and the sharing of many regulatory motifs suggest neofunctionalization as the best fitted model of the functional divergence of SERPINB3 and B4 duplicates.
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Affiliation(s)
- Sílvia Gomes
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- * E-mail: (SG); (SS)
| | - Patrícia I. Marques
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Rune Matthiesen
- National Health Institute Doutor Ricardo Jorge (INSA), Lisboa, Portugal
| | - Susana Seixas
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- * E-mail: (SG); (SS)
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36
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Therapeutic targeting of misfolding and conformational change in α1-antitrypsin deficiency. Future Med Chem 2014; 6:1047-65. [DOI: 10.4155/fmc.14.58] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Misfolding and conformational diseases are increasing in prominence and prevalence. Both misfolding and ‘postfolding’ conformational mechanisms can contribute to pathogenesis and can coexist. The different contexts of folding and native state behavior may have implications for the development of therapeutic strategies. α1-antitrypsin deficiency illustrates how these issues can be addressed with therapeutic approaches to rescue folding, ameliorate downstream consequences of aberrant polymerization and/or maintain physiological function. Small-molecule strategies have successfully targeted structural features of the native conformer. Recent developments include the capability to follow solution behavior of α1-antitrypsin in the context of disease mutations and interactions with drug-like compounds. Moreover, preclinical studies in cells and organisms support the potential of manipulating cellular response repertoires to process misfolded and polymer states.
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37
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Budrikis Z, Costantini G, La Porta CAM, Zapperi S. Protein accumulation in the endoplasmic reticulum as a non-equilibrium phase transition. Nat Commun 2014; 5:3620. [PMID: 24722051 PMCID: PMC4048836 DOI: 10.1038/ncomms4620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 03/11/2014] [Indexed: 12/03/2022] Open
Abstract
Several neurological disorders are associated with the aggregation of aberrant proteins, often localized in intracellular organelles such as the endoplasmic reticulum. Here we study protein aggregation kinetics by mean-field reactions and three dimensional Monte carlo simulations of diffusion-limited aggregation of linear polymers in a confined space, representing the endoplasmic reticulum. By tuning the rates of protein production and degradation, we show that the system undergoes a non-equilibrium phase transition from a physiological phase with little or no polymer accumulation to a pathological phase characterized by persistent polymerization. A combination of external factors accumulating during the lifetime of a patient can thus slightly modify the phase transition control parameters, tipping the balance from a long symptomless lag phase to an accelerated pathological development. The model can be successfully used to interpret experimental data on amyloid-β clearance from the central nervous system. Misfolded protein accumulation is a hallmark of many neurodegenerative diseases. Here Budrikis et al. model protein aggregation in the endoplasmic reticulum and show that it is the result of a non-equilibrium phase transition caused by tipping the balance from the rates of protein production to degradation.
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Affiliation(s)
- Zoe Budrikis
- Institute for Scientific Interchange Foundation, Via Alassio 11/C, Torino 10126, Italy
| | - Giulio Costantini
- Istituto per l'Energetica e le Interfasi, CNR-Consiglio Nazionale delle Ricerche, Via R. Cozzi 53, Milano 20125, Italy
| | - Caterina A M La Porta
- Department of Biosciences, University of Milano, via Celoria 26, Milano 20133, Italy
| | - Stefano Zapperi
- 1] Institute for Scientific Interchange Foundation, Via Alassio 11/C, Torino 10126, Italy [2] Istituto per l'Energetica e le Interfasi, CNR-Consiglio Nazionale delle Ricerche, Via R. Cozzi 53, Milano 20125, Italy
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38
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Gooptu B, Dickens JA, Lomas DA. The molecular and cellular pathology of α₁-antitrypsin deficiency. Trends Mol Med 2013; 20:116-27. [PMID: 24374162 DOI: 10.1016/j.molmed.2013.10.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/28/2013] [Accepted: 10/31/2013] [Indexed: 12/30/2022]
Abstract
Since its discovery 50 years ago, α₁-antitrypsin deficiency has represented a case study in molecular medicine, with careful clinical characterisation guiding genetic, biochemical, biophysical, structural, cellular, and in vivo studies. Here we highlight the milestones in understanding the disease mechanisms and show how they have spurred the development of novel therapeutic strategies. α₁-Antitrypsin deficiency is an archetypal conformational disease. Its pathogenesis demonstrates the interplay between protein folding and quality control mechanisms, with aberrant conformational changes causing liver and lung disease through combined loss- and toxic gain-of-function effects. Moreover, α₁-antitrypsin exemplifies the ability of diverse proteins to self-associate into a range of morphologically distinct polymers, suggesting a mechanism for protein and cell evolution.
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Affiliation(s)
- Bibek Gooptu
- Division of Asthma, Allergy, and Lung Biology, King's College London, 5th Floor, Tower Wing, Guy's Hospital, London, SE1 9RT, UK; Institute of Structural and Molecular Biology/Crystallography, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK
| | - Jennifer A Dickens
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, CB2 0XY, UK
| | - David A Lomas
- Institute of Structural and Molecular Biology/Crystallography, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK; Division of Medicine, University College London, 1st Floor, Maple House, 149, Tottenham Court Road, London, W1T 7NF, UK.
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39
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Mechanistic characterization and crystal structure of a small molecule inactivator bound to plasminogen activator inhibitor-1. Proc Natl Acad Sci U S A 2013; 110:E4941-9. [PMID: 24297881 DOI: 10.1073/pnas.1216499110] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Plasminogen activator inhibitor type-1 (PAI-1) is a member of the serine protease inhibitor (serpin) family. Excessive PAI-1 activity is associated with human disease, making it an attractive pharmaceutical target. However, like other serpins, PAI-1 has a labile structure, making it a difficult target for the development of small molecule inhibitors, and to date, there are no US Food and Drug Administration-approved small molecule inactivators of any serpins. Here we describe the mechanistic and structural characterization of a high affinity inactivator of PAI-1. This molecule binds to PAI-1 reversibly and acts through an allosteric mechanism that inhibits PAI-1 binding to proteases and to its cofactor vitronectin. The binding site is identified by X-ray crystallography and mutagenesis as a pocket at the interface of β-sheets B and C and α-helix H. A similar pocket is present on other serpins, suggesting that this site could be a common target in this structurally conserved protein family.
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40
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Heit C, Jackson BC, McAndrews M, Wright MW, Thompson DC, Silverman GA, Nebert DW, Vasiliou V. Update of the human and mouse SERPIN gene superfamily. Hum Genomics 2013; 7:22. [PMID: 24172014 PMCID: PMC3880077 DOI: 10.1186/1479-7364-7-22] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/15/2013] [Indexed: 12/14/2022] Open
Abstract
The serpin family comprises a structurally similar, yet functionally diverse, set of proteins. Named originally for their function as serine proteinase inhibitors, many of its members are not inhibitors but rather chaperones, involved in storage, transport, and other roles. Serpins are found in genomes of all kingdoms, with 36 human protein-coding genes and five pseudogenes. The mouse has 60 Serpin functional genes, many of which are orthologous to human SERPIN genes and some of which have expanded into multiple paralogous genes. Serpins are found in tissues throughout the body; whereas most are extracellular, there is a class of intracellular serpins. Serpins appear to have roles in inflammation, immune function, tumorigenesis, blood clotting, dementia, and cancer metastasis. Further characterization of these proteins will likely reveal potential biomarkers and therapeutic targets for disease.
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Affiliation(s)
| | | | | | | | | | | | - Daniel W Nebert
- Department of Pharmaceutical Sciences, Molecular Toxicology and Environmental Health Sciences Program, University of Colorado Anschutz Medical Center, Aurora, CO 80045, USA.
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41
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Maddur AA, Swanson R, Izaguirre G, Gettins PGW, Olson ST. Kinetic intermediates en route to the final serpin-protease complex: studies of complexes of α1-protease inhibitor with trypsin. J Biol Chem 2013; 288:32020-35. [PMID: 24047901 DOI: 10.1074/jbc.m113.510990] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Serpin protein protease inhibitors inactivate their target proteases through a unique mechanism in which a major serpin conformational change, resulting in a 70-Å translocation of the protease from its initial reactive center loop docking site to the opposite pole of the serpin, kinetically traps the acyl-intermediate complex. Although the initial Michaelis and final trapped acyl-intermediate complexes have been well characterized structurally, the intermediate stages involved in this remarkable transformation are not well understood. To better characterize such intermediate steps, we undertook rapid kinetic studies of the FRET and fluorescence perturbation changes of site-specific fluorophore-labeled derivatives of the serpin, α1-protease inhibitor (α1PI), which report the serpin and protease conformational changes involved in transforming the Michaelis complex to the trapped acyl-intermediate complex in reactions with trypsin. Two kinetically resolvable conformational changes were observed in the reactions, ascribable to (i) serpin reactive center loop insertion into sheet A with full protease translocation but incomplete protease distortion followed by, (ii) full conformational distortion and movement of the protease and coupled serpin conformational changes involving the F helix-sheet A interface. Kinetic studies of calcium effects on the labeled α1PI-trypsin reactions demonstrated both inactive and low activity states of the distorted protease in the final complex that were distinct from the intermediate distorted state. These studies provide new insights into the nature of the serpin and protease conformational changes involved in trapping the acyl-intermediate complex in serpin-protease reactions and support a previously proposed role for helix F in the trapping mechanism.
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Affiliation(s)
- Ashoka A Maddur
- From the Center for Molecular Biology of Oral Diseases and Department of Periodontics and
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42
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Haq I, Irving J, Faull S, Dickens J, Ordóñez A, Belorgey D, Gooptu B, Lomas D. Reactive centre loop mutants of α-1-antitrypsin reveal position-specific effects on intermediate formation along the polymerization pathway. Biosci Rep 2013; 33:e00046. [PMID: 23659468 PMCID: PMC3691886 DOI: 10.1042/bsr20130038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 04/22/2013] [Accepted: 04/25/2013] [Indexed: 11/29/2022] Open
Abstract
The common severe Z mutation (E342K) of α1-antitrypsin forms intracellular polymers that are associated with liver cirrhosis. The native fold of this protein is well-established and models have been proposed from crystallographic and biophysical data for the stable inter-molecular configuration that terminates the polymerization pathway. Despite these molecular 'snapshots', the details of the transition between monomer and polymer remain only partially understood. We surveyed the RCL (reactive centre loop) of α1-antitrypsin to identify sites important for progression, through intermediate states, to polymer. Mutations at P14P12 and P4, but not P10P8 or P2P1', resulted in a decrease in detectable polymer in a cell model that recapitulates the intracellular polymerization of the Z variant, consistent with polymerization from a near-native conformation. We have developed a FRET (Förster resonance energy transfer)-based assay to monitor polymerization in small sample volumes. An in vitro assessment revealed the position-specific effects on the unimolecular and multimolecular phases of polymerization: the P14P12 region self-inserts early during activation, while the interaction between P6P4 and β-sheet A presents a kinetic barrier late in the polymerization pathway. Correspondingly, mutations at P6P4, but not P14P12, yield an increase in the overall apparent activation energy of association from ~360 to 550 kJ mol(-1).
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Key Words
- cirrhosis
- emphysema
- fret
- intermediate
- polymerization
- serpin
- ans, 8-anilinonaphthalene-1-sulfonic acid
- bis-ans, 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid
- fret, förster resonance energy transfer
- nta, nitrilotriacetic acid
- rcl, reactive centre loop
- si, stoichiometry of inhibition
- tm,midpoint of thermal denaturation
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Affiliation(s)
- Imran Haq
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - James A. Irving
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Sarah V. Faull
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Jennifer A. Dickens
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Adriana Ordóñez
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Didier Belorgey
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Bibek Gooptu
- †Institute of Structural and Molecular Biology, Birkbeck, University of London, London, U.K
| | - David A. Lomas
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, U.K
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43
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Lomas DA. Twenty Years of Polymers: A Personal Perspective on Alpha-1 Antitrypsin Deficiency. COPD 2013; 10 Suppl 1:17-25. [DOI: 10.3109/15412555.2013.764401] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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44
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Chang YP, Chu YH. Blocking formation of large protein aggregates by small peptides. Chem Commun (Camb) 2013; 49:4591-600. [DOI: 10.1039/c3cc37518h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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45
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Martínez-Martínez I, Johnson DJD, Yamasaki M, Navarro-Fernández J, Ordóñez A, Vicente V, Huntington JA, Corral J. Type II antithrombin deficiency caused by a large in-frame insertion: structural, functional and pathological relevance. J Thromb Haemost 2012; 10:1859-66. [PMID: 22758787 DOI: 10.1111/j.1538-7836.2012.04839.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The metastable native conformation of serpins is required for their protease inhibition mechanism, but also renders them vulnerable to missense mutations that promote protein misfolding with pathological consequences. OBJECTIVE To characterize the first antithrombin deficiency caused by a large in-frame insertion. PATIENTS/METHODS Functional, biochemical and molecular analysis of the proband and relatives was performed. Recombinant antithrombin was expressed in HEK-EBNA cells. Plasma and recombinant antithrombins were purified and sequenced by Edman degradation. The stability was evaluated by calorimetry. Reactive centre loop (RCL) exposure was determined by thrombin cleavage. Mutant antithrombin was crystallized as a dimer with latent plasma antithrombin. RESULTS The patient, with a spontaneous pulmonary embolism, belongs to a family with significant thrombotic history. We identified a complex heterozygous in-frame insertion of 24 bp in SERPINC1, affecting strand 3 of β-sheet A, a region highly conserved in serpins. Surprisingly, the insertion resulted in a type II antithrombin deficiency with heparin binding defect. The mutant antithrombin, with a molecular weight of 59 kDa, had a proteolytic cleavage at W49 but maintained the N-terminal disulphide bonds, and was conformationally sensitive. The variant was non-inhibitory. Analysis of the crystal structure of the hyperstable recombinant protein showed that the inserted sequence annealed into β-sheet A as the fourth strand, and maintained a native RCL. CONCLUSIONS This is the first case of a large in frame-insertion that allows correct folding, glycosylation, and secretion of a serpin, resulting in a conformationally sensitive non-inhibitory variant, which acquires a hyperstable conformation with a native RCL.
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Affiliation(s)
- I Martínez-Martínez
- Centro Regional de Hemodonación, University of Murcia, Regional Campus of International Excellence Campus Mare Nostrum, Murcia, Spain
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46
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Nyon M, Segu L, Cabrita L, Lévy G, Kirkpatrick J, Roussel B, Patschull A, Barrett T, Ekeowa U, Kerr R, Waudby C, Kalsheker N, Hill M, Thalassinos K, Lomas D, Christodoulou J, Gooptu B. Structural dynamics associated with intermediate formation in an archetypal conformational disease. Structure 2012; 20:504-12. [PMID: 22405009 PMCID: PMC3314904 DOI: 10.1016/j.str.2012.01.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/02/2011] [Accepted: 01/03/2012] [Indexed: 11/21/2022]
Abstract
In conformational diseases, native protein conformers convert to pathological intermediates that polymerize. Structural characterization of these key intermediates is challenging. They are unstable and minimally populated in dynamic equilibria that may be perturbed by many analytical techniques. We have characterized a forme fruste deficiency variant of α1-antitrypsin (Lys154Asn) that forms polymers recapitulating the conformer-specific neo-epitope observed in polymers that form in vivo. Lys154Asn α1-antitrypsin populates an intermediate ensemble along the polymerization pathway at physiological temperatures. Nuclear magnetic resonance spectroscopy was used to report the structural and dynamic changes associated with this. Our data highlight an interaction network likely to regulate conformational change and do not support the recent contention that the disease-relevant intermediate is substantially unfolded. Conformational disease intermediates may best be defined using powerful but minimally perturbing techniques, mild disease mutants, and physiological conditions.
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Affiliation(s)
- Mun Peak Nyon
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
| | - Lakshmi Segu
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
| | - Lisa D. Cabrita
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Géraldine R. Lévy
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - John Kirkpatrick
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Benoit D. Roussel
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, CB2 0XY, UK
| | - Anathe O.M. Patschull
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Tracey E. Barrett
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
| | - Ugo I. Ekeowa
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, CB2 0XY, UK
| | - Richard Kerr
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Christopher A. Waudby
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Noor Kalsheker
- Division of Clinical Chemistry, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Marian Hill
- Division of Clinical Chemistry, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - David A. Lomas
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, CB2 0XY, UK
- Corresponding author
| | - John Christodoulou
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- ISMB, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Corresponding author
| | - Bibek Gooptu
- Institute of Structural and Molecular Biology (ISMB), Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK
- Corresponding author
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Fra AM, Gooptu B, Ferrarotti I, Miranda E, Scabini R, Ronzoni R, Benini F, Corda L, Medicina D, Luisetti M, Schiaffonati L. Three new alpha1-antitrypsin deficiency variants help to define a C-terminal region regulating conformational change and polymerization. PLoS One 2012; 7:e38405. [PMID: 22723858 PMCID: PMC3377647 DOI: 10.1371/journal.pone.0038405] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 05/05/2012] [Indexed: 11/19/2022] Open
Abstract
Alpha1-antitrypsin (AAT) deficiency is a hereditary disorder associated with reduced AAT plasma levels, predisposing adults to pulmonary emphysema. The most common genetic AAT variants found in patients are the mildly deficient S and the severely deficient Z alleles, but several other pathogenic rare alleles have been reported. While the plasma AAT deficiency is a common trait of the disease, only a few AAT variants, including the prototypic Z AAT and some rare variants, form cytotoxic polymers in the endoplasmic reticulum of hepatocytes and predispose to liver disease. Here we report the identification of three new rare AAT variants associated to reduced plasma levels and characterize their molecular behaviour in cellular models. The variants, called Mpisa (Lys259Ile), Etaurisano (Lys368Glu) and Yorzinuovi (Pro391His), showed reduced secretion compared to control M AAT, and accumulated to different extents in the cells as ordered polymeric structures resembling those formed by the Z variant. Structural analysis of the mutations showed that they may facilitate polymerization both by loosening ‘latch’ interactions constraining the AAT reactive loop and through effects on core packing. In conclusion, the new AAT deficiency variants, besides increasing the risk of lung disease, may predispose to liver disease, particularly if associated with the common Z variant. The new mutations cluster structurally, thus defining a region of the AAT molecule critical for regulating its conformational state.
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Affiliation(s)
- Anna M Fra
- Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy.
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48
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Tsutsui Y, Sarkar A, Wintrode PL. Probing serpin conformational change using mass spectrometry and related methods. Methods Enzymol 2012; 501:325-50. [PMID: 22078541 DOI: 10.1016/b978-0-12-385950-1.00015-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The folding, misfolding, and inhibitory mechanisms of serpins are linked to both thermodynamic metastability and conformational flexibility. Characterizing the structural distribution of stability and flexibility in serpins in solution is challenging due to their large size and propensity for aggregation. Structural mass spectrometry techniques offer powerful tools for probing the mechanisms of serpin function and disfunction. In this chapter, we review the principles of the two most commonly employed structural mass spectrometry techniques--hydrogen/deuterium exchange and chemical footprinting--and describe their application to studying serpin flexibility, stability, and conformational change in solution. We also review the application of both hydrogen/deuterium exchange and ion mobility mass spectrometry to probe the mechanism of serpin polymerization and the structure of serpin polymers.
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Affiliation(s)
- Yuko Tsutsui
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
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49
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Noto R, Santangelo MG, Ricagno S, Mangione MR, Levantino M, Pezzullo M, Martorana V, Cupane A, Bolognesi M, Manno M. The tempered polymerization of human neuroserpin. PLoS One 2012; 7:e32444. [PMID: 22412873 PMCID: PMC3295756 DOI: 10.1371/journal.pone.0032444] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/31/2012] [Indexed: 11/24/2022] Open
Abstract
Neuroserpin, a member of the serpin protein superfamily, is an inhibitor of proteolytic activity that is involved in pathologies such as ischemia, Alzheimer's disease, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). The latter belongs to a class of conformational diseases, known as serpinopathies, which are related to the aberrant polymerization of serpin mutants. Neuroserpin is known to polymerize, even in its wild type form, under thermal stress. Here, we study the mechanism of neuroserpin polymerization over a wide range of temperatures by different techniques. Our experiments show how the onset of polymerization is dependent on the formation of an intermediate monomeric conformer, which then associates with a native monomer to yield a dimeric species. After the formation of small polymers, the aggregation proceeds via monomer addition as well as polymer-polymer association. No further secondary mechanism takes place up to very high temperatures, thus resulting in the formation of neuroserpin linear polymeric chains. Most interesting, the overall aggregation is tuned by the co-occurrence of monomer inactivation (i.e. the formation of latent neuroserpin) and by a mechanism of fragmentation. The polymerization kinetics exhibit a unique modulation of the average mass and size of polymers, which might suggest synchronization among the different processes involved. Thus, fragmentation would control and temper the aggregation process, instead of enhancing it, as typically observed (e.g.) for amyloid fibrillation.
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Affiliation(s)
- Rosina Noto
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | | | - Stefano Ricagno
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | | | | | - Margherita Pezzullo
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Antonio Cupane
- Department of Physics, University of Palermo, Palermo, Italy
| | - Martino Bolognesi
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
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50
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Abstract
Serine protease inhibitors (serpins) are a superfamily of structurally conserved proteins that inhibit serine proteases and play key physiological roles in numerous biological systems such as blood coagulation, complement activation and inflammation. A number of serpins have now been identified in parasitic helminths with putative involvement in immune regulation and in parasite survival through interference with the host immune response. This review describes the serpins and smapins (small serine protease inhibitors) that have been identified in Ascaris spp., Brugia malayi, Ancylostoma caninum Onchocerca volvulus, Haemonchus contortus, Trichinella spiralis, Trichostrongylus vitrinus, Anisakis simplex, Trichuris suis, Schistosoma spp., Clonorchis sinensis, Paragonimus westermani and Echinococcus spp. and discusses their possible biological functions, including roles in host-parasite interplay and their evolutionary relationships.
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