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Strand 1A variant in neuroserpin shows increased aggregation and no loss of inhibition: implication in ameliorating polymerization to retain activity. Biosci Rep 2022; 42:232125. [PMID: 36408789 PMCID: PMC9760604 DOI: 10.1042/bsr20221825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/31/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
Neuroserpin (NS) is predominantly expressed in the brain and is the primary inhibitor of tissue plasminogen activator (tPA). NS variants are associated with the neurogenerative disease termed familial encephalopathy with neuroserpin inclusion bodies (FENIB). The disease is characterized by variable age of onset and severity. The reactive center loop (RCL) insertion-based inhibitory mechanism of NS requires a coordinated conformational change leading to a shift in the strands of the β-sheet A and movement of helix F. Strand 1A is connected to the helix F at its C terminal end and with the strand 2A at its N terminal, both these domain move for accommodating the inserting loop; therefore, a variant that influences their movement may alter the inhibition rates. A molecular dynamic simulation analysis of a H138C NS variant from strand 1A showed a large decrease in conformational fluctuations as compared with wild-type NS. H138 was mutated, expressed, purified and a native-PAGE and transmission electron microscopy (TEM) analysis showed that this variant forms large molecular weight aggregates on a slight increase in temperature. However, a circular dichroism analysis showed its secondary structure to be largely conserved. Surprisingly, its tPA inhibition activity and complex formation remain unhindered even after the site-specific labeling of H138C with Alexa fluor C5 maleimide. Further, a helix F-strand 1A (W154C-H138C) double variant still shows appreciable inhibitory activity. Increasingly, it appears that aggregation and not loss of inhibition is the more likely cause of shutter region-based variants phenotypes, indicating that hindering polymer formation using small molecules may retain inhibitory activity in pathological variants of NS.
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Godinez A, Rajput R, Chitranshi N, Gupta V, Basavarajappa D, Sharma S, You Y, Pushpitha K, Dhiman K, Mirzaei M, Graham S, Gupta V. Neuroserpin, a crucial regulator for axogenesis, synaptic modelling and cell-cell interactions in the pathophysiology of neurological disease. Cell Mol Life Sci 2022; 79:172. [PMID: 35244780 PMCID: PMC8897380 DOI: 10.1007/s00018-022-04185-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 01/31/2023]
Abstract
Neuroserpin is an axonally secreted serpin that is involved in regulating plasminogen and its enzyme activators, such as tissue plasminogen activator (tPA). The protein has been increasingly shown to play key roles in neuronal development, plasticity, maturation and synaptic refinement. The proteinase inhibitor may function both independently and through tPA-dependent mechanisms. Herein, we discuss the recent evidence regarding the role of neuroserpin in healthy and diseased conditions and highlight the participation of the serpin in various cellular signalling pathways. Several polymorphisms and mutations have also been identified in the protein that may affect the serpin conformation, leading to polymer formation and its intracellular accumulation. The current understanding of the involvement of neuroserpin in Alzheimer's disease, cancer, glaucoma, stroke, neuropsychiatric disorders and familial encephalopathy with neuroserpin inclusion bodies (FENIB) is presented. To truly understand the detrimental consequences of neuroserpin dysfunction and the effective therapeutic targeting of this molecule in pathological conditions, a cross-disciplinary understanding of neuroserpin alterations and its cellular signaling networks is essential.
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Affiliation(s)
- Angela Godinez
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Rashi Rajput
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Nitin Chitranshi
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia.
| | - Veer Gupta
- School of Medicine, Deakin University, Melbourne, VIC, Australia
| | - Devaraj Basavarajappa
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Samridhi Sharma
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Yuyi You
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Kanishka Pushpitha
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Kunal Dhiman
- School of Medicine, Deakin University, Melbourne, VIC, Australia
| | - Mehdi Mirzaei
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
| | - Stuart Graham
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia
- Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Vivek Gupta
- Faculty of Medicine, Health and Human Sciences, Macquarie University, F10A, 2 Technology Place, North Ryde, NSW, 2109, Australia.
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D'Acunto E, Fra A, Visentin C, Manno M, Ricagno S, Galliciotti G, Miranda E. Neuroserpin: structure, function, physiology and pathology. Cell Mol Life Sci 2021; 78:6409-6430. [PMID: 34405255 PMCID: PMC8558161 DOI: 10.1007/s00018-021-03907-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/24/2022]
Abstract
Neuroserpin is a serine protease inhibitor identified in a search for proteins implicated in neuronal axon growth and synapse formation. Since its discovery over 30 years ago, it has been the focus of active research. Many efforts have concentrated in elucidating its neuroprotective role in brain ischemic lesions, the structural bases of neuroserpin conformational change and the effects of neuroserpin polymers that underlie the neurodegenerative disease FENIB (familial encephalopathy with neuroserpin inclusion bodies), but the investigation of the physiological roles of neuroserpin has increased over the last years. In this review, we present an updated and critical revision of the current literature dealing with neuroserpin, covering all aspects of research including the expression and physiological roles of neuroserpin, both inside and outside the nervous system; its inhibitory and non-inhibitory mechanisms of action; the molecular structure of the monomeric and polymeric conformations of neuroserpin, including a detailed description of the polymerisation mechanism; and the involvement of neuroserpin in human disease, with particular emphasis on FENIB. Finally, we briefly discuss the identification by genome-wide screening of novel neuroserpin variants and their possible pathogenicity.
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Affiliation(s)
- Emanuela D'Acunto
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Cristina Visentin
- Department of Biosciences, University of Milan, Milan, Italy
- Institute of Molecular and Translational Cardiology, I.R.C.C.S. Policlinico San Donato, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Stefano Ricagno
- Department of Biosciences, University of Milan, Milan, Italy
| | - Giovanna Galliciotti
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy.
- Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy.
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4
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Abstract
Serine proteinase inhibitors (serpins), typically fold to a metastable native state and undergo a major conformational change in order to inhibit target proteases. However, conformational lability of the native serpin fold renders them susceptible to misfolding and aggregation, and underlies misfolding diseases such as α1-antitrypsin deficiency. Serpin specificity towards its protease target is dictated by its flexible and solvent exposed reactive centre loop (RCL), which forms the initial interaction with the target protease during inhibition. Previous studies have attempted to alter the specificity by mutating the RCL to that of a target serpin, but the rules governing specificity are not understood well enough yet to enable specificity to be engineered at will. In this paper, we use conserpin, a synthetic, thermostable serpin, as a model protein with which to investigate the determinants of serpin specificity by engineering its RCL. Replacing the RCL sequence with that from α1-antitrypsin fails to restore specificity against trypsin or human neutrophil elastase. Structural determination of the RCL-engineered conserpin and molecular dynamics simulations indicate that, although the RCL sequence may partially dictate specificity, local electrostatics and RCL dynamics may dictate the rate of insertion during protease inhibition, and thus whether it behaves as an inhibitor or a substrate. Engineering serpin specificity is therefore substantially more complex than solely manipulating the RCL sequence, and will require a more thorough understanding of how conformational dynamics achieves the delicate balance between stability, folding and function required by the exquisite serpin mechanism of action.
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Higgins WJ, Grehan GT, Wynne KJ, Worrall DM. SerpinI2 (pancpin) is an inhibitory serpin targeting pancreatic elastase and chymotrypsin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:195-200. [DOI: 10.1016/j.bbapap.2016.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/11/2016] [Accepted: 10/26/2016] [Indexed: 10/20/2022]
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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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7
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Carlson KSB, Nguyen L, Schwartz K, Lawrence DA, Schwartz BS. Neuroserpin Differentiates Between Forms of Tissue Type Plasminogen Activator via pH Dependent Deacylation. Front Cell Neurosci 2016; 10:154. [PMID: 27378851 PMCID: PMC4908126 DOI: 10.3389/fncel.2016.00154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 05/27/2016] [Indexed: 11/17/2022] Open
Abstract
Tissue-type plasminogen activator (t-PA), initially characterized for its critical role in fibrinolysis, also has key functions in both physiologic and pathologic processes in the CNS. Neuroserpin (NSP) is a t-PA specific serine protease inhibitor (serpin) found almost exclusively in the CNS that regulates t-PA's proteolytic activity and protects against t-PA mediated seizure propagation and blood-brain barrier disruption. This report demonstrates that NSP inhibition of t-PA varies profoundly as a function of pH within the biologically relevant pH range for the CNS, and reflects the stability, rather than the formation of NSP: t-PA acyl-enzyme complexes. Moreover, NSP differentiates between the zymogen-like single chain form (single chain t-PA, sct-PA) and the mature protease form (two chain t-PA, tct-PA) of t-PA, demonstrating different pH profiles for protease inhibition, different pH ranges over which catalytic deacylation occurs, and different pH dependent profiles of deacylation rates for each form of t-PA. NSP's pH dependent inhibition of t-PA is not accounted for by differential acylation, and is specific for the NSP-t-PA serpin-protease pair. These results demonstrate a novel mechanism for the differential regulation of the two forms of t-PA in the CNS, and suggest a potential specific regulatory role for CNS pH in controlling t-PA proteolytic activity.
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Affiliation(s)
- Karen-Sue B. Carlson
- Department of Biomolecular Chemistry, University of Wisconsin, MadisonWI, USA
- Medical Scientist Training Program, University of Wisconsin, MadisonWI, USA
| | - Lan Nguyen
- Departments of Biochemistry and Medicine, University of Illinois, UrbanaIL, USA
| | - Kat Schwartz
- Departments of Biochemistry and Medicine, University of Illinois, UrbanaIL, USA
| | - Daniel A. Lawrence
- Departments of Medicine and Molecular and Integrative Physiology, University of Michigan, Ann ArborMI, USA
| | - Bradford S. Schwartz
- Department of Biomolecular Chemistry, University of Wisconsin, MadisonWI, USA
- Departments of Biochemistry and Medicine, University of Illinois, UrbanaIL, USA
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8
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Lee TW, Tsang VWK, Birch NP. Physiological and pathological roles of tissue plasminogen activator and its inhibitor neuroserpin in the nervous system. Front Cell Neurosci 2015; 9:396. [PMID: 26528129 PMCID: PMC4602146 DOI: 10.3389/fncel.2015.00396] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/22/2015] [Indexed: 12/03/2022] Open
Abstract
Although its roles in the vascular space are most well-known, tissue plasminogen activator (tPA) is widely expressed in the developing and adult nervous system, where its activity is believed to be regulated by neuroserpin, a predominantly brain-specific member of the serpin family of protease inhibitors. In the normal physiological state, tPA has been shown to play roles in the development and plasticity of the nervous system. Ischemic damage, however, may lead to excess tPA activity in the brain and this is believed to contribute to neurodegeneration. In this article, we briefly review the physiological and pathological roles of tPA in the nervous system, which includes neuronal migration, axonal growth, synaptic plasticity, neuroprotection and neurodegeneration, as well as a contribution to neurological disease. We summarize tPA's multiple mechanisms of action and also highlight the contributions of the inhibitor neuroserpin to these processes.
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Affiliation(s)
- Tet Woo Lee
- School of Biological Sciences and Centre for Brain Research, University of Auckland Auckland, New Zealand
| | - Vicky W K Tsang
- School of Biological Sciences and Centre for Brain Research, University of Auckland Auckland, New Zealand
| | - Nigel P Birch
- School of Biological Sciences and Centre for Brain Research, University of Auckland Auckland, New Zealand ; Brain Research New Zealand, Rangahau Roro Aotearoa Auckland, New Zealand
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Noto R, Randazzo L, Raccosta S, Caccia S, Moriconi C, Miranda E, Martorana V, Manno M. The stability and activity of human neuroserpin are modulated by a salt bridge that stabilises the reactive centre loop. Sci Rep 2015; 5:13666. [PMID: 26329378 PMCID: PMC4556959 DOI: 10.1038/srep13666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 08/03/2015] [Indexed: 11/26/2022] Open
Abstract
Neuroserpin (NS) is an inhibitory protein belonging to the serpin family and involved in several pathologies, including the dementia Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), a genetic neurodegenerative disease caused by accumulation of NS polymers. Our Molecular Dynamics simulations revealed the formation of a persistent salt bridge between Glu289 on strand s2C and Arg362 on the Reactive Centre Loop (RCL), a region important for the inhibitory activity of NS. Here, we validated this structural feature by simulating the Glu289Ala mutant, where the salt bridge is not present. Further, MD predictions were tested in vitro by purifying recombinant Glu289Ala NS from E. coli. The thermal and chemical stability along with the polymerisation propensity of both Wild Type and Glu289Ala NS were characterised by circular dichroism, emission spectroscopy and non-denaturant gel electrophoresis, respectively. The activity of both variants against the main target protease, tissue-type plasminogen activator (tPA), was assessed by SDS-PAGE and chromogenic kinetic assay. Our results showed that deletion of the salt bridge leads to a moderate but clear reduction of the overall protein stability and activity.
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Affiliation(s)
- Rosina Noto
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Loredana Randazzo
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Samuele Raccosta
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Sonia Caccia
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
| | - Claudia Moriconi
- Department of Biology and Biotechnologies “Charles Darwin” and Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Elena Miranda
- Department of Biology and Biotechnologies “Charles Darwin” and Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Vincenzo Martorana
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Mauro Manno
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
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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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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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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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13
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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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15
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Belorgey D, Irving JA, Ekeowa UI, Freeke J, Roussel BD, Miranda E, Pérez J, Robinson CV, Marciniak SJ, Crowther DC, Michel CH, Lomas DA. Characterisation of serpin polymers in vitro and in vivo. Methods 2010; 53:255-66. [PMID: 21115126 DOI: 10.1016/j.ymeth.2010.11.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 11/21/2010] [Indexed: 10/18/2022] Open
Abstract
Neuroserpin is a member of the serine protease inhibitor or serpin superfamily of proteins. It is secreted by neurones and plays an important role in the regulation of tissue plasminogen activator at the synapse. Point mutations in the neuroserpin gene cause the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. This is one of a group of disorders caused by mutations in the serpins that are collectively known as the serpinopathies. Others include α(1)-antitrypsin deficiency and deficiency of C1 inhibitor, antithrombin and α(1)-antichymotrypsin. The serpinopathies are characterised by delays in protein folding and the retention of ordered polymers of the mutant serpin within the cell of synthesis. The clinical phenotype results from either a toxic gain of function from the inclusions or a loss of function, as there is insufficient protease inhibitor to regulate important proteolytic cascades. We describe here the methods required to characterise the polymerisation of neuroserpin and draw parallels with the polymerisation of α(1)-antitrypsin. It is important to recognise that the conditions in which experiments are performed will have a major effect on the findings. For example, incubation of monomeric serpins with guanidine or urea will produce polymers that are not found in vivo. The characterisation of the pathological polymers requires heating of the folded protein or alternatively the assessment of ordered polymers from cell and animal models of disease or from the tissues of humans who carry the mutation.
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Affiliation(s)
- Didier Belorgey
- Dept. of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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Ricagno S, Pezzullo M, Barbiroli A, Manno M, Levantino M, Santangelo MG, Bonomi F, Bolognesi M. Two latent and two hyperstable polymeric forms of human neuroserpin. Biophys J 2010; 99:3402-11. [PMID: 21081089 PMCID: PMC2980742 DOI: 10.1016/j.bpj.2010.09.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 09/08/2010] [Accepted: 09/09/2010] [Indexed: 02/02/2023] Open
Abstract
Human neuroserpin (hNS) is a serine protease inhibitor that belongs to the serpin superfamily and is expressed in nervous tissues. The serpin fold is generally characterized by a long exposed loop, termed the reactive center loop, that acts as bait for the target protease. Intramolecular insertion of the reactive center loop into the main serpin β-sheet leads to the serpin latent form. As with other known serpins, hNS pathological mutants have been shown to accumulate as polymers composed of quasi-native protein molecules. Although hNS polymerization has been intensely studied, a general agreement about serpin polymer organization is still lacking. Here we report a biophysical characterization of native hNS that is shown to undergo two distinct conformational transitions, at 55°C and 85°C, both leading to distinct latent and polymeric species. The latent and polymer hNS forms obtained at 45°C and 85°C differ in their chemical and thermal stabilities; furthermore, the hNS polymers also differ in size and morphology. Finally, the 85°C polymer shows a higher content of intermolecular β-sheet interactions than the 45°C polymer. Together, these results suggest a more complex conformational scenario than was previously envisioned, and, in a general context, may help reconcile the current contrasting views on serpin polymerization.
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Affiliation(s)
- Stefano Ricagno
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
- Dipartimento di Biochimica, Università di Pavia, Pavia, Italy
- Laboratori di Biotecnologie, Istituto Di Ricovero e Cura a Carattere Scientifico Fondazione Policlinico San Matteo, Pavia, Italy
| | - Margherita Pezzullo
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
| | - Alberto Barbiroli
- Sezione di Biochimica, Dipartimento di Scienze Molecolari Agroalimentari, Università di Milano, Milan, Italy
| | - Mauro Manno
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, CNR, Palermo, Italy
| | - Matteo Levantino
- Dipartimento di Scienze Fisiche ed Astronomiche, Università of Palermo, Palermo, Italy
| | | | - Francesco Bonomi
- Sezione di Biochimica, Dipartimento di Scienze Molecolari Agroalimentari, Università di Milano, Milan, Italy
| | - Martino Bolognesi
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
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