1
|
Visentin C, Musso L, Broggini L, Bonato F, Russo R, Moriconi C, Bolognesi M, Miranda E, Dallavalle S, Passarella D, Ricagno S. Embelin as Lead Compound for New Neuroserpin Polymerization Inhibitors. Life (Basel) 2020; 10:life10070111. [PMID: 32664592 PMCID: PMC7400170 DOI: 10.3390/life10070111] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a severe and lethal neurodegenerative disease. Upon specific point mutations in the SERPINI1gene-coding for the human protein neuroserpin (NS) the resulting pathologic NS variants polymerize and accumulate within the endoplasmic reticulum of neurons in the central nervous system. To date, embelin (EMB) is the only known inhibitor of NS polymerization in vitro. This molecule is capable of preventing NS polymerization and dissolving preformed polymers. Here, we show that lowering EMB concentration results in increasing size of NS oligomers in vitro. Moreover, we observe that in cells expressing NS, the polymerization of G392E NS is reduced, but this effect is mediated by an increased proteasomal degradation rather than polymerization impairment. For these reasons we designed a systematic chemical evolution of the EMB scaffold aimed to improve its anti-polymerization properties. The effect of EMB analogs against NS polymerization was assessed in vitro. None of the EMB analogs displayed an anti-polymerization activity better than the one reported for EMB, indicating that the EMB–NS interaction surface is very specific and highly optimized. Thus, our results indicate that EMB is, to date, still the best candidate for developing a treatment against NS polymerization.
Collapse
Affiliation(s)
- Cristina Visentin
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (M.B.)
| | - Loana Musso
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy; (L.M.); (S.D.)
| | - Luca Broggini
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (M.B.)
| | - Francesca Bonato
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi, 19, 20133 Milan, Italy; (F.B.); (D.P.)
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Via Fratelli Cervi, 93, 20090 Segrate, Italy;
| | - Claudia Moriconi
- Dipartimento di Biologia e Biotecnologie ‘Charles Darwin’, Sapienza Università di Roma, Piazzale Aldo Moro, 5, 00185 Rome, Italy; (C.M.); (E.M.)
| | - Martino Bolognesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (M.B.)
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie ‘Charles Darwin’, Sapienza Università di Roma, Piazzale Aldo Moro, 5, 00185 Rome, Italy; (C.M.); (E.M.)
- Istituto Pasteur—Cenci Bolognetti Foundation, Sapienza Università di Roma, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Sabrina Dallavalle
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy; (L.M.); (S.D.)
| | - Daniele Passarella
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi, 19, 20133 Milan, Italy; (F.B.); (D.P.)
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (M.B.)
- Correspondence: ; Tel.: +39-02-5031-4914
| |
Collapse
|
2
|
Visentin C, Broggini L, Sala BM, Russo R, Barbiroli A, Santambrogio C, Nonnis S, Dubnovitsky A, Bolognesi M, Miranda E, Achour A, Ricagno S. Glycosylation Tunes Neuroserpin Physiological and Pathological Properties. Int J Mol Sci 2020; 21:E3235. [PMID: 32375228 PMCID: PMC7247563 DOI: 10.3390/ijms21093235] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 02/03/2023] Open
Abstract
Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation in the biochemical properties of NS. Here, we report the expression and purification of human glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to study the molecular bases of FENIB.
Collapse
Affiliation(s)
- Cristina Visentin
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Luca Broggini
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Benedetta Maria Sala
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Via Fratelli Cervi, 93, 20090 Segrate, Italy;
| | - Alberto Barbiroli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l′Ambiente, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy;
| | - Carlo Santambrogio
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza dell’Ateneo Nuovo, 1, 20126 Milan, Italy;
| | - Simona Nonnis
- Departimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell’Università, 6, 26900 Lodi, Italy;
| | - Anatoly Dubnovitsky
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Rheumatology, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
| | - Martino Bolognesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie ‘Charles Darwin’, and Istituto Pasteur - Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro, 5, 00185 Rome, Italy;
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| |
Collapse
|
3
|
Bonnet J, Garcia C, Leger T, Couquet MP, Vignoles P, Vatunga G, Ndung'u J, Boudot C, Bisser S, Courtioux B. Proteome characterization in various biological fluids of Trypanosoma brucei gambiense-infected subjects. J Proteomics 2018; 196:150-161. [PMID: 30414516 DOI: 10.1016/j.jprot.2018.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/02/2018] [Accepted: 11/05/2018] [Indexed: 02/04/2023]
Abstract
Human African trypanosomiasis (HAT) is a neglected tropical disease that is endemic in sub-Saharan Africa. Control of the disease has been recently improved by better screening and treatment strategies, and the disease is on the WHO list of possible elimination. However, some physiopathological aspects of the disease transmission and progression remain unclear. We propose a new proteomic approach to identify new targets and thus possible new biomarkers of the disease. We also focused our attention on fluids classically associated with HAT (serum and cerebrospinal fluid (CSF)) and on the more easily accessible biological fluids urine and saliva. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) established the proteomic profile of patients with early and late stage disease. The serum, CSF, urine and saliva of 3 uninfected controls, 3 early stage patients and 4 late stage patients were analyzed. Among proteins identified, in CSF, urine and saliva, respectively, 37, 8 and 24 proteins were differentially expressed and showed particular interest with regards to their function. The most promising proteins (Neogenin, Neuroserpin, secretogranin 2 in CSF; moesin in urine and intelectin 2 in saliva) were quantified by enzyme-linked immunosorbent assay in a confirmatory cohort of 14 uninfected controls, 23 patients with early stage disease and 43 patients with late stage disease. The potential of two proteins, neuroserpin and moesin, with the latter present in urine, were further characterized. Our results showed the potential of proteomic analysis to discover new biomarkers and provide the basis of the establishment of a new proteomic catalogue applied to HAT-infected subjects and controls. SIGNIFICANCE: Sleeping sickness, also called Human African Trypanosomiasis (HAT), is a parasitic infection caused by a parasitic protozoan, Trypanosoma brucei gambiense or T. b. rhodesiense which are transmitted via an infected tsetse fly: Glossina. For both, the haemolymphatic stage (or first stage) signs and symptoms are intermittent fever, lymphadenopathy, hepatosplenomegaly, headaches, pruritus, and for T. b. rhodesiense infection a chancre is often formed at the bite site. Meningoencephalitic stage (or second stage) occurs when parasites invade the CNS, it is characterised by neurological signs and symptoms such as altered gait, tremors, neuropathy, somnolence which can lead to coma and death if untreated. first stage of the disease is characterizing by fevers, headaches, itchiness, and joint pains and progressive lethargy corresponding to the second stage with confusion, poor coordination, numbness and trouble sleeping. Actually, diagnosing HAT requires specialized expertise and significant resources such as well-equipped health centers and qualified staff. Such resources are lacking in many endemic areas that are often in rural locales, so many individuals with HAT die before the diagnosis is established. In this study, we analysed by mass spectrometry the entire proteome of serum, CSF, urine and saliva samples from infected and non-infected Angolan individuals to define new biomarkers of the disease. This work of proteomics analysis is a preliminary stage to the characterization of the whole proteome, of these 4 biological fluids, of HAT patients. We have identified 69 new biomarkers. Five of them have been thoroughly investigated by ELISA quantification. Neuroserpine and Moesin are respectively promising new biomarkers in CSF and urine's patient for a better diagnosis.
Collapse
Affiliation(s)
- Julien Bonnet
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Camille Garcia
- Jacques Monod Institute, Proteomics Facility, University Paris Diderot Sorbonne Paris Cité, Paris, France..
| | - Thibaut Leger
- Jacques Monod Institute, Proteomics Facility, University Paris Diderot Sorbonne Paris Cité, Paris, France..
| | - Marie-Pauline Couquet
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Philippe Vignoles
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Gedeao Vatunga
- Instituto de Combate e controlo das Tripanossomiases (ICCT), Luanda, Angola.
| | - Joseph Ndung'u
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland.
| | - Clotilde Boudot
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Sylvie Bisser
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France; Pasteur Institute in French Guiana, 23 Boulevard Pasteur, 973006, Cayenne Cedex, French Guiana.
| | - Bertrand Courtioux
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| |
Collapse
|
4
|
Saga G, Sessa F, Barbiroli A, Santambrogio C, Russo R, Sala M, Raccosta S, Martorana V, Caccia S, Noto R, Moriconi C, Miranda E, Grandori R, Manno M, Bolognesi M, Ricagno S. Embelin binds to human neuroserpin and impairs its polymerisation. Sci Rep 2016; 6:18769. [PMID: 26732982 PMCID: PMC4702122 DOI: 10.1038/srep18769] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/26/2015] [Indexed: 01/07/2023] Open
Abstract
Neuroserpin (NS) is a serpin inhibitor of tissue plasminogen activator (tPA) in the brain. The polymerisation of NS pathologic mutants is responsible for a genetic dementia known as familial encephalopathy with neuroserpin inclusion bodies (FENIB). So far, a pharmacological treatment of FENIB, i.e. an inhibitor of NS polymerisation, remains an unmet challenge. Here, we present a biophysical characterisation of the effects caused by embelin (EMB a small natural compound) on NS conformers and NS polymerisation. EMB destabilises all known NS conformers, specifically binding to NS molecules with a 1:1 NS:EMB molar ratio without unfolding the NS fold. In particular, NS polymers disaggregate in the presence of EMB, and their formation is prevented. The NS/EMB complex does not inhibit tPA proteolytic activity. Both effects are pharmacologically relevant: firstly by inhibiting the NS polymerisation associated to FENIB, and secondly by potentially antagonizing metastatic processes facilitated by NS activity in the brain.
Collapse
Affiliation(s)
- Giorgia Saga
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Fabio Sessa
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Alberto Barbiroli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l′Ambiente, Università degli Studi di Milano, Milan, Italy
| | - Carlo Santambrogio
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di MilanoItaly
| | - Michela Sala
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Samuele Raccosta
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Vincenzo Martorana
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Sonia Caccia
- Dipartimento di Biotecnologie Mediche e Medicina traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Rosina Noto
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Claudia Moriconi
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Rita Grandori
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Mauro Manno
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Martino Bolognesi
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
- Istituto di Biofisica, National Research Council of Italy, c/o Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
5
|
Moriconi C, Ordoñez A, Lupo G, Gooptu B, Irving JA, Noto R, Martorana V, Manno M, Timpano V, Guadagno NA, Dalton L, Marciniak SJ, Lomas DA, Miranda E. Interactions between N-linked glycosylation and polymerisation of neuroserpin within the endoplasmic reticulum. FEBS J 2015; 282:4565-79. [PMID: 26367528 PMCID: PMC4949553 DOI: 10.1111/febs.13517] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 07/26/2015] [Accepted: 09/10/2015] [Indexed: 01/04/2023]
Abstract
The neuronal serpin neuroserpin undergoes polymerisation as a consequence of point mutations that alter its conformational stability, leading to a neurodegenerative dementia called familial encephalopathy with neuroserpin inclusion bodies (FENIB). Neuroserpin is a glycoprotein with predicted glycosylation sites at asparagines 157, 321 and 401. We used site-directed mutagenesis, transient transfection, western blot, metabolic labelling and ELISA to probe the relationship between glycosylation, folding, polymerisation and degradation of neuroserpin in validated cell models of health and disease. Our data show that glycosylation at N157 and N321 plays an important role in maintaining the monomeric state of neuroserpin, and we propose this is the result of steric hindrance or effects on local conformational dynamics that can contribute to polymerisation. Asparagine residue 401 is not glycosylated in wild type neuroserpin and in several polymerogenic variants that cause FENIB, but partial glycosylation was observed in the G392E mutant of neuroserpin that causes severe, early-onset dementia. Our findings indicate that N401 glycosylation reports lability of the C-terminal end of neuroserpin in its native state. This C-terminal lability is not required for neuroserpin polymerisation in the endoplasmic reticulum, but the additional glycan facilitates degradation of the mutant protein during proteasomal impairment. In summary, our results indicate how normal and variant-specific N-linked glycosylation events relate to intracellular folding, misfolding, degradation and polymerisation of neuroserpin.
Collapse
Affiliation(s)
- Claudia Moriconi
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Italy
| | - Adriana Ordoñez
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, UK
| | - Giuseppe Lupo
- Department of Chemistry, Sapienza University of Rome, Italy
| | - Bibek Gooptu
- Division of Asthma, Allergy and Lung Biology, King's College London, UK
| | - James A Irving
- Wolfson Institute for Biomedical Research, University College London, UK
| | - Rosina Noto
- National Research Council of Italy, Institute of Biophysics, Palermo, 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
| | - Valentina Timpano
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Italy
| | - Noemi A Guadagno
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Italy
| | - Lucy Dalton
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, UK
| | - Stefan J Marciniak
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, UK
| | - David A Lomas
- Wolfson Institute for Biomedical Research, University College London, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Italy
- Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Italy
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Santangelo MG, Noto R, Levantino M, Cupane A, Ricagno S, Pezzullo M, Bolognesi M, Mangione MR, Martorana V, Manno M. On the molecular structure of human neuroserpin polymers. Proteins 2012; 80:8-13. [PMID: 22072549 DOI: 10.1002/prot.23197] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/04/2011] [Accepted: 09/14/2011] [Indexed: 11/12/2022]
Abstract
The polymerization of serpins is at the root of a large class of diseases; the molecular structure of serpin polymers has been recently debated. In this work, we study the polymerization kinetics of human neuroserpin by Fourier Transform Infra Red spectroscopy and by time-lapse Size Exclusion Chromatography. First, we show that two distinct neuroserpin polymers, formed at 45 and 85°C, display the same isosbestic points in the Amide I' band, and therefore share common secondary structure features. We also find a concentration independent polymerization rate at 45°C suggesting that the polymerization rate-limiting step is the formation of an activated monomeric species. The polymer structures are consistent with a model that predicts the bare insertion of portions of the reactive center loop into the A β-sheet of neighboring serpin molecule, although with different extents at 45 and 85°C.
Collapse
|