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Diana D, Pirone L, Russo L, D'Abrosca G, Madheswaran M, Benfante R, Di Lascio S, Caldinelli L, Fornasari D, Acconcia C, Corvino A, Ventserova N, Pollegioni L, Isernia C, Di Gaetano S, Malgieri G, Pedone EM, Fattorusso R. Structural characterization of PHOX2B and its DNA interaction shed light on the molecular basis of the +7Ala variant pathogenicity in CCHS. Chem Sci 2024; 15:8858-8872. [PMID: 38873078 PMCID: PMC11168103 DOI: 10.1039/d3sc06427a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/12/2024] [Indexed: 06/15/2024] Open
Abstract
An expansion of poly-alanine up to +13 residues in the C-terminus of the transcription factor PHOX2B underlies the onset of congenital central hypoventilation syndrome (CCHS). Recent studies demonstrated that the alanine tract expansion influences PHOX2B folding and activity. Therefore, structural information on PHOX2B is an important target for obtaining clues to elucidate the insurgence of the alanine expansion-related syndrome and also for defining a viable therapy. Here we report by NMR spectroscopy the structural characterization of the homeodomain (HD) of PHOX2B and HD + C-terminus PHOX2B protein, free and in the presence of the target DNA. The obtained structural data are then exploited to obtain a structural model of the PHOX2B-DNA interaction. In addition, the variant +7Ala, responsible for one of the most frequent forms of the syndrome, was analysed, showing different conformational proprieties in solution and a strong propensity to aggregation. Our data suggest that the elongated poly-alanine tract would be related to disease onset through a loss-of-function mechanism. Overall, this study paves the way for the future rational design of therapeutic drugs, suggesting as a possible therapeutic route the use of specific anti-aggregating molecules capable of preventing variant aggregation and possibly restoring the DNA-binding activity of PHOX2B.
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Affiliation(s)
- Donatella Diana
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luciano Pirone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Gianluca D'Abrosca
- Department of Clinical and Experimental Medicine - University of Foggia Viale Luigi Pinto 71122 Foggia Italy
| | - Manoj Madheswaran
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
- CNR - Institute of Neuroscience Vedano Al Lambro (MB) Italy
- NeuroMi - Milan Center for Neuroscience, University of Milano Bicocca Milan Italy
| | - Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Laura Caldinelli
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano Milan Italy
| | - Clementina Acconcia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Andrea Corvino
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Nataliia Ventserova
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria Via J.H. Dunant 3 21100 Varese Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Sonia Di Gaetano
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
| | - Emilia M Pedone
- CNR - Institute of Biostructures and Bioimaging Via Pietro Castellino 111 80131 Naples Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies - University of Campania "Luigi Vanvitelli" Via Vivaldi 43 81100 Caserta Italy
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2
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Cardani S, Janes TA, Betzner W, Pagliardini S. Knockdown of PHOX2B in the retrotrapezoid nucleus reduces the central CO 2 chemoreflex in rats. eLife 2024; 13:RP94653. [PMID: 38727716 PMCID: PMC11087052 DOI: 10.7554/elife.94653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024] Open
Abstract
PHOX2B is a transcription factor essential for the development of different classes of neurons in the central and peripheral nervous system. Heterozygous mutations in the PHOX2B coding region are responsible for the occurrence of Congenital Central Hypoventilation Syndrome (CCHS), a rare neurological disorder characterised by inadequate chemosensitivity and life-threatening sleep-related hypoventilation. Animal studies suggest that chemoreflex defects are caused in part by the improper development or function of PHOX2B expressing neurons in the retrotrapezoid nucleus (RTN), a central hub for CO2 chemosensitivity. Although the function of PHOX2B in rodents during development is well established, its role in the adult respiratory network remains unknown. In this study, we investigated whether reduction in PHOX2B expression in chemosensitive neuromedin-B (NMB) expressing neurons in the RTN altered respiratory function. Four weeks following local RTN injection of a lentiviral vector expressing the short hairpin RNA (shRNA) targeting Phox2b mRNA, a reduction of PHOX2B expression was observed in Nmb neurons compared to both naive rats and rats injected with the non-target shRNA. PHOX2B knockdown did not affect breathing in room air or under hypoxia, but ventilation was significantly impaired during hypercapnia. PHOX2B knockdown did not alter Nmb expression but it was associated with reduced expression of both Task2 and Gpr4, two CO2/pH sensors in the RTN. We conclude that PHOX2B in the adult brain has an important role in CO2 chemoreception and reduced PHOX2B expression in CCHS beyond the developmental period may contribute to the impaired central chemoreflex function.
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Affiliation(s)
- Silvia Cardani
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
| | - Tara A Janes
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
| | - William Betzner
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
| | - Silvia Pagliardini
- Department of Physiology, Faculty of Medicine and Dentistry, University of AlbertaEdmontonCanada
- Women and Children’s Health Research Institute, University of AlbertaEdmontonCanada
- Neuroscience and Mental Health Institute, University of AlbertaEdmontonCanada
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3
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Antón R, Treviño MÁ, Pantoja-Uceda D, Félix S, Babu M, Cabrita EJ, Zweckstetter M, Tinnefeld P, Vera AM, Oroz J. Alternative low-populated conformations prompt phase transitions in polyalanine repeat expansions. Nat Commun 2024; 15:1925. [PMID: 38431667 PMCID: PMC10908835 DOI: 10.1038/s41467-024-46236-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 02/19/2024] [Indexed: 03/05/2024] Open
Abstract
Abnormal trinucleotide repeat expansions alter protein conformation causing malfunction and contribute to a significant number of incurable human diseases. Scarce structural insights available on disease-related homorepeat expansions hinder the design of effective therapeutics. Here, we present the dynamic structure of human PHOX2B C-terminal fragment, which contains the longest polyalanine segment known in mammals. The major α-helical conformation of the polyalanine tract is solely extended by polyalanine expansions in PHOX2B, which are responsible for most congenital central hypoventilation syndrome cases. However, polyalanine expansions in PHOX2B additionally promote nascent homorepeat conformations that trigger length-dependent phase transitions into solid condensates that capture wild-type PHOX2B. Remarkably, HSP70 and HSP90 chaperones specifically seize PHOX2B alternative conformations preventing phase transitions. The precise observation of emerging polymorphs in expanded PHOX2B postulates unbalanced phase transitions as distinct pathophysiological mechanisms in homorepeat expansion diseases, paving the way towards the search of therapeutics modulating biomolecular condensates in central hypoventilation syndrome.
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Affiliation(s)
- Rosa Antón
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Miguel Á Treviño
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - David Pantoja-Uceda
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Sara Félix
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - María Babu
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
| | - Eurico J Cabrita
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
| | - Philip Tinnefeld
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Andrés M Vera
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Javier Oroz
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain.
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Manzo M, Serra A, Pedone E, Pirone L, Scognamiglio V, De Felice M, De Falco M. DNA Polymerase I Large Fragment from Deinococcus radiodurans, a Candidate for a Cutting-Edge Room-Temperature LAMP. Int J Mol Sci 2024; 25:1392. [PMID: 38338670 PMCID: PMC10855757 DOI: 10.3390/ijms25031392] [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: 12/21/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
In recent years, the loop-mediated isothermal amplification (LAMP) technique, designed for microbial pathogen detection, has acquired fundamental importance in the biomedical field, providing rapid and precise responses. However, it still has some drawbacks, mainly due to the need for a thermostatic block, necessary to reach 63 °C, which is the BstI DNA polymerase working temperature. Here, we report the identification and characterization of the DNA polymerase I Large Fragment from Deinococcus radiodurans (DraLF-PolI) that functions at room temperature and is resistant to various environmental stress conditions. We demonstrated that DraLF-PolI displays efficient catalytic activity over a wide range of temperatures and pH, maintains its activity even after storage under various stress conditions, including desiccation, and retains its strand-displacement activity required for isothermal amplification technology. All of these characteristics make DraLF-PolI an excellent candidate for a cutting-edge room-temperature LAMP that promises to be very useful for the rapid and simple detection of pathogens at the point of care.
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Affiliation(s)
- Marilena Manzo
- Institute of Bioscience and BioResources, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Assunta Serra
- Institute of Bioscience and BioResources, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Emilia Pedone
- Institute of Biostructures and Bioimaging, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Luciano Pirone
- Institute of Biostructures and Bioimaging, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Viviana Scognamiglio
- Institute of Crystallography, National Research Council, Department of Chemical Sciences and Materials Technologies, Via Salaria km 29.300, Monterotondo, 00015 Rome, Italy
| | - Mariarita De Felice
- Institute of Bioscience and BioResources, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Mariarosaria De Falco
- Institute of Bioscience and BioResources, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
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5
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Guan WL, Jiang LL, Yin XF, Hu HY. PABPN1 aggregation is driven by Ala expansion and poly(A)-RNA binding, leading to CFIm25 sequestration that impairs alternative polyadenylation. J Biol Chem 2023; 299:105019. [PMID: 37422193 PMCID: PMC10403730 DOI: 10.1016/j.jbc.2023.105019] [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: 03/08/2023] [Revised: 06/24/2023] [Accepted: 06/26/2023] [Indexed: 07/10/2023] Open
Abstract
Poly(A)-binding protein nuclear 1 (PABPN1) is an RNA-binding protein localized in nuclear speckles, while its alanine (Ala)-expanded variants accumulate as intranuclear aggregates in oculopharyngeal muscular dystrophy. The factors that drive PABPN1 aggregation and its cellular consequences remain largely unknown. Here, we investigated the roles of Ala stretch and poly(A) RNA in the phase transition of PABPN1 using biochemical and molecular cell biology methods. We have revealed that the Ala stretch controls its mobility in nuclear speckles, and Ala expansion leads to aggregation from the dynamic speckles. Poly(A) nucleotide is essential to the early-stage condensation that thereby facilitates speckle formation and transition to solid-like aggregates. Moreover, the PABPN1 aggregates can sequester CFIm25, a component of the pre-mRNA 3'-UTR processing complex, in an mRNA-dependent manner and consequently impair the function of CFIm25 in alternative polyadenylation. In conclusion, our study elucidates a molecular mechanism underlying PABPN1 aggregation and sequestration, which will be beneficial for understanding PABPN1 proteinopathy.
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Affiliation(s)
- Wen-Liang Guan
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Xiao-Fang Yin
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
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6
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Exploring the Molecular Interactions of Symmetrical and Unsymmetrical Selenoglycosides with Human Galectin-1 and Galectin-3. Int J Mol Sci 2022; 23:ijms23158273. [PMID: 35955408 PMCID: PMC9368490 DOI: 10.3390/ijms23158273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 11/16/2022] Open
Abstract
Galectins (Gals) are small cytosolic proteins that bind β-galactoside residues via their evolutionarily conserved carbohydrate recognition domain. Their dysregulation has been shown to be associated with many diseases. Consequently, targeting galectins for clinical applications has become increasingly relevant to develop tailored inhibitors selectively for one galectin. Accordingly, binding studies providing the molecular details of the interaction between galectin and inhibitor may be useful for the rational design of potent and selective antagonists. Gal-1 and Gal-3 are among the best-studied galectins, mainly for their roles in cancer progression; therefore, the molecular details of their interaction with inhibitors are demanded. This work gains more value by focusing on the interaction between Gal-1 and Gal-3 with the selenylated analogue of the Gal inhibitor thiodigalactose, characterized by a selenoglycoside bond (SeDG), and with unsymmetrical diglycosyl selenides (unsym(Se). Gal-1 and Gal-3 were produced heterologously and biophysically characterized. Interaction studies were performed by ITC, NMR spectroscopy, and MD simulation, and thermodynamic values were discussed and integrated with spectroscopic and computational results. The 3D complexes involving SeDG when interacting with Gal-1 and Gal-3 were depicted. Overall, the collected results will help identify hot spots for the design of new, better performing, and more specific Gal inhibitors.
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7
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Etonogestrel Administration Reduces the Expression of PHOX2B and Its Target Genes in the Solitary Tract Nucleus. Int J Mol Sci 2022; 23:ijms23094816. [PMID: 35563209 PMCID: PMC9101578 DOI: 10.3390/ijms23094816] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 11/17/2022] Open
Abstract
Heterozygous mutations of the transcription factor PHOX2B are responsible for Congenital Central Hypoventilation Syndrome, a neurological disorder characterized by inadequate respiratory response to hypercapnia and life-threatening hypoventilation during sleep. Although no cure is currently available, it was suggested that a potent progestin drug provides partial recovery of chemoreflex response. Previous in vitro data show a direct molecular link between progestins and PHOX2B expression. However, the mechanism through which these drugs ameliorate breathing in vivo remains unknown. Here, we investigated the effects of chronic administration of the potent progestin drug Etonogestrel (ETO) on respiratory function and transcriptional activity in adult female rats. We assessed respiratory function with whole-body plethysmography and measured genomic changes in brain regions important for respiratory control. Our results show that ETO reduced metabolic activity, leading to an enhanced chemoreflex response and concurrent increased breathing cycle variability at rest. Furthermore, ETO-treated brains showed reduced mRNA and protein expression of PHOX2B and its target genes selectively in the dorsal vagal complex, while other areas were unaffected. Histological analysis suggests that changes occurred in the solitary tract nucleus (NTS). Thus, we propose that the NTS, rich in both progesterone receptors and PHOX2B, is a good candidate for ETO-induced respiratory modulation.
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Di Lascio S, Benfante R, Cardani S, Fornasari D. Research Advances on Therapeutic Approaches to Congenital Central Hypoventilation Syndrome (CCHS). Front Neurosci 2021; 14:615666. [PMID: 33510615 PMCID: PMC7835644 DOI: 10.3389/fnins.2020.615666] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Congenital central hypoventilation syndrome (CCHS) is a genetic disorder of neurodevelopment, with an autosomal dominant transmission, caused by heterozygous mutations in the PHOX2B gene. CCHS is a rare disorder characterized by hypoventilation due to the failure of autonomic control of breathing. Until now no curative treatment has been found. PHOX2B is a transcription factor that plays a crucial role in the development (and maintenance) of the autonomic nervous system, and in particular the neuronal structures involved in respiratory reflexes. The underlying pathogenetic mechanism is still unclear, although studies in vivo and in CCHS patients indicate that some neuronal structures may be damaged. Moreover, in vitro experimental data suggest that transcriptional dysregulation and protein misfolding may be key pathogenic mechanisms. This review summarizes latest researches that improved the comprehension of the molecular pathogenetic mechanisms responsible for CCHS and discusses the search for therapeutic intervention in light of the current knowledge about PHOX2B function.
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Affiliation(s)
- Simona Di Lascio
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Roberta Benfante
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy.,CNR-Institute of Neuroscience, Milan, Italy.,NeuroMi-Milan Center for Neuroscience, University of Milano Bicocca, Milan, Italy
| | - Silvia Cardani
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy
| | - Diego Fornasari
- Department of Medical Biotechnology and Translational Medicine (BIOMETRA), Università degli Studi di Milano, Milan, Italy.,CNR-Institute of Neuroscience, Milan, Italy
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Herrera MG, Gómez Castro MF, Prieto E, Barrera E, Dodero VI, Pantano S, Chirdo F. Structural conformation and self-assembly process of p31-43 gliadin peptide in aqueous solution. Implications for celiac disease. FEBS J 2019; 287:2134-2149. [PMID: 31659864 DOI: 10.1111/febs.15109] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 09/06/2019] [Accepted: 10/25/2019] [Indexed: 12/13/2022]
Abstract
Celiac disease (CeD) is a highly prevalent chronic immune-mediated enteropathy developed in genetically predisposed individuals after ingestion of a group of wheat proteins (called gliadins and glutenins). The 13mer α-gliadin peptide, p31-43, induces proinflammatory responses, observed by in vitro assays and animal models, that may contribute to innate immune mechanisms of CeD pathogenesis. Since a cellular receptor for p31-43 has not been identified, this raises the question of whether this peptide could mediate different biological effects. In this work, we aimed to characterize the p31-43 secondary structure by different biophysical and in silico techniques. By dynamic light scattering and using an oligomer/fibril-sensitive fluorescent probe, we showed the presence of oligomers of this peptide in solution. Furthermore, atomic force microscopy analysis showed p31-43 oligomers with different height distribution. Also, peptide concentration had a very strong influence on peptide self-organization process. Oligomers gradually increased their size at lower concentration. Whereas, at higher ones, oligomers increased their complexity, forming branched structures. By CD, we observed that p31-43 self-organized in a polyproline II conformation in equilibrium with β-sheets-like structures, whose pH remained stable in the range of 3-8. In addition, these findings were supported by molecular dynamics simulation. The formation of p31-43 nanostructures with increased β-sheet structure may help to explain the molecular etiopathogenesis in the induction of proinflammatory effects and subsequent damage at the intestinal mucosa in CeD.
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Affiliation(s)
- María Georgina Herrera
- Instituto de Química y Fisicoquímica Biológicas - IQUIFIB (UBA-CONICET), Buenos Aires, Argentina
| | | | - Eduardo Prieto
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, UNLP-CONICET), La Plata, Argentina
| | | | | | - Sergio Pantano
- Institut Pasteur de Montevideo, Uruguay.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, China
| | - Fernando Chirdo
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, UNLP-CONICET), La Plata, Argentina
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