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D'Arco A, Di Fabrizio M, Mancini T, Mosetti R, Macis S, Tranfo G, Della Ventura G, Marcelli A, Petrarca M, Lupi S. Secondary Structures of MERS-CoV, SARS-CoV, and SARS-CoV-2 Spike Proteins Revealed by Infrared Vibrational Spectroscopy. Int J Mol Sci 2023; 24:ijms24119550. [PMID: 37298500 DOI: 10.3390/ijms24119550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/28/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
All coronaviruses are characterized by spike glycoproteins whose S1 subunits contain the receptor binding domain (RBD). The RBD anchors the virus to the host cellular membrane to regulate the virus transmissibility and infectious process. Although the protein/receptor interaction mainly depends on the spike's conformation, particularly on its S1 unit, their secondary structures are poorly known. In this paper, the S1 conformation was investigated for MERS-CoV, SARS-CoV, and SARS-CoV-2 at serological pH by measuring their Amide I infrared absorption bands. The SARS-CoV-2 S1 secondary structure revealed a strong difference compared to those of MERS-CoV and SARS-CoV, with a significant presence of extended β-sheets. Furthermore, the conformation of the SARS-CoV-2 S1 showed a significant change by moving from serological pH to mild acidic and alkaline pH conditions. Both results suggest the capability of infrared spectroscopy to follow the secondary structure adaptation of the SARS-CoV-2 S1 to different environments.
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Affiliation(s)
- Annalisa D'Arco
- Laboratori Nazionali Frascati, National Institute for Nuclear Physics (INFN-LNF), Via E. Fermi 54, 00044 Frascati, Italy
- Department of Physics, University of Rome 'La Sapienza', P.le A. Moro 2, 00185 Rome, Italy
| | - Marta Di Fabrizio
- Laboratory of Biological Electron Microscopy, School of Basic Sciences, Institute of Physics, EPFL & Department of Fundamental Microbiology, Faculty of Biology and Medicine, UNIL, 1015 Lausanne, Switzerland
| | - Tiziana Mancini
- Department of Physics, University of Rome 'La Sapienza', P.le A. Moro 2, 00185 Rome, Italy
| | - Rosanna Mosetti
- Department of Physics, University of Rome 'La Sapienza', P.le A. Moro 2, 00185 Rome, Italy
| | - Salvatore Macis
- Department of Physics, University of Rome 'La Sapienza', P.le A. Moro 2, 00185 Rome, Italy
| | - Giovanna Tranfo
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Monte Porzio Catone, 00078 Rome, Italy
| | - Giancarlo Della Ventura
- Laboratori Nazionali Frascati, National Institute for Nuclear Physics (INFN-LNF), Via E. Fermi 54, 00044 Frascati, Italy
- Department of Science, University Rome Tre, Largo San Leonardo Murialdo 1, 00146 Rome, Italy
| | - Augusto Marcelli
- Laboratori Nazionali Frascati, National Institute for Nuclear Physics (INFN-LNF), Via E. Fermi 54, 00044 Frascati, Italy
- Rome International Centre for Materials Science Superstipes, Via dei Sabelli 119A, 00185 Rome, Italy
| | - Massimo Petrarca
- National Institute for Nuclear Physics Section Rome1, P.le A. Moro 2, 00185 Rome, Italy
- Department of Basic and Applied Sciences for Engineering (SBAI), University of Rome 'La Sapienza', Via Scarpa 16, 00161 Rome, Italy
| | - Stefano Lupi
- Department of Physics, University of Rome 'La Sapienza', P.le A. Moro 2, 00185 Rome, Italy
- National Institute for Nuclear Physics Section Rome1, P.le A. Moro 2, 00185 Rome, Italy
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Evaluation of Proton-Induced Biomolecular Changes in MCF-10A Breast Cells by Means of FT-IR Microspectroscopy. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12105074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Radiotherapy (RT) with accelerated beams of charged particles (protons and carbon ions), also known as hadrontherapy, is a treatment modality that is increasingly being adopted thanks to the several benefits that it grants compared to conventional radiotherapy (CRT) treatments performed by means of high-energy photons/electrons. Hence, information about the biomolecular effects in exposed cells caused by such particles is needed to better realize the underlying radiobiological mechanisms and to improve this therapeutic strategy. To this end, Fourier transform infrared microspectroscopy (μ-FT-IR) can be usefully employed, in addition to long-established radiobiological techniques, since it is currently considered a helpful tool for examining radiation-induced cellular changes. In the present study, MCF-10A breast cells were chosen to evaluate the effects of proton exposure using μ-FT-IR. They were exposed to different proton doses and fixed at various times after exposure to evaluate direct effects due to proton exposure and the kinetics of DNA damage repair. Irradiated and control cells were examined in transflection mode using low-e substrates that have been recently demonstrated to offer a fast and direct way to examine proton-exposed cells. The acquired spectra were analyzed using a deconvolution procedure and a ratiometric approach, both of which showed the different contributions of DNA, protein, lipid, and carbohydrate cell components. These changes were particularly significant for cells fixed 48 and 72 h after exposure. Lipid changes were related to variations in membrane fluidity, and evidence of DNA damage was highlighted. The analysis of the Amide III band also indicated changes that could be related to different enzyme contributions in DNA repair.
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