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Ludwig N, Galindo C, Witjaksono C, Danvin A, Peaupardin P, Muller D, Kusumoto T, Kodaira S, Barillon R, Raffy Q. Radiolysis of myoglobin concentrated gels by protons: specific changes in secondary structure and production of carbon monoxide. Sci Rep 2024; 14:8625. [PMID: 38616193 PMCID: PMC11016545 DOI: 10.1038/s41598-024-58378-z] [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: 09/14/2023] [Accepted: 03/28/2024] [Indexed: 04/16/2024] Open
Abstract
While particle therapy has been used for decades for cancer treatment, there is still a lack of information on the molecular mechanisms of biomolecules radiolysis by accelerated ions. Here, we examine the effects of accelerated protons on highly concentrated native myoglobin, by means of Fourier transform infrared and UV-Visible spectroscopies. Upon irradiation, the secondary structure of the protein is drastically modified, from mostly alpha helices conformation to mostly beta elements at highest fluence. These changes are accompanied by significant production of carbon monoxide, which was shown to come from heme degradation under irradiation. The radiolytic yields of formation of denatured protein, carbon monoxide, and of heme degradation were determined, and found very close to each other: G+denatured Mb ≈ G+CO ≈ G-heme = 1.6 × 10-8 ± 0.1 × 10-8 mol/J = 0.16 ± 0.01 species/100 eV. The denaturation of the protein to a beta structure and the production of carbon monoxide under ion irradiation are phenomena that may play an important role in the biological effects of ionizing radiation.
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Affiliation(s)
- Nicolas Ludwig
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
- Aerial, Parc D'innovation, 250 Rue Laurent Fries, F-67400, Illkirch, France
| | - Catherine Galindo
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
| | - Clea Witjaksono
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
- Institut de Chimie, UMR 7177, Université de Strasbourg and CNRS, 4 rue Blaise Pascal, F-67070, Strasbourg, France
| | - Antoine Danvin
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
| | - Philippe Peaupardin
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
| | - Dominique Muller
- ICube, UMR7357, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
| | - Tamon Kusumoto
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Satoshi Kodaira
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Rémi Barillon
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France
| | - Quentin Raffy
- IPHC, UMR 7178, Université de Strasbourg and CNRS, 23 rue du Loess, F-67037, Strasbourg, France.
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Razumovitch JA, Fuchs D, Semenkova GN, Cherenkevich SN. Influence of neopterin on generation of reactive species by myeloperoxidase in human neutrophils. Biochim Biophys Acta Gen Subj 2004; 1672:46-50. [PMID: 15056492 DOI: 10.1016/j.bbagen.2004.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Revised: 01/08/2004] [Accepted: 02/17/2004] [Indexed: 11/28/2022]
Abstract
Increased neopterin concentrations in human serum indicate activation of cell-mediated immune response. Earlier we have shown that neopterin enhanced generation of singlet oxygen, hydroxyl radical and nitric oxide in human peripheral blood neutrophils by NADPH-independent pathways. To further investigate a participation of neopterin in reactive species production by neutrophils, we studied its influence on myeloperoxidase (MPO) activity. MPO was isolated from human peripheral blood neutrophils from healthy donors. Generation of reactive species by MPO/H(2)O(2) in Earl's solution (pH=7.2) at 37 degrees C was investigated by monitoring of chemiluminescence using luminol as light emitter. In the MPO/H(2)O(2) system, neopterin increased singlet oxygen in a concentration-dependent manner, but it decreased formation of other oxidizing species. Comparing several oxygen scavengers, formation of reactive species was totally blocked by sodium azide (NaN(3)), both in the presence and in the absence of neopterin. Superoxide dismutase (SOD) and d-mannitol insignificantly decreased chemiluminescence of this reaction, but diazabicyclo[2.2.2]octane (DABCO) strongly inhibited it. We conclude that the effects of neopterin on neutrophils' MPO are directed to increase singlet oxygen and to decrease other reactive species via inhibition of MPO and/or scavenging of reactive species.
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Affiliation(s)
- Julia A Razumovitch
- Department of Biophysics, Physics Faculty, Belarusian State University, Scoryny Avenue 4, 220050 Minsk, Belarus.
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