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Saintmont F, Hoyas S, Rosu F, Gabélica V, Brocorens P, Gerbaux P. Structural Characterization of Dendriplexes In Vacuo: A Joint Ion Mobility/Molecular Dynamics Investigation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1555-1568. [PMID: 35875874 DOI: 10.1021/jasms.2c00122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The combination between ion mobility mass spectrometry and molecular dynamics simulations is demonstrated for the first time to afford valuable information on structural changes undergone by dendriplexes containing ds-DNA and low-generation dendrimers when transferred from the solution to the gas phase. Dendriplex ions presenting 1:1 and 2:1 stoichiometries are identified using mass spectrometry experiments, and the collision cross sections (CCS) of the 1:1 ions are measured using drift time ion mobility experiments. Structural predictions using Molecular Dynamics (MD) simulations showed that gas-phase relevant structures, i.e., with a good match between the experimental and theoretical CCS, are generated when the global electrospray process is simulated, including the solvent molecule evaporation, rather than abruptly transferring the ions from the solution to the gas phase. The progressive migration of ammonium groups (either NH4+ from the buffer or protonated amines of the dendrimer) into the minor and major grooves of DNA all along the evaporation processes is shown to compact the DNA structure by electrostatic and hydrogen-bond interactions. The subsequent proton transfer from the ammonium (NH4+ or protonated amino groups) to the DNA phosphate groups allows creation of protonated phosphate/phosphate hydrogen bonds within the compact structures. MD simulations showed major structural differences between the dendriplexes in solution and in the gas phase, not only due to the loss of the solvent but also due to the proton transfers and the huge difference between the solution and gas-phase charge states.
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Affiliation(s)
- Fabrice Saintmont
- Organic Synthesis & Mass Spectrometry Laboratory, Interdisciplinary Center for Mass Spectrometry (CISMa), Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
- Laboratory for Chemistry of Novel Materials, Center of Innovation and Research in Materials and Polymers, Research Institute for Science and Engineering of Materials, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Sébastien Hoyas
- Organic Synthesis & Mass Spectrometry Laboratory, Interdisciplinary Center for Mass Spectrometry (CISMa), Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
- Laboratory for Chemistry of Novel Materials, Center of Innovation and Research in Materials and Polymers, Research Institute for Science and Engineering of Materials, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Frédéric Rosu
- Univ. Bordeaux, CNRS, INSERM, Institut Européen de Chimie et Biologie (IECB, UAR3033, US001), 2 rue Robert Escarpait, 33607 Pessac, France
| | - Valérie Gabélica
- Univ. Bordeaux, CNRS, INSERM, Institut Européen de Chimie et Biologie (IECB, UAR3033, US001), 2 rue Robert Escarpait, 33607 Pessac, France
- Univ. Bordeaux, INSERM, CNRS, Acides Nucléiques Régulations Naturelle et Artificielle (ARNA, U1212, UMR5320), IECB, 2 rue Robert Escarpit, 33607 Pessac, France
| | - Patrick Brocorens
- Laboratory for Chemistry of Novel Materials, Center of Innovation and Research in Materials and Polymers, Research Institute for Science and Engineering of Materials, University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
| | - Pascal Gerbaux
- Organic Synthesis & Mass Spectrometry Laboratory, Interdisciplinary Center for Mass Spectrometry (CISMa), Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons - UMONS, 23 Place du Parc, 7000 Mons, Belgium
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