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Wan J, Brož B, Liu Y, Huang SR, Marek A, Tureček F. The DNA Radical Code. Resolution of Identity in Dissociations of Trinucleotide Codon Cation Radicals in the Gas Phase. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:304-319. [PMID: 36596259 DOI: 10.1021/jasms.2c00322] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Sixty DNA trinucleotide cation radicals covering a large part of the genetic code alphabet were generated by electron transfer in the gas phase, and their chemistry was studied by collision-induced dissociation tandem mass spectrometry and theoretical calculations. The major dissociations involved loss of nucleobase molecules and radicals, backbone cleavage, and cross-ring fragmentations that depended on the nature and position of the nucleobases. Mass identity in dissociations of symmetrical trinucleotide cation radicals of the (XXX+2H)+• and (XYX+2H)+• type was resolved by specific 15N labeling. The specific features of trinucleotide cation radical dissociations involved the dominant formation of d2+ ions, hydrogen atom migrations accompanying the formation of (w2+H)+•, (w2+2H)+, and (d2+2H)+ sequence ions, and cross-ring cleavages in the 3'- and 5'-deoxyribose moieties that depended on the nucleobase type and its position in the ion. Born-Oppenheimer molecular dynamics (BOMD) and density functional theory calculations were used to obtain structures and energies of several cation-radical protomers and conformers for (AAA+2H)+•, (CCC+2H)+•, (GGG+2H)+•, (ACA+2H)+•, and (CAA+2H)+• that were representative of the different types of backbone dissociations. The ion electronic structure, protonation and radical sites, and hydrogen bonding were used to propose reaction mechanisms for the dissociations.
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Affiliation(s)
- Jiahao Wan
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Břetislav Brož
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - Yue Liu
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Shu R Huang
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - František Tureček
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
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Wan J, Brož B, Liu Y, Huang SR, Marek A, Tureček F. Resolution of Identity in Gas-Phase Dissociations of Mono- and Diprotonated DNA Trinucleotide Codons by 15N-Labeling and Computational Structure Analysis. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1936-1950. [PMID: 36040435 DOI: 10.1021/jasms.2c00194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Dissociations of DNA trinucleotide codons as gas-phase singly and doubly protonated ions were studied by tandem mass spectrometry using 15N-labeling to resolve identity in the nucleobase loss and backbone cleavages. The monocations showed different distributions of nucleobase loss from the 5'-, middle, and 3'-positions depending on the nucleobase, favoring cytosine over guanine, adenine, and thymine in an ensemble-averaged 62:27:11:<1 ratio. The distribution for the loss of the 5'-, middle, and 3'-nucleobase was 49:18:33, favoring the 5'-nucleobase, but also depending on its nature. The formation of sequence w2+ ions was unambiguously established for all codon mono- and dications. Structures of low-Gibbs-energy protomers and conformers of dAAA+, dGGG+, dCCC+, dTTT+, dACA+, and dATC+ were established by Born-Oppenheimer molecular dynamics and density functional theory calculations. Monocations containing guanine favored classical structures protonated at guanine N7. Structures containing adenine and cytosine produced classical nucleobase-protonated isomers as well as zwitterions in which two protonated bases were combined with a phosphate anion. Protonation at thymine was disfavored. Low threshold energies for nucleobase loss allowed extensive proton migration to occur prior to dissociation. Loss of the nucleobase from monocations was assisted by neighboring group participation in nucleophilic addition or proton abstraction, as well as allosteric proton migrations remote from the reaction center. The optimized structures of diprotonated isomers for dAAA2+ and dACA2+ revealed combinations of classical and zwitterionic structures. The threshold and transition-state energies for nucleobase-ion loss from dications were low, resulting in facile dissociations involving cytosine, guanine, and adenine.
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Affiliation(s)
- Jiahao Wan
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Břetislav Brož
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - Yue Liu
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Shu R Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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Tang WK, Mu X, Li M, Martens J, Berden G, Oomens J, Chu IK, Siu CK. Formation of n → π + interaction facilitating dissociative electron transfer in isolated tyrosine-containing molecular peptide radical cations. Phys Chem Chem Phys 2021; 22:21393-21402. [PMID: 32940309 DOI: 10.1039/d0cp00533a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Long-range electron transfer in proteins can be rationalized as a sequential short-distance electron-hopping processes via amino acid residues having low ionization energy as relay stations. Tyrosine residues can serve as such redox-active intermediates through one-electron oxidation to form a π-radical cation at its phenol side chain. An electron transfer from a vicinal functional group to this π-electron hole completes an elementary step of charge migration. However, transient oxidized/reduced intermediates formed at those relay stations during electron transfer processes have not been observed. In this study, formation of analog reactive intermediates via electron donor-acceptor coupling is observed by using IRMPD action spectroscopy. An elementary charge migration at the molecular level in model tyrosine-containing peptide radical cations [M]˙+ in the gas phase is revealed with its unusual Cα-Cβ bond cleavage at the side chain of the N-terminal residue. This reaction is induced by the radical character of the N-terminal amino group (-NH2˙+) resulting from an n → π+ interaction between the nonbonding electron pair of NH2 (n) and the π-electron hole at the Tyr side chain (π+). The formation of -NH2˙+ is supported by the IRMPD spectrum showing a characteristic NH2 scissor vibration coupled with Tyr side-chain stretches at 1577 cm-1. This n → π+ interaction facilitates a dissociative electron transfer with NH2 as the relay station. The occurrence of this side-chain cleavage may be an indicator of the formation of reactive conformers featuring the n → π+ interaction.
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Affiliation(s)
- Wai Kit Tang
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China.
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4
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Omidyan R, Abedini F, Shahrokh L, Azimi G. Excited State Deactivation Mechanism in Protonated Uracil: New Insights from Theoretical Studies. J Phys Chem A 2020; 124:5089-5097. [PMID: 32469520 DOI: 10.1021/acs.jpca.0c02284] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We have conducted here a theoretical exploration, discussing the distinct excited state lifetimes reported experimentally for the two lowest lying protonated isomers of uracil. In this regard, the first-principal computational levels as well as the nonadiabatic surface hopping dynamics have been employed. It has been revealed that relaxation of the 1ππ* state of enol-enol form (EE+) to the ground is barrier-free via out-of-plane coordinates, resulting in an ultrashort S1 lifetime of this species. For the second most stable isomer (EK+), however, a significant barrier predicted in the CASPT2 S1 potential energy profile along the twisting coordinate has been proposed to explain the relevant long lifetime reported experimentally.
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Affiliation(s)
- Reza Omidyan
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
| | - Fatemeh Abedini
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
| | - Leila Shahrokh
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
| | - Gholamhassan Azimi
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
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He CC, Hamlow LA, Zhu Y, Nei YW, Fan L, McNary CP, Maître P, Steinmetz V, Schindler B, Compagnon I, Armentrout PB, Rodgers MT. Structural and Energetic Effects of O2'-Ribose Methylation of Protonated Pyrimidine Nucleosides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2318-2334. [PMID: 31435890 DOI: 10.1007/s13361-019-02300-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/18/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
The 2'-substituents distinguish DNA from RNA nucleosides. 2'-O-methylation occurs naturally in RNA and plays important roles in biological processes. Such 2'-modifications may alter the hydrogen-bonding interactions of the nucleoside and thus may affect the conformations of the nucleoside in an RNA chain. Structures of the protonated 2'-O-methylated pyrimidine nucleosides were examined by infrared multiple photon dissociation (IRMPD) action spectroscopy, assisted by electronic structure calculations. The glycosidic bond stabilities of the protonated 2'-O-methylated pyrimidine nucleosides, [Nuom+H]+, were also examined and compared to their DNA and RNA nucleoside analogues via energy-resolved collision-induced dissociation (ER-CID). The preferred sites of protonation of the 2'-O-methylated pyrimidine nucleosides parallel their canonical DNA and RNA nucleoside analogues, [dNuo+H]+ and [Nuo+H]+, yet their nucleobase orientation and sugar puckering differ. The glycosidic bond stabilities of the protonated pyrimidine nucleosides follow the order: [dNuo+H]+ < [Nuo+H]+ < [Nuom+H]+. The slightly altered structures help explain the stabilization induced by 2'-O-methylation of the pyrimidine nucleosides.
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Affiliation(s)
- C C He
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - L A Hamlow
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Y Zhu
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Y-W Nei
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - L Fan
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - C P McNary
- Department of Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - P Maître
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS, Université Paris Saclay, 91405, Orsay, France
| | - V Steinmetz
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS, Université Paris Saclay, 91405, Orsay, France
| | - B Schindler
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France
| | - I Compagnon
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France
| | - P B Armentrout
- Department of Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - M T Rodgers
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA.
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Ponikvar-Svet M, Zeiger DN, Liebman JF. Interplay of thermochemistry and Structural Chemistry: the journal (volume 29, 2018, issues 5–6) and the discipline. Struct Chem 2019. [DOI: 10.1007/s11224-019-01398-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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7
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Hamlow LA, Nei YW, Wu RR, Gao J, Steill JD, Berden G, Oomens J, Rodgers MT. Impact of Sodium Cationization on Gas-Phase Conformations of DNA and RNA Cytidine Mononucleotides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1758-1767. [PMID: 31286444 DOI: 10.1007/s13361-019-02274-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 06/09/2023]
Abstract
Gas-phase conformations of the sodium-cationized forms of the 2'-deoxycytidine and cytidine mononucleotides, [pdCyd+Na]+ and [pCyd+Na]+, are examined by infrared multiple photon dissociation action spectroscopy. Complimentary electronic structure calculations at the B3LYP/6-311+G(2d,2p)//B3LYP/6-311+G(d,p) level of theory provide candidate conformations and their respective predicted IR spectra for comparison across the IR fingerprint and hydrogen-stretching regions. Comparisons of the predicted IR spectra and the measured infrared multiple photon dissociation action spectra provide insight into the impact of sodium cationization on intrinsic mononucleotide structure. Further, comparison of present results with those reported for the sodium-cationized cytidine nucleoside analogues elucidates the impact of the phosphate moiety on gas-phase structure. Across the neutral, protonated, and sodium-cationized cytidine mononucleotides, a preference for stabilization of the phosphate moiety and nucleobase orientation is observed, although the details of this stabilization differ with the state of cationization. Several low-energy conformations of [pdCyd+Na]+ and [pCyd+Na]+ involving several different orientations of the phosphate moiety and sugar puckering modes are observed experimentally.
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Affiliation(s)
- L A Hamlow
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI, 48202, USA
| | - Y-W Nei
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI, 48202, USA
| | - R R Wu
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI, 48202, USA
| | - J Gao
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, Netherlands
| | - J D Steill
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, Netherlands
| | - G Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, Netherlands
| | - J Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, Netherlands
| | - M T Rodgers
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI, 48202, USA.
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Fuchs E, Falschlunger C, Micura R, Breuker K. The effect of adenine protonation on RNA phosphodiester backbone bond cleavage elucidated by deaza-nucleobase modifications and mass spectrometry. Nucleic Acids Res 2019; 47:7223-7234. [PMID: 31276590 PMCID: PMC6698743 DOI: 10.1093/nar/gkz574] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/15/2019] [Accepted: 06/21/2019] [Indexed: 12/14/2022] Open
Abstract
The catalytic strategies of small self-cleaving ribozymes often involve interactions between nucleobases and the ribonucleic acid (RNA) backbone. Here we show that multiply protonated, gaseous RNA has an intrinsic preference for the formation of ionic hydrogen bonds between adenine protonated at N3 and the phosphodiester backbone moiety on its 5'-side that facilitates preferential phosphodiester backbone bond cleavage upon vibrational excitation by low-energy collisionally activated dissociation. Removal of the basic N3 site by deaza-modification of adenine was found to abrogate preferential phosphodiester backbone bond cleavage. No such effects were observed for N1 or N7 of adenine. Importantly, we found that the pH of the solution used for generation of the multiply protonated, gaseous RNA ions by electrospray ionization affects phosphodiester backbone bond cleavage next to adenine, which implies that the protonation patterns in solution are at least in part preserved during and after transfer into the gas phase. Our study suggests that interactions between protonated adenine and phosphodiester moieties of RNA may play a more important mechanistic role in biological processes than considered until now.
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Affiliation(s)
- Elisabeth Fuchs
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Christoph Falschlunger
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Kathrin Breuker
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
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9
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Devereaux ZJ, He CC, Zhu Y, Roy HA, Cunningham NA, Hamlow LA, Berden G, Oomens J, Rodgers MT. Structures and Relative Glycosidic Bond Stabilities of Protonated 2'-Fluoro-Substituted Purine Nucleosides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1521-1536. [PMID: 31111413 DOI: 10.1007/s13361-019-02222-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
The 2'-substituent is the primary distinguishing feature between DNA and RNA nucleosides. Modifications to this critical position, both naturally occurring and synthetic, can produce biologically valuable nucleoside analogues. The unique properties of fluorine make it particularly interesting and medically useful as a synthetic nucleoside modification. In this work, the effects of 2'-fluoro modification on the protonated gas-phase purine nucleosides are examined using complementary tandem mass spectrometry and computational methods. Direct comparisons are made with previous studies on related nucleosides. Infrared multiple photon dissociation action spectroscopy performed in both the fingerprint and hydrogen-stretching regions allows for the determination of the experimentally populated conformations. The populated conformers of protonated 2'-fluoro-2'-deoxyadenosine, [Adofl+H]+, and 2'-fluoro-2'-deoxyguanosine, [Guofl+H]+, are highly parallel to their respective canonical DNA and RNA counterparts. Both N3 and N1 protonation sites are accessed by [Adofl+H]+, stabilizing syn and anti nucleobase orientations, respectively. N7 protonation and anti nucleobase orientation dominates in [Guofl+H]+. Spectroscopically observable intramolecular hydrogen-bonding interactions with fluorine allow more definitive sugar puckering determinations than possible for the canonical systems. [Adofl+H]+ adopts C2'-endo sugar puckering, whereas [Guofl+H]+ adopts both C2'-endo and C3'-endo sugar puckering. Energy-resolved collision-induced dissociation experiments with survival yield analyses provide relative glycosidic bond stabilities. The N-glycosidic bond stabilities of the protonated 2'-fluoro-substituted purine nucleosides are found to exceed those of their canonical analogues. Further, the N-glycosidic bond stability is found to increase with increasing electronegativity of the 2'-substituent, i.e., H < OH < F. The N-glycosidic bond stability is also greater for the adenine nucleoside analogues than the guanine nucleoside analogues.
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Affiliation(s)
- Zachary J Devereaux
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - C C He
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - Y Zhu
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - H A Roy
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - N A Cunningham
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - L A Hamlow
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - G Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - J Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - M T Rodgers
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA.
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Vandavasi VG, Blakeley MP, Keen DA, Hu LR, Huang Z, Kovalevsky A. Temperature-Induced Replacement of Phosphate Proton with Metal Ion Captured in Neutron Structures of A-DNA. Structure 2018; 26:1645-1650.e3. [PMID: 30244969 PMCID: PMC6281803 DOI: 10.1016/j.str.2018.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/02/2018] [Accepted: 08/01/2018] [Indexed: 11/18/2022]
Abstract
Nucleic acids can fold into well-defined 3D structures that help determine their function. Knowing precise nucleic acid structures can also be used for the design of nucleic acid-based therapeutics. However, locations of hydrogen atoms, which are key players of nucleic acid function, are normally not determined with X-ray crystallography. Accurate determination of hydrogen atom positions can provide indispensable information on protonation states, hydrogen bonding, and water architecture in nucleic acids. Here, we used neutron crystallography in combination with X-ray diffraction to obtain joint X-ray/neutron structures at both room and cryo temperatures of a self-complementary A-DNA oligonucleotide d[GTGG(CSe)CAC]2 containing 2'-SeCH3 modification on Cyt5 (CSe) at pH 5.6. We directly observed protonation of a backbone phosphate oxygen of Ade7 at room temperature. The proton is replaced with hydrated Mg2+ upon cooling the crystal to 100 K, indicating that metal binding is favored at low temperature, whereas proton binding is dominant at room temperature.
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Affiliation(s)
- Venu Gopal Vandavasi
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37922, USA
| | - Matthew P Blakeley
- Large Scale Structures Group, Institut Laue-Langevin, Grenoble 38000, France
| | - David A Keen
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | | | - Zhen Huang
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.
| | - Andrey Kovalevsky
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37922, USA.
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11
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van Outersterp RE, Martens J, Berden G, Steill JD, Oomens J, Rijs AM. Structural characterization of nucleotide 5'-triphosphates by infrared ion spectroscopy and theoretical studies. Phys Chem Chem Phys 2018; 20:28319-28330. [PMID: 30398499 DOI: 10.1039/c8cp03314e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The molecular family of nucleotide triphosphates (NTPs), with adenosine 5'-triphosphate (ATP) as its best-known member, is of high biochemical importance as their phosphodiester bonds form Nature's main means to store and transport energy. Here, gas-phase IR spectroscopic studies and supporting theoretical studies have been performed on adenosine 5'-triphosphate, cytosine 5'-triphosphate and guanosine 5'-triphosphate to elucidate the intrinsic structural properties of NTPs, focusing on the influence of the nucleobase and the extent of deprotonation. Mass spectrometric studies involving collision induced dissociation showed similar fragmentation channels for the three studied NTPs within a selected charge state. The doubly charged anions exhibit fragmentation similar to the energy-releasing hydrolysis reaction in nature, while the singly charged anions show different dominant fragmentation channels, suggesting that the charge state plays a significant role in the favorability of the hydrolysis reaction. A combination of infrared ion spectroscopy and quantum-chemical computations indicates that the singly charged anions of all NTPs are preferentially deprotonated at their β-phosphates, while the doubly-charged anions are dominantly αβ-deprotonated. The assigned three-dimensional structure differs for ATP and CTP on the one hand and GTP on the other, in the sense that ATP and CTP show no interaction between nucleobase and phosphate tail, while in GTP they are hydrogen bonded. This can be rationalized by considering the structure and geometry of the NTPs where the final three dimensional structure depends on a subtle balance between hydrogen bond strength, flexibility and steric hindrance.
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Affiliation(s)
- Rianne E van Outersterp
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525ED, Nijmegen, The Netherlands.
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12
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He CC, Hamlow LA, Devereaux ZJ, Zhu Y, Nei YW, Fan L, McNary CP, Maitre P, Steinmetz V, Schindler B, Compagnon I, Armentrout PB, Rodgers MT. Structural and Energetic Effects of O2'-Ribose Methylation of Protonated Purine Nucleosides. J Phys Chem B 2018; 122:9147-9160. [PMID: 30203656 DOI: 10.1021/acs.jpcb.8b07687] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The chemical difference between DNA and RNA nucleosides is their 2'-hydrogen versus 2'-hydroxyl substituents. Modification of the ribosyl moiety at the 2'-position and 2'-O-methylation in particular, is common among natural post-transcriptional modifications of RNA. 2'-Modification may alter the electronic properties and hydrogen-bonding characteristics of the nucleoside and thus may lead to enhanced stabilization or malfunction. The structures and relative glycosidic bond stabilities of the protonated forms of the 2'-O-methylated purine nucleosides, 2'-O-methyladenosine (Adom) and 2'-O-methylguanosine (Guom), were examined using two complementary tandem mass spectrometry approaches, infrared multiple photon dissociation action spectroscopy and energy-resolved collision-induced dissociation. Theoretical calculations were also performed to predict the structures and relative stabilities of stable low-energy conformations of the protonated forms of the 2'-O-methylated purine nucleosides and their infrared spectra in the gas phase. Low-energy conformations highly parallel to those found for the protonated forms of the canonical DNA and RNA purine nucleosides are also found for the protonated 2'-O-methylated purine nucleosides. Importantly, the preferred site of protonation, nucleobase orientation, and sugar puckering are preserved among the DNA, RNA, and 2'-O-methylated variants of the protonated purine nucleosides. The 2'-substituent does however influence hydrogen-bond stabilization as the 2'-O-methyl and 2'-hydroxyl substituents enable a hydrogen-bonding interaction between the 2'- and 3'-substituents, whereas a 2'-hydrogen atom does not. Further, 2'-O-methylation reduces the number of stable low-energy hydrogen-bonded conformations possible and importantly inverts the preferred polarity of this interaction versus that of the RNA analogues. Trends in the CID50% values extracted from survival yield analyses of the 2'-O-methylated and canonical DNA and RNA forms of the protonated purine nucleosides are employed to elucidate their relative glycosidic bond stabilities. The glycosidic bond stability of Adom is found to exceed that of its DNA and RNA analogues. The glycosidic bond stability of Guom is also found to exceed that of its DNA analogue; however, this modification weakens this bond relative to its RNA counterpart. The glycosidic bond stability of the protonated purine nucleosides appears to be correlated with the hydrogen-bond stabilization of the sugar moiety.
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Affiliation(s)
- C C He
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - L A Hamlow
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - Zachary J Devereaux
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - Y Zhu
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - Y-W Nei
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - L Fan
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
| | - C P McNary
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - P Maitre
- Laboratoire de Chimie Physique (UMR8000), CNRS, Université Paris-Sud, Université Paris-Saclay , 91405 Orsay , France
| | - V Steinmetz
- Laboratoire de Chimie Physique (UMR8000), CNRS, Université Paris-Sud, Université Paris-Saclay , 91405 Orsay , France
| | - B Schindler
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière , F-69622 Villeurbanne , France
| | - I Compagnon
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière , F-69622 Villeurbanne , France
| | - P B Armentrout
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - M T Rodgers
- Department of Chemistry , Wayne State University , Detroit , Michigan 48202 , United States
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