1
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DeFiglia SA, Szot CW, Håkansson K. Negative-Ion Electron Capture Dissociation of MALDI-Generated Peptide Anions. Anal Chem 2024; 96:8800-8806. [PMID: 38742421 DOI: 10.1021/acs.analchem.4c01292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Negative-ion electron capture dissociation (niECD) is an anion MS/MS technique that provides fragmentation analogous to conventional ECD, including high peptide sequence coverage and retention of labile post-translational modifications (PTMs). niECD has been proposed to be the most efficient for salt-bridged zwitterionic precursor ion structures. Several important PTMs, e.g., sulfation and phosphorylation, are acidic and can, therefore, be challenging to characterize in the positive-ion mode. Furthermore, PTM-friendly techniques, such as ECD, require multiple precursor ion-positive charges. By contrast, singly charged ions, refractory to ECD, are most compatible with niECD. Because electrospray ionization (ESI) typically yields multiply charged ions, we sought to explore matrix-assisted laser desorption/ionization (MALDI) in combination with niECD. However, the requirement for zwitterionic gaseous structures may preclude efficient niECD of MALDI-generated anions. Unexpectedly, we found that niECD of anions from MALDI is not only possible but proceeds with similar or higher efficiency compared with ESI-generated anions. Matrix selection did not appear to have a major effect. With MALDI, niECD is demonstrated up to m/z ∼4300. For such larger analytes, multiple electron captures are observed, resulting in triply charged fragments from singly charged precursor ions. Such charge-increased fragments show improved detectability. Furthermore, significantly improved (∼20-fold signal-to-noise increase) niECD spectral quality is achieved with equivalent sample amounts from MALDI vs ESI. Overall, the reported combination with MALDI significantly boosts the analytical utility of niECD.
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Affiliation(s)
- Steven A DeFiglia
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Carson W Szot
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Kristina Håkansson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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2
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Damont A, Legrand A, Cao C, Fenaille F, Tabet JC. Hydrogen/deuterium exchange mass spectrometry in the world of small molecules. MASS SPECTROMETRY REVIEWS 2023; 42:1300-1331. [PMID: 34859466 DOI: 10.1002/mas.21765] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 06/07/2023]
Abstract
The combined use of hydrogen/deuterium exchange (HDX) and mass spectrometry (MS), referred to as HDX-MS, is a powerful tool for exploring molecular edifices and has been used for over 60 years. Initially for structural and mechanistic investigation of low-molecular weight organic compounds, then to study protein structure and dynamics, then, the craze to study small molecules by HDX-MS accelerated and has not stopped yet. The purpose of this review is to present its different facets with particular emphasis on recent developments and applications. Reversible H/D exchanges of mobilizable protons as well as stable exchanges of non-labile hydrogen are considered whether they are taking place in solution or in the gas phase, or enzymatically in a biological media. Some fundamental principles are restated, especially for gas-phase processes, and an overview of recent applications, ranging from identification to quantification through the study of metabolic pathways, is given.
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Affiliation(s)
- Annelaure Damont
- Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Anaïs Legrand
- Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Chenqin Cao
- Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - François Fenaille
- Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Jean-Claude Tabet
- Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
- Faculté des Sciences et de l'Ingénierie, Institut Parisien de Chimie Moléculaire (IPCM), Sorbonne Université, Paris, France
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3
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Crespi S, Vadivel D, Bellisario A, Dondi D. Computational Study of the Stability of Natural Amino Acid isomers. ORIGINS LIFE EVOL B 2021; 51:287-298. [PMID: 34739664 DOI: 10.1007/s11084-021-09615-2] [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: 04/14/2021] [Accepted: 08/10/2021] [Indexed: 10/19/2022]
Abstract
The secular debate on the origin of life on our planet represents one of the open challenges for the scientific community. In this endeavour, chemistry has a pivotal role in disclosing novel scenarios that allow us to understand how the formation of simple organic molecules would be possible in the early primitive geological ages of Earth. Amino acids play a crucial role in biological processes. They are known to be formed in experiments simulating primitive conditions and were found in meteoric samples retrieved throughout the years. Understanding their formation is a key step for prebiotic chemistry. Following this reasoning, we performed a computational investigation over 100'000 structural isomers of natural amino acids. The results we have found suggest that natural amino acids are among the most thermodynamically stable structures and, therefore, one of the most probable ones to be synthesised among their possible isomers.
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Affiliation(s)
- Stefano Crespi
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Dhanalakshmi Vadivel
- Dipartimento Di Chimica, Università Di Pavia, Via Taramelli 12, 27100, Pavia, Italy. .,Istituto Nazionale Di Fisica Nucleare (INFN), Via Bassi 6, 27100, Pavia, Italy.
| | - Alfredo Bellisario
- Department of Cell and Molecular Biology, Molecular Biophysics, Husargatan 3, 752 37, Uppsala, Sweden
| | - Daniele Dondi
- Dipartimento Di Chimica, Università Di Pavia, Via Taramelli 12, 27100, Pavia, Italy.,Istituto Nazionale Di Fisica Nucleare (INFN), Via Bassi 6, 27100, Pavia, Italy
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4
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Darii E, Gimbert Y, Alves S, Damont A, Perret A, Woods AS, Fenaille F, Tabet JC. First Direct Evidence of Interpartner Hydride/Deuteride Exchanges for Stored Sodiated Arginine/Fructose-6-phosphate Complex Anions within Salt-Solvated Structures. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1424-1440. [PMID: 33929837 DOI: 10.1021/jasms.1c00040] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Mass spectrometric investigations of noncovalent binding between low molecular weight compounds revealed the existence of gas-phase (GP) noncovalent complex (NCC) ions involving zwitterionic structures. ESI MS is used to prove the formation of stable sodiated NCC anions between fructose (F6P) and arginine (R) moieties. Theoretical calculations indicate a folded solvated salt (i.e., sodiated carboxylate interacting with phosphate) rather than a charge-solvated form. Under standard CID conditions, [(F6P+R-H+Na)-H]- competitively forms two major product ions (PIs) through partner splitting [(R-H+Na) loss] and charge-induced cross-ring cleavage while preserving the noncovalent interactions (noncovalent product ions (NCPIs)). MS/MS experiments combined with in-solution proton/deuteron exchanges (HDXs) demonstrated an unexpected labeling of PIs, i.e., a correlated D-enrichment/D-depletion. An increase in activation time up to 3000 ms favors such processes when limited to two H/D exchanges. These results are rationalized by interpartner hydride/deuteride exchanges (⟨HDX⟩) through stepwise isomerization/dissociation of sodiated NCC-d11 anions. In addition, the D-enrichment/D-depletion discrepancy is further explained by back HDX with residual water in LTQ (selective for the isotopologue NCPIs as shown by PI relaxation experiments). Each isotopologue leads to only one back HDX unlike multiple HDXs generally observed in GP. This behavior shows that NCPIs are zwitterions with charges solvated by a single water molecule, thus generating a back HDX through a relay mechanism, which quenches the charges and prevents further back HDX. By estimating back HDX impact on D-depletion, the interpartner ⟨HDX⟩ complementarity was thus illustrated. This is the first description of interpartner ⟨HDX⟩ and selective back HDX validating salt-solvated structures.
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Affiliation(s)
- Ekaterina Darii
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057 Evry, France
| | - Yves Gimbert
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, 38058 Grenoble, France
- Sorbonne Université, Faculté des Sciences et de l'Ingénierie, Institut Parisien de Chimie Moléculaire (IPCM), F-75005 Paris, France
| | - Sandra Alves
- Sorbonne Université, Faculté des Sciences et de l'Ingénierie, Institut Parisien de Chimie Moléculaire (IPCM), F-75005 Paris, France
| | - Annelaure Damont
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, F-91191 Gif sur Yvette, France
| | - Alain Perret
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057 Evry, France
| | - Amina S Woods
- NIDA IRP, NIH Structural Biology Unit Cellular Neurobiology Branch, 333 Cassell Drive, Baltimore, Maryland 21224, United States
- The Johns Hopkins University School of Medicine, Pharmacology and Molecular Sciences, Baltimore, Maryland 21205, United States
| | - François Fenaille
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, F-91191 Gif sur Yvette, France
| | - Jean-Claude Tabet
- Sorbonne Université, Faculté des Sciences et de l'Ingénierie, Institut Parisien de Chimie Moléculaire (IPCM), F-75005 Paris, France
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, F-91191 Gif sur Yvette, France
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5
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Kostko O, Xu B, Ahmed M. Local electronic structure of histidine in aqueous solution. Phys Chem Chem Phys 2021; 23:8847-8853. [DOI: 10.1039/d1cp00361e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
X-Ray spectroscopy coupled with DFT calculations reveals the pH dependent electronic structure of an amino acid in an aqueous environment.
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Affiliation(s)
- O. Kostko
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Advanced Light Source
| | - B. Xu
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - M. Ahmed
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
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6
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Miller ZM, Zhang JD, Donald WA, Prell JS. Gas-Phase Protonation Thermodynamics of Biological Lipids: Experiment, Theory, and Implications. Anal Chem 2020; 92:10365-10374. [PMID: 32628014 DOI: 10.1021/acs.analchem.0c00613] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Phospholipids are important to cellular function and are a vital structural component of plasma and organelle membranes. These membranes isolate the cell from its environment, allow regulation of the internal concentrations of ions and small molecules, and host diverse types of membrane proteins. It remains extremely challenging to identify specific membrane protein-lipid interactions and their relative strengths. Native mass spectrometry, an intrinsically gas-phase method, has recently been demonstrated as a promising tool for identifying endogenous protein-lipid interactions. However, to what extent the identified interactions reflect solution- versus gas-phase binding strengths is not known. Here, the "Extended" Kinetic Method and ab initio computations at three different levels of theory are used to experimentally and theoretically determine intrinsic gas-phase basicities (GB, ΔG for deprotonation of the protonated base) and proton affinities (PA, ΔH for deprotonation of the protonated base) of six lipids representing common phospholipid types. Gas-phase acidities (ΔG and ΔH for deprotonation) of neutral phospholipids are also evaluated computationally and ranked experimentally. Intriguingly, it is found that two of these phospholipids, sphingomyelin and phosphatidylcholine, have the highest GB of any small, monomeric biomolecules measured to date and are more basic than arginine. Phosphatidylethanolamine and phosphatidylserine are found to be similar in GB to basic amino acids lysine and histidine, and phosphatidic acid and phosphatidylglycerol are the least basic of the six lipid types studied, though still more basic than alanine. Kinetic Method experiments and theory show that the gas-phase acidities of these phospholipids are high but less extreme than their GB values, with phosphatidylserine and phosphatidylglycerol being the most acidic. These results indicate that sphingomyelin and phosphatidylcholine lipids can act as charge-reducing agents when dissociated from native membrane protein-lipid complexes in the gas phase and provide a straightforward model to explain the results of several recent native mass spectrometry studies of protein-lipid complexes.
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Affiliation(s)
- Zachary M Miller
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - J Diana Zhang
- School of Chemistry, University of New South Wales, Sydney, New South Wales, Australia, 2052
| | - W Alexander Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales, Australia, 2052
| | - James S Prell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States.,Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1252, United States
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7
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Andersson Å, Poline M, Kodambattil M, Rebrov O, Loire E, Maître P, Zhaunerchyk V. Structure of Proton-Bound Methionine and Tryptophan Dimers in the Gas Phase Investigated with IRMPD Spectroscopy and Quantum Chemical Calculations. J Phys Chem A 2020; 124:2408-2415. [PMID: 32106670 PMCID: PMC7307929 DOI: 10.1021/acs.jpca.9b11811] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
The
structures of three proton-bound dimers (Met2H+, MetTrpH+, and Trp2H+) are
investigated in the gas phase with infrared multiple photon disassociation
(IRMPD) spectroscopy in combination with quantum chemical calculations.
Their IRMPD spectra in the range of 600–1850 cm–1 are obtained experimentally using an FT-ICR mass spectrometer and
the CLIO free electron laser as an IR light source. The most abundant
conformers are elucidated by comparing the IRMPD spectra with harmonic
frequencies obtained at the B3LYP-GD3BJ/6-311++G** level of theory.
Discrepancies between the experimental and theoretical data in the
region of 1500–1700 cm–1 are attributed to
the anharmonicity of the amino bending modes. We confirm the result
of a previous IRMPD study that the structure of gas-phase Trp2H+ is charge-solvated but find that there are more
stable structures than originally reported (Feng, R.; Yin, H.; Kong,
X. Rapid Commun. Mass Spectrom.2016, 30, 24–28). In addition, gas-phase Met2H+ and MetTrpH+ have been revealed to
have charge-solvated structures. For all three dimers, the most stable
conformer is found to be of type A. The spectrum of Met2H+, however, cannot be explained without some abundance
of type B charge-solvated conformers as well as salt-bridged structures.
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Affiliation(s)
- Åke Andersson
- Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Mathias Poline
- Department of Physics, Stockholm University, 114 19 Stockholm, Sweden
| | - Meena Kodambattil
- Department of Physics, University of Gothenburg, 405 30 Gothenburg, Sweden.,International School of Photonics, Cochin University of Science and Technology, Kochi, Kerala 682022, India
| | - Oleksii Rebrov
- Department of Physics, Stockholm University, 114 19 Stockholm, Sweden
| | - Estelle Loire
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS, Université Paris Saclay, Orsay 91405, France
| | - Philippe Maître
- Laboratoire de Chimie Physique (UMR8000), Université Paris-Sud, CNRS, Université Paris Saclay, Orsay 91405, France
| | - Vitali Zhaunerchyk
- Department of Physics, University of Gothenburg, 405 30 Gothenburg, Sweden
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8
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Donor MT, Shepherd SO, Prell JS. Rapid Determination of Activation Energies for Gas-Phase Protein Unfolding and Dissociation in a Q-IM-ToF Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:602-610. [PMID: 32126776 PMCID: PMC8063716 DOI: 10.1021/jasms.9b00055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ion mobility-mass spectrometry has emerged as a powerful tool for interrogating a wide variety of chemical systems. Collision-induced unfolding (CIU), typically performed in time-of-flight instruments, has been utilized to obtain valuable qualitative insight into protein structure and illuminate subtle differences between related species. CIU experiments can be performed relatively quickly, but unfolding energy information obtained from them has not yet been interpreted quantitatively. While several methods can determine quantitative dissociation energetics for small molecules, clusters, and peptides, these methods have rarely been applied to proteins, and never to study unfolding. Here, we present a method to rapidly determine activation energies for protein unfolding and dissociation, built on a model for energy deposition during collisional activation. The method is validated by comparing activation energies for dissociation of three complexes with those obtained using blackbody infrared radiative dissociation (BIRD); values from the two methods are in agreement. Several protein monomers were unfolded using CIU, including multiple charge states of both cations and anions, and activation energies determined. ΔH⧧ and ΔS⧧ values are found to be correlated, leading to ΔG⧧ values that lie within a narrow range (∼70-80 kJ/mol) and vary more with charge state than with protein identity. ΔG⧧ is anticorrelated with charge density, highlighting the key role of Coulombic repulsion in gas-phase unfolding. Measured ΔG⧧ values are similar to those computed for proton transfer within small peptides, suggesting that proton transfer is the rate-limiting step in gas-phase unfolding and providing evidence of a link between the Mobile Proton model and CIU.
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Affiliation(s)
- Micah T. Donor
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - Samantha O. Shepherd
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - James S. Prell
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
- Materials Science Institute, University of Oregon, 1252 University of Oregon, Eugene, OR 97403-1252
- Address reprint requests to James S. Prell, 1253 University of Oregon, Eugene, OR 97405, Tel: +1 (541) 346-2597,
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9
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Poline M, Rebrov O, Larsson M, Zhaunerchyk V. Theoretical studies of infrared signatures of proton-bound amino acid dimers with homochiral and heterochiral moieties. Chirality 2020; 32:359-369. [PMID: 31943359 DOI: 10.1002/chir.23165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/14/2019] [Accepted: 12/16/2019] [Indexed: 01/23/2023]
Abstract
Proton-bound homochiral and heterochiral dimers, X-H+ -X, of five amino acids (X = Ser, Ala, Thr, Phe, and Arg) are investigated theoretically using quantum chemical density functional theory (DFT) calculations and molecular dynamics simulations with the aim to unveil diastereomer-specific mid-infrared (mid-IR) absorption bands in the spectral range of 1000 to 1800 cm-1 . The theoretical calculations performed in this work imply that all systems, except Ala2 H+ , have distinct mid-IR absorption bands in homochiral and heterochiral configurations, which make them appropriate systems to be studied experimentally with mid-IR spectroscopy. We show that intermolecular interaction with the side chain, in the form of hydrogen bonding or cation-π interaction, is necessary for chiral effects to be present in the mid-IR spectra of proton-bound dimers of amino acids. We also report new conformers for Ala2 H+ , Thr2 H+ , Phe2 H+ , and Arg2 H+ , which were not found in earlier studies of these dimers.
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Affiliation(s)
- Mathias Poline
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Oleksii Rebrov
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Mats Larsson
- Department of Physics, Stockholm University, Stockholm, Sweden
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10
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Design, synthesis, molecular docking, antimicrobial, and antioxidant activities of new phenylsulfamoyl carboxylic acids of pharmacological interest. Med Chem Res 2019. [DOI: 10.1007/s00044-019-02440-3] [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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11
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Gantman T, Goldstein M, Segev E, Gerber RB. Conformers of Ubiquitin 6+ for Different Charge Distributions: Atomistic Structures and Ion Mobility Cross Sections. J Phys Chem B 2019; 123:6401-6409. [DOI: 10.1021/acs.jpcb.9b02720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tamara Gantman
- The Fritz Haber Research Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Moshe Goldstein
- The Fritz Haber Research Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Computer Science, Jerusalem College of Technology (JCT), Jerusalem 9372115, Israel
| | - Elad Segev
- The Fritz Haber Research Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Applied Mathematics, Holon Institute of Technology, Holon 5810201, Israel
| | - R. Benny Gerber
- The Fritz Haber Research Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Chemistry, University of California, Irvine, California 92697, United States
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12
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McNary CP, Nei YW, Maitre P, Rodgers MT, Armentrout PB. Infrared multiple photon dissociation action spectroscopy of protonated glycine, histidine, lysine, and arginine complexed with 18-crown-6 ether. Phys Chem Chem Phys 2019; 21:12625-12639. [PMID: 31155616 DOI: 10.1039/c9cp02265a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complexes of 18-crown-6 ether (18C6) with four protonated amino acids (AAs) are examined using infrared multiple photon dissociation (IRMPD) action spectroscopy utilizing light generated by the infrared free electron laser at the Centre Laser Infrarouge d'Orsay (CLIO). The AAs examined in this work include glycine (Gly) and the three basic AAs: histidine (His), lysine (Lys), and arginine (Arg). To identify the (AA)H+(18C6) conformations present in the experimental studies, the measured IRMPD spectra are compared to spectra calculated at the B3LYP/6-311+G(d,p) level of theory. Relative energies of various conformers and isomers are provided by single point energy calculations carried out at the B3LYP, B3P86, M06, and MP2(full) levels using the 6-311+G(2p,2d) basis set. The comparisons between the IRMPD and theoretical IR spectra indicate that 18C6 binds to Gly and His via the protonated backbone amino group, whereas protonated Lys prefers binding via the protonated side-chain amino group. Results for Arg are less definitive with strong evidence for binding to the protonated guanidino side chain (the calculated ground conformer at most levels of theory), but contributions from backbone binding to a zwitterionic structure are likely.
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Affiliation(s)
- Christopher P McNary
- Department of Chemistry, University of Utah, 315 S. 1400 E. Room 2020, Salt Lake City, Utah 84112, USA.
| | - Y-W Nei
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - Philippe Maitre
- Université Paris Sud, Laboratoire de Chimie Physique, UMR8000 CNRS, Faculté des Sciences, Bâtiment 350, 91405 Orsay Cedex, France
| | - M T Rodgers
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - P B Armentrout
- Department of Chemistry, University of Utah, 315 S. 1400 E. Room 2020, Salt Lake City, Utah 84112, USA.
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13
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Structural behavior of phenylalanine–tryptophan peptide nanotubes at anhydrous conditions: a theoretical investigation. Theor Chem Acc 2019. [DOI: 10.1007/s00214-019-2457-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Oomens J, Polfer NC, Berden G, Eyler JR. Gas-phase metal ion chelation investigated with IRMPD spectroscopy: A brief review of Robert Dunbar's contributions. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2019; 25:86-96. [PMID: 30205710 DOI: 10.1177/1469066718799175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
With the passing of Prof. Robert C. Dunbar on 31 October 2017, the field of ion chemistry lost one of its modern heroes. Throughout his career in mass spectrometry, two of his main research interests involved the interaction of trapped ions with electromagnetic radiation and the chelation motifs of metal ions with organic ligands. The focus of his early career was on the fundamental processes that take place in molecules upon ultraviolet and infrared excitation. From 2003 to 2017, his scientific interests shifted to more structural questions, notably to resolving the structures and binding motifs of metal ion chelation complexes by application of infrared photodissociation spectroscopy. These experiments were carried out during numerous visits to the (Free Electron Laser for Infrared eXperiments) (FELIX) facility in the Netherlands and were complemented by extensive theoretical investigations by Rob. As a tribute to our friend, we present in this contribution a brief review of this work.
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Affiliation(s)
- Jos Oomens
- 1 FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
- 2 Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Nicolas C Polfer
- 3 Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Giel Berden
- 1 FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - John R Eyler
- 3 Department of Chemistry, University of Florida, Gainesville, Florida, USA
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15
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Pitts-McCoy AM, Harrilal CP, McLuckey SA. Gas-Phase Ion/Ion Chemistry as a Probe for the Presence of Carboxylate Groups in Polypeptide Cations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:329-338. [PMID: 30341581 PMCID: PMC6347497 DOI: 10.1007/s13361-018-2079-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 10/04/2018] [Indexed: 05/31/2023]
Abstract
The reactivity of 1-hydroxybenzoyl triazole (HOBt) esters with the carboxylate functionality present in peptides is demonstrated in the gas phase with a doubly deprotonated dianion. The reaction forms an anhydride linkage at the carboxylate site. Upon ion trap collisional-induced dissociation (CID) of the modified peptide, the resulting spectrum shows a nominal loss of the mass of the reagent and a water molecule. Analogous phenomenology was also noted for model peptide cations that likely contain zwitterionic/salt-bridged motifs in reactions with a negatively charged HOBt ester. Control experiments indicate that a carboxylate group is the likely reactive site, rather than other possible nucleophilic sites present in the peptide. These observations suggest that HOBt ester chemistry may be used as a chemical probe for the presence and location of carboxylate groups in net positively charged polypeptide ions. As an illustration, deprotonated sulfobenzoyl HOBt was reacted with the [M+7H]7+ ion of ubiquitin. The ion was shown to react with the reagent and CID of the covalent reaction product yielded an abundant [M+6H-H2O]6+ ion. Comparison of the CID product ion spectrum of this ion with that of the water loss product generated from CID of the unmodified [M+6H]6+ ion revealed the glutamic acid at residue 64 as a reactive site, suggesting that it is present in the deprotonated form. Graphical Abstract ᅟ.
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Affiliation(s)
- Anthony M Pitts-McCoy
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Christopher P Harrilal
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA.
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16
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Czapla M, Freza S. Functionalized ACC molecule as an effective peptide clasp. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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17
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Smith ZM, Steinmetz V, Martens J, Oomens J, Poutsma JC. Infrared Multiple Photon Dissociation Spectroscopy of Cationized Canavanine: Side-Chain Substitution Influences Gas-Phase Zwitterion Formation †. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2018; 429:158-173. [PMID: 29962900 PMCID: PMC6020040 DOI: 10.1016/j.ijms.2017.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Infrared multiple photon dissociation spectroscopy was performed on protonated and cationized canavanine (Cav), a non-protein amino acid oxy-analog of arginine. Infrared spectra in the XH stretching region (3000 - 4000 cm-1) were obtained at the Centre Laser Infrarouge d'Orsay (CLIO) facility. Comparison of the experimental infrared spectra with scaled harmonic frequencies at the B3LYP/6-31+G(d,p) level of theory indicates that canavanine is in a canonical neutral form in CavH+, CavLi+, and CavNa+; therefore, these cations are charge-solvated structures. The infrared spectrum of CavK+ is consistent with a mixture of Cav in canonical and zwitterionic forms leading to both charge-solvated and salt-bridged cationic structures. The Cav moiety in CavCs+ is shown to be zwitterionic, forming a salt-bridged structure for the cation. Infrared spectra in the fingerprint region (1000 - 2000 cm-1) obtained at the FELIX Laboratory in Nijmegen, Netherlands support these assignments. These results show that that a single oxygen atom substitution in the side chain reduces the stability of the zwitterion compared to that of the protein amino acid arginine (Arg), which has been shown previously to adopt a zwitterionic structure in ArgNa+ and ArgK+. This difference can be explained in part due to the decreased basicity of Cav (PA = 1001 kJ/mol) as compared to arginine (PA = 1051 kJ/mol), but not entirely, as lysine, which has nearly the same proton affinity as Cav, (~993 kJ/mol) forms only canonical structures with Na+, K+, and Cs+. A major difference between the zwitterionic forms of ArgM+ and CavM+ is that the protonation site is on the side chain for Arg and on the N-terminus for Cav. This results in systematically weaker salt bridges in the Cav zwitterions. In addition, the presence of another hydrogen-bonding acceptor atom in the side chain contributes to the stability of the canonical structures for the smaller alkali cations.
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Affiliation(s)
- Zachary M Smith
- Department of Chemistry, The College of William and Mary, Williamsburg, VA 23187-8795
| | - Vincent Steinmetz
- Laboratoire de Chimie Physique, CNRS UMR 8000, Université Paris Sud, Université Paris Saclay, CNRS, Orsay France
| | - Jonathan Martens
- Radboud University, Institute for Molecules and Materials FELIX Laboratory, Nijmegen, The Netherlands
| | - Jos Oomens
- Radboud University, Institute for Molecules and Materials FELIX Laboratory, Nijmegen, The Netherlands
- Van't Hoff Institute for Molecular Sciences University of Amsterdam, Amsterdam, The Netherlands
| | - John C Poutsma
- Department of Chemistry, The College of William and Mary, Williamsburg, VA 23187-8795
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18
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Li H, Jiang J, Luo Y. Identification of the smallest peptide with a zwitterion as the global minimum: a first-principles study on arginine-containing peptides. Phys Chem Chem Phys 2018; 19:12117-12126. [PMID: 28443881 DOI: 10.1039/c7cp01380a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zwitterions are believed to play an important role in determining the structures, properties and functions of peptides and proteins. However, the smallest peptide with a zwitterionic structure as the global minimum in the gas phase is still not yet identified. In this study, an effective step-by-step strategy has been used to characterize the stable conformers of arginine-containing peptides arginylalanine (ArgAla) and arginylserine (ArgSer). Energy calculations at the DSD-PBEP86-D3BJ/aug-cc-pVTZ level and further extrapolation to the complete basis set (CBS) limit have confirmed, for the first time, that ArgSer appears to be a promising candidate as the smallest peptide with a zwitterionic global minimum structure. First-principles simulations have been performed for near-edge X-ray absorption fine-structure (NEXAFS) spectra and X-ray photoelectron spectra (XPS) at C, N and O K-edges, as well as for infrared (IR) spectra of these arginine-containing peptides. Notable spectral differences were found which enable the unambiguous identification of different neutral forms in future experiments. Our study thus provides valuable insights into the structural stability of zwitterions with the increase of molecular size and illustrates the competition between the canonical and zwitterionic isomers.
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Affiliation(s)
- Hongbao Li
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
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19
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Heiles S, Berden G, Oomens J, Williams ER. Competition between salt bridge and non-zwitterionic structures in deprotonated amino acid dimers. Phys Chem Chem Phys 2018; 20:15641-15652. [DOI: 10.1039/c8cp01458b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The effect of side chain functional groups on salt bridge structures in deprotonated amino acid homodimers is investigated using both infrared multiple photon dissociation spectroscopy between 650 and 1850 cm−1 and theory.
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Affiliation(s)
- Sven Heiles
- Department of Chemistry
- University of California
- Berkeley
- USA
- Institute of Inorganic and Analytical Chemistry
| | - Giel Berden
- Radboud University
- Institute for Molecules and Materials
- FELIX Laboratory
- 6525 ED Nijmegen
- The Netherlands
| | - Jos Oomens
- Radboud University
- Institute for Molecules and Materials
- FELIX Laboratory
- 6525 ED Nijmegen
- The Netherlands
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20
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Jarrell TM, Owen BC, Riedeman JS, Prentice BM, Pulliam CJ, Max J, Kenttämaa HI. Laser-Induced Acoustic Desorption/Electron Ionization of Amino Acids and Small Peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1091-1098. [PMID: 28500583 DOI: 10.1007/s13361-017-1684-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 04/05/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Laser-induced acoustic desorption (LIAD) allows for desorption of neutral nonvolatile compounds independent of their volatility or thermal stability. Many different ionization methods have been coupled with LIAD. Hence, this setup provides a better control over the types of ions formed than other mass spectrometry evaporation/ionization methods commonly used to characterize biomolecules, such as ESI or MALDI. In this study, the utility of LIAD coupled with electron ionization (EI) was tested for the analysis of common amino acids with no derivatization. The results compared favorably with previously reported EI mass spectra obtained using thermal desorption/EI. Further, LIAD/EI mass spectra collected for hydrochloride salts of two amino acids were found to be similar to those measured for the neutral amino acids with the exception of the appearance of an HCl+● ion. However, the hydrochloride salt of arginine showed a distinctly different LIAD/EI mass spectrum than the previously published literature EI mass spectrum, likely due to its highly basic side chain that makes a specific zwitterionic form particularly favorable. Finally, EI mass spectra were measured for seven small peptides, including di-, tri-, and tetrapeptides. These mass spectra show a variety of ion types. However, an type ions are prevalent. Also, electron-induced dissociation (EID) of protonated peptides has been reported to form primarily an type ions. In addition, the loss of small neutral molecules and side-chain cleavages were observed that are reminiscent of other high-energy fragmentation methods, such as EID. Finally, the isomeric dipeptides LG and IG were found to produce drastically different EI mass spectra, thus allowing differentiation of the leucine and isoleucine amino acids in these dipeptides. Graphical Abstract ᅟ.
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Affiliation(s)
- Tiffany M Jarrell
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Benjamin C Owen
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - James S Riedeman
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Boone M Prentice
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Chris J Pulliam
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Joann Max
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Hilkka I Kenttämaa
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.
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21
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Xu B, Jacobs MI, Kostko O, Ahmed M. Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution. Chemphyschem 2017; 18:1503-1506. [DOI: 10.1002/cphc.201700197] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Bo Xu
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Michael I. Jacobs
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry University of California Berkeley CA 94720 USA
| | - Oleg Kostko
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Musahid Ahmed
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
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22
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Strazdaite S, Meister K, Bakker HJ. Reduced Acid Dissociation of Amino-Acids at the Surface of Water. J Am Chem Soc 2017; 139:3716-3720. [PMID: 28177623 PMCID: PMC5355887 DOI: 10.1021/jacs.6b12079] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We use surface-specific intensity vibrational sum-frequency generation and attenuated total reflection spectroscopy to probe the ionization state of the amino-acids l-alanine and l-proline at the air/water surface and in the bulk. The ionization state is determined by probing the vibrational signatures of the carboxylic acid group, representing the nondissociated acid form, and the carboxylate anion group, representing the dissociated form, over a wide range of pH values. We find that the carboxylic acid group deprotonates at a significantly higher pH at the surface than in the bulk.
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Affiliation(s)
| | - Konrad Meister
- Amolf , Science Park 102, Amsterdam 1098XG, The Netherlands
| | - Huib J Bakker
- Amolf , Science Park 102, Amsterdam 1098XG, The Netherlands
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23
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Darii E, Alves S, Gimbert Y, Perret A, Tabet JC. Meaning and consequence of the coexistence of competitive hydrogen bond/salt forms on the dissociation orientation of non-covalent complexes. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1047:45-58. [DOI: 10.1016/j.jchromb.2016.09.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/23/2016] [Accepted: 09/25/2016] [Indexed: 10/20/2022]
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24
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Raczyńska ED, Gal JF, Maria PC. Enhanced Basicity of Push-Pull Nitrogen Bases in the Gas Phase. Chem Rev 2016; 116:13454-13511. [PMID: 27739663 DOI: 10.1021/acs.chemrev.6b00224] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitrogen bases containing one or more pushing amino-group(s) directly linked to a pulling cyano, imino, or phosphoimino group, as well as those in which the pushing and pulling moieties are separated by a conjugated spacer (C═X)n, where X is CH or N, display an exceptionally strong basicity. The n-π conjugation between the pushing and pulling groups in such systems lowers the basicity of the pushing amino-group(s) and increases the basicity of the pulling cyano, imino, or phosphoimino group. In the gas phase, most of the so-called push-pull nitrogen bases exhibit a very high basicity. This paper presents an analysis of the exceptional gas-phase basicity, mostly in terms of experimental data, in relation with structure and conjugation of various subfamilies of push-pull nitrogen bases: nitriles, azoles, azines, amidines, guanidines, vinamidines, biguanides, and phosphazenes. The strong basicity of biomolecules containing a push-pull nitrogen substructure, such as bioamines, amino acids, and peptides containing push-pull side chains, nucleobases, and their nucleosides and nucleotides, is also analyzed. Progress and perspectives of experimental determinations of GBs and PAs of highly basic compounds, termed as "superbases", are presented and benchmarked on the basis of theoretical calculations on existing or hypothetical molecules.
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Affiliation(s)
- Ewa D Raczyńska
- Department of Chemistry, Warsaw University of Life Sciences (SGGW) , ul. Nowoursynowska 159c, 02-776 Warszawa, Poland
| | - Jean-François Gal
- Institut de Chimie de Nice (ICN) - UMR CNRS 7272, University Nice Sophia Antipolis , Parc Valrose, 06108 Nice Cedex 2, France
| | - Pierre-Charles Maria
- Institut de Chimie de Nice (ICN) - UMR CNRS 7272, University Nice Sophia Antipolis , Parc Valrose, 06108 Nice Cedex 2, France
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25
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Ling S, Gutowski M. Different Conformations of 2′-Deoxycytidine in the Gas and Solid Phases: Competition between Intra- and Intermolecular Hydrogen Bonds. J Phys Chem A 2016; 120:8199-8210. [DOI: 10.1021/acs.jpca.6b09384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sanliang Ling
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Maciej Gutowski
- Institute
of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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26
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Barbier Saint Hilaire P, Warnet A, Gimbert Y, Hohenester UM, Giorgi G, Olivier MF, Fenaille F, Colsch B, Junot C, Tabet JC. Mechanistic study of competitive releases of H 2O, NH 3 and CO 2 from deprotonated aspartic and glutamic acids: Role of conformation. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1047:64-74. [PMID: 27592168 DOI: 10.1016/j.jchromb.2016.08.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 07/22/2016] [Accepted: 08/22/2016] [Indexed: 11/27/2022]
Abstract
The aims of this study were to highlight the impact of minor structural differences (e.g. an aminoacid side chain enlargement by one methylene group), on ion dissociation under collision-induced dissociation conditions, and to determine the underlying chemical mechanisms. Therefore, we compared fragmentations of deprotonated aspartic and glutamic acids generated in negative electrospray ionization. Energy-resolved mass spectrometry breakdown curves were recorded and MS3 experiments performed on an Orbitrap Fusion for high-resolution and high-mass accuracy measurements. Activated fragmentations were performed using both the resonant and non-resonant excitation modes (i.e., CID and HCD, respectively) in order to get complementary information on the competitive and consecutive dissociative pathways. These experiments showed a specific loss of ammonia from the activated aspartate but not from the activated glutamate. We mainly focused on this specific observed loss from aspartate. Two different mechanisms based on intramolecular reactions (similar to those occurring in organic chemistry) were proposed, such as intramolecular elimination (i.e. Ei-like) and nucleophilic substitution (i.e. SNi-like) reactions, respectively, yielding anions as fumarate and α lactone from a particular conformation with the lowest steric hindrance (i.e. with antiperiplanar carboxyl groups). The detected deaminated aspartate anion can then release CO2 as observed in the MS3 experimental spectra. However, quantum calculations did not indicate the formation of such a deaminated aspartate product ion without loss of carbon dioxide. Actually, calculations displayed the double neutral (NH3+CO2) loss as a concomitant pathway (from a particular conformation) with relative high activation energy instead of a consecutive process. This disagreement is apparent since the concomitant pathway may be changed into consecutive dissociations according to the collision energy i.e., at higher collision energy and at lower excitation conditions, respectively. The latter takes place by stabilization of the deaminated aspartate solvated with two residual molecules of water (present in the collision cell). This desolvated anion formed is an α lactone substituted by a methylene carboxylate group. The vibrational excitation acquired by [(D-H)-NH3]-during its isolation is enough to allow its prompt decarboxylation with a barrier lower than 8.4kJ/mol. In addition, study of glutamic acid-like diastereomers constituted by a cyclopropane, hindering any side chain rotation, confirms the impact of the three-dimensional geometry on fragmentation pathways. A significant specific loss of water is only observed for one of these diastereomers. Other experiments, such as stable isotope labeling, need to be performed to elucidate all the observed losses from activated aspartate and glutamate anions. These first mechanistic interpretations enhance understanding of this dissociative pathway and underline the necessity of studying fragmentation of a large number of various compounds to implement properly new algorithms for de novo elucidation of unknown metabolites.
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Affiliation(s)
| | - Anna Warnet
- CEA, iBiTec-S, SPI, LEMM, Metabohub Gif Sur Yvette, France; Université Paris VI (UPMC), CNRS UMR 7201, Paris Cedex 05, France.
| | - Yves Gimbert
- Université Grenoble Alpes et CNRS, DCM UMR 5250, Grenoble, France
| | | | - Gianluca Giorgi
- University of Siena, Department of Biotechnology, Chemistry and Pharmacy, Via Aldo Moro, I-53100 Siena, Italy
| | | | | | - Benoît Colsch
- CEA, iBiTec-S, SPI, LEMM, Metabohub Gif Sur Yvette, France
| | | | - Jean-Claude Tabet
- CEA, iBiTec-S, SPI, LEMM, Metabohub Gif Sur Yvette, France; Université Paris VI (UPMC), CNRS UMR 7201, Paris Cedex 05, France
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27
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Scherbakov KA, Kondratiev MS, Samchenko AA, Kabanov AV, Komarov VM. The electronic structure properties of 20 L-amino acids in neutral and zwitterion forms: Quantum-chemical calculations. Biophysics (Nagoya-shi) 2016. [DOI: 10.1134/s0006350916030167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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28
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Wileńska D, Skurski P, Anusiewicz I. Gas-phase quasi-degeneracy of zwitterionic and canonical tautomers of glycine and proline induced by the presence of the MAlF 4(M = Li, Na, K) salts. Mol Phys 2016. [DOI: 10.1080/00268976.2015.1136007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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29
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Lutsker V, Aradi B, Niehaus TA. Implementation and benchmark of a long-range corrected functional in the density functional based tight-binding method. J Chem Phys 2016; 143:184107. [PMID: 26567646 DOI: 10.1063/1.4935095] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bridging the gap between first principles methods and empirical schemes, the density functional based tight-binding method (DFTB) has become a versatile tool in predictive atomistic simulations over the past years. One of the major restrictions of this method is the limitation to local or gradient corrected exchange-correlation functionals. This excludes the important class of hybrid or long-range corrected functionals, which are advantageous in thermochemistry, as well as in the computation of vibrational, photoelectron, and optical spectra. The present work provides a detailed account of the implementation of DFTB for a long-range corrected functional in generalized Kohn-Sham theory. We apply the method to a set of organic molecules and compare ionization potentials and electron affinities with the original DFTB method and higher level theory. The new scheme cures the significant overpolarization in electric fields found for local DFTB, which parallels the functional dependence in first principles density functional theory (DFT). At the same time, the computational savings with respect to full DFT calculations are not compromised as evidenced by numerical benchmark data.
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Affiliation(s)
- V Lutsker
- Department of Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
| | - B Aradi
- BCCMS, University of Bremen, 28359 Bremen, Germany
| | - T A Niehaus
- Department of Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
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30
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Heiles S, Cooper RJ, Berden G, Oomens J, Williams ER. Hydrogen bond mediated stabilization of the salt bridge structure for the glycine dimer anion. Phys Chem Chem Phys 2016; 17:30642-7. [PMID: 26524433 DOI: 10.1039/c5cp06120b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of a salt bridge in deprotonated glycine dimer anions in a solvent-free environment is investigated using both infrared multiple photon dissociation spectroscopy between 600 and 1800 cm(-1) and theory. The zwitterionic and nonzwitterionic forms of glycine in this complex are computed to be nearly iso-energetic, yet predominantly the zwitterionic form is observed experimentally. The zwitterion stability is attributed to both the Coulombic attraction and the high stabilization from intramolecular hydrogen bonding that drives the energetic cost of proton transfer in a solvent free environment. These results show that there is a fine balance between the stabilities of these two forms of the anion. Elucidating the role of intrinsic factors, such as hydrogen bonding, can lead to a better understanding of the stabilities of salt bridges in the interiors of large proteins or at protein interfaces.
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Affiliation(s)
- S Heiles
- Department of Chemistry, University of California, B42 Hildebrand Hall, Berkeley, CA 94720, USA.
| | - Richard J Cooper
- Department of Chemistry, University of California, B42 Hildebrand Hall, Berkeley, CA 94720, USA.
| | - Giel Berden
- Radboud University Nijmegen, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Jos Oomens
- Radboud University Nijmegen, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands and Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Evan R Williams
- Department of Chemistry, University of California, B42 Hildebrand Hall, Berkeley, CA 94720, USA.
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31
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Manz TA, Limas NG. Introducing DDEC6 atomic population analysis: part 1. Charge partitioning theory and methodology. RSC Adv 2016. [DOI: 10.1039/c6ra04656h] [Citation(s) in RCA: 389] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We introduce a new atomic population analysis method that performs exceptionally well across an extremely broad range of periodic and non-periodic material types.
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Affiliation(s)
- Thomas A. Manz
- Department of Chemical & Materials Engineering
- New Mexico State University
- Las Cruces
- USA
| | - Nidia Gabaldon Limas
- Department of Chemical & Materials Engineering
- New Mexico State University
- Las Cruces
- USA
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32
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Stover ML, Plummer CE, Miller SR, Cassady CJ, Dixon DA. Gas-Phase Acidities of Phosphorylated Amino Acids. J Phys Chem B 2015; 119:14604-21. [DOI: 10.1021/acs.jpcb.5b08616] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michele L. Stover
- Chemistry
Department, Shelby
Hall, The University of Alabama, Shelby Hall, Box
870336, Tuscaloosa, Alabama 35487-0336, United States
| | - Chelsea E. Plummer
- Chemistry
Department, Shelby
Hall, The University of Alabama, Shelby Hall, Box
870336, Tuscaloosa, Alabama 35487-0336, United States
| | - Sean R. Miller
- Chemistry
Department, Shelby
Hall, The University of Alabama, Shelby Hall, Box
870336, Tuscaloosa, Alabama 35487-0336, United States
| | - Carolyn J. Cassady
- Chemistry
Department, Shelby
Hall, The University of Alabama, Shelby Hall, Box
870336, Tuscaloosa, Alabama 35487-0336, United States
| | - David A. Dixon
- Chemistry
Department, Shelby
Hall, The University of Alabama, Shelby Hall, Box
870336, Tuscaloosa, Alabama 35487-0336, United States
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Kleisath E, Marta RA, Martens S, Martens J, McMahon T. Structures and Energetics of Protonated Clusters of Methylamine with Phenylalanine Analogs, Characterized by Infrared Multiple Photon Dissociation Spectroscopy and Electronic Structure Calculations. J Phys Chem A 2015; 119:6689-702. [DOI: 10.1021/acs.jpca.5b02794] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth Kleisath
- Department
of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Rick A. Marta
- Department
of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Sabrina Martens
- Department
of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jon Martens
- Department
of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Terry McMahon
- Department
of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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34
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Liu X, Cho B, Chan LY, Kwan WL, Ken Lee CL. Development of asymmetrical near infrared squaraines with large Stokes shift. RSC Adv 2015. [DOI: 10.1039/c5ra18998e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New asymmetrical squaraines with large Stokes shifts of up to 90 nm were synthesized. TDDFT calculations indicate that steric effects from N,N-dibutylaniline and squaraine contribute to the large geometric change, resulting in the large Stokes shift.
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Affiliation(s)
- Xiaoqian Liu
- Centre for Biomedical and Life Sciences
- Department of Technology
- Innovation and Enterprise (TIE)
- Singapore Polytechnic
- Singapore
| | - Bokun Cho
- Energetics Research Institute (EnRI)
- Nanyang Technological University
- Singapore
| | - Li-Yan Chan
- Centre for Biomedical and Life Sciences
- Department of Technology
- Innovation and Enterprise (TIE)
- Singapore Polytechnic
- Singapore
| | - Wei Lek Kwan
- Engineering Product Development
- Singapore University of Technology and Design
- Singapore
| | - Chi-Lik Ken Lee
- Centre for Biomedical and Life Sciences
- Department of Technology
- Innovation and Enterprise (TIE)
- Singapore Polytechnic
- Singapore
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Li H, Li L, Jiang J, Lin Z, Luo Y. Theoretical spectroscopic studies on chemical and electronic structures of arginylglycine. Phys Chem Chem Phys 2015; 17:24754-60. [DOI: 10.1039/c5cp03729h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The global minimum of the dipeptide ArgGly is found to be in the canonical form, rather than the zwitterionic form.
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Affiliation(s)
- Hongbao Li
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science and Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology
- Guizhou Normal College
- Guiyang
- China
| | - Leilei Li
- Hefei National Laboratory for Physical Sciences at the Microscale
- School of Chemistry and Materials Science
- University of Science and Technology of China
- Hefei
- China
| | - Jun Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale
- School of Chemistry and Materials Science
- University of Science and Technology of China
- Hefei
- China
| | - Zijing Lin
- Hefei National Laboratory for Physical Sciences at the Microscale
- School of Chemistry and Materials Science
- University of Science and Technology of China
- Hefei
- China
| | - Yi Luo
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science and Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology
- Guizhou Normal College
- Guiyang
- China
- Hefei National Laboratory for Physical Sciences at the Microscale
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36
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37
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Delaney SP, Smith TM, Korter TM. Conformation versus cohesion in the relative stabilities of gabapentin polymorphs. RSC Adv 2014. [DOI: 10.1039/c3ra43887b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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38
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Kim JY, Ahn DS, Park SW, Lee S. Gas phase hydration of amino acids and dipeptides: effects on the relative stability of zwitterion vs. canonical conformers. RSC Adv 2014. [DOI: 10.1039/c4ra01217h] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This review highlights the effects of explicit water molecules on the structures of amino acids and dipeptides, focusing on the relative stability of canonical vs. zwitterionic conformers.
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Affiliation(s)
- Ju-Young Kim
- Department of Applied Chemistry
- College of Applied Sciences
- Kyung Hee University
- Kyungki 446-701, S. Korea
| | - Doo-Sik Ahn
- Department of Applied Chemistry
- College of Applied Sciences
- Kyung Hee University
- Kyungki 446-701, S. Korea
| | - Sung-Woo Park
- Department of Applied Chemistry
- College of Applied Sciences
- Kyung Hee University
- Kyungki 446-701, S. Korea
| | - Sungyul Lee
- Department of Applied Chemistry
- College of Applied Sciences
- Kyung Hee University
- Kyungki 446-701, S. Korea
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39
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Walker M, Sen A, Harvey AJ, Dessent CE. Complexation of anions to gas-phase amino acids: Conformation is critical in determining if the global minimum is canonical or zwitterionic. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.09.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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40
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Zhang W, Zhou X, Xie Z, Yang B, Liu L, Ma Y. Reaction of tetrachlorinated perylene bisimide in a strong base to form an asymmetric compound with charge transfer optical properties. Chem Commun (Camb) 2013; 49:11560-2. [DOI: 10.1039/c3cc46472e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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42
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Strittmatter EF, Wong RL, Williams ER. Effects of Gas-Phase Basicity on the Proton Transfer between Organic Bases and Trifluoroacetic Acid in the Gas Phase: Energetics of Charge Solvation and Salt Bridges. J Phys Chem A 2012; 104:10271-9. [PMID: 16554909 PMCID: PMC1409764 DOI: 10.1021/jp0012505] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The unimolecular dissociation pathways and kinetics of a series of protonated trimer ions consisting of two organic bases and trifluoroacetic acid were investigated using blackbody infrared radiative dissociation. Five bases with gas-phase basicities (GB) ranging from 238.4 to 246.2 kcal/mol were used. Both the dissociation pathways and the threshold dissociation energies depend on the GB of the base. Trimers consisting of the two most basic molecules dissociate to form protonated base monomers with an E(0) ~ 1.4 eV. Trimers consisting of the two least basic molecules dissociate to form protonated base dimers with an E(0) ~ 1.1-1.2 eV. These results indicate that the structures of the trimers change as a function of the GB of the basic molecule. The predominant structure of the protonated trimers consisting of the two most basic molecules is consistent with a salt bridge in which both of the basic molecules are protonated, and the trifluoroacetic acid molecule is deprotonated, whereas the predominant structure of the protonated trimers consisting of the two least basic molecules are consistent with charge-solvated complexes in which the proton is shared. The structure of the trimer consisting of the base of intermediate basicity is less clear; it dissociates to form primarily protonated base dimer, but has an E(0) ~ 1.2 eV. These results are consistent with the structure of this trimer as a salt bridge, but the resulting dissociation A(-). BH(+) product does not appear to be stable as an ion pair in the dissociative transition state.
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Affiliation(s)
- E F Strittmatter
- Department of Chemistry, University of California, Berkeley, California 94720-1460
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43
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Jockusch RA, Price WD, Williams ER. Structure of cationized arginine (arg.m, m = h, li, na, k, rb, and cs) in the gas phase: further evidence for zwitterionic arginine. J Phys Chem A 2012; 103:9266-74. [PMID: 16479275 PMCID: PMC1365274 DOI: 10.1021/jp9931307] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The gas-phase structures of cationized arginine, Arg.M(+), M = Li, Na, K, Rb, and Cs, were studied both by hybrid method density functional theory calculations and experimentally using low-energy collisionally activated and thermal radiative dissociation. Calculations at the B3LYP/LACVP++** level of theory show that the salt-bridge structures in which the arginine is a zwitterion (protonated side chain, deprotonated C-terminus) become more stable than the charge-solvated structures with increasing metal ion size. The difference in energy between the most stable charge-solvated structure and salt-bridge structure of Arg.M(+) increases from -0.7 kcal/mol for Arg.Li(+) to +3.3 kcal/mol for Arg.Cs(+). The stabilities of the salt-bridge and charge-solvated structures reverse between M = Li and Na. These calculations are in good agreement with the results of dissociation experiments. The low-energy dissociation pathways depend on the cation size. Arginine complexed with small cations (Li and Na) loses H(2)O, while arginine complexed with larger cations (K, Rb, and Cs) loses NH(3). Loss of H(2)O must come from a charge-solvated ion, whereas the loss of NH(3) can come from the protonated side chain of a salt-bridge structure. The results of dissociation experiments using several cationized arginine derivatives are consistent with the existence of these two distinct structures. In particular, arginine methyl esters, which cannot form salt bridges, dissociate by loss of methanol, analogous to loss of H(2)O from Arg.M(+); no loss of NH(3) is observed. Although dissociation experiments probe gas-phase structure indirectly, the observed fragmentation pathways are in good agreement with the calculated lowest energy isomers. The combination of the results from experiment and theory provides strong evidence that the structure of arginine-alkali metal ion complexes in the gas phase changes from a charge-solvated structure to a salt-bridge structure as the size of the metal ion increases.
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Affiliation(s)
- R A Jockusch
- Department of Chemistry, University of California, Berkeley, California 94720-1460
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44
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Yang G, Zhu R, Zhou L, Liu C. Interactions of Zn(II) with single and multiple amino acids. Insights from density functional and ab initio calculations. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:1372-1383. [PMID: 23019170 DOI: 10.1002/jms.3075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Calculations were performed to study the interactions of metal ions (M) with (multiple) amino acids (AA) and fill the gap between single AA and proteins. A complete conformational search results in nine and eleven ZnGly isomers at B3P86 and MP2 levels, respectively, and four populated conformers of glycine are responsible for production of these isomers. For all M, the isomers via the OO and NO binding modes are the main constituents, and the OO mode is favored by stronger electrostatic interactions. Binding with more glycines causes larger structural distortions, improves relative stabilities of monodentate binding isomers and generates new binding modes (e.g. ZnB(III) via only the hydroxyl group). The scaling factor of Zn(Gly)(n) structures, the ratio of its binding affinity versus the sum of comprising ZnGly isomers, is linear with glycine number (n), and the linear relationship may not be altered by mutations of glycines and M. It thus allows to estimate M(AA)(n) binding affinities (n ≥ 2) from the comprising MAA structures and analyze their structures with kinetic methods. The DFT and MP2 results become comparable by increasing metal coordination, e.g. the ZnB(III) versus ZnA(I) (zwitterionic) relative energy differs by 41.9 kcal mol(-1) at B3P86 and MP2 levels and is close by addition of three water molecules (4.1 kcal mol(-1)). The presence of water solvent improves the relative stabilities of monodentate binding isomers and results in a broader conformational distribution.
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Affiliation(s)
- Gang Yang
- Institute of Theoretical Chemistry, Shandong University, Jinan, P R China.
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45
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Humelnicu I, Würthwein EU, Haufe G. The conformers of 3-fluoroalanine. A theoretical study. Org Biomol Chem 2012; 10:2084-93. [PMID: 22286189 DOI: 10.1039/c2ob06492h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum chemical calculations (DFT, SCS-MP2) show that the relative energies of the four principal alanine conformations are only marginally altered by the introduction of a single fluorine substituent into the methyl group. The fluorine gauche effect and attractive interactions of fluorine to the O-H or N-H moieties (formation of hydrogen bridges) do stabilize particular conformers of 3-fluoroalanine. This is true for the neutral molecule both in the gas phase and in aqueous solution (CPCM-model), but also for the zwitterionic forms and the conformers of the related carboxylate ions and also for the respective ammonium ions in aqueous solution. In water (CPCM calculations), the zwitterion is almost equal in energy to the most stable conformer of the neutral 3-fluoroalanine. Compared to alanine the atomic charges of the amino group and the carboxyl function of 3-fluoroalanine are not significantly influenced by the fluorine at C3, which relates to the fact that both experimental pK(a) values are almost equal for alanine and 3-fluoroalanine.
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Affiliation(s)
- Ionel Humelnicu
- Organisch Chemisches Institut, Universität Münster, Corrensstr. 40, D-48149 Münster, Germany.
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46
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Stover ML, Jackson VE, Matus MH, Adams MA, Cassady CJ, Dixon DA. Fundamental Thermochemical Properties of Amino Acids: Gas-Phase and Aqueous Acidities and Gas-Phase Heats of Formation. J Phys Chem B 2012; 116:2905-16. [DOI: 10.1021/jp207271p] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michele L. Stover
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
| | - Virgil E. Jackson
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
| | - Myrna H. Matus
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
| | - Margaret A. Adams
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
| | - Carolyn J. Cassady
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
| | - David A. Dixon
- Chemistry
Department, The University of Alabama, Shelby Hall, Box 870336,
Tuscaloosa, Alabama 35487-0336, United States
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47
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Patel JR, Carlton RA, Yuniatine F, Needham TE, Wu L, Vogt FG. Preparation and Structural Characterization of Amorphous Spray-Dried Dispersions of Tenoxicam with Enhanced Dissolution. J Pharm Sci 2012; 101:641-63. [DOI: 10.1002/jps.22800] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 09/30/2011] [Accepted: 10/07/2011] [Indexed: 11/05/2022]
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48
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Milner EM, Nix MGD, Dessent CEH. Collision-Induced Dissociation of Halide Ion–Arginine Complexes: Evidence for Anion-Induced Zwitterion Formation in Gas-Phase Arginine. J Phys Chem A 2012; 116:801-9. [DOI: 10.1021/jp208183p] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Edward M. Milner
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Michael G. D. Nix
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
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49
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Burt MB, Fridgen TD. Structures and physical properties of gaseous metal cationized biological ions. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2012; 18:235-250. [PMID: 22641728 DOI: 10.1255/ejms.1177] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Metal chelation can alter the activity of free biomolecules by modifying their structures or stabilizing higher energy tautomers. In recent years, mass spectrometric techniques have been used to investigate the effects of metal complexation with proteins, nucleobases and nucleotides, where small conformational changes can have significant physiological consequences. In particular, infrared multiple photon dissociation spectroscopy has emerged as an important tool for determining the structure and reactivity of gas-phase ions. Unlike other mass spectrometric approaches, this method is able to directly resolve structural isomers using characteristic vibrational signatures. Other activation and dissociation methods, such as blackbody infrared radiative dissociation or collision-induced dissociation can also reveal information about the thermochemistry and dissociative pathways of these biological ions. This information can then be used to provide information about the structures of the ionic complexes under study. In this article, we review the use of gas-phase techniques in characterizing metal-bound biomolecules. Particular attention will be given to our own contributions, which detail the ability of metal cations to disrupt nucleobase pairs, direct the self-assembly of nucleobase clusters and stabilize non-canonical isomers of amino acids.
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Affiliation(s)
- Michael B Burt
- Department of Chemistry, Memorial University of Newfoundland, St John's, Newfoundland and Labrador, Canada, A1B 3X7
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50
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Donald WA, Leib RD, Demireva M, Williams ER. Ions in size-selected aqueous nanodrops: sequential water molecule binding energies and effects of water on ion fluorescence. J Am Chem Soc 2011; 133:18940-9. [PMID: 21999364 DOI: 10.1021/ja208072z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of water on ion fluorescence were investigated, and average sequential water molecule binding energies to hydrated ions, M(z)(H(2)O)(n), at large cluster size were measured using ion nanocalorimetry. Upon 248-nm excitation, nanodrops with ~25 or more water molecules that contain either rhodamine 590(+), rhodamine 640(+), or Ce(3+) emit a photon with average energies of approximately 548, 590, and 348 nm, respectively. These values are very close to the emission maxima of the corresponding ions in solution, indicating that the photophysical properties of these ions in the nanodrops approach those of the fully hydrated ions at relatively small cluster size. As occurs in solution, these ions in nanodrops with 8 or more water molecules fluoresce with a quantum yield of ~1. Ce(3+) containing nanodrops that also contain OH(-) fluoresce, whereas those with NO(3)(-) do not. This indirect fluorescence detection method has the advantages of high sensitivity, and both the size of the nanodrops as well as their constituents can be carefully controlled. For ions that do not fluoresce in solution, such as protonated tryptophan, full internal conversion of the absorbed 248-nm photon occurs, and the average sequential water molecule binding energies to the hydrated ions can be accurately obtained at large cluster sizes. The average sequential water molecule binding energies for TrpH(+)(H(2)O)(n) and a doubly protonated tripeptide, [KYK + 2H](2+)(H(2)O)(n), approach asymptotic values of ~9.3 (n ≥ 11) and ~10.0 kcal/mol (n ≥ 25), respectively, consistent with a liquidlike structure of water in these nanodrops.
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Affiliation(s)
- William A Donald
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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