1
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Kenderdine T, Fabris D. The multifaceted roles of mass spectrometric analysis in nucleic acids drug discovery and development. MASS SPECTROMETRY REVIEWS 2023; 42:1332-1357. [PMID: 34939674 PMCID: PMC9218015 DOI: 10.1002/mas.21766] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/23/2021] [Accepted: 11/22/2021] [Indexed: 06/07/2023]
Abstract
The deceptively simple concepts of mass determination and fragment analysis are the basis for the application of mass spectrometry (MS) to a boundless range of analytes, including fundamental components and polymeric forms of nucleic acids (NAs). This platform affords the intrinsic ability to observe first-hand the effects of NA-active drugs on the chemical structure, composition, and conformation of their targets, which might affect their ability to interact with cognate NAs, proteins, and other biomolecules present in a natural environment. The possibility of interfacing with high-performance separation techniques represents a multiplying factor that extends these capabilities to cover complex sample mixtures obtained from organisms that were exposed to NA-active drugs. This report provides a brief overview of these capabilities in the context of the analysis of the products of NA-drug activity and NA therapeutics. The selected examples offer proof-of-principle of the applicability of this platform to all phases of the journey undertaken by any successful NA drug from laboratory to bedside, and provide the rationale for its rapid expansion outside traditional laboratory settings in support to ever growing manufacturing operations.
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Affiliation(s)
| | - Dan Fabris
- Department of Chemistry, University of Connecticut
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2
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Marty MT. Fundamentals: How Do We Calculate Mass, Error, and Uncertainty in Native Mass Spectrometry? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1807-1812. [PMID: 36130030 DOI: 10.1021/jasms.2c00218] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Mass spectrometry (MS) is uniquely powerful for measuring the mass of intact proteins and other biomolecules. New applications have expanded intact protein analysis into biopharmaceuticals, native MS, and top-down proteomics, all of which have driven the need for more automated data-processing pipelines. However, key metrics in the field are often not precisely defined. For example, there are different views on how to calculate uncertainty from spectra. This Critical Insight will explore the different definitions of mass, error, and uncertainty. It will discuss situations where different definitions may be more suitable and provide recommendations for best practices. Targeting both beginners and experts, the goal of the discussion is to provide a common foundation of terminology, enhance statistical rigor, and improve automation of data analysis.
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Affiliation(s)
- Michael T Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, Arizona 85721, United States
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3
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Bui D, Li Z, Kitov PI, Han L, Kitova EN, Fortier M, Fuselier C, Granger Joly de Boissel P, Chatenet D, Doucet N, Tompkins SM, St-Pierre Y, Mahal LK, Klassen JS. Quantifying Biomolecular Interactions Using Slow Mixing Mode (SLOMO) Nanoflow ESI-MS. ACS CENTRAL SCIENCE 2022; 8:963-974. [PMID: 35912341 PMCID: PMC9335916 DOI: 10.1021/acscentsci.2c00215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) is a powerful label-free assay for detecting noncovalent biomolecular complexes in vitro and is increasingly used to quantify binding thermochemistry. A common assumption made in ESI-MS affinity measurements is that the relative ion signals of free and bound species quantitatively reflect their relative concentrations in solution. However, this is valid only when the interacting species and their complexes have similar ESI-MS response factors (RFs). For many biomolecular complexes, such as protein-protein interactions, this condition is not satisfied. Existing strategies to correct for nonuniform RFs are generally incompatible with static nanoflow ESI (nanoESI) sources, which are typically used for biomolecular interaction studies, thereby significantly limiting the utility of ESI-MS. Here, we introduce slow mixing mode (SLOMO) nanoESI-MS, a direct technique that allows both the RF and affinity (K d) for a biomolecular interaction to be determined from a single measurement using static nanoESI. The approach relies on the continuous monitoring of interacting species and their complexes under nonhomogeneous solution conditions. Changes in ion signals of free and bound species as the system approaches or moves away from a steady-state condition allow the relative RFs of the free and bound species to be determined. Combining the relative RF and the relative abundances measured under equilibrium conditions enables the K d to be calculated. The reliability of SLOMO and its ease of use is demonstrated through affinity measurements performed on peptide-antibiotic, protease-protein inhibitor, and protein oligomerization systems. Finally, affinities measured for the binding of human and bacterial lectins to a nanobody, a viral glycoprotein, and glycolipids displayed within a model membrane highlight the tremendous power and versatility of SLOMO for accurately quantifying a wide range of biomolecular interactions important to human health and disease.
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Affiliation(s)
- Duong
T. Bui
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Zhixiong Li
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Pavel I. Kitov
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Ling Han
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Elena N. Kitova
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Marlène Fortier
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Camille Fuselier
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Philippine Granger Joly de Boissel
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - David Chatenet
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Nicolas Doucet
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Stephen M. Tompkins
- Center
for Vaccines and Immunology, University
of Georgia, Athens, Georgia 30605, United States
- Emory-UGA
Centers of Excellence for Influenza Research and Surveillance (CEIRS), Emory University School of Medicine, Athens, Georgia 30322, United States
| | - Yves St-Pierre
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Lara K. Mahal
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - John S. Klassen
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- . Telephone: (780) 492-3501. Fax: (780) 492-8231
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4
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Abstract
Native mass spectrometry (MS) involves the analysis and characterization of macromolecules, predominantly intact proteins and protein complexes, whereby as much as possible the native structural features of the analytes are retained. As such, native MS enables the study of secondary, tertiary, and even quaternary structure of proteins and other biomolecules. Native MS represents a relatively recent addition to the analytical toolbox of mass spectrometry and has over the past decade experienced immense growth, especially in enhancing sensitivity and resolving power but also in ease of use. With the advent of dedicated mass analyzers, sample preparation and separation approaches, targeted fragmentation techniques, and software solutions, the number of practitioners and novel applications has risen in both academia and industry. This review focuses on recent developments, particularly in high-resolution native MS, describing applications in the structural analysis of protein assemblies, proteoform profiling of─among others─biopharmaceuticals and plasma proteins, and quantitative and qualitative analysis of protein-ligand interactions, with the latter covering lipid, drug, and carbohydrate molecules, to name a few.
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Affiliation(s)
- Sem Tamara
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584
CH Utrecht, The Netherlands
- Netherlands
Proteomics Center, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Maurits A. den Boer
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584
CH Utrecht, The Netherlands
- Netherlands
Proteomics Center, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Albert J. R. Heck
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584
CH Utrecht, The Netherlands
- Netherlands
Proteomics Center, Padualaan
8, 3584 CH Utrecht, The Netherlands
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5
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Scalabrin M, Nadai M, Tassinari M, Lago S, Doria F, Frasson I, Freccero M, Richter SN. Selective Recognition of a Single HIV-1 G-Quadruplex by Ultrafast Small-Molecule Screening. Anal Chem 2021; 93:15243-15252. [PMID: 34762806 PMCID: PMC8613737 DOI: 10.1021/acs.analchem.0c04106] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 10/18/2021] [Indexed: 12/05/2022]
Abstract
G-quadruplexes (G4s) are implicated in pathological processes such as cancer and infective diseases. Their targeting with G4-ligands has shown therapeutic capacity. Most of the current G4-ligands are planar molecules, do not discriminate among G4s, and have poor druglike properties. The available methods to identify compounds selective for one single G4 are often time-consuming. Here, we describe the development, validation, and application of an affinity-selection mass spectrometry method that employs unlabeled G4 oligonucleotides as targets and allows testing of up to 320 unmodified small molecules in a single tube. As a proof of concept, this method was applied to screen a library of 40 000 druglike molecules against two G4s, transcriptional regulators of the HIV-1 LTR promoter. We identified nonplanar pyrazolopyrimidines that selectively recognize and stabilize the major HIV-1 LTR G4 possibly by fitting and binding through H-bonding in its unique binding pocket. The compounds inhibit LTR promoter activity and HIV-1 replication. We propose this method to prompt the fast development of new G4-based therapeutics.
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Affiliation(s)
- Matteo Scalabrin
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Matteo Nadai
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Martina Tassinari
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Sara Lago
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Filippo Doria
- Department
of Chemistry, University of Pavia, 27100 Pavia, Italy
| | - Ilaria Frasson
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Mauro Freccero
- Department
of Chemistry, University of Pavia, 27100 Pavia, Italy
| | - Sara N. Richter
- Department
of Molecular Medicine, University of Padua, 35121 Padua, Italy
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6
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Gabelica V. Native Mass Spectrometry and Nucleic Acid G-Quadruplex Biophysics: Advancing Hand in Hand. Acc Chem Res 2021; 54:3691-3699. [PMID: 34546031 DOI: 10.1021/acs.accounts.1c00396] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
While studying nucleic acids to reveal the weak interactions responsible for their three-dimensional structure and for their interactions with drugs, we also contributed to the field of biomolecular mass spectrometry, both in terms of fundamental understanding and with new methodological developments. A first goal was to develop mass spectrometry approaches to detect noncovalent interactions between antitumor drugs and their DNA target. Twenty years ago, our attention turned toward specific DNA structures such as the G-quadruplex (a structure formed by guanine-rich strands). Mass spectrometry allows one to discern which molecules interact with one another by measuring the masses of the complexes, and quantify the affinities by measuring their abundance. The most important findings came from unexpected masses. For example, we showed the formation of higher- or lower-order structures by G-quadruplexes used in traditional biophysical assays. We also derived complete thermodynamic and kinetic description of G-quadruplex folding pathways by measuring cation binding, one at a time. Getting quantitative information requires accounting for nonspecific adduct formation and for the response factors of the different molecular forms. With these caveats in mind, the approach is now mature enough for routine biophysical characterization of nucleic acids. A second goal is to obtain more detailed structural information on each of the complexes separated by the mass spectrometer. One such approach is ion mobility spectrometry, and even today the challenge lies in the structural interpretation of the measurements. We showed that, although structures such as G-quadruplexes are well-preserved in the MS conditions, double helices actually get more compact in the gas phase. These major rearrangements forced us to challenge comfortable assumptions. Further work is still needed to generalize how to deduce structures in solution from ion mobility spectrometry data and, in particular, how to account for the electrospray charging mechanisms and for ion internal energy effects. These studies also called for complementary approaches to ion mobility spectrometry. Recently, we applied isotope exchange labeling mass spectrometry to characterize nucleic acid structures for the first time, and we reported the first ever circular dichroism ion spectroscopy measurement on mass-selected trapped ions. Circular dichroism plays a key role in assigning the stacking topology, and our new method now opens the door to characterizing a wide variety of chiral molecules by mass spectrometry. In summary, advanced mass spectrometry approaches to characterize gas-phase structures work well for G-quadruplexes because they are stiffened by inner cations. The next objective will be to generalize these methodologies to a wider range of nucleic acid structures.
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Affiliation(s)
- Valérie Gabelica
- Université de Bordeaux, CNRS, INSERM,
ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
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7
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Largy E, König A, Ghosh A, Ghosh D, Benabou S, Rosu F, Gabelica V. Mass Spectrometry of Nucleic Acid Noncovalent Complexes. Chem Rev 2021; 122:7720-7839. [PMID: 34587741 DOI: 10.1021/acs.chemrev.1c00386] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nucleic acids have been among the first targets for antitumor drugs and antibiotics. With the unveiling of new biological roles in regulation of gene expression, specific DNA and RNA structures have become very attractive targets, especially when the corresponding proteins are undruggable. Biophysical assays to assess target structure as well as ligand binding stoichiometry, affinity, specificity, and binding modes are part of the drug development process. Mass spectrometry offers unique advantages as a biophysical method owing to its ability to distinguish each stoichiometry present in a mixture. In addition, advanced mass spectrometry approaches (reactive probing, fragmentation techniques, ion mobility spectrometry, ion spectroscopy) provide more detailed information on the complexes. Here, we review the fundamentals of mass spectrometry and all its particularities when studying noncovalent nucleic acid structures, and then review what has been learned thanks to mass spectrometry on nucleic acid structures, self-assemblies (e.g., duplexes or G-quadruplexes), and their complexes with ligands.
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Affiliation(s)
- Eric Largy
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Alexander König
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Anirban Ghosh
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Debasmita Ghosh
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Sanae Benabou
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Frédéric Rosu
- Univ. Bordeaux, CNRS, INSERM, IECB, UMS 3033, F-33600 Pessac, France
| | - Valérie Gabelica
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
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8
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Bennett JL, Nguyen GTH, Donald WA. Protein-Small Molecule Interactions in Native Mass Spectrometry. Chem Rev 2021; 122:7327-7385. [PMID: 34449207 DOI: 10.1021/acs.chemrev.1c00293] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Small molecule drug discovery has been propelled by the continual development of novel scientific methodologies to occasion therapeutic advances. Although established biophysical methods can be used to obtain information regarding the molecular mechanisms underlying drug action, these approaches are often inefficient, low throughput, and ineffective in the analysis of heterogeneous systems including dynamic oligomeric assemblies and proteins that have undergone extensive post-translational modification. Native mass spectrometry can be used to probe protein-small molecule interactions with unprecedented speed and sensitivity, providing unique insights into polydisperse biomolecular systems that are commonly encountered during the drug discovery process. In this review, we describe potential and proven applications of native MS in the study of interactions between small, drug-like molecules and proteins, including large multiprotein complexes and membrane proteins. Approaches to quantify the thermodynamic and kinetic properties of ligand binding are discussed, alongside a summary of gas-phase ion activation techniques that have been used to interrogate the structure of protein-small molecule complexes. We additionally highlight some of the key areas in modern drug design for which native mass spectrometry has elicited significant advances. Future developments and applications of native mass spectrometry in drug discovery workflows are identified, including potential pathways toward studying protein-small molecule interactions on a whole-proteome scale.
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Affiliation(s)
- Jack L Bennett
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giang T H Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - William A Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
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9
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Dahabra L, Broadberry G, Le Gresley A, Najlah M, Khoder M. Sunscreens Containing Cyclodextrin Inclusion Complexes for Enhanced Efficiency: A Strategy for Skin Cancer Prevention. Molecules 2021; 26:1698. [PMID: 33803643 PMCID: PMC8003006 DOI: 10.3390/molecules26061698] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/09/2021] [Accepted: 03/16/2021] [Indexed: 11/19/2022] Open
Abstract
Unprotected exposure of skin to solar ultraviolet radiation (UVR) may damage the DNA of skin cells and can lead to skin cancer. Sunscreens are topical formulations used to protect skin against UVR. The active ingredients of sunscreens are UV filters that absorb, scatter, and/or reflect UVR. Preventing the formation of free radicals and repairing DNA damages, natural antioxidants are also added to sunscreens as a second fold of protection against UVR. Antioxidants can help stabilise these formulations during the manufacturing process and upon application on skin. However, UV filters and antioxidants are both susceptible to degradation upon exposure to sunlight and oxygen. Additionally, due to their poor water solubility, natural antioxidants are challenging to formulate and exhibit limited penetration and bioavailability in the site of action (i.e., deeper skin layers). Cyclodextrins (CDs) are cyclic oligosaccharides that are capable of forming inclusion complexes with poorly soluble drugs, such as antioxidants. In this review, we discuss the use of CDs inclusion complexes to enhance the aqueous solubility of antioxidants and chemical UV filters and provide a protective shield against degradative factors. The role of CDs in providing a controlled drug release profile from sunscreens is also discussed. Finally, incorporating CDs inclusion complexes into sunscreens has the potential to increase their efficiency and hence improve their skin cancer prevention.
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Affiliation(s)
- Layan Dahabra
- School of Life Sciences, Pharmacy and Chemistry, SEC Faculty, Kingston University, Kingston-upon-Thames KT1 2EE, UK; (L.D.); (G.B.); (A.L.G.)
| | - Grace Broadberry
- School of Life Sciences, Pharmacy and Chemistry, SEC Faculty, Kingston University, Kingston-upon-Thames KT1 2EE, UK; (L.D.); (G.B.); (A.L.G.)
| | - Adam Le Gresley
- School of Life Sciences, Pharmacy and Chemistry, SEC Faculty, Kingston University, Kingston-upon-Thames KT1 2EE, UK; (L.D.); (G.B.); (A.L.G.)
| | - Mohammad Najlah
- Pharmaceutical Research Group, School of Allied Health, Faculty of Health, Education, Medicine and Social Care, Anglia Ruskin University, Bishops Hall Lane, Chelmsford CM1 1SQ, UK;
| | - Mouhamad Khoder
- School of Life Sciences, Pharmacy and Chemistry, SEC Faculty, Kingston University, Kingston-upon-Thames KT1 2EE, UK; (L.D.); (G.B.); (A.L.G.)
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10
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Lee JU, Lee SS, Lee S, Oh HB. Noncovalent Complexes of Cyclodextrin with Small Organic Molecules: Applications and Insights into Host-Guest Interactions in the Gas Phase and Condensed Phase. Molecules 2020; 25:molecules25184048. [PMID: 32899713 PMCID: PMC7571109 DOI: 10.3390/molecules25184048] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/29/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
Cyclodextrins (CDs) have drawn a lot of attention from the scientific communities as a model system for host–guest chemistry and also due to its variety of applications in the pharmaceutical, cosmetic, food, textile, separation science, and essential oil industries. The formation of the inclusion complexes enables these applications in the condensed phases, which have been confirmed by nuclear magnetic resonance (NMR) spectroscopy, X-ray crystallography, and other methodologies. The advent of soft ionization techniques that can transfer the solution-phase noncovalent complexes to the gas phase has allowed for extensive examination of these complexes and provides valuable insight into the principles governing the formation of gaseous noncovalent complexes. As for the CDs’ host–guest chemistry in the gas phase, there has been a controversial issue as to whether noncovalent complexes are inclusion conformers reflecting the solution-phase structure of the complex or not. In this review, the basic principles governing CD’s host–guest complex formation will be described. Applications and structures of CDs in the condensed phases will also be presented. More importantly, the experimental and theoretical evidence supporting the two opposing views for the CD–guest structures in the gas phase will be intensively reviewed. These include data obtained via mass spectrometry, ion mobility measurements, infrared multiphoton dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations.
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Affiliation(s)
- Jae-ung Lee
- Department of Chemistry, Sogang University, Seoul 04107, Korea;
| | - Sung-Sik Lee
- Department of Applied Chemistry, Kyung Hee University, Gyeonggi 17104, Korea;
| | - Sungyul Lee
- Department of Applied Chemistry, Kyung Hee University, Gyeonggi 17104, Korea;
- Correspondence: (S.L.); (H.B.O.); Tel.: +82-31-201-2423 (S.L.); +82-2-705-8444 (H.B.O.)
| | - Han Bin Oh
- Department of Chemistry, Sogang University, Seoul 04107, Korea;
- Correspondence: (S.L.); (H.B.O.); Tel.: +82-31-201-2423 (S.L.); +82-2-705-8444 (H.B.O.)
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11
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Structural insights into Escherichia coli phosphopantothenoylcysteine synthetase by native ion mobility-mass spectrometry. Biochem J 2020; 476:3125-3139. [PMID: 31488574 DOI: 10.1042/bcj20190318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/22/2019] [Accepted: 09/05/2019] [Indexed: 12/19/2022]
Abstract
CoaBC, part of the vital coenzyme A biosynthetic pathway in bacteria, has recently been validated as a promising antimicrobial target. In this work, we employed native ion mobility-mass spectrometry to gain structural insights into the phosphopantothenoylcysteine synthetase domain of E. coli CoaBC. Moreover, native mass spectrometry was validated as a screening tool to identify novel inhibitors of this enzyme, highlighting the utility and versatility of this technique both for structural biology and for drug discovery.
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12
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Marchand A, Czar MF, Eggel EN, Kaeslin J, Zenobi R. Studying biomolecular folding and binding using temperature-jump mass spectrometry. Nat Commun 2020; 11:566. [PMID: 31992698 PMCID: PMC6987177 DOI: 10.1038/s41467-019-14179-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/19/2019] [Indexed: 01/14/2023] Open
Abstract
Characterizing folding and complex formation of biomolecules provides a view into their thermodynamics, kinetics and folding pathways. Deciphering kinetic intermediates is particularly important because they can often be targeted by drugs. The key advantage of native mass spectrometry over conventional methods that monitor a single observable is its ability to identify and quantify coexisting species. Here, we show the design of a temperature-jump electrospray source for mass spectrometry that allows one to perform fast kinetics experiments (0.16-32 s) at different temperatures (10-90 °C). The setup allows recording of both folding and unfolding kinetics by using temperature jumps from high to low, and low to high, temperatures. Six biological systems, ranging from peptides to proteins to DNA complexes, exemplify the use of this device. Using temperature-dependent experiments, the folding and unfolding of a DNA triplex are studied, providing detailed information on its thermodynamics and kinetics.
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Affiliation(s)
- Adrien Marchand
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Martin F Czar
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Elija N Eggel
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Jérôme Kaeslin
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland.
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13
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Nguyen GTH, Leung WY, Tran TN, Wang H, Murray V, Donald WA. Mechanism for the Binding of Netropsin to Hairpin DNA Revealed Using Nanoscale Ion Emitters in Native Mass Spectrometry. Anal Chem 2019; 92:1130-1137. [PMID: 31778608 DOI: 10.1021/acs.analchem.9b04209] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Netropsin is one of the first ligands to be discovered that selectively binds to the minor groove of DNA and is actively used as a scaffold for developing potential anticancer and antibiotic agents. The mechanism by which netropsin binds to hairpin DNA remains controversial with two competing mechanisms having been proposed. In one mechanism, netropsin binding induces a hairpin-to-duplex DNA transition. Alternatively, netropsin binds in two thermodynamically different modes at a single duplexed AATT site. Here, results from native mass spectrometry (MS) with nanoscale ion emitters indicate that netropsin can simultaneously and sequentially bind to both hairpin and duplex DNA. Duplex DNA was not detected using conventional MS with larger emitters because nanoscale emitters significantly reduce the extent of salt adduction to ligand-DNA complex ions, including in the presence of relatively high concentrations of nonvolatile salts. Based on native MS and polyacrylamide gel electrophoresis results, the abundances of hairpin and duplex DNA are unaffected by the addition of netropsin. By native MS, the binding affinities for five ligand-DNA and DNA-DNA interactions can be rapidly obtained simultaneously. This research indicates a "simultaneous binding mechanism" for the interactions of netropsin with DNA.
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Affiliation(s)
- Giang T H Nguyen
- School of Chemistry , University of New South Wales , Sydney New South Wales 2052 , Australia
| | - Wai Yu Leung
- School of Biotechnology and Biomolecular Sciences , University of New South Wales , Sydney New South Wales 2052 , Australia
| | - Thinh N Tran
- School of Chemistry , University of New South Wales , Sydney New South Wales 2052 , Australia
| | - Huixin Wang
- School of Chemistry , University of New South Wales , Sydney New South Wales 2052 , Australia.,Mark Wainwright Analytical Centre , University of New South Wales , Sydney New South Wales 2052 , Australia
| | - Vincent Murray
- School of Biotechnology and Biomolecular Sciences , University of New South Wales , Sydney New South Wales 2052 , Australia
| | - William A Donald
- School of Chemistry , University of New South Wales , Sydney New South Wales 2052 , Australia
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14
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Silion M, Fifere A, Lungoci AL, Marangoci NL, Ibanescu SA, Zonda R, Rotaru A, Pinteală M. Mass Spectrometry as a Complementary Approach for Noncovalently Bound Complexes Based on Cyclodextrins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:685-701. [PMID: 31347079 DOI: 10.1007/978-3-030-15950-4_41] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
An important and well-designed solution to overcome some of the problems associated with new drugs is provided by the molecular encapsulation of the drugs in the cyclodextrins (CDs) cavity, yielding corresponding inclusion complexes (ICs). These types of non-covalent complexes are of current interest to the pharmaceutical industry, as they improve the solubility, stability and bioavailability of the guest molecules. This review highlights several methods for cyclodextrin ICs preparation and characterization, focusing mostly on the mass spectrometry (MS) studies that have been used for the detection of noncovalent interactions of CDs inclusion complexes and binding selectivity of guest molecules with CDs. Furthermore, the MS investigations of several ICs of the CD with antifungal, antioxidants or fluorescent dyes are presented in greater details, pointing out the difficulties overcome in the analysis of this type of compounds.
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Affiliation(s)
- Mihaela Silion
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania.
| | - Adrian Fifere
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Ana Lacramioara Lungoci
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Narcisa Laura Marangoci
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Sorin Alexandru Ibanescu
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Radu Zonda
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Alexandru Rotaru
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
| | - Mariana Pinteală
- Advanced Research Centre for Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania
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15
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Archer JJ, Karki S, Shi F, Sistani H, Levis RJ. Quantification of Protein-Ligand Interactions by Laser Electrospray Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1484-1492. [PMID: 29654537 DOI: 10.1007/s13361-018-1935-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Laser electrospray mass spectrometry (LEMS) measurement of the dissociation constant (Kd) for hen egg white lysozyme (HEWL) and N,N',N″-triacetylchitotriose (NAG3) revealed an apparent Kd value of 313.2 ± 25.9 μM for the ligand titration method. Similar measurements for N,N',N″,N″'-tetraacetylchitotetraose (NAG4) revealed an apparent Kd of 249.3 ± 13.6 μM. An electrospray ionization mass spectrometry (ESI-MS) experiment determined a Kd value of 9.8 ± 0.6 μM. In a second LEMS approach, a calibrated measurement was used to determine a Kd value of 6.8 ± 1.5 μM for NAG3. The capture efficiency of LEMS was measured to be 3.6 ± 1.8% and is defined as the fraction of LEMS sample detected after merging with the ESI plume. When the dilution is factored into the ligand titration measurement, the adjusted Kd value was 11.3 μM for NAG3 and 9.0 μM for NAG4. The calibration method for measuring Kd developed in this study can be applied to solutions containing unknown analyte concentrations. Graphical Abstract.
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Affiliation(s)
- Jieutonne J Archer
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Santosh Karki
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Fengjian Shi
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Habiballah Sistani
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Robert J Levis
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA.
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16
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Gülbakan B, Barylyuk K, Schneider P, Pillong M, Schneider G, Zenobi R. Native Electrospray Ionization Mass Spectrometry Reveals Multiple Facets of Aptamer–Ligand Interactions: From Mechanism to Binding Constants. J Am Chem Soc 2018; 140:7486-7497. [DOI: 10.1021/jacs.7b13044] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Basri Gülbakan
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Hacettepe University Institute of Child Health, Ihsan Dogramaci Children’s Hospital, Sıhhiye Square, 06100 Ankara, Turkey
| | - Konstantin Barylyuk
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Petra Schneider
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Max Pillong
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Gisbert Schneider
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
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17
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Hochberg GKA, Shepherd DA, Marklund EG, Santhanagoplan I, Degiacomi MT, Laganowsky A, Allison TM, Basha E, Marty MT, Galpin MR, Struwe WB, Baldwin AJ, Vierling E, Benesch JLP. Structural principles that enable oligomeric small heat-shock protein paralogs to evolve distinct functions. Science 2018; 359:930-935. [PMID: 29472485 PMCID: PMC6587588 DOI: 10.1126/science.aam7229] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 09/25/2017] [Accepted: 01/08/2018] [Indexed: 12/26/2022]
Abstract
Oligomeric proteins assemble with exceptional selectivity, even in the presence of closely related proteins, to perform their cellular roles. We show that most proteins related by gene duplication of an oligomeric ancestor have evolved to avoid hetero-oligomerization and that this correlates with their acquisition of distinct functions. We report how coassembly is avoided by two oligomeric small heat-shock protein paralogs. A hierarchy of assembly, involving intermediates that are populated only fleetingly at equilibrium, ensures selective oligomerization. Conformational flexibility at noninterfacial regions in the monomers prevents coassembly, allowing interfaces to remain largely conserved. Homomeric oligomers must overcome the entropic benefit of coassembly and, accordingly, homomeric paralogs comprise fewer subunits than homomers that have no paralogs.
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Affiliation(s)
- Georg K A Hochberg
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Dale A Shepherd
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Erik G Marklund
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Indu Santhanagoplan
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Matteo T Degiacomi
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Arthur Laganowsky
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Timothy M Allison
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Eman Basha
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Michael T Marty
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Martin R Galpin
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Weston B Struwe
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Andrew J Baldwin
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK
| | - Elizabeth Vierling
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Justin L P Benesch
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK.
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18
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Yefremova Y, Danquah BD, Opuni KF, El-Kased R, Koy C, Glocker MO. Mass spectrometric characterization of protein structures and protein complexes in condensed and gas phase. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2017; 23:445-459. [PMID: 29183193 DOI: 10.1177/1469066717722256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Proteins are essential for almost all physiological processes of life. They serve a myriad of functions which are as varied as their unique amino acid sequences and their corresponding three-dimensional structures. To fulfill their tasks, most proteins depend on stable physical associations, in the form of protein complexes that evolved between themselves and other proteins. In solution (condensed phase), proteins and/or protein complexes are in constant energy exchange with the surrounding solvent. Albeit methods to describe in-solution thermodynamic properties of proteins and of protein complexes are well established and broadly applied, they do not provide a broad enough access to life-science experimentalists to study all their proteins' properties at leisure. This leaves great desire to add novel methods to the analytical biochemist's toolbox. The development of electrospray ionization created the opportunity to characterize protein higher order structures and protein complexes rather elegantly by simultaneously lessening the need of sophisticated sample preparation steps. Electrospray mass spectrometry enabled us to translate proteins and protein complexes very efficiently into the gas phase under mild conditions, retaining both, intact protein complexes, and gross protein structures upon phase transition. Moreover, in the environment of the mass spectrometer (gas phase, in vacuo), analyte molecules are free of interactions with surrounding solvent molecules and, therefore, the energy of inter- and intramolecular forces can be studied independently from interference of the solvating environment. Provided that gas phase methods can give information which is relevant for understanding in-solution processes, gas phase protein structure studies and/or investigations on the characterization of protein complexes has rapidly gained more and more attention from the bioanalytical scientific community. Recent reports have shown that electrospray mass spectrometry provides direct access to six prime protein complex properties: stabilities, compositions, binding surfaces (epitopes), disassembly processes, stoichiometries, and thermodynamic parameters.
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Affiliation(s)
- Yelena Yefremova
- 1 Proteome Center Rostock, University of Rostock, Rostock, Germany
| | - Bright D Danquah
- 1 Proteome Center Rostock, University of Rostock, Rostock, Germany
| | | | - Reham El-Kased
- 3 Microbiology and Immunology, Faculty of Pharmacy, The British University in Egypt, Cairo, Egypt
| | - Cornelia Koy
- 1 Proteome Center Rostock, University of Rostock, Rostock, Germany
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19
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Ishii K, Zhou M, Uchiyama S. Native mass spectrometry for understanding dynamic protein complex. Biochim Biophys Acta Gen Subj 2017; 1862:275-286. [PMID: 28965879 DOI: 10.1016/j.bbagen.2017.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/17/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022]
Abstract
Biomolecules have evolved to perform specific and sophisticated activities in a highly coordinated manner organizing into multi-component complexes consisting of proteins, nucleic acids, cofactors or ligands. Understanding such complexes represents a task in earnest for modern bioscience. Traditional structural techniques when extrapolating to macromolecules of ever increasing sizes are confronted with limitations posed by the difficulty in enrichment, solubility, stability as well as lack of homogeneity of these complexes. Alternative approaches are therefore prompted to bridge the gap, one of which is native mass spectrometry. Here we demonstrate the strength of native mass spectrometry, used alone or in combination with other biophysical methods such as analytical ultracentrifugation, small-angle neutron scattering, and small-angle X-ray scattering etc., in addressing dynamic aspects of protein complexes including structural reorganization, subunit exchange, as well as the assembly/disassembly processes in solution that are dictated by transient non-covalent interactions. We review recent studies from our laboratories and others applying native mass spectrometry to both soluble and membrane-embedded assemblies. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
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Affiliation(s)
- Kentaro Ishii
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Min Zhou
- Institute of Bio-analytical Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, No. 200 Xiaolingwei Street, Nanjing 210094, China.
| | - Susumu Uchiyama
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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20
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Rautenbach M, Vlok NM, Eyéghé-Bickong HA, van der Merwe MJ, Stander MA. An Electrospray Ionization Mass Spectrometry Study on the "In Vacuo" Hetero-Oligomers Formed by the Antimicrobial Peptides, Surfactin and Gramicidin S. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1623-1637. [PMID: 28560564 DOI: 10.1007/s13361-017-1685-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Abstract
It was previously observed that the lipopeptide surfactants in surfactin (Srf) have an antagonistic action towards the highly potent antimicrobial cyclodecapeptide, gramicidin S (GS). This study reports on some of the molecular aspects of the antagonism as investigated through complementary electrospray ionization mass spectrometry techniques. We were able to detect stable 1:1 and 2:1 hetero-oligomers in a mixture of surfactin and gramicidin S. The noncovalent interaction between GS and Srf, with the proposed equilibrium: GS~Srf↔GS+Srf correlated to apparent K d values of 6-9 μM in gas-phase and 1 μM in aqueous solution. The apparent K d values decreased with a longer incubation time and indicated a slow oligomerization equilibrium. Furthermore, the low μM K dapp values of GS~Srf↔GS+Srf fell within the biological concentration range and related to the 2- to 3-fold increase in [GS] needed for bacterial growth inhibition in the presence of Srf. Competition studies indicated that neither Na+ nor Ca2+ had a major effect on the stability of preformed heterodimers and that GS in fact out-competed Ca2+ and Na+ from Srf. Traveling wave ion mobility mass spectrometry revealed near symmetrical peaks of the heterodimers correlating to a compact dimer conformation that depend on specific interactions. Collision-induced dissociation studies indicated that the peptide interaction is most probably between one Orn residue in GS and the Asp residue, but not the Glu residue in Srf. We propose that flanking hydrophobic residues in both peptides stabilize the antagonistic and inactive peptide hetero-oligomers and shield the specific polar interactions in an aqueous environment. Graphical Abstract ᅟ.
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Affiliation(s)
- Marina Rautenbach
- BIOPEP® Peptide Group, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa.
- Department of Biochemistry, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa.
| | - N Maré Vlok
- BIOPEP® Peptide Group, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
- Department of Biochemistry, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
| | - Hans A Eyéghé-Bickong
- BIOPEP® Peptide Group, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
- Department of Biochemistry, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
| | - Marthinus J van der Merwe
- Department of Biochemistry, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
- LCMS Central Analytical Facility, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
| | - Marietjie A Stander
- Department of Biochemistry, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
- LCMS Central Analytical Facility, University of Stellenbosch, Stellenbosch, 7602, Republic of South Africa
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21
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Abstract
The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR]-, in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies.
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22
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Li W, Yu J, Kane MA. Quantitation of the Noncovalent Cellular Retinol-Binding Protein, Type 1 Complex Through Native Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:29-37. [PMID: 27709511 PMCID: PMC5728378 DOI: 10.1007/s13361-016-1499-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 05/22/2023]
Abstract
Native mass spectrometry (MS) has become a valuable tool in probing noncovalent protein-ligand interactions in a sample-efficient way, yet the quantitative application potential of native MS has not been fully explored. Cellular retinol binding protein, type I (CrbpI) chaperones retinol and retinal in the cell, protecting them from nonspecific oxidation and delivering them to biosynthesis enzymes where the bound (holo-) and unbound (apo-) forms of CrbpI exert distinct biological functions. Using nanoelectrospray, we developed a native MS assay for probing apo- and holo-CrbpI abundance to facilitate exploring their biological functions in retinoid metabolism and signaling. The methods were developed on two platforms, an Orbitrap-based Thermo Exactive and a Q-IMS-TOF-based Waters Synapt G2S, where similar ion behaviors under optimized conditions were observed. Overall, our results suggested that within the working range (~1-10 μM), gas-phase ions in the native state linearly correspond to solution concentration and relative ion intensities of the apo- and holo-protein ions can linearly respond to the solution ratios, suggesting native MS is a viable tool for relative quantitation in this system. Graphical Abstract ᅟ.
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Affiliation(s)
- Wenjing Li
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street, Room 723, Baltimore, MD, 21201, USA
| | - Jianshi Yu
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street, Room 723, Baltimore, MD, 21201, USA
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street, Room 723, Baltimore, MD, 21201, USA.
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23
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Factors Affecting the Formation of 2:1 Host:Guest Inclusion Complexes of 2-[(R-Phenyl)amine]-1,4-naphthalenediones (PAN) in β- and γ-Cyclodextrins. Molecules 2016; 21:molecules21111568. [PMID: 27869734 PMCID: PMC6274144 DOI: 10.3390/molecules21111568] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 12/03/2022] Open
Abstract
The molecular hosts cyclodextrins form inclusion complexes with a wide variety of guests, resulting in complexes with various host:guest stoichiometries. In the case of a series of 19 1,4-naphthoquinolines as guests with either β- or γ-cyclodextrin studied using electrospray mass spectroscopy, in most cases only 1:1 complexes were observed, with 2:1 host:guest complexes observed in just 6 out of 38 host:guest combinations. It is shown that these higher-order complexes were observed only in the case of small (or no) electronically withdrawing substituents, and were much less likely in the case of the larger γ-cyclodextrin host. The size and electronic properties of the substituents involved shows that both steric and electronic factors must be taken into account in predicting which cyclodextrin host:guest stoichiometries will be stable enough to form (or once formed, be robust enough to be observed in the ESI-MS experiments). It is clear that the prediction of host-guest stoichiometry for a specific host-guest pair is complicated, and involves a subtle interplay of both electronic and steric factors. However, there are definite trends, which can be used to help predict host:guest stoichiometry for a given host-guest pair.
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24
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Pedro L, Van Voorhis WC, Quinn RJ. Optimization of Electrospray Ionization by Statistical Design of Experiments and Response Surface Methodology: Protein-Ligand Equilibrium Dissociation Constant Determinations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1520-30. [PMID: 27225419 PMCID: PMC4972871 DOI: 10.1007/s13361-016-1417-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 04/29/2016] [Accepted: 05/04/2016] [Indexed: 05/28/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) binding studies between proteins and ligands under native conditions require that instrumental ESI source conditions are optimized if relative solution-phase equilibrium concentrations between the protein-ligand complex and free protein are to be retained. Instrumental ESI source conditions that simultaneously maximize the relative ionization efficiency of the protein-ligand complex over free protein and minimize the protein-ligand complex dissociation during the ESI process and the transfer from atmospheric pressure to vacuum are generally specific for each protein-ligand system and should be established when an accurate equilibrium dissociation constant (KD) is to be determined via titration. In this paper, a straightforward and systematic approach for ESI source optimization is presented. The method uses statistical design of experiments (DOE) in conjunction with response surface methodology (RSM) and is demonstrated for the complexes between Plasmodium vivax guanylate kinase (PvGK) and two ligands: 5'-guanosine monophosphate (GMP) and 5'-guanosine diphosphate (GDP). It was verified that even though the ligands are structurally similar, the most appropriate ESI conditions for KD determination by titration are different for each. Graphical Abstract ᅟ.
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Affiliation(s)
- Liliana Pedro
- Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | | | - Ronald J Quinn
- Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia.
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25
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Ishii K, Noda M, Uchiyama S. Mass spectrometric analysis of protein-ligand interactions. Biophys Physicobiol 2016; 13:87-95. [PMID: 27924262 PMCID: PMC5042164 DOI: 10.2142/biophysico.13.0_87] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/16/2016] [Indexed: 12/01/2022] Open
Abstract
The interactions of small molecules with proteins (protein–ligand interactions) mediate various biological phenomena including signal transduction and protein transcription and translation. Synthetic compounds such as drugs can also bind to target proteins, leading to the inhibition of protein–ligand interactions. These interactions typically accompany association–dissociation equilibrium according to the free energy difference between free and bound states; therefore, the quantitative biophysical analysis of the interactions, which uncovers the stoichiometry and dissociation constant, is important for understanding biological reactions as well as for rational drug development. Mass spectrometry (MS) has been used to determine the precise molecular masses of molecules. Recent advancements in MS enable us to determine the molecular masses of protein–ligand complexes without disrupting the non-covalent interactions through the gentle desolvation of the complexes by increasing the vacuum pressure of a chamber in a mass spectrometer. This method is called MS under non-denaturing conditions or native MS and allows the unambiguous determination of protein–ligand interactions. Under a few assumptions, MS has also been applied to determine the dissociation constants for protein–ligand interactions. The structural information of a protein–ligand interaction, such as the location of the interaction and conformational change in a protein, can also be analyzed using hydrogen/deuterium exchange MS. In this paper, we briefly describe the history, principle, and recent applications of MS for the study of protein–ligand interactions.
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Affiliation(s)
- Kentaro Ishii
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Masanori Noda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Susumu Uchiyama
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
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26
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Lee HHL, Lee JW, Jang Y, Ko YH, Kim K, Kim HI. Manifesting Subtle Differences of Neutral Hydrophilic Guest Isomers in a Molecular Container by Phase Transfer. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Hyun Hee L. Lee
- Department of Chemistry; Korea University; Seoul 02841 Republic of Korea
| | - Jong Wha Lee
- Department of Chemistry; Korea University; Seoul 02841 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology (POSTECH); Pohang 37673 Republic of Korea
| | - Yoonjung Jang
- Department of Chemistry; Pohang University of Science and Technology (POSTECH); Pohang 37673 Republic of Korea
- Center for Self-Assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
| | - Young Ho Ko
- Center for Self-Assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
| | - Kimoon Kim
- Department of Chemistry; Pohang University of Science and Technology (POSTECH); Pohang 37673 Republic of Korea
- Center for Self-Assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
| | - Hugh I. Kim
- Department of Chemistry; Korea University; Seoul 02841 Republic of Korea
- Center for Self-Assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
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27
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Berezovskaya Y, Porrini M, Nortcliffe C, Barran PE. The use of ion mobility mass spectrometry to assist protein design: a case study on zinc finger fold versus coiled coil interactions. Analyst 2016; 140:2847-56. [PMID: 25734188 DOI: 10.1039/c4an00427b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dramatic conformational change in zinc fingers on binding metal ions for DNA recognition makes their structure-function behaviour an attractive target to mimic in de novo designed peptides. Mass spectrometry, with its high throughput and low sample consumption provides insight into how primary amino acid sequence can encode stable tertiary fold. We present here the use of ion mobility mass spectrometry (IM-MS) coupled with molecular dynamics (MD) simulations as a rapid analytical platform to inform de novo design efforts for peptide-metal and peptide-peptide interactions. A dual peptide-based synthetic system, ZiCop based on a zinc finger peptide motif, and a coiled coil partner peptide Pp, have been investigated. Titration mass spectrometry determines the relative binding affinities of different divalent metal ions as Zn(2+) > Co(2+) ≫ Ca(2+). With collision induced dissociation (CID), we probe complex stability, and establish that peptide-metal interactions are stronger and more 'specific' than those of peptide-peptide complexes, and the anticipated hetero-dimeric complex is more stable than the two homo-dimers. Collision cross-sections (CCS) measurements by IM-MS reveal increased stability with respect to unfolding of the metal-bound peptide over its apo-form, and further, larger collision cross sections for the hetero-dimeric forms suggest that dimeric species formed in the absence of metal are coiled coil like. MD supports these structural assignments, backed up by data from visible light absorbance measurements.
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28
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Molecular and environmental factors governing non–covalent bonding interactions and conformations of phosphorous functionalized γ-cyclodextrin hydrate systems. Int J Biol Macromol 2016; 87:263-72. [DOI: 10.1016/j.ijbiomac.2016.02.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 01/17/2023]
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29
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Lee HHL, Lee JW, Jang Y, Ko YH, Kim K, Kim HI. Manifesting Subtle Differences of Neutral Hydrophilic Guest Isomers in a Molecular Container by Phase Transfer. Angew Chem Int Ed Engl 2016; 55:8249-53. [PMID: 27192972 DOI: 10.1002/anie.201601320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/25/2016] [Indexed: 11/09/2022]
Abstract
Achieving strong host-guest interactions between synthetic hosts and hydrophilic guests in solution is challenging because solvation effects overwhelm other effects. To resolve this issue, we transferred complexes of cucurbit[7]uril (CB[7]) and monosaccharides to the gas phase and report here their intrinsic host-guest chemistry in the absence of solvation effects. It was observed that effective host-guest interactions in the gas phase mediated by ammonium cations allow the differentiation of the monosaccharide isomers in complex with CB[7] upon vibrational excitation. The potential of the unique observation was extended to a quantitative supramolecular analytical method for the monosaccharide guests. The combination of host-guest chemistry and phase transfer presented in this study is an effective approach to overcome current limitations in supramolecular chemistry.
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Affiliation(s)
- Hyun Hee L Lee
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea
| | - Jong Wha Lee
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea.,Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Yoonjung Jang
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.,Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
| | - Young Ho Ko
- Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
| | - Kimoon Kim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. .,Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea.
| | - Hugh I Kim
- Department of Chemistry, Korea University, Seoul, 02841, Republic of Korea. .,Center for Self-Assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea.
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30
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31
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Shamsipur M, Allahyari L, Fasihi J, Taherpour A(A, Asfari Z, Valinejad A. Study of complexation between two 1,3-alternate calix[4]crown derivatives and alkali metal ions by electrospray ionization mass spectrometry and density functional theory calculations. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2015.11.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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32
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Berland K, Renaud JB, Mayer PM. Utilizing ion mobility and tandem mass spectrometry to evaluate the structure and behaviour of multimeric cyclodextrin complexes. CAN J CHEM 2015. [DOI: 10.1139/cjc-2014-0419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Characterizing noncovalent complexes of molecular dimers and higher complexes using tandem mass spectrometry (MS/MS) can be hindered due to spectral overlap in both the MS and the MS/MS. We investigated the structures and dissociation energetics of multimeric β-cyclodextrin (β-CD) complexes alone or with substrates using combinations of ion mobility spectrometry (IMS), MS/MS, and Rice–Ramsperger–Kassel–Marcus (RRKM) unimolecular rate modelling. The doubly charged β-CD dimers ([(β-CD)2 – 2H+]2−) dissociate to two [β-CD – H+]− ions with the same m/z. IMS was used to separate source generated [(β-CD)2 – 2H+]2− from [β-CD – H+]− and the extent of [(β-CD)2 – 2H+]2− dissociation versus collision energy was determined by modelling changes in the ion’s isotopic profile. The RRKM derived critical energy (E0) for dissociation of [(β-CD)2 – H+]− and [(β-CD)2 – 2H+]2− were 1.85 ± 0.11 eV and 1.79 ± 0.09 eV, respectively, corresponding to a slight decrease in complex stability due to increased charge–charge repulsion in the dianion. This approach was extended to include dimeric complexes complexed to 4,4′-(propane-1,3-diyl) dibenzoic acid (PDDA) and ibuprofen (Ibu).
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Affiliation(s)
- Kevin Berland
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Justin B. Renaud
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Paul M. Mayer
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
- Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
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33
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Laughlin S, Wilson WD. May the Best Molecule Win: Competition ESI Mass Spectrometry. Int J Mol Sci 2015; 16:24506-31. [PMID: 26501262 PMCID: PMC4632762 DOI: 10.3390/ijms161024506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/18/2015] [Accepted: 10/09/2015] [Indexed: 02/07/2023] Open
Abstract
Electrospray ionization mass spectrometry has become invaluable in the characterization of macromolecular biological systems such as nucleic acids and proteins. Recent advances in the field of mass spectrometry and the soft conditions characteristic of electrospray ionization allow for the investigation of non-covalent interactions among large biomolecules and ligands. Modulation of genetic processes through the use of small molecule inhibitors with the DNA minor groove is gaining attention as a potential therapeutic approach. In this review, we discuss the development of a competition method using electrospray ionization mass spectrometry to probe the interactions of multiple DNA sequences with libraries of minor groove binding molecules. Such an approach acts as a high-throughput screening method to determine important information including the stoichiometry, binding mode, cooperativity, and relative binding affinity. In addition to small molecule-DNA complexes, we highlight other applications in which competition mass spectrometry has been used. A competitive approach to simultaneously investigate complex interactions promises to be a powerful tool in the discovery of small molecule inhibitors with high specificity and for specific, important DNA sequences.
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Affiliation(s)
- Sarah Laughlin
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.
| | - W David Wilson
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.
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34
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Pujol-Pina R, Vilaprinyó-Pascual S, Mazzucato R, Arcella A, Vilaseca M, Orozco M, Carulla N. SDS-PAGE analysis of Aβ oligomers is disserving research into Alzheimer´s disease: appealing for ESI-IM-MS. Sci Rep 2015; 5:14809. [PMID: 26450154 PMCID: PMC4598734 DOI: 10.1038/srep14809] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/09/2015] [Indexed: 12/20/2022] Open
Abstract
The characterization of amyloid-beta peptide (Aβ) oligomer forms and structures is crucial to the advancement in the field of Alzheimer´s disease (AD). Here we report a critical evaluation of two methods used for this purpose, namely sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), extensively used in the field, and ion mobility coupled to electrospray ionization mass spectrometry (ESI-IM-MS), an emerging technique with great potential for oligomer characterization. To evaluate their performance, we first obtained pure cross-linked Aβ40 and Aβ42 oligomers of well-defined order. Analysis of these samples by SDS-PAGE revealed that SDS affects the oligomerization state of Aβ42 oligomers, thus providing flawed information on their order and distribution. In contrast, ESI-IM-MS provided accurate information, while also reported on the chemical nature and on the structure of the oligomers. Our findings have important implications as they challenge scientific paradigms in the AD field built upon SDS-PAGE characterization of Aβ oligomer samples.
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Affiliation(s)
- Rosa Pujol-Pina
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | | | - Roberta Mazzucato
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Annalisa Arcella
- Joint IRB-BSC Research Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Marta Vilaseca
- Mass Spectrometry Core Facility, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Modesto Orozco
- Joint IRB-BSC Research Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.,Department of Biochemistry and Molecular Biology, University of Barcelona, Diagonal 647, Barcelona 08028, Spain
| | - Natàlia Carulla
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
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35
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Przybylski C, Bonnet V, Cézard C. Probing the common alkali metal affinity of native and variously methylated β-cyclodextrins by combining electrospray-tandem mass spectrometry and molecular modeling. Phys Chem Chem Phys 2015; 17:19288-305. [PMID: 26138713 DOI: 10.1039/c5cp02895g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In the study herein, we investigated the solution and gas phase affinity of native and variously methylated β-cyclodextrins (CDs) as hosts towards three common alkali metals as guests namely lithium, sodium and potassium. For this purpose, two complementary approaches have been employed: electrospray-tandem mass spectrometry (ESI-MS/MS) with two energetic regimes: Collision Induced Dissociation (CID) and Higher Collision Dissociation (HCD), respectively, and DFT molecular modeling. These approaches have been achieved by taking into account the interaction of either one or two alkali metals with the host molecules. The results showed a good agreement between experimental and theoretical data. It was demonstrated that increasing the methylation degree strengthened the gas phase affinity towards all studied alkali metals. Furthermore, it was established that the cation selectivity was Na(+) > Li(+) > K(+) and Li(+) > Na(+) > K(+) for the solution and gas phase, respectively.
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Affiliation(s)
- Cédric Przybylski
- Université d'Evry-Val-d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, CNRS UMR 8587, Bâtiment Maupertuis, Bld F. Mitterrand, F-91025 Evry, France.
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36
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Santos IC, Waybright VB, Fan H, Ramirez S, Mesquita RBR, Rangel AOSS, Fryčák P, Schug KA. Determination of Noncovalent Binding Using a Continuous Stirred Tank Reactor as a Flow Injection Device Coupled to Electrospray Ionization Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1204-1212. [PMID: 25832030 DOI: 10.1007/s13361-015-1113-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 06/04/2023]
Abstract
Described is a new method based on the concept of controlled band dispersion, achieved by hyphenating flow injection analysis with ESI-MS for noncovalent binding determinations. A continuous stirred tank reactor (CSTR) was used as a FIA device for exponential dilution of an equimolar host-guest solution over time. The data obtained was treated for the noncovalent binding determination using an equimolar binding model. Dissociation constants between vancomycin and Ac-Lys(Ac)-Ala-Ala-OH peptide stereoisomers were determined using both the positive and negative ionization modes. The results obtained for Ac-L-Lys(Ac)-D-Ala-D-Ala (a model for a Gram-positive bacterial cell wall) binding were in reasonable agreement with literature values made by other mass spectrometry binding determination techniques. Also, the developed method allowed the determination of dissociation constants for vancomycin with Ac-L-Lys(Ac)-D-Ala-L-Ala, Ac-L-Lys(Ac)-L-Ala-D-Ala, and Ac-L-Lys(Ac)-L-Ala-L-Ala. Although some differences in measured binding affinities were noted using different ionization modes, the results of each determination were generally consistent. Differences are likely attributable to the influence of a pseudo-physiological ammonium acetate buffer solution on the formation of positively- and negatively-charged ionic complexes.
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Affiliation(s)
- Inês C Santos
- CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401, Porto, Portugal
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37
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Laughlin S, Wang S, Kumar A, Farahat AA, Boykin DW, Wilson WD. Resolution of mixed site DNA complexes with dimer-forming minor-groove binders by using electrospray ionization mass spectrometry: compound structure and DNA sequence effects. Chemistry 2015; 21:5528-39. [PMID: 25703690 PMCID: PMC4732565 DOI: 10.1002/chem.201406322] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 12/18/2022]
Abstract
Small-molecule targeting of the DNA minor groove is a promising approach to modulate genomic processes necessary for normal cellular function. For instance, dicationic diamindines, a well-known class of minor groove binding compounds, have been shown to inhibit interactions of transcription factors binding to genomic DNA. The applications of these compounds could be significantly expanded if we understand sequence-specific recognition of DNA better and could use the information to design more sequence-specific compounds. Aside from polyamides, minor groove binders typically recognize DNA at A-tract or alternating AT base pair sites. Targeting sites with GC base pairs, referred to here as mixed base pair sequences, is much more difficult than those rich in AT base pairs. Compound 1 is the first dicationic diamidine reported to recognize a mixed base pair site. It binds in the minor groove of ATGA sequences as a dimer with positive cooperativity. Due to the well-characterized behavior of 1 with ATGA and AT rich sequences, it provides a paradigm for understanding the elements that are key for recognition of mixed sequence sites. Electrospray ionization mass spectrometry (ESI-MS) is a powerful method to screen DNA complexes formed by analogues of 1 for specific recognition. We also report a novel approach to determine patterns of recognition by 1 for cognate ATGA and ATGA-mutant sequences. We found that functional group modifications and mutating the DNA target site significantly affect binding and stacking, respectively. Both compound conformation and DNA sequence directionality are crucial for recognition.
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Affiliation(s)
- Sarah Laughlin
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - Siming Wang
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - Arvind Kumar
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - Abdelbasset A. Farahat
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - David W. Boykin
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - W. David Wilson
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
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38
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Otsuka Y, Minamisawa T. Evaluation of intermolecular association of glycosaminoglycan oligosaccharides using nanoelectrospray ionization mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2015; 21:669-678. [PMID: 26353989 DOI: 10.1255/ejms.1376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study examines the non-covalent interactions between glycosaminoglycan (GAG) oligosaccharides using nanoelectrospray ionization mass spectrometry (nanoESI-MS). It is the first time that interactions between oligosaccharides have been observed using MS. The importance of interactions between GAGs has recently attracted much interest because they are related to biological functions. For instance, hyaluronic acid (HA) is known to associate with chondroitin sulfates (CSs), although the details of the interaction remain unclear. In general, non-covalent interactions between glycans are too weak to detect by general means. In this work, we applied nanoESI-MS with high sensitivity, which is widely used to observe non-covalent interactions, to investigate the interaction between HA and CSs. HA and CS oligosaccharides are used to discuss the results in a simplified manner. Our approach is aimed at interpreting the behavior of GAG polysaccharides from the information obtained using the oligosaccharides. HA and CS tetrasaccharides were demonstrated to associate to form heterodimer ions that were easily detected using nanoESI-MS. We also determined the stoichiometry of the interaction and calculated the K(d) values of the interactions between HA and CS tetrasaccharides. How these structures affect the strength and stability of the non-covalent complexes is discussed. Further study of the interactions between HA and CS oligosaccharides will clarify the biological meaning of the coexistence of HA and CS in body fluids and tissues.
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Affiliation(s)
- Yuya Otsuka
- Central Research Laboratories, Seikagaku Corporation, 1253, Tateno 3-chome, Higashiyamato-shi, Tokyo, 207-0021, Japan.
| | - Toshikazu Minamisawa
- Central Research Laboratories, Seikagaku Corporation, 1253, Tateno 3-chome, Higashiyamato-shi, Tokyo, 207-0021, Japan.
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39
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Beveridge R, Covill S, Pacholarz KJ, Kalapothakis JMD, MacPhee CE, Barran PE. A Mass-Spectrometry-Based Framework To Define the Extent of Disorder in Proteins. Anal Chem 2014; 86:10979-91. [DOI: 10.1021/ac5027435] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rebecca Beveridge
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Sam Covill
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Kamila J. Pacholarz
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Jason M. D. Kalapothakis
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Cait E. MacPhee
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Perdita E. Barran
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
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40
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Podjava A, Kistkin S, Ausekle E, Priede E, Mekss P, Zicmanis A. Electrospray ionization mass spectrometry of non-covalent complexes formed between N-alkylimidazolium-containing zwitterionic sulfonates and protonated bases. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2014; 20:467-475. [PMID: 25905871 DOI: 10.1255/ejms.1303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper describes non-covalent complexes between zwitterionic 3-(1-alkyl-3N-imidazolio)- propane-1-sulfonates and different amines. Electrospray ionization (ESI) mass spectrometry and collision- induced dissociation were used to measure the stability of such complexes in solution and in the gas phase. Generally, zwitterionic sulfonates formed more abundant complexes with protonated 5-methylcytosine (5-MCH) than with aliphatic amines. The results show that the association constants and half-dissociation threshold energies of these complexes nonlinearly depend on the alkyl chain length of the zwitterion. It is shown that the complexes with the lowest stability exist in acetonitrile solution or in the gas phase. The factors responsible for this complicated behavior are discussed. The structure of the complexes was investigated by quantum chemical calculations using molecular mechanics and density functional theory. Hydrogen bonding is proposed as the main type of interaction responsible for the stability of ion-zwitterion complexes. In summary, the information obtained in this study could be used for the development of the new derivatization reagents for some compounds containing amidinium groups, like 5-MCH, to increase selectivity of ESI-based methods.
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Affiliation(s)
- Anton Podjava
- Department of Chemistry, University of Latvia, Riga, Latvia.
| | | | - Elina Ausekle
- Department of Chemistry, University of Latvia, Riga, Latvia.
| | - Elina Priede
- Department of Chemistry, University of Latvia, Riga, Latvia.
| | - Peteris Mekss
- Department of Chemistry, University of Latvia, Riga, Latvia.
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41
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Barylyuk K, Gülbakan B, Xie X, Zenobi R. DNA oligonucleotides: a model system with tunable binding strength to study monomer-dimer equilibria with electrospray ionization-mass spectrometry. Anal Chem 2013; 85:11902-12. [PMID: 24274465 DOI: 10.1021/ac402669e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Electrospray ionization (ESI) is increasingly used to measure binding strengths, but it is not always clear whether the ESI process introduces artifacts. Here we propose a model monomer-dimer equilibrium system based on DNA oligonucleotides to systematically explore biomolecular self-association with the ESI-mass spectrometry (MS) titration method. The oligonucleotides are designed to be self-complementary and have the same chemical composition and mass, allowing for equal ionization probability, ion transmission, and detection efficiency in ESI-MS. The only difference is the binding strength, which is determined by the nucleotide sequence and can be tuned to cover a range of dissociation constant values. This experimental design allows one to focus on the impact of ESI on the chemical equilibrium and to avoid the other typical sources of variation in ESI-MS signal responses, which yields a direct comparison of samples with different binding strengths. For a set of seven model DNA oligonucleotides, the monomer-dimer binding equilibrium was probed with the ESI-MS titration method in both positive and negative ion modes. A mathematical model describing the dependence of the monomer-to-dimer peak intensity ratio on the DNA concentration was proposed and used to extract apparent Kd values and the fraction of DNA duplex that irreversibly dissociates in the gas phase. The Kd values determined via ESI-MS titration were compared to those determined in solution with isothermal titration calorimetry and equilibrium thermal denaturation methods and were found to be significantly lower. The observed discrepancy was attributed to a greater electrospray response of dimers relative to that of monomers.
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Affiliation(s)
- Konstantin Barylyuk
- Department of Chemistry and Applied Biosciences, ETH Zurich , Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
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Affiliation(s)
- Shengwen Shen
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
| | - Xing-Fang Li
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
| | - William R. Cullen
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver,
British Columbia, Canada, V6T 1Z1
| | - Michael Weinfeld
- Department of Oncology, Cross
Cancer Institute, University of Alberta, 11560 University Avenue, Edmonton, Alberta, Canada, T6G 1Z2
| | - X. Chris Le
- Department
of Laboratory Medicine
and Pathology, 10-102 Clinical Sciences Building, University
of Alberta, Edmonton, Alberta, Canada, T6G 2G3
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43
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Lin H, Kitova EN, Klassen JS. Quantifying Protein–Ligand Interactions by Direct Electrospray Ionization-MS Analysis: Evidence of Nonuniform Response Factors Induced by High Molecular Weight Molecules and Complexes. Anal Chem 2013; 85:8919-22. [DOI: 10.1021/ac401936x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hong Lin
- Department
of Chemistry and
Alberta Glycomics Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Elena N. Kitova
- Department
of Chemistry and
Alberta Glycomics Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - John S. Klassen
- Department
of Chemistry and
Alberta Glycomics Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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44
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Weidmann S, Mikutis G, Barylyuk K, Zenobi R. Mass discrimination in high-mass MALDI-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:1396-1404. [PMID: 23836380 DOI: 10.1007/s13361-013-0686-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 05/27/2013] [Accepted: 05/28/2013] [Indexed: 06/02/2023]
Abstract
In high-mass matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), the accessible m/z range is limited by the detector used. Therefore, special high-mass detectors based on ion conversion dynodes (ICDs) have been developed. Recently, we have found that mass bias may exist when such ICD detectors are used [Weidmann et al., Anal. Chem. 85(6), 3425-3432 (2013)]. In this contribution, the mass-dependent response of an ICD detector was systematically studied, the response factors for proteins with molecular weights from 35.9 to 129.9 kDa were determined, and the reasons for mass bias were identified. Compared with commonly employed microchannel plate detectors, we found that the mass discrimination is less pronounced, although ions with higher masses are weakly favored when using an ICD detector. The relative response was found to depend on the laser power used for MALDI; low-mass ions are discriminated against with higher laser power. The effect of mutual ion suppression in dependence of the proteins used and their molar ratio is shown. Mixtures consisting of protein oligomers that only differ in mass show less mass discrimination than mixtures consisting of different proteins with similar masses. Furthermore, mass discrimination increases for molar ratios far from 1. Finally, we present clear guidelines that help to choose the experimental parameters such that the response measured matches the actual molar fraction as closely as possible.
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Affiliation(s)
- Simon Weidmann
- Department of Chemistry and Applied Biosciences, ETH (Swiss Federal Institute of Technology) Zürich, Zürich, Switzerland
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He X, Wei W, Chu Y, Liu Z, Ding C. Investigation on Non‐covalent Complexes of Cyclodextrins with Li+ in Gas Phase by Mass Spectrometry. CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/03/287-294] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Nguyen SN, Bobst CE, Kaltashov IA. Mass spectrometry-guided optimization and characterization of a biologically active transferrin-lysozyme model drug conjugate. Mol Pharm 2013; 10:1998-2007. [PMID: 23534953 DOI: 10.1021/mp400026y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Transferrin is a promising drug carrier that has the potential to deliver metals, small organic molecules and therapeutic proteins to cancer cells and/or across physiological barriers (such as the blood-brain barrier). Despite this promise, very few transferrin-based therapeutics have been developed and reached clinical trials. This modest success record can be explained by the complexity and heterogeneity of protein conjugation products, which also pose great challenges to their analytical characterization. In this work, we use lysozyme conjugated to transferrin as a model therapeutic that targets the central nervous system (where its bacteriostatic properties may be exploited to control infection) and develop analytical protocols based on electrospray ionization mass spectrometry to characterize its structure and interactions with therapeutic targets and physiological partners critical for its successful delivery. Mass spectrometry has already become an indispensable tool facilitating all stages of the protein drug development process, and this work demonstrates the enormous potential of this technique in facilitating the development of a range of therapeutically effective protein-drug conjugates.
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Affiliation(s)
- Son N Nguyen
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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Chen F, Gülbakan B, Zenobi R. Direct access to aptamer–protein complexes via MALDI-MS. Chem Sci 2013. [DOI: 10.1039/c3sc51410b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Atmanene C, Wagner-Rousset E, Corvaïa N, Van Dorsselaer A, Beck A, Sanglier-Cianférani S. Noncovalent mass spectrometry for the characterization of antibody/antigen complexes. Methods Mol Biol 2013; 988:243-268. [PMID: 23475725 DOI: 10.1007/978-1-62703-327-5_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Monoclonal antibodies (mAbs) have taken on an increasing importance for the treatment of various diseases including cancers, immunological disorders, and other pathologies. These large biomolecules display specific structural features, which affect their efficiency and need therefore to be extensively characterized using sensitive and orthogonal analytical techniques. Among them, mass spectrometry (MS) has become the method of choice to study mAb amino acid sequences as well as their posttranslational modifications with the aim of reducing their chemistry, manufacturing, and control liabilities. This chapter will provide the reader with a description of the general approach allowing antibody/antigen systems to be characterized by noncovalent MS. In the present chapter, we describe how recent noncovalent MS technologies are used to characterize immune complexes involving both murine and humanized mAb 6F4 directed against human JAM-A, a newly identified antigenic protein (Ag) over-expressed in tumor cells. We will detail experimental conditions (sample preparation, optimization of instrumental parameters, etc.) required for the detection of noncovalent antibody/antigen complexes by MS. We will then focus on the type and the reliability of the information that we get from noncovalent MS data, with emphasis on the determination of the stoichiometry of antibody/antigen systems. Noncovalent MS appears as an additional supporting technique for therapeutic mAbs lead characterization and development.
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Affiliation(s)
- Cédric Atmanene
- Laboratoire de Spectrométrie de Masse Bio-Organique, IPHC, CNRS, UMR7178, Université de Strasbourg, Strasbourg, France
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Ferreira R, Marchand A, Gabelica V. Mass spectrometry and ion mobility spectrometry of G-quadruplexes. A study of solvent effects on dimer formation and structural transitions in the telomeric DNA sequence d(TAGGGTTAGGGT). Methods 2012; 57:56-63. [PMID: 22465284 DOI: 10.1016/j.ymeth.2012.03.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/14/2012] [Accepted: 03/17/2012] [Indexed: 11/25/2022] Open
Abstract
We survey here state of the art mass spectrometry methodologies for investigating G-quadruplexes, and will illustrate them with a new study on a simple model system: the dimeric G-quadruplex of the 12-mer telomeric DNA sequence d(TAGGGTTAGGGT), which can adopt either a parallel or an antiparallel structure. We will discuss the solution conditions compatible with electrospray ionisation, the quantification of complexes using ESI-MS, the interpretation of ammonium ion preservation in the complexes in the gas phase, and the use of ion mobility spectrometry to resolve ambiguities regarding the strand stoichiometry, or separate and characterise different structural isomers. We also describe that adding electrospray-compatible organic co-solvents (methanol, ethanol, isopropanol or acetonitrile) to aqueous ammonium acetate increases the stability and rate of formation of dimeric G-quadruplexes, and causes structural transitions to parallel structures. Structural changes were probed by circular dichroism and ion mobility spectrometry, and the excellent correlation between the two techniques validates the use of ion mobility to investigate G-quadruplex folding. We also demonstrate that parallel G-quadruplex structures are easier to preserve in the gas phase than antiparallel structures.
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Affiliation(s)
- Rubén Ferreira
- Department of Chemistry and Molecular Pharmacology, Institute for Research in Biomedicine (IRB Barcelona), IQAC-CSIC, CIBER-BNN, Baldiri i Reixac 10, E-08028 Barcelona, Spain
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Kitova EN, El-Hawiet A, Schnier PD, Klassen JS. Reliable determinations of protein-ligand interactions by direct ESI-MS measurements. Are we there yet? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:431-41. [PMID: 22270873 DOI: 10.1007/s13361-011-0311-9] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 11/25/2011] [Accepted: 11/29/2011] [Indexed: 05/11/2023]
Abstract
The association-dissociation of noncovalent interactions between protein and ligands, such as other proteins, carbohydrates, lipids, DNA, or small molecules, are critical events in many biological processes. The discovery and characterization of these interactions is essential to a complete understanding of biochemical reactions and pathways and to the design of novel therapeutic agents that may be used to treat a variety of diseases and infections. Over the last 20 y, electrospray ionization mass spectrometry (ESI-MS) has emerged as a versatile tool for the identification and quantification of protein-ligand interactions in vitro. Here, we describe the implementation of the direct ESI-MS assay for the determination of protein-ligand binding stoichiometry and affinity. Additionally, we outline common sources of error encountered with these measurements and various strategies to overcome them. Finally, we comment on some of the outstanding challenges associated with the implementation of the assay and highlight new areas where direct ESI-MS measurements are expected to make significant contributions in the future.
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Affiliation(s)
- Elena N Kitova
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2
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