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Krylov SN. Underestimation of the Complexity of K d Determination: Causes, Implications, and Ways to Improve. ACS MEASUREMENT SCIENCE AU 2024; 4:231-232. [PMID: 38910863 PMCID: PMC11191718 DOI: 10.1021/acsmeasuresciau.4c00023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Indexed: 06/25/2024]
Affiliation(s)
- Sergey N. Krylov
- Department
of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
- Centre
for Research on Biomolecular Interactions, York University 4700
Keele Street, Toronto, Ontario M3J 1P3, Canada
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2
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Ives CM, Nguyen L, Fogarty CA, Harbison AM, Durocher Y, Klassen J, Fadda E. Role of N343 glycosylation on the SARS-CoV-2 S RBD structure and co-receptor binding across variants of concern. eLife 2024; 13:RP95708. [PMID: 38864493 PMCID: PMC11168744 DOI: 10.7554/elife.95708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024] Open
Abstract
Glycosylation of the SARS-CoV-2 spike (S) protein represents a key target for viral evolution because it affects both viral evasion and fitness. Successful variations in the glycan shield are difficult to achieve though, as protein glycosylation is also critical to folding and structural stability. Within this framework, the identification of glycosylation sites that are structurally dispensable can provide insight into the evolutionary mechanisms of the shield and inform immune surveillance. In this work, we show through over 45 μs of cumulative sampling from conventional and enhanced molecular dynamics (MD) simulations, how the structure of the immunodominant S receptor binding domain (RBD) is regulated by N-glycosylation at N343 and how this glycan's structural role changes from WHu-1, alpha (B.1.1.7), and beta (B.1.351), to the delta (B.1.617.2), and omicron (BA.1 and BA.2.86) variants. More specifically, we find that the amphipathic nature of the N-glycan is instrumental to preserve the structural integrity of the RBD hydrophobic core and that loss of glycosylation at N343 triggers a specific and consistent conformational change. We show how this change allosterically regulates the conformation of the receptor binding motif (RBM) in the WHu-1, alpha, and beta RBDs, but not in the delta and omicron variants, due to mutations that reinforce the RBD architecture. In support of these findings, we show that the binding of the RBD to monosialylated ganglioside co-receptors is highly dependent on N343 glycosylation in the WHu-1, but not in the delta RBD, and that affinity changes significantly across VoCs. Ultimately, the molecular and functional insight we provide in this work reinforces our understanding of the role of glycosylation in protein structure and function and it also allows us to identify the structural constraints within which the glycosylation site at N343 can become a hotspot for mutations in the SARS-CoV-2 S glycan shield.
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Affiliation(s)
- Callum M Ives
- Department of Chemistry, Maynooth UniversityMaynoothIreland
| | - Linh Nguyen
- Department of Chemistry, University of AlbertaEdmontonCanada
| | - Carl A Fogarty
- Department of Chemistry, Maynooth UniversityMaynoothIreland
| | | | - Yves Durocher
- Human Health Therapeutics Research Centre, Life Sciences Division, National Research Council CanadaQuébecCanada
- Département de Biochimie et Médecine Moléculaire, Université de MontréalQuébecCanada
| | - John Klassen
- Department of Chemistry, University of AlbertaEdmontonCanada
| | - Elisa Fadda
- School of Biological Sciences, University of SouthamptonSouthamptonUnited Kingdom
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3
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Yabut KCB, Martynova A, Nath A, Zercher BP, Bush MF, Isoherranen N. Drugs Form Ternary Complexes with Human Liver Fatty Acid Binding Protein 1 (FABP1) and FABP1 Binding Alters Drug Metabolism. Mol Pharmacol 2024; 105:395-410. [PMID: 38580446 PMCID: PMC11114116 DOI: 10.1124/molpharm.124.000878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/24/2024] [Accepted: 03/26/2024] [Indexed: 04/07/2024] Open
Abstract
Liver fatty acid binding protein 1 (FABP1) binds diverse endogenous lipids and is highly expressed in the human liver. Binding to FABP1 alters the metabolism and homeostasis of endogenous lipids in the liver. Drugs have also been shown to bind to rat FABP1, but limited data are available for human FABP1 (hFABP1). FABP1 has a large binding pocket, and up to two fatty acids can bind to FABP1 simultaneously. We hypothesized that drug binding to hFABP1 results in formation of ternary complexes and that FABP1 binding alters drug metabolism. To test these hypotheses, native protein mass spectrometry (MS) and fluorescent 11-(dansylamino)undecanoic acid (DAUDA) displacement assays were used to characterize drug binding to hFABP1, and diclofenac oxidation by cytochrome P450 2C9 (CYP2C9) was studied in the presence and absence of hFABP1. DAUDA binding to hFABP1 involved high (Kd,1 = 0.2 μM) and low (Kd,2 > 10 μM) affinity binding sites. Nine drugs bound to hFABP1 with equilibrium dissociation constant (Kd) values ranging from 1 to 20 μM. None of the tested drugs completely displaced DAUDA from hFABP1, and fluorescence spectra showed evidence of ternary complex formation. Formation of DAUDA-hFABP1-diclofenac ternary complex was verified with native MS. Docking predicted diclofenac binding in the portal region of FABP1 with DAUDA in the binding cavity. The catalytic rate constant of diclofenac hydroxylation by CYP2C9 was decreased by ∼50% (P < 0.01) in the presence of FABP1. Together, these results suggest that drugs form ternary complexes with hFABP1 and that hFABP1 binding in the liver will alter drug metabolism and clearance. SIGNIFICANCE STATEMENT: Many commonly prescribed drugs bind fatty acid binding protein 1 (FABP1), forming ternary complexes with FABP1 and the fluorescent fatty acid 11-(dansylamino)undecanoic acid. These findings suggest that drugs will bind to apo-FABP1 and fatty acid-bound FABP1 in the human liver. The high expression of FABP1 in the liver, together with drug binding to FABP1, may alter drug disposition processes in vivo.
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Affiliation(s)
- King Clyde B Yabut
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
| | - Alice Martynova
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
| | - Abhinav Nath
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
| | - Benjamin P Zercher
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
| | - Matthew F Bush
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
| | - Nina Isoherranen
- Department of Pharmaceutics, School of Pharmacy (K.C.B.Y., N.I.), Department of Chemistry (A.M., B.P.Z., M.F.B.), and Department of Medicinal Chemistry (A.N.), University of Washington, Seattle, Washington
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4
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Jordan JS, Lee KJ, Williams ER. Overcoming aggregation with laser heated nanoelectrospray mass spectrometry: thermal stability and pathways for loss of bicarbonate from carbonic anhydrase II. Analyst 2024; 149:2281-2290. [PMID: 38497240 DOI: 10.1039/d4an00229f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Variable temperature electrospray mass spectrometry is useful for multiplexed measurements of the thermal stabilities of biomolecules, but the ionization process can be disrupted by aggregation-prone proteins/complexes that have irreversible unfolding transitions. Resistively heating solutions containing a mixture of bovine carbonic anhydrase II (BCAII), a CO2 fixing enzyme involved in many biochemical pathways, and cytochrome c leads to complete loss of carbonic anhydrase signal and a significant reduction in cytochrome c signal above ∼72 °C due to aggregation. In contrast, when the tips of borosilicate glass nanoelectrospray emitters are heated with a laser, complete thermal denaturation curves for both proteins are obtained in <1 minute. The simultaneous measurements of the melting temperature of BCAII and BCAII bound to bicarbonate reveal that the bicarbonate stabilizes the folded form of this protein by ∼6.4 °C. Moreover, the temperature dependences of different bicarbonate loss pathways are obtained. Although protein analytes are directly heated by the laser for only 140 ms, heat conduction further up the emitter leads to a total analyte heating time of ∼41 s. Pulsed laser heating experiments could reduce this time to ∼0.5 s for protein aggregation that occurs on a faster time scale. Laser heating provides a powerful method for studying the detailed mechanisms of cofactor/ligand loss with increasing temperature and promises a new tool for studying the effect of ligands, drugs, growth conditions, buffer additives, or other treatments on the stabilities of aggregation-prone biomolecules.
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Affiliation(s)
- Jacob S Jordan
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
| | - Katherine J Lee
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
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5
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Gu Y, Liu M, Ma L, Quinn RJ. Advancing Kir4.2 Channel Ligand Identification through Collision-Induced Affinity Selection Mass Spectrometry. ACS Chem Biol 2024; 19:763-773. [PMID: 38449446 PMCID: PMC10949200 DOI: 10.1021/acschembio.3c00781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/31/2024] [Accepted: 02/21/2024] [Indexed: 03/08/2024]
Abstract
The inwardly rectifying potassium Kir4.2 channel plays a crucial role in regulating membrane potentials and maintaining potassium homeostasis. Kir4.2 has been implicated in various physiological processes, including insulin secretion, gastric acid regulation, and the pathogenesis of central nervous system diseases. Despite its significance, the number of identified ligands for Kir4.2 remains limited. In this study, we established a method to directly observe ligands avoiding a requirement to observe the high-mass ligand-membrane protein-detergent complexes. This method used collision-induced affinity selection mass spectrometry (CIAS-MS) to identify ligands dissociated from the Kir4.2 channel-detergent complex. The CIAS-MS approach integrated all stages of affinity selection within the mass spectrometer, offering advantages in terms of time efficiency and cost-effectiveness. Additionally, we explored the effect of collisional voltage ramps on the dissociation behavior of the ligand and the ligand at different concentrations, demonstrating dose dependency.
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Affiliation(s)
- Yushu Gu
- Griffith
Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia
| | - Miaomiao Liu
- Griffith
Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia
| | - Linlin Ma
- Griffith
Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia
- School
of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia
| | - Ronald J. Quinn
- Griffith
Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia
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6
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Gu Y, Liu M, Ma L, Quinn RJ. Identification of Ligands for Ion Channels: TRPM2. Chembiochem 2024; 25:e202300790. [PMID: 38242853 DOI: 10.1002/cbic.202300790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/09/2024] [Accepted: 01/17/2024] [Indexed: 01/21/2024]
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, nonselective cation channel with a widespread distribution throughout the body. It is involved in many pathological and physiological processes, making it a potential therapeutic target for various diseases, including Alzheimer's disease, Parkinson's disease, and cancers. New analytical techniques are beneficial for gaining a deeper understanding of its involvement in disease pathogenesis and for advancing the drug discovery for TRPM2-related diseases. In this work, we present the application of collision-induced affinity selection mass spectrometry (CIAS-MS) for the direct identification of ligands binding to TRPM2. CIAS-MS circumvents the need for high mass detection typically associated with mass spectrometry of large membrane proteins. Instead, it focuses on the detection of small molecules dissociated from the ligand-protein-detergent complexes. This affinity selection approach consolidates all affinity selection steps within the mass spectrometer, resulting in a streamlined process. We showed the direct identification of a known TRPM2 ligand dissociated from the protein-ligand complex. We demonstrated that CIAS-MS can identify binding ligands from complex mixtures of compounds and screened a compound library against TRPM2. We investigated the impact of voltage increments and ligand concentrations on the dissociation behavior of the binding ligand, revealing a dose-dependent relationship.
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Affiliation(s)
- Yushu Gu
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Brisbane, Queensland, 4111, Australia
| | - Miaomiao Liu
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Brisbane, Queensland, 4111, Australia
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Brisbane, Queensland, 4111, Australia
- School of Environment and Science, Griffith University, N34 1.29, Nathan Campus, Brisbane, Queensland, 4111, Australia
| | - Ronald J Quinn
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Brisbane, Queensland, 4111, Australia
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7
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Ward JA, Romartinez-Alonso B, Kay DF, Bellamy-Carter J, Thurairajah B, Basran J, Kwon H, Leney AC, Macip S, Roversi P, Muskett FW, Doveston RG. Characterizing the protein-protein interaction between MDM2 and 14-3-3σ; proof of concept for small molecule stabilization. J Biol Chem 2024; 300:105651. [PMID: 38237679 PMCID: PMC10864208 DOI: 10.1016/j.jbc.2024.105651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/01/2023] [Accepted: 01/01/2024] [Indexed: 02/10/2024] Open
Abstract
Mouse Double Minute 2 (MDM2) is a key negative regulator of the tumor suppressor protein p53. MDM2 overexpression occurs in many types of cancer and results in the suppression of WT p53. The 14-3-3 family of adaptor proteins are known to bind MDM2 and the 14-3-3σ isoform controls MDM2 cellular localization and stability to inhibit its activity. Therefore, small molecule stabilization of the 14-3-3σ/MDM2 protein-protein interaction (PPI) is a potential therapeutic strategy for the treatment of cancer. Here, we provide a detailed biophysical and structural characterization of the phosphorylation-dependent interaction between 14-3-3σ and peptides that mimic the 14-3-3 binding motifs within MDM2. The data show that di-phosphorylation of MDM2 at S166 and S186 is essential for high affinity 14-3-3 binding and that the binary complex formed involves one MDM2 di-phosphorylated peptide bound to a dimer of 14-3-3σ. However, the two phosphorylation sites do not simultaneously interact so as to bridge the 14-3-3 dimer in a 'multivalent' fashion. Instead, the two phosphorylated MDM2 motifs 'rock' between the two binding grooves of the dimer, which is unusual in the context of 14-3-3 proteins. In addition, we show that the 14-3-3σ-MDM2 interaction is amenable to small molecule stabilization. The natural product fusicoccin A forms a ternary complex with a 14-3-3σ dimer and an MDM2 di-phosphorylated peptide resulting in the stabilization of the 14-3-3σ/MDM2 PPI. This work serves as a proof-of-concept of the drugability of the 14-3-3/MDM2 PPI and paves the way toward the development of more selective and efficacious small molecule stabilizers.
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Affiliation(s)
- Jake A Ward
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; Mechanisms of Cancer and Aging Laboratory, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Beatriz Romartinez-Alonso
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Danielle F Kay
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | | | - Bethany Thurairajah
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; School of Chemistry, University of Leicester, Leicester, UK
| | - Jaswir Basran
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Hanna Kwon
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Aneika C Leney
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Salvador Macip
- Mechanisms of Cancer and Aging Laboratory, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK; FoodLab, Faculty of Health Sciences, Universitat Oberta de Catalunya, Barcelona, Spain; Josep Carreras Leukaemia Research Institute, Ctra de Can Ruti, Camí de les Escoles, s/n, Badalona, Barcelona, Spain
| | - Pietro Roversi
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; Institute of Agricultural Biology and Biotechnology, C.N.R., Unit of Milan, Milano, Italy
| | - Frederick W Muskett
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Richard G Doveston
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, UK; School of Chemistry, University of Leicester, Leicester, UK.
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8
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Yabut KCB, Martynova A, Nath A, Zercher BP, Bush MF, Isoherranen N. Drugs Form Ternary Complexes with Human Liver Fatty Acid Binding Protein (FABP1) and FABP1 Binding Alters Drug Metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.576032. [PMID: 38293009 PMCID: PMC10827205 DOI: 10.1101/2024.01.17.576032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Liver fatty acid binding protein (FABP1) binds diverse endogenous lipids and is highly expressed in the human liver. Binding to FABP1 alters the metabolism and homeostasis of endogenous lipids in the liver. Drugs have also been shown to bind to rat FABP1, but limited data is available for human FABP1 (hFABP1). FABP1 has a large binding pocket and multiple fatty acids can bind to FABP1 simultaneously. We hypothesized that drug binding to hFABP1 results in formation of ternary complexes and that FABP1 binding alters drug metabolism. To test these hypotheses native protein mass spectrometry (MS) and fluorescent 11-(dansylamino)undecanoic acid (DAUDA) displacement assays were used to characterize drug binding to hFABP1 and diclofenac oxidation by cytochrome P450 2C9 (CYP2C9) was studied in the presence and absence of hFABP1. DAUDA binding to hFABP1 involved high (Kd,1=0.2 µM) and low affinity (Kd,2 >10 µM) binding sites. Nine drugs bound to hFABP1 with Kd values ranging from 1 to 20 µM. None of the tested drugs completely displaced DAUDA from hFABP1 and fluorescence spectra showed evidence of ternary complex formation. Formation of DAUDA-diclofenac-hFABP1 ternary complex was verified with native MS. Docking placed diclofenac in the portal region of FABP1 with DAUDA in the binding cavity. Presence of hFABP1 decreased the kcat and Km,u of diclofenac with CYP2C9 by ~50% suggesting that hFABP1 binding in the liver will alter drug metabolism and clearance. Together, these results suggest that drugs form ternary complexes with hFABP1 and that hFABP1 interacts with CYP2C9.
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Affiliation(s)
- King Clyde B. Yabut
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA, United States
| | - Alice Martynova
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Abhinav Nath
- Department of Medicinal Chemistry, University of Washington, Seattle, WA
| | - Benjamin P. Zercher
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Matthew F. Bush
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Nina Isoherranen
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA, United States
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9
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Kundlacz T, Schmidt C. Deciphering Solution and Gas-Phase Interactions between Peptides and Lipids by Native Mass Spectrometry. Anal Chem 2023; 95:17292-17299. [PMID: 37956985 PMCID: PMC10688224 DOI: 10.1021/acs.analchem.3c03428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 11/21/2023]
Abstract
Many biological processes depend on the interactions between proteins and lipids. Accordingly, the analysis of protein-lipid complexes has become increasingly important. Native mass spectrometry is often used to identify and characterize specific protein-lipid interactions. However, it requires the transfer of the analytes into the gas phase, where electrostatic interactions are enhanced and hydrophobic interactions do not exist. Accordingly, the question remains whether interactions that are observed in the gas phase accurately reflect interactions that are formed in solution. Here, we systematically explore noncovalent interactions between the antimicrobial peptide LL-37 and glycerophospholipids containing different headgroups or varying in fatty acyl chain length. We observe differences in peak intensities for different peptide-lipid complexes, as well as their relative binding strength in the gas phase. Accordingly, we found that ion intensities and gas-phase stability correlate well for complexes formed by electrostatic interactions. Probing hydrophobic interactions by varying the length of fatty acyl chains, we detected differences in ion intensities based on hydrophobic interactions formed in solution. The relative binding strength of these peptide-lipid complexes revealed only minor differences originating from van der Waals interactions and different binding modes of lipid headgroups in solution. In summary, our results demonstrate that hydrophobic interactions are reflected by ion intensities, while electrostatic interactions, including van der Waals interactions, determine the gas-phase stability of complexes.
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Affiliation(s)
- Til Kundlacz
- Interdisciplinary
Research Centre HALOmem, Institute of Biochemistry and Biotechnology,
Charles Tanford Protein Centre, Martin Luther
University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120 Halle, Germany
- Institute
of Chemistry, Martin Luther University Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle, Germany
| | - Carla Schmidt
- Interdisciplinary
Research Centre HALOmem, Institute of Biochemistry and Biotechnology,
Charles Tanford Protein Centre, Martin Luther
University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120 Halle, Germany
- Department
of Chemistry—Biochemistry, Johannes
Gutenberg University Mainz, Biocenter II, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany
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10
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Konermann L, Liu Z, Haidar Y, Willans MJ, Bainbridge NA. On the Chemistry of Aqueous Ammonium Acetate Droplets during Native Electrospray Ionization Mass Spectrometry. Anal Chem 2023; 95:13957-13966. [PMID: 37669319 DOI: 10.1021/acs.analchem.3c02546] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Ammonium acetate (NH4Ac) is a widely used solvent additive in native electrospray ionization (ESI) mass spectrometry. NH4Ac can undergo proton transfer to form ammonia and acetic acid (NH4+ + Ac- → NH3 + HAc). The volatility of these products ensures that electrosprayed ions are free of undesired adducts. NH4Ac dissolution in water yields pH 7, providing "physiological" conditions. However, NH4Ac is not a buffer at pH 7 because NH4+ and Ac- are not a conjugate acid/base pair (Konermann, L. J. Am. Soc. Mass Spectrom. 2017, 28, 1827-1835.). In native ESI, it is desirable that analytes experience physiological conditions not only in bulk solution but also while they reside in ESI droplets. Little is known about the internal milieu of NH4Ac-containing ESI droplets. The current work explored the acid/base chemistry of such droplets, starting from a pH 7 analyte solution. We used a two-pronged approach involving evaporation experiments on bulk solutions under ESI-mimicking conditions, as well as molecular dynamics simulations using a newly developed algorithm that allows for proton transfer. Our results reveal that during droplet formation at the tip of the Taylor cone, electrolytically generated protons get neutralized by Ac-, making NH4+ the net charge carriers in the weakly acidic nascent droplets. During the subsequent evaporation, the droplets lose water as well as NH3 and HAc that were generated by proton transfer. NH3 departs more quickly because of its greater volatility, causing the accumulation of HAc. Together with residual Ac-, these HAc molecules form an acetate buffer that stabilizes the average droplet pH at 5.4 ± 0.1, as governed by the Henderson-Hasselbalch equation. The remarkable success of native ESI investigations in the literature implies that this pH drop by ∼1.6 units relative to the initially neutral analyte solution can be tolerated by most biomolecular analytes on the short time scale of the ESI process.
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Affiliation(s)
- Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Zeyuan Liu
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Yousef Haidar
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Mathew J Willans
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Nicholas A Bainbridge
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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11
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Panda A, Brown C, Gupta K. Studying Membrane Protein-Lipid Specificity through Direct Native Mass Spectrometric Analysis from Tunable Proteoliposomes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1917-1927. [PMID: 37432128 PMCID: PMC10932607 DOI: 10.1021/jasms.3c00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Native mass spectrometry (nMS) has emerged as a key analytical tool to study the organizational states of proteins and their complexes with both endogenous and exogenous ligands. Specifically, for membrane proteins, it provides a key analytical dimension to determine the identity of bound lipids and to decipher their effects on the observed structural assembly. We recently developed an approach to study membrane proteins directly from intact and tunable lipid membranes where both the biophysical properties of the membrane and its lipid compositions can be customized. Extending this, we use our liposome-nMS platform to decipher the lipid specificity of membrane proteins through their multiorganelle trafficking pathways. To demonstrate this, we used VAMP2 and reconstituted it in the endoplasmic reticulum (ER), Golgi, synaptic vesicle (SV), and plasma membrane (PM) mimicking liposomes. By directly studying VAMP2 from these customized liposomes, we show how the same transmembrane protein can bind to different sets of lipids in different organellar-mimicking membranes. Considering that the cellular trafficking pathway of most eukaryotic integral membrane proteins involves residence in multiple organellar membranes, this study highlights how the lipid-specificity of the same integral membrane protein may change depending on the membrane context. Further, leveraging the capability of the platform to study membrane proteins from liposomes with curated biophysical properties, we show how we can disentangle chemical versus biophysical properties, of individual lipids in regulating membrane protein assembly.
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Affiliation(s)
- Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Caroline Brown
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
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12
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Wang Y, Peng Y, Long R, Shi P, Zhang Y, Kong DX, Zheng J, Wang X. Sequence variety in the CC' loop of Siglec-8/9/3 determines the recognitions to sulfated oligosaccharides. Comput Struct Biotechnol J 2023; 21:4159-4171. [PMID: 37675287 PMCID: PMC10477811 DOI: 10.1016/j.csbj.2023.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023] Open
Abstract
Siglecs are important lectins found in different types of immune cells and function as regulatory molecules by recognizing self-associated glycans and converting extracellular interactions into signals for inhibiting immune cell functions. Although many Siglecs have been found to show broad specificities and recognize different types of sulfated oligosaccharides, Siglec-8 and Siglec-9 displayed a high degree of specificity for sialyl N-acetyllactosamine (sLacNAc) with sulfations at O6-positions of the galactose (6'-sulfation) and N-acetylglucosamine (6-sulfation), respectively. Siglec-3 was recently discovered to bind sLacNAc both sulfations. In addition to a conserved arginine residue for binding to sialic acid residue, the sequence variety in the CC' loop may provide binding specificities to sulfated oligosaccharides in Siglecs. Thus, the present study employed molecular models to study the impact of different residues in the CC' loops of Siglec-8/9/3 to the recognitions of 6-sulfations in Gal and/or GlcNAc of sLacNAc. The negatively charged residues in the CC' loop of Siglec-9 formed unfavorable electrostatic repulsions with the 6-sulfate in Gal and resulted no recognitions, in contrast to the favorable interactions formed between the positively charged residues in the CC' loop of Siglec-8 and the 6-sulfate in Gal resulting strong specificity. A two-state binding model was proposed for Siglec-3 recognizing 6-sulfations in Gal and GlcNAc of sLacNAc, as the neutral residues in the CC' loop of Siglec-3 could not form strong favorable interactions to lock the 6-sulfate in Gal within a single binding pose or strong unfavorable interactions to repel the 6-sulfate in Gal. The oligosaccharide adopted two distinctive binding poses and oriented the sulfate groups to form interactions with residues in the CC' loop and G-strand. The present study provided a structural mechanism for the sequence variety in the CC' loop of Siglec-8/9/3 determining the recognitions to the sulfated oligosaccharides and offered insights into the binding specificities for Siglecs.
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Affiliation(s)
- Yucheng Wang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yujie Peng
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Rui Long
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Peiting Shi
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yinghao Zhang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - De-Xin Kong
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jinshui Zheng
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xiaocong Wang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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13
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Xia M, Vago F, Han L, Huang P, Nguyen L, Boons GJ, Klassen JS, Jiang W, Tan M. The αTSR Domain of Plasmodium Circumsporozoite Protein Bound Heparan Sulfates and Elicited High Titers of Sporozoite Binding Antibody After Displayed by Nanoparticles. Int J Nanomedicine 2023; 18:3087-3107. [PMID: 37312932 PMCID: PMC10259582 DOI: 10.2147/ijn.s406314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 05/31/2023] [Indexed: 06/15/2023] Open
Abstract
Introduction Malaria is a devastating infectious illness caused by protozoan Plasmodium parasites. The circumsporozoite protein (CSP) on Plasmodium sporozoites binds heparan sulfate proteoglycan (HSPG) receptors for liver invasion, a critical step for prophylactic and therapeutic interventions. Methods In this study, we characterized the αTSR domain that covers region III and the thrombospondin type-I repeat (TSR) of the CSP using various biochemical, glycobiological, bioengineering, and immunological approaches. Results We found for the first time that the αTSR bound heparan sulfate (HS) glycans through support by a fused protein, indicating that the αTSR is a key functional domain and thus a vaccine target. When the αTSR was fused to the S domain of norovirus VP1, the fusion protein self-assembled into uniform S60-αTSR nanoparticles. Three-dimensional structure reconstruction revealed that each nanoparticle consists of an S60 nanoparticle core and 60 surface displayed αTSR antigens. The nanoparticle displayed αTSRs retained the binding function to HS glycans, indicating that they maintained authentic conformations. Both tagged and tag-free S60-αTSR nanoparticles were produced via the Escherichia coli system at high yield by scalable approaches. They are highly immunogenic in mice, eliciting high titers of αTSR-specific antibody that bound specifically to the CSPs of Plasmodium falciparum sporozoites at high titer. Discussion and Conclusion Our data demonstrated that the αTSR is an important functional domain of the CSP. The S60-αTSR nanoparticle displaying multiple αTSR antigens is a promising vaccine candidate potentially against attachment and infection of Plasmodium parasites.
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Affiliation(s)
- Ming Xia
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Frank Vago
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Ling Han
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Pengwei Huang
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Linh Nguyen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Department of Chemistry, University of Georgia, Athens, GA, USA
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Wen Jiang
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Ming Tan
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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14
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Wolf E, Lento C, Pu J, Dickinson BC, Wilson DJ. Innate Conformational Dynamics Drive Binding Specificity in Anti-Apoptotic Proteins Mcl-1 and Bcl-2. Biochemistry 2023; 62:1619-1630. [PMID: 37192192 PMCID: PMC10249625 DOI: 10.1021/acs.biochem.2c00709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/02/2023] [Indexed: 05/18/2023]
Abstract
The structurally conserved B-cell lymphoma 2 (Bcl-2) family of protein function to promote or inhibit apoptosis through an exceedingly complex web of specific, intrafamilial protein-protein interactions. The critical role of these proteins in lymphomas and other cancers has motivated a widespread interest in understanding the molecular mechanisms that drive specificity in Bcl-2 family interactions. However, the high degree of structural similarity among Bcl-2 homologues has made it difficult to rationalize the highly specific (and often divergent) binding behavior exhibited by these proteins using conventional structural arguments. In this work, we use time-resolved hydrogen deuterium exchange mass spectrometry to explore shifts in conformational dynamics associated with binding partner engagement in the Bcl-2 family proteins Bcl-2 and Mcl-1. Using this approach combined with homology modeling, we reveal that Mcl-1 binding is driven by a large-scale shift in conformational dynamics, while Bcl-2 complexation occurs primarily through a classical charge compensation mechanism. This work has implications for understanding the evolution of internally regulated biological systems composed of structurally similar proteins and for the development of drugs targeting Bcl-2 family proteins for promotion of apoptosis in cancer.
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Affiliation(s)
- Esther Wolf
- Department
of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Cristina Lento
- Department
of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Jinyue Pu
- Department
of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Bryan C. Dickinson
- Department
of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Derek J. Wilson
- Department
of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
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15
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Panda A, Giska F, Duncan AL, Welch AJ, Brown C, McAllister R, Hariharan P, Goder JND, Coleman J, Ramakrishnan S, Pincet F, Guan L, Krishnakumar S, Rothman JE, Gupta K. Direct determination of oligomeric organization of integral membrane proteins and lipids from intact customizable bilayer. Nat Methods 2023; 20:891-897. [PMID: 37106230 PMCID: PMC10932606 DOI: 10.1038/s41592-023-01864-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 03/23/2023] [Indexed: 04/29/2023]
Abstract
Hierarchical organization of integral membrane proteins (IMP) and lipids at the membrane is essential for regulating myriad downstream signaling. A quantitative understanding of these processes requires both detections of oligomeric organization of IMPs and lipids directly from intact membranes and determination of key membrane components and properties that regulate them. Addressing this, we have developed a platform that enables native mass spectrometry (nMS) analysis of IMP-lipid complexes directly from intact and customizable lipid membranes. Both the lipid composition and membrane properties (such as curvature, tension, and fluidity) of these bilayers can be precisely customized to a target membrane. Subsequent direct nMS analysis of these intact proteolipid vesicles can yield the oligomeric states of the embedded IMPs, identify bound lipids, and determine the membrane properties that can regulate the observed IMP-lipid organization. Applying this method, we show how lipid binding regulates neurotransmitter release and how membrane composition regulates the functional oligomeric state of a transporter.
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Affiliation(s)
- Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Fabian Giska
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, Oxford, UK
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | | | - Caroline Brown
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Rachel McAllister
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Parameswaran Hariharan
- Department of Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Jean N D Goder
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Jeff Coleman
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Sathish Ramakrishnan
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Frédéric Pincet
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, CNRS, Université PSL, Sorbonne Université, Université Paris-Cité, Paris, France
| | - Lan Guan
- Department of Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Shyam Krishnakumar
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - James E Rothman
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, CT, USA.
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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16
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Liu S, Abboud M, Mikhailov V, Liu X, Reinbold R, Schofield CJ. Differentiating Inhibition Selectivity and Binding Affinity of Isocitrate Dehydrogenase 1 Variant Inhibitors. J Med Chem 2023; 66:5279-5288. [PMID: 36952395 PMCID: PMC10108345 DOI: 10.1021/acs.jmedchem.3c00203] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Indexed: 03/25/2023]
Abstract
Isocitrate dehydrogenase (IDH) 1/2 gain-of-function variants catalyze the production of the oncometabolite 2-hydroxyglutarate and are validated targets for leukemia treatment. We report binding and inhibition studies on 13 IDH1/2 variant inhibitors, including clinical candidates and drugs, with wild-type (wt) IDH1 and its cancer-associated variant, IDH1 R132H. Interestingly, all the variant inhibitors bind wt IDH1 despite not, or only weakly, inhibiting it. Selective inhibition of the IDH1 R132H variant over wt IDH1 does not principally relate to the affinities of the inhibitors for the resting forms of the enzymes. Rather, the independent binding of Mg2+ and 2-oxoglutarate to the IDH1 variant makes the variant more susceptible to allosteric inhibition, compared to the tighter binding of the isocitrate-Mg2+ complex substrate to wt IDH1. The results highlight that binding affinity need not correlate with inhibition selectivity and have implications for interpretation of inhibitor screening results with IDH and related enzymes using turnover versus binding assays.
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Affiliation(s)
| | | | - Victor Mikhailov
- Chemistry Research Laboratory, Department
of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Xiao Liu
- Chemistry Research Laboratory, Department
of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Raphael Reinbold
- Chemistry Research Laboratory, Department
of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Christopher J. Schofield
- Chemistry Research Laboratory, Department
of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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17
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Fiorentino F, Rotili D, Mai A. Native mass spectrometry-directed drug discovery: Recent advances in investigating protein function and modulation. Drug Discov Today 2023; 28:103548. [PMID: 36871843 DOI: 10.1016/j.drudis.2023.103548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/15/2023] [Accepted: 02/28/2023] [Indexed: 03/07/2023]
Abstract
Native mass spectrometry (nMS) is a biophysical method for studying protein complexes and can provide insights into subunit stoichiometry and composition, protein-ligand, and protein-protein interactions (PPIs). These analyses are made possible by preserving non-covalent interactions in the gas phase, thereby allowing the analysis of proteins in their native state. Consequently, nMS has been increasingly applied in early drug discovery campaigns for the characterization of protein-drug interactions and the evaluation of PPI modulators. Here, we discuss recent developments in nMS-directed drug discovery and provide a timely perspective on the possible applications of this technology in drug discovery.
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Affiliation(s)
- Francesco Fiorentino
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.
| | - Dante Rotili
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.
| | - Antonello Mai
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; Pasteur Institute, Cenci-Bolognetti Foundation, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
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18
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Gheorghita AA, Li YE, Kitova EN, Bui DT, Pfoh R, Low KE, Whitfield GB, Walvoort MTC, Zhang Q, Codée JDC, Klassen JS, Howell PL. Structure of the AlgKX modification and secretion complex required for alginate production and biofilm attachment in Pseudomonas aeruginosa. Nat Commun 2022; 13:7631. [PMID: 36494359 PMCID: PMC9734138 DOI: 10.1038/s41467-022-35131-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
Synthase-dependent secretion systems are a conserved mechanism for producing exopolysaccharides in Gram-negative bacteria. Although widely studied, it is not well understood how these systems are organized to coordinate polymer biosynthesis, modification, and export across both membranes and the peptidoglycan. To investigate how synthase-dependent secretion systems produce polymer at a molecular level, we determined the crystal structure of the AlgK-AlgX (AlgKX) complex involved in Pseudomonas aeruginosa alginate exopolysaccharide acetylation and export. We demonstrate that AlgKX directly binds alginate oligosaccharides and that formation of the complex is vital for polymer production and biofilm attachment. Finally, we propose a structural model for the AlgEKX outer membrane modification and secretion complex. Together, our study provides insight into how alginate biosynthesis proteins coordinate production of a key exopolysaccharide involved in establishing persistent Pseudomonas lung infections.
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Affiliation(s)
- Andreea A. Gheorghita
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Biochemistry, University of Toronto, Toronto, ON Canada
| | - Yancheng E. Li
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Biochemistry, University of Toronto, Toronto, ON Canada ,grid.20861.3d0000000107068890Present Address: Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA USA
| | - Elena N. Kitova
- grid.17089.370000 0001 2190 316XDepartment of Chemistry, University of Alberta, Edmonton, AB Canada
| | - Duong T. Bui
- grid.17089.370000 0001 2190 316XDepartment of Chemistry, University of Alberta, Edmonton, AB Canada
| | - Roland Pfoh
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada
| | - Kristin E. Low
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada ,grid.55614.330000 0001 1302 4958Present Address: Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB Canada
| | - Gregory B. Whitfield
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Biochemistry, University of Toronto, Toronto, ON Canada ,grid.14848.310000 0001 2292 3357Present Address: Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC Canada
| | - Marthe T. C. Walvoort
- grid.5132.50000 0001 2312 1970Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands ,grid.4830.f0000 0004 0407 1981Present Address: Department of Chemical Biology, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Qingju Zhang
- grid.5132.50000 0001 2312 1970Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands ,grid.411862.80000 0000 8732 9757Present Address: National Research Centre for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang, China
| | - Jeroen D. C. Codée
- grid.5132.50000 0001 2312 1970Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - John S. Klassen
- grid.17089.370000 0001 2190 316XDepartment of Chemistry, University of Alberta, Edmonton, AB Canada
| | - P. Lynne Howell
- grid.42327.300000 0004 0473 9646Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Biochemistry, University of Toronto, Toronto, ON Canada
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19
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Konermann L, Haidar Y. Mechanism of Magic Number NaCl Cluster Formation from Electrosprayed Water Nanodroplets. Anal Chem 2022; 94:16491-16501. [DOI: 10.1021/acs.analchem.2c04141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Yousef Haidar
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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20
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Han L, Nguyen L, Schmidt EN, Esmaili M, Kitova EN, Overduin M, Macauley MS, Klassen JS. How Choice of Model Membrane Affects Protein–Glycosphingolipid Interactions: Insights from Native Mass Spectrometry. Anal Chem 2022; 94:16042-16049. [PMID: 36367338 DOI: 10.1021/acs.analchem.2c03067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Interactions between glycan-binding proteins (GBPs) and glycosphingolipids (GSLs) are involved in numerous physiological and pathophysiological processes. Many model membrane systems are available for studying GBP-GSL interactions, but a systematic investigation has not been carried out on how the nature of the model membrane affects binding. In this work, we use electrospray ionization mass spectrometry (ESI-MS), both direct and competitive assays, to measure the binding of cholera toxin B subunit homopentamer (CTB5) to GM1 ganglioside in liposomes, bilayer islands [styrene maleic acid lipid particles (SMALPs), nanodiscs (NDs), and picodiscs (PDs)], and micelles. We find that direct ESI-MS analysis of CTB5 binding to GM1 is unreliable due to non-uniform response factors, incomplete extraction of bound GM1 in the gas phase, and nonspecific CTB5-GM1 interactions. Conversely, indirect proxy ligand ESI-MS measurements show that the intrinsic (per binding site) association constants of CTB5 for PDs, NDs, and SMALPs are similar and comparable to the affinity of soluble GM1 pentasaccharide (GM1os). The observed affinity decreases with increasing GM1 content due to molecular crowding stemming from GM1 clustering. Unlike the smaller model membranes, the observed affinity of CTB5 toward GM1 liposomes is ∼10-fold weaker than GM1os and relatively insensitive to the GM1 content. GM1 glycomicelles exhibit the lowest affinity, ∼35-fold weaker than GM1os. Together, the results highlight experimental design considerations for quantitative GBP-GSL binding studies involving multisubunit GBPs and factors to consider when comparing results obtained with different membrane systems. Notably, they suggest that bilayer islands with a low percentage of GSL, wherein clustering is minimized, are ideal for assessing intrinsic strength of GBP-GSL interactions in a membrane environment, while binding to liposomes, which is sub-optimal due to extensive clustering, may be more representative of authentic cellular environments.
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Affiliation(s)
- Ling Han
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
| | - Linh Nguyen
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
| | - Edward N. Schmidt
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
| | - Mansoore Esmaili
- Department of Biochemistry, University of Alberta, Edmonton T6G 2R3, Canada
| | - Elena N. Kitova
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
| | - Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton T6G 2R3, Canada
| | - Matthew S. Macauley
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton T6G 2E1, Alberta, Canada
| | - John S. Klassen
- Department of Chemistry, University of Alberta, Edmonton T6G 2G2, Alberta, Canada
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21
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Sharif D, Foroushani SH, Attanayake K, Dewasurendra VK, DeBastiani A, DeVor A, Johnson MB, Li P, Valentine SJ. Capillary Vibrating Sharp-Edge Spray Ionization Augments Field-Free Ionization Techniques to Promote Conformer Preservation in the Gas-Phase for Intractable Biomolecular Ions. J Phys Chem B 2022; 126:8970-8984. [PMID: 36318704 PMCID: PMC10278089 DOI: 10.1021/acs.jpcb.2c04960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Field-free capillary vibrating sharp-edge spray ionization (cVSSI) is evaluated for its ability to conduct native mass spectrometry (MS) experiments. The charge state distributions for nine globular proteins are compared using field-free cVSSI, field-enabled cVSSI, and electrospray ionization (ESI). In general, for both positive and negative ion mode, the average charge state (qavg) increases for field-free cVSSI with increasing molecular weight similar to ESI. A clear difference is that the qavg is significantly lower for field-free conditions in both analyses. Two proteins, leptin and thioredoxin, exhibit bimodal charge state distributions (CSDs) upon the application of voltage in positive ion mode; only a monomodal distribution is observed for field-free conditions. In negative ion mode, thioredoxin exhibits a multimodal CSD upon the addition of voltage to cVSSI. Extensive molecular dynamics (MD) simulations of myoglobin and leptin in nanodroplets suggest that the multimodal CSD for leptin may originate from increased conformational "breathing" (decreased packing) and association with the droplet surface. These properties along with increased droplet charge appear to play critical roles in shifting ionization processes for some proteins. Further exploration and development of field-free cVSSI as a new ionization source for native MS especially as applied to more flexible biomolecular species is warranted.
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Affiliation(s)
- Daud Sharif
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Samira Hajian Foroushani
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Kushani Attanayake
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Vikum K Dewasurendra
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia26506, United States
| | - Anthony DeBastiani
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Amanda DeVor
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Matthew B Johnson
- Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia26506, United States
| | - Peng Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia26506, United States
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22
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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: 0] [Impact Index Per Article: 0] [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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23
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Ning X, Wang L, Jin S, Fu X, Sun X, Cao J. A Strategy for Sample Preparation: Using Egg White Gel to Promote the Determination of Aflatoxin M1 Content in Milk Samples. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27155039. [PMID: 35956995 PMCID: PMC9370593 DOI: 10.3390/molecules27155039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/31/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022]
Abstract
The analysis of food samples is a challenging task. The high complexity of food matrices hinders the extraction and detection of analytes from them. Therefore, the correct preparation of food samples is a crucial step for their subsequent analysis, as it achieves the proper isolation and preconcentration of analytes and removes the interfering proportion of the food matrix before instrumental analysis. We aimed to develop a method that not only satisfies the requirement of detecting trace compounds in complex matrices but also achieves a “greener” approach by reducing the use of organic solvents and non-degradable materials to minimize the health hazards posed to the operators as well as pollution to the environment. In this study, we prepared egg white as a concentrated gel and used this material for the biological purification of milk samples. After the milk protein was removed by acidification and salting, the residual amount of aflatoxin M1 in milk samples was quantitatively determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the novel egg white purification method possessed advantages over the immunoaffinity technique used as the reference method in extraction recovery, sensitivity, repeatability, and operability. The limit of detection (LOD) was 0.001 μg/kg. In spiked samples containing 0.01 μg/kg to 2 μg/kg of AFM1, the average recovery was 88.3–94.7%, with a precision of 6.1–11.0%. Improved repeatability was obtained by significantly reducing the operation time and resource requirements compared with the immunoaffinity technique currently used internationally. This study provides a reference for the further improvement of the relevant international standards in place for the detection of aflatoxin M1 in milk.
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Affiliation(s)
- Xiao Ning
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Food Quality and Safety for State Market Regulation, National Institute of Food and Drug Control, Beijing 100050, China
| | - Lulu Wang
- Key Laboratory of Food Quality and Safety for State Market Regulation, National Institute of Food and Drug Control, Beijing 100050, China
| | - Shaoming Jin
- Key Laboratory of Food Quality and Safety for State Market Regulation, National Institute of Food and Drug Control, Beijing 100050, China
| | - Xuran Fu
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiulan Sun
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Correspondence: (X.S.); (J.C.); Tel.: +86-0510-8591-2330 (X.S.); +86-010-6709-5070 (J.C.)
| | - Jin Cao
- Key Laboratory of Food Quality and Safety for State Market Regulation, National Institute of Food and Drug Control, Beijing 100050, China
- Correspondence: (X.S.); (J.C.); Tel.: +86-0510-8591-2330 (X.S.); +86-010-6709-5070 (J.C.)
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24
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The TPR domain of PgaA is a multifunctional scaffold that binds PNAG and modulates PgaB-dependent polymer processing. PLoS Pathog 2022; 18:e1010750. [PMID: 35930610 PMCID: PMC9384988 DOI: 10.1371/journal.ppat.1010750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 08/17/2022] [Accepted: 07/19/2022] [Indexed: 11/30/2022] Open
Abstract
The synthesis of exopolysaccharides as biofilm matrix components by pathogens is a crucial factor for chronic infections and antibiotic resistance. Many periplasmic proteins involved in polymer processing and secretion in Gram-negative synthase dependent exopolysaccharide biosynthetic systems have been individually characterized. The operons responsible for the production of PNAG, alginate, cellulose and the Pel polysaccharide each contain a gene that encodes an outer membrane associated tetratricopeptide repeat (TPR) domain containing protein. While the TPR domain has been shown to bind other periplasmic proteins, the functional consequences of these interactions for the polymer remain poorly understood. Herein, we show that the C-terminal TPR region of PgaA interacts with the de-N-acetylase domain of PgaB, and increases its deacetylase activity. Additionally, we found that when the two proteins form a complex, the glycoside hydrolase activity of PgaB is also increased. To better understand structure-function relationships we determined the crystal structure of a stable TPR module, which has a conserved groove formed by three repeat motifs. Tryptophan quenching, mass spectrometry analysis and molecular dynamics simulation studies suggest that the crystallized TPR module can bind PNAG/dPNAG via its electronegative groove on the concave surface, and potentially guide the polymer through the periplasm towards the porin for export. Our results suggest a scaffolding role for the TPR domain that combines PNAG/dPNAG translocation with the modulation of its chemical structure by PgaB. Exopolysaccharides are an important component of the extracellular matrix of bacterial and fungal biofilms and provide protection against the host immune response and antibiotics. In Gram-negative bacteria, these polymers are synthesized in the inner membrane and translocated across the periplasm before being secreted across the outer membrane. The periplasm presents both a challenge as an additional environment to cross and an opportunity to chemically alter the polymer prior to secretion to render it more effective. This study focuses on a periplasmic alpha-helical repeat domain whose wide-spread homologues are involved in the export of many chemically distinct exopolysaccharides. We found that in E. coli this superhelical TPR domain acts as a scaffold that can bind the polymer PNAG and alter the enzymatic activity of PgaB, thus providing a means to affect the deacetylation level and chain length of the secreted polymer. Scaffold proteins are known as binding hubs within cellular pathways that often have a central regulatory function and facilitate evolution due to their repetitive modular building blocks. Our study sheds light on the principles of polysaccharide modification and export, which we hope will promote the development of applications against bacterial infections.
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25
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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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26
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Illes-Toth E, Stubbs CJ, Sisley EK, Bellamy-Carter J, Simmonds AL, Mize TH, Styles IB, Goodwin RJA, Cooper HJ. Quantitative Characterization of Three Carbonic Anhydrase Inhibitors by LESA Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1168-1175. [PMID: 35675480 PMCID: PMC9264382 DOI: 10.1021/jasms.2c00024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Liquid extraction surface analysis (LESA) coupled to native mass spectrometry (MS) presents unique analytical opportunities due to its sensitivity, speed, and automation. Here, we examine whether this tool can be used to quantitatively probe protein-ligand interactions through calculation of equilibrium dissociation constants (Kd values). We performed native LESA MS analyses for a well-characterized system comprising bovine carbonic anhydrase II and the ligands chlorothiazide, dansylamide, and sulfanilamide, and compared the results with those obtained from direct infusion mass spectrometry and surface plasmon resonance measurements. Two LESA approaches were considered: In one approach, the protein and ligand were premixed in solution before being deposited and dried onto a solid substrate for LESA sampling, and in the second, the protein alone was dried onto the substrate and the ligand was included in the LESA sampling solvent. Good agreement was found between the Kd values derived from direct infusion MS and LESA MS when the protein and ligand were premixed; however, Kd values determined from LESA MS measurements where the ligand was in the sampling solvent were inconsistent. Our results suggest that LESA MS is a suitable tool for quantitative analysis of protein-ligand interactions when the dried sample comprises both protein and ligand.
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Affiliation(s)
- Eva Illes-Toth
- School
of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Christopher J. Stubbs
- Mechanistic
and Structural Biology, Discovery Sciences,
R&D, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - Emma K. Sisley
- School
of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | - Anna L. Simmonds
- School
of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Todd H. Mize
- School
of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Iain B. Styles
- School
of Computer Science and Centre of Membrane Proteins and Receptors
(COMPARE), University of Birmingham, Birmingham B15 2TT, United Kingdom
- The Alan Turing Institute, London NW1 2DB, United Kingdom
- University of Nottingham, Midlands NG7 2RD, United Kingdom
| | - Richard J. A. Goodwin
- Imaging and
Data Analytics, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals
R&D, AstraZeneca, Cambridge CB4 0WG, United Kingdom
| | - Helen J. Cooper
- School
of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
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27
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Vallejo DD, Rojas Ramírez C, Parson KF, Han Y, Gadkari VV, Ruotolo BT. Mass Spectrometry Methods for Measuring Protein Stability. Chem Rev 2022; 122:7690-7719. [PMID: 35316030 DOI: 10.1021/acs.chemrev.1c00857] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mass spectrometry is a central technology in the life sciences, providing our most comprehensive account of the molecular inventory of the cell. In parallel with developments in mass spectrometry technologies targeting such assessments of cellular composition, mass spectrometry tools have emerged as versatile probes of biomolecular stability. In this review, we cover recent advancements in this branch of mass spectrometry that target proteins, a centrally important class of macromolecules that accounts for most biochemical functions and drug targets. Our efforts cover tools such as hydrogen-deuterium exchange, chemical cross-linking, ion mobility, collision induced unfolding, and other techniques capable of stability assessments on a proteomic scale. In addition, we focus on a range of application areas where mass spectrometry-driven protein stability measurements have made notable impacts, including studies of membrane proteins, heat shock proteins, amyloidogenic proteins, and biotherapeutics. We conclude by briefly discussing the future of this vibrant and fast-moving area of research.
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Affiliation(s)
- Daniel D Vallejo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Carolina Rojas Ramírez
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kristine F Parson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yilin Han
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Varun V Gadkari
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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28
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Bui DT, Jung J, Kitova EN, Li Z, Willows SD, Boddington ME, Kitov PI, Mason AL, Capicciotti CJ, Mahal LK, Macauley MS, Klassen JS. Mass Spectrometry-Based Shotgun Glycomics Using Labeled Glycan Libraries. Anal Chem 2022; 94:4997-5005. [PMID: 35302744 DOI: 10.1021/acs.analchem.1c04779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mass spectrometry-based shotgun glycomics (MS-SG) is a rapid, sensitive, label-, and immobilization-free approach for the discovery of natural ligands of glycan-binding proteins (GBPs). To perform MS-SG, natural libraries of glycans derived from glycoconjugates in cells or tissues are screened against a target GBP using catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS). Because glycan concentrations are challenging to determine, ligand affinities cannot be directly measured. In principle, relative affinities can be ranked by combining CaR-ESI-MS data with relative concentrations established by hydrophilic interaction liquid chromatography (HILIC) performed on the fluorophore-labeled glycan library. To validate this approach, as well as the feasibility of performing CaR-ESI-MS directly on labeled glycans, libraries of labeled N-glycans extracted from the human monocytic U937 cells or intestinal tissues were labeled with 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA), or procainamide (proA). The libraries were screened against plant and human GBPs with known specificities for α2-3- and α2-6-linked sialosides and quantified by HILIC. Dramatic differences, in some cases, were found for affinity rankings obtained with libraries labeled with different fluorophores, as well as those produced using the combined unlabeled/labeled library approach. The origin of these differences could be explained by differential glycan labeling efficiencies, the impact of specific labels on glycan affinities for the GBPs, and the relative efficiency of release of ligands from GBPs in CaR-ESI-MS. Overall, the results of this study suggest that the 2-AB(CaR-ESI-MS)/2-AB(HILIC) combination provides the most reliable description of the binding specificities of GBPs for N-glycans and is recommended for MS-SG applications.
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Affiliation(s)
- Duong T Bui
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Zhixiong Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Steven D Willows
- Division of Gastroenterology and Hepatology, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - Marie E Boddington
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Pavel I Kitov
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Andrew L Mason
- Division of Gastroenterology and Hepatology, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - Chantelle J Capicciotti
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6.,Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Lara K Mahal
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2E1
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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29
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Joyner PM, Tran DP, Zenaidee MA, Loo JA. Characterization of protein-ligand binding interactions of enoyl-ACP reductase (FabI) by native MS reveals allosteric effects of coenzymes and the inhibitor triclosan. Protein Sci 2022; 31:568-579. [PMID: 34882866 PMCID: PMC8862436 DOI: 10.1002/pro.4252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 01/08/2023]
Abstract
The enzyme enoyl-ACP reductase (also called FabI in bacteria) is an essential member of the fatty acid synthase II pathway in plants and bacteria. This enzyme is the target of the antibacterial drug triclosan and has been the subject of extensive studies for the past 20 years. Despite the large number of reports describing the biochemistry of this enzyme, there have been no studies that provided direct observation of the protein and its various ligands. Here we describe the use of native MS to characterize the protein-ligand interactions of FabI with its coenzymes NAD+ and NADH and with the inhibitor triclosan. Measurements of the gas-phase affinities of the enzyme for these ligands yielded values that are in close agreement with solution-phase affinity measurements. Additionally, FabI is a homotetramer and we were able to measure the affinity of each subunit for each coenzyme, which revealed that both coenzymes exhibit a positive homotropic allosteric effect. An allosteric effect was also observed in association with the inhibitor triclosan. These observations provide new insights into this well-studied enzyme and suggest that there may still be gaps in the existing mechanistic models that explain FabI inhibition.
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Affiliation(s)
- P. Matthew Joyner
- Natural Science DivisionPepperdine UniversityMalibuCaliforniaUSA,Department of Chemistry & BiochemistryUniversity of California‐Los AngelesLos AngelesCaliforniaUSA
| | - Denise P. Tran
- Department of Chemistry & BiochemistryUniversity of California‐Los AngelesLos AngelesCaliforniaUSA,Sydney Mass SpectrometryThe University of Sydney, Charles Perkins CentreCamperdownNew South WalesAustralia
| | - Muhammad A. Zenaidee
- Department of Chemistry & BiochemistryUniversity of California‐Los AngelesLos AngelesCaliforniaUSA,Australian Proteome Analysis FacilityMacquarie UniversityMacquarieNew South WalesAustralia
| | - Joseph A. Loo
- Department of Chemistry & BiochemistryUniversity of California‐Los AngelesLos AngelesCaliforniaUSA
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30
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Bellamy-Carter J, Sound JK, Leney AC. Probing heavy metal binding to phycobiliproteins. FEBS J 2022; 289:4646-4656. [PMID: 35156751 PMCID: PMC9542875 DOI: 10.1111/febs.16396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/31/2022] [Accepted: 02/11/2022] [Indexed: 01/26/2023]
Abstract
Blue-green algae, also known as cyanobacteria, contain some of the most efficient light-harvesting complexes known. These large, colourful complexes consist of phycobiliproteins which are extremely valuable in the cosmetics, food, nutraceutical and pharmaceutical industries. Additionally, the colourful and fluorescent properties of phycobiliproteins can be modulated by metal ions, making them highly attractive as heavy metal sensors and heavy metal scavengers. Although the overall quenching ability metal ions have on phycobiliproteins is known, the mechanism of heavy metal binding to phycobiliproteins is not fully understood, limiting their widespread quantitative applications. Here, we show using high-resolution native mass spectrometry that phycobiliprotein complexes bind metal ions in different manners. Through monitoring the binding equilibria and metal-binding stoichiometry, we show in particular copper and silver to have drastic, yet different effects on phycobiliprotein structure, both copper and silver modulate the overall complex properties. Together, the data reveals the mechanisms by which metal ions can modulate phycobiliprotein properties which can be used as a basis for the future design of metal-related phycobiliprotein applications.
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31
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Heine V, Dey C, Bojarová P, Křen V, Elling L. Methods of in vitro study of galectin-glycomaterial interaction. Biotechnol Adv 2022; 58:107928. [DOI: 10.1016/j.biotechadv.2022.107928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 02/08/2023]
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32
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Muneeruddin K, Kaltashov IA, Wang G. Characterizing Soluble Protein Aggregates Using Native Mass Spectrometry Coupled with Temperature-Controlled Electrospray Ionization and Size-Excl usion Chromatography. Methods Mol Biol 2022; 2406:455-468. [PMID: 35089574 DOI: 10.1007/978-1-0716-1859-2_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Characterization of soluble protein aggregates provides valuable information for revealing mechanisms of protein aggregation process and assessing the activity and safety of protein therapeutics. However, the noncovalent interaction, the transient nature and higher degree of structural heterogeneity of the soluble aggregation system hinders precise characterization at the molecular level. Here, we describe methods using native mass spectrometry coupled with temperature-control electrospray ionization and size-exclusion chromatography to monitor the aggregation process and profile the aggregates in detail.
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Affiliation(s)
- Khaja Muneeruddin
- The Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, MA, USA
| | - Igor A Kaltashov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA
| | - Guanbo Wang
- Biomedical Pioneering Innovation Center, Peking University, Beijing, China.
- Institute for Cell Analysis, Shenzhen Bay Laboratory, Shenzhen, China.
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33
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Nguyen L, McCord KA, Bui DT, Bouwman KM, Kitova EN, Elaish M, Kumawat D, Daskhan GC, Tomris I, Han L, Chopra P, Yang TJ, Willows SD, Mason AL, Mahal LK, Lowary TL, West LJ, Hsu STD, Hobman T, Tompkins SM, Boons GJ, de Vries RP, Macauley MS, Klassen JS. Sialic acid-containing glycolipids mediate binding and viral entry of SARS-CoV-2. Nat Chem Biol 2022; 18:81-90. [PMID: 34754101 DOI: 10.1038/s41589-021-00924-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 10/15/2021] [Indexed: 11/09/2022]
Abstract
Emerging evidence suggests that host glycans influence severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we reveal that the receptor-binding domain (RBD) of the spike (S) protein on SARS-CoV-2 recognizes oligosaccharides containing sialic acid (Sia), with preference for monosialylated gangliosides. Gangliosides embedded within an artificial membrane also bind to the RBD. The monomeric affinities (Kd = 100-200 μM) of gangliosides for the RBD are similar to another negatively charged glycan ligand of the RBD proposed as a viral co-receptor, heparan sulfate (HS) dp2-dp6 oligosaccharides. RBD binding and infection of SARS-CoV-2 pseudotyped lentivirus to angiotensin-converting enzyme 2 (ACE2)-expressing cells is decreased following depletion of cell surface Sia levels using three approaches: sialyltransferase (ST) inhibition, genetic knockout of Sia biosynthesis, or neuraminidase treatment. These effects on RBD binding and both pseudotyped and authentic SARS-CoV-2 viral entry are recapitulated with pharmacological or genetic disruption of glycolipid biosynthesis. Together, these results suggest that sialylated glycans, specifically glycolipids, facilitate viral entry of SARS-CoV-2.
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Affiliation(s)
- Linh Nguyen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Kelli A McCord
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Duong T Bui
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Kim M Bouwman
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mohamed Elaish
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.,Poultry Disease Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Dhanraj Kumawat
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Gour C Daskhan
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ilhan Tomris
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Ling Han
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Pradeep Chopra
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Tzu-Jing Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Steven D Willows
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew L Mason
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Lara K Mahal
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Todd L Lowary
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.,Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Lori J West
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Tom Hobman
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Stephen M Tompkins
- Center for Vaccines and Immunology, University of Georgia, Athens, GA, USA.,Emory-UGA Centers of Excellence for Influenza Research and Surveillance (CEIRS), Athens, GA, USA
| | - Geert-Jan Boons
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.,Department of Chemistry, University of Georgia, Athens, GA, USA.,Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Robert P de Vries
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada. .,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.
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34
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den Boer MA, Lai SH, Xue X, van Kampen MD, Bleijlevens B, Heck AJR. Comparative Analysis of Antibodies and Heavily Glycosylated Macromolecular Immune Complexes by Size-Exclusion Chromatography Multi-Angle Light Scattering, Native Charge Detection Mass Spectrometry, and Mass Photometry. Anal Chem 2021; 94:892-900. [PMID: 34939405 PMCID: PMC8771642 DOI: 10.1021/acs.analchem.1c03656] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Qualitative and quantitative mass analysis of antibodies and related macromolecular immune complexes is a prerequisite for determining their identity, binding partners, stoichiometries, and affinities. A plethora of bioanalytical technologies exist to determine such characteristics, typically based on size, interaction with functionalized surfaces, light scattering, or direct mass measurements. While these methods are highly complementary, they also exhibit unique strengths and weaknesses. Here, we benchmark mass photometry (MP), a recently introduced technology for mass measurement, against native mass spectrometry (MS) and size exclusion chromatography multi-angle light scattering (SEC-MALS). We examine samples of variable complexity, namely, IgG4Δhinge dimerizing half-bodies, IgG-RGY hexamers, heterogeneously glycosylated IgG:sEGFR antibody-antigen complexes, and finally megadalton assemblies involved in complement activation. We thereby assess the ability to determine (1) binding affinities and stoichiometries, (2) accurate masses, for extensively glycosylated species, and (3) assembly pathways of large heterogeneous immune complexes. We find that MP provides a sensitive approach for characterizing antibodies and stable assemblies, with dissociation correction enabling us to expand the measurable affinity range. In terms of mass resolution and accuracy, native MS performs the best but is occasionally hampered by artifacts induced by electrospray ionization, and its resolving power diminishes when analyzing extensively glycosylated proteins. In the latter cases, MP performs well, but single-particle charge detection MS can also be useful in this respect, measuring masses of heterogeneous assemblies even more accurately. Both methods perform well compared to SEC-MALS, still being the most established method in biopharma. Together, our data highlight the complementarity of these approaches, each having its unique strengths and weaknesses.
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Affiliation(s)
- Maurits A den Boer
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Szu-Hsueh Lai
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Xiaoguang Xue
- Genmab, Uppsalalaan 15, 3584 CT Utrecht, The Netherlands
| | | | | | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
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35
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Gigl M, Hofmann T, Frank O. NMR-Based Studies on Odorant-Melanoidin Interactions in Coffee Beverages. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:15334-15344. [PMID: 34874702 DOI: 10.1021/acs.jafc.1c06163] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A quantitative 1H NMR-based approach was established, which allowed the direct and noninvasive analysis of molecular interactions between key coffee odorants and high-molecular-weight (HMW) melanoidin polymers. A clear distinction between covalent and noncovalent interactions was achieved by monitoring the time dependency of odorant-polymer interactions, resulting in four scenarios: covalent, π-π, covalent and π-π-, as well as no interactions. Evaluation of temperature influence on e.g. 2-furfurylthiol (FFT), revealed an altered behavior with increased π-π stacking at lower temperatures and accelerated covalent interactions at higher temperatures. Human sensory experiments with HMW material and a coffee aroma reconstitution model showed a drastic reduction of "roasty/sulfury" aroma notes, as well as an increased "sweetish/caramel-like" flavor. The lack of interactions between the "sweetish/caramel" smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone with the HMW melanoidins in combination with the high binding affinity of coffee thiols explains the sensory evaluation and is obviously the reason for the fast disappearance of the typical "roasty/sulfury" aroma impressions of a freshly prepared coffee brew.
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Affiliation(s)
- Michael Gigl
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, Freising D-85354, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, Freising D-85354, Germany
| | - Oliver Frank
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Str. 34, Freising D-85354, Germany
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36
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Płonka D, Kotuniak R, Dąbrowska K, Bal W. Electrospray-Induced Mass Spectrometry Is Not Suitable for Determination of Peptidic Cu(II) Complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2766-2776. [PMID: 34738801 PMCID: PMC8640992 DOI: 10.1021/jasms.1c00206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
The toolset of mass spectrometry (MS) is still expanding, and the number of metal ion complexes researched this way is growing. The Cu(II) ion forms particularly strong peptide complexes of biological interest which are frequent objects of MS studies, but quantitative aspects of some reported results are at odds with those of experiments performed in solution. Cu(II) complexes are usually characterized by fast ligand exchange rates, despite their high affinity, and we speculated that such kinetic lability could be responsible for the observed discrepancies. In order to resolve this issue, we selected peptides belonging to the ATCUN family characterized with high and thoroughly determined Cu(II) binding constants and re-estimated them using two ESI-MS techniques: standard conditions in combination with serial dilution experiments and very mild conditions for competition experiments. The sample acidification, which accompanies the electrospray formation, was simulated with the pH-jump stopped-flow technique. Our results indicate that ESI-MS should not be used for quantitative studies of Cu(II)-peptide complexes because the electrospray formation process compromises the entropic contribution to the complex stability, yielding underestimations of complex stability constants.
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37
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Li Z, Kitov PI, Kitova EN, Bui DT, Moremen KW, Wakarchuk WW, Mahal LK, Macauley MS, Klassen JS. Quantifying Carbohydrate-Active Enzyme Activity with Glycoprotein Substrates Using Electrospray Ionization Mass Spectrometry and Center-of-Mass Monitoring. Anal Chem 2021; 93:15262-15270. [PMID: 34752696 DOI: 10.1021/acs.analchem.1c02089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carbohydrate-active enzymes (CAZymes) play critical roles in diverse physiological and pathophysiological processes and are important for a wide range of biotechnology applications. Kinetic measurements offer insight into the activity and substrate specificity of CAZymes, information that is of fundamental interest and supports diverse applications. However, robust and versatile kinetic assays for monitoring the kinetics of intact glycoprotein and glycolipid substrates are lacking. Here, we introduce a simple but quantitative electrospray ionization mass spectrometry (ESI-MS) method for measuring the kinetics of CAZyme reactions involving glycoprotein substrates. The assay, referred to as center-of-mass (CoM) monitoring (CoMMon), relies on continuous (real-time) monitoring of the CoM of an ensemble of glycoprotein substrates and their corresponding CAZyme products. Notably, there is no requirement for calibration curves, internal standards, labeling, or mass spectrum deconvolution. To demonstrate the reliability of CoMMon, we applied the method to the neuraminidase-catalyzed cleavage of N-acetylneuraminic acid (Neu5Ac) residues from a series of glycoproteins of varying molecular weights and degrees of glycosylation. Reaction progress curves and initial rates determined with CoMMon are in good agreement (initial rates within ≤5%) with results obtained, simultaneously, using an isotopically labeled Neu5Ac internal standard, which enabled the time-dependent concentration of released Neu5Ac to be precisely measured. To illustrate the applicability of CoMMon to glycosyltransferase reactions, the assay was used to measure the kinetics of sialylation of a series of asialo-glycoproteins by a human sialyltransferase. Finally, we show how combining CoMMon and the competitive universal proxy receptor assay enables the relative reactivity of glycoprotein substrates to be quantitatively established.
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Affiliation(s)
- 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
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Duong T Bui
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, United States.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Warren W Wakarchuk
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Lara K Mahal
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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38
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Jung J, Enterina JR, Bui DT, Mozaneh F, Lin PH, Nitin, Kuo CW, Rodrigues E, Bhattacherjee A, Raeisimakiani P, Daskhan GC, St. Laurent CD, Khoo KH, Mahal LK, Zandberg WF, Huang X, Klassen JS, Macauley MS. Carbohydrate Sulfation As a Mechanism for Fine-Tuning Siglec Ligands. ACS Chem Biol 2021; 16:2673-2689. [PMID: 34661385 DOI: 10.1021/acschembio.1c00501] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The immunomodulatory family of Siglecs recognizes sialic acid-containing glycans as "self", which is exploited in cancer for immune evasion. The biochemical nature of Siglec ligands remains incompletely understood, with emerging evidence suggesting the importance of carbohydrate sulfation. Here, we investigate how specific sulfate modifications affect Siglec ligands by overexpressing eight carbohydrate sulfotransferases (CHSTs) in five cell lines. Overexpression of three CHSTs─CHST1, CHST2, or CHST4─significantly enhance the binding of numerous Siglecs. Unexpectedly, two other CHSTs (Gal3ST2 and Gal3ST3) diminish Siglec binding, suggesting a new mode to modulate Siglec ligands via sulfation. Results are cell type dependent, indicating that the context in which sulfated glycans are presented is important. Moreover, a pharmacological blockade of N- and O-glycan maturation reveals a cell-type-specific pattern of importance for either class of glycan. Production of a highly homogeneous Siglec-3 (CD33) fragment enabled a mass-spectrometry-based binding assay to determine ≥8-fold and ≥2-fold enhanced affinity for Neu5Acα2-3(6-O-sulfo)Galβ1-4GlcNAc and Neu5Acα2-3Galβ1-4(6-O-sulfo)GlcNAc, respectively, over Neu5Acα2-3Galβ1-4GlcNAc. CD33 shows significant additivity in affinity (≥28-fold) for the disulfated ligand, Neu5Acα2-3(6-O-sulfo)Galβ1-4(6-O-sulfo)GlcNAc. Moreover, joint overexpression of CHST1 with CHST2 in cells greatly enhanced the binding of CD33 and several other Siglecs. Finally, we reveal that CHST1 is upregulated in numerous cancers, correlating with poorer survival rates and sodium chlorate sensitivity for the binding of Siglecs to cancer cell lines. These results provide new insights into carbohydrate sulfation as a general mechanism for tuning Siglec ligands on cells, including in cancer.
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Affiliation(s)
- Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | - Jhon R. Enterina
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2J7, Canada
| | - Duong T. Bui
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | - Fahima Mozaneh
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | - Po-Han Lin
- Departments of Chemistry and Biomedical Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Nitin
- Department of Chemistry, The University of British Columbia, Kelowna, V1V 1V7, Canada
| | - Chu-Wei Kuo
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Emily Rodrigues
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | | | | | - Gour C. Daskhan
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | | | - Kay-Hooi Khoo
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Lara K. Mahal
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | - Wesley F. Zandberg
- Department of Chemistry, The University of British Columbia, Kelowna, V1V 1V7, Canada
| | - Xuefei Huang
- Departments of Chemistry and Biomedical Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - John S. Klassen
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
| | - Matthew S. Macauley
- Department of Chemistry, University of Alberta, Edmonton, T6G 2G2, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, T6G 2J7, Canada
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39
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Schwarz M, Eno RFM, Freitag-Pohl S, Coxon CR, Straker HE, Wortley DJ, Hughes DJ, Mitchell G, Moore J, Cummins I, Onkokesung N, Brazier-Hicks M, Edwards R, Pohl E, Steel PG. Flavonoid-based inhibitors of the Phi-class glutathione transferase from black-grass to combat multiple herbicide resistance. Org Biomol Chem 2021; 19:9211-9222. [PMID: 34643629 PMCID: PMC8564858 DOI: 10.1039/d1ob01802g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The evolution and growth of multiple-herbicide resistance (MHR) in grass weeds continues to threaten global cereal production. While various processes can contribute to resistance, earlier work has identified the phi class glutathione-S-transferase (AmGSTF1) as a functional biomarker of MHR in black-grass (Alopecurus myosuroides). This study provides further insights into the role of AmGSTF1 in MHR using a combination of chemical and structural biology. Crystal structures of wild-type AmGSTF1, together with two specifically designed variants that allowed the co-crystal structure determination with glutathione and a glutathione adduct of the AmGSTF1 inhibitor 4-chloro-7-nitro-benzofurazan (NBD-Cl) were obtained. These studies demonstrated that the inhibitory activity of NBD-Cl was associated with the occlusion of the active site and the impediment of substrate binding. A search for other selective inhibitors of AmGSTF1, using ligand-fishing experiments, identified a number of flavonoids as potential ligands. Subsequent experiments using black-grass extracts discovered a specific flavonoid as a natural ligand of the recombinant enzyme. A series of related synthetic flavonoids was prepared and their binding to AmGSTF1 was investigated showing a high affinity for derivatives bearing a O-5-decyl-α-carboxylate. Molecular modelling based on high-resolution crystal structures allowed a binding pose to be defined which explained flavonoid binding specificity. Crucially, high binding affinity was linked to a reversal of the herbicide resistance phenotype in MHR black-grass. Collectively, these results present a nature-inspired new lead for the development of herbicide synergists to counteract MHR in weeds. Nature inspired flavonoid derivatives bind to AmGSTF1 and overcome herbicide resistance in multiple herbicide resistant (MHR) Black Grass.![]()
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Affiliation(s)
- Maria Schwarz
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
| | - Rebecca F M Eno
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
| | - Stefanie Freitag-Pohl
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
| | - Christopher R Coxon
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
| | - Hannah E Straker
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
| | - David J Wortley
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, UK
| | - David J Hughes
- Syngenta, Jealott's Hill International Research Station, Bracknell, Berks RG42 6EY, UK
| | - Glynn Mitchell
- Syngenta, Jealott's Hill International Research Station, Bracknell, Berks RG42 6EY, UK
| | - Jenny Moore
- Syngenta, Jealott's Hill International Research Station, Bracknell, Berks RG42 6EY, UK
| | - Ian Cummins
- Department of Biosciences, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK
| | - Nawaporn Onkokesung
- Agriculture, School of Natural and Environmental Sciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Melissa Brazier-Hicks
- Agriculture, School of Natural and Environmental Sciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Robert Edwards
- Agriculture, School of Natural and Environmental Sciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Ehmke Pohl
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK. .,Department of Biosciences, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK
| | - Patrick G Steel
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, UK.
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40
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Donor MT, Wilson JW, Shepherd SO, Prell JS. Lipid Head Group Adduction to Soluble Proteins Follows Gas-Phase Basicity Predictions: Dissociation Barriers and Charge Abstraction. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2021; 469:116670. [PMID: 34421332 PMCID: PMC8372978 DOI: 10.1016/j.ijms.2021.116670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Native mass spectrometry analysis of membrane proteins has yielded many useful insights in recent years with respect to membrane protein-lipid interactions, including identifying specific interactions and even measuring binding affinities based on observed abundances of lipid-bound ions after collision-induced dissociation (CID). However, the behavior of non-covalent complexes subjected to extensive CID can in principle be affected by numerous factors related to gas-phase chemistry, including gas-phase basicity (GB) and acidity, shared-proton bonds, and other factors. A recent report from our group showed that common lipids span a wide range of GB values. Notably, phosphatidylcholine (PC) and sphingomyelin lipids are more basic than arginine, suggesting they may strip charge upon dissociation in positive ion mode, while phosphoserine lipids are slightly less basic than arginine and may form especially strong shared-proton bonds. Here, we use CID to probe the strength of non-specific gas-phase interactions between lipid head groups and several soluble proteins, used to deliberately avoid possible physiological protein-lipid interactions. The strengths of the protein-head group interactions follow the trend predicted based solely on lipid and amino acid GBs: phosphoserine (PS) head group forms the strongest bonds with these proteins and out-competes the other head groups studied, while glycerophosphocholine (GPC) head groups form the weakest interactions and dissociate carrying away a positive charge. These results indicate that gas-phase thermochemistry can play an important role in determining which head groups remain bound to protein ions with native-like structures and charge states in positive ion mode upon extensive collisional activation.
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Affiliation(s)
- Micah T. Donor
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - Jesse W. Wilson
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - Samantha O. Shepherd
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - James S. Prell
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
- Materials Science Institute, University of Oregon, 1252 University of Oregon, Eugene, OR 97403-1252
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41
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Kaeslin J, Brunner C, Ghiasikhou S, Schneider G, Zenobi R. Bioaffinity Screening with a Rapid and Sample-Efficient Autosampler for Native Electrospray Ionization Mass Spectrometry. Anal Chem 2021; 93:13342-13350. [PMID: 34546705 DOI: 10.1021/acs.analchem.1c03130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fast and efficient handling of ligands and biological targets are required in bioaffinity screening based on native electrospray ionization mass spectrometry (ESI-MS). We use a prototype microfluidic autosampler, called the "gap sampler", to sequentially mix and electrospray individual small molecule ligands together with a target protein and compare the screening results with data from thermal shift assay and surface plasmon resonance. In a first round, all three techniques were used for a screening of 110 ligands against bovine carbonic anhydrase II, which resulted in five mutual hits and some false positives with ESI-MS presumably due to the high ligand concentration or interferences from dimethyl sulfoxide. In a second round, 33 compounds were screened in lower concentrations and in a less complex matrix, resulting in only true positives with ESI-MS. Within a cycle time of 30 s, dissociation constants were determined within an order of magnitude accuracy consuming only 5 pmol of ligand and less than 15 pmol of protein per screened compound. In a third round, dissociation constants of five compounds were accurately determined in a titration experiment. Thus, the gap sampler can rapidly and efficiently be used for high-throughput screening.
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Affiliation(s)
- Jérôme Kaeslin
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Cyrill Brunner
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Sahar Ghiasikhou
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Gisbert Schneider
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
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42
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Aliyari E, Konermann L. Atomistic Insights into the Formation of Nonspecific Protein Complexes during Electrospray Ionization. Anal Chem 2021; 93:12748-12757. [PMID: 34494821 DOI: 10.1021/acs.analchem.1c02836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Native electrospray ionization (ESI)-mass spectrometry (MS) is widely used for the detection and characterization of multi-protein complexes. A well-known problem with this approach is the possible occurrence of nonspecific protein clustering in the ESI plume. This effect can distort the results of binding affinity measurements, and it can even generate gas-phase complexes from proteins that are strictly monomeric in bulk solution. By combining experiments and molecular dynamics (MD) simulations, the current work for the first time provides detailed insights into the ESI clustering of proteins. Using ubiquitin as a model system, we demonstrate how the entrapment of more than one protein molecule in an ESI droplet can generate nonspecific clusters (e.g., dimers or trimers) via solvent evaporation to dryness. These events are in line with earlier proposals, according to which protein clustering is associated with the charged residue model (CRM). MD simulations on cytochrome c (which carries a large intrinsic positive charge) confirmed the viability of this CRM avenue. In addition, the cytochrome c data uncovered an alternative mechanism where protein-protein contacts were formed early within ESI droplets, followed by cluster ejection from the droplet surface. This second pathway is consistent with the ion evaporation model (IEM). The observation of these IEM events for large protein clusters is unexpected because the IEM has been thought to be associated primarily with low-molecular-weight analytes. In all cases, our MD simulations produced protein clusters that were stabilized by intermolecular salt bridges. The MD-generated charge states agreed with experiments. Overall, this work reveals that ESI-induced protein clustering does not follow a tightly orchestrated pathway but can proceed along different avenues.
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Affiliation(s)
- Elnaz Aliyari
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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43
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Rogawski R, Rogel A, Bloch I, Gal M, Horovitz A, London N, Sharon M. Intracellular Protein–Drug Interactions Probed by Direct Mass Spectrometry of Cell Lysates. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Rivkah Rogawski
- Department of Biomolecular Sciences Weizmann Institute of Science Rehovot 7610001 Israel
| | - Adi Rogel
- Department of Chemical and Structural Biology Weizmann Institute of Science Rehovot 7610001 Israel
| | - Itai Bloch
- Biotechnology Department MIGAL-Galilee Research Institute Kiryat-Shmona 11016 Israel
| | - Maayan Gal
- Department of Oral Biology The Goldschleger School of Dental Medicine Sackler Faculty of Medicine Tel Aviv University Tel Aviv 6997801 Israel
| | - Amnon Horovitz
- Department of Chemical and Structural Biology Weizmann Institute of Science Rehovot 7610001 Israel
| | - Nir London
- Department of Chemical and Structural Biology Weizmann Institute of Science Rehovot 7610001 Israel
| | - Michal Sharon
- Department of Biomolecular Sciences Weizmann Institute of Science Rehovot 7610001 Israel
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44
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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: 31] [Impact Index Per Article: 10.3] [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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45
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Bellamy-Carter J, Mohata M, Falcicchio M, Basran J, Higuchi Y, Doveston RG, Leney AC. Discovering protein-protein interaction stabilisers by native mass spectrometry. Chem Sci 2021; 12:10724-10731. [PMID: 34447561 PMCID: PMC8372317 DOI: 10.1039/d1sc01450a] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/10/2021] [Indexed: 11/21/2022] Open
Abstract
Protein-protein interactions (PPIs) are key therapeutic targets. Most PPI-targeting drugs in the clinic inhibit these important interactions; however, stabilising PPIs is an attractive alternative in cases where a PPI is disrupted in a disease state. The discovery of novel PPI stabilisers has been hindered due to the lack of tools available to monitor PPI stabilisation. Moreover, for PPI stabilisation to be detected, both the stoichiometry of binding and the shift this has on the binding equilibria need to be monitored simultaneously. Here, we show the power of native mass spectrometry (MS) in the rapid search for PPI stabilisers. To demonstrate its capability, we focussed on three PPIs between the eukaryotic regulatory protein 14-3-3σ and its binding partners estrogen receptor ERα, the tumour suppressor p53, and the kinase LRRK2, whose interactions upon the addition of a small molecule, fusicoccin A, are differentially stabilised. Within a single measurement the stoichiometry and binding equilibria between 14-3-3 and each of its binding partners was evident. Upon addition of the fusicoccin A stabiliser, a dramatic shift in binding equilibria was observed with the 14-3-3:ERα complex compared with the 14-3-3:p53 and 14-3-3:LRRK2 complexes. Our results highlight how native MS can not only distinguish the ability of stabilisers to modulate PPIs, but also give important insights into the dynamics of ternary complex formation. Finally, we show how native MS can be used as a screening tool to search for PPI stabilisers, highlighting its potential role as a primary screening technology in the hunt for novel therapeutic PPI stabilisers.
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Affiliation(s)
| | - Manjari Mohata
- School of Biosciences, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Marta Falcicchio
- Leicester Institute of Structural and Chemical Biology and School of Chemistry, University of Leicester Leicester LE1 7RH UK
| | - Jaswir Basran
- Department of Molecular and Cell Biology, University of Leicester Leicester LE1 7RH UK
| | - Yusuke Higuchi
- Department of Molecular Medicine, Beckman Research Institute of City of Hope Duarte CA 91010 USA
| | - Richard G Doveston
- Leicester Institute of Structural and Chemical Biology and School of Chemistry, University of Leicester Leicester LE1 7RH UK
| | - Aneika C Leney
- School of Biosciences, University of Birmingham Edgbaston Birmingham B15 2TT UK
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46
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Rogawski R, Rogel A, Bloch I, Gal M, Horovitz A, London N, Sharon M. Intracellular Protein-Drug Interactions Probed by Direct Mass Spectrometry of Cell Lysates. Angew Chem Int Ed Engl 2021; 60:19637-19642. [PMID: 34101963 PMCID: PMC8457057 DOI: 10.1002/anie.202104947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/23/2021] [Indexed: 12/22/2022]
Abstract
Understanding protein–ligand interactions in a cellular context is an important goal in molecular biology and biochemistry, and particularly for drug development. Investigators must demonstrate that drugs penetrate cells and specifically bind their targets. Towards that end, we present a native mass spectrometry (MS)‐based method for analyzing drug uptake and target engagement in eukaryotic cells. This method is based on our previously introduced direct‐MS method for rapid analysis of proteins directly from crude samples. Here, direct‐MS enables label‐free studies of protein–drug binding in human cells and is used to determine binding affinities of lead compounds in crude samples. We anticipate that this method will enable the application of native MS to a range of problems where cellular context is important, including protein–protein interactions, drug uptake and binding, and characterization of therapeutic proteins.
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Affiliation(s)
- Rivkah Rogawski
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Adi Rogel
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Itai Bloch
- Biotechnology Department, MIGAL-Galilee Research Institute, Kiryat-Shmona, 11016, Israel
| | - Maayan Gal
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Amnon Horovitz
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Nir London
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
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47
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Weerasinghe NW, Habibi Y, Uggowitzer KA, Thibodeaux CJ. Exploring the Conformational Landscape of a Lanthipeptide Synthetase Using Native Mass Spectrometry. Biochemistry 2021; 60:1506-1519. [PMID: 33887902 DOI: 10.1021/acs.biochem.1c00085] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lanthipeptides are ribosomally synthesized and post-translationally modified peptide (RiPP) natural products. These genetically encoded peptides are biosynthesized by multifunctional enzymes (lanthipeptide synthetases) that possess relaxed substrate specificity and catalyze iterative rounds of post-translational modification. Recent evidence has suggested that some lanthipeptide synthetases are structurally dynamic enzymes that are allosterically activated by precursor peptide binding and that conformational sampling of the enzyme-peptide complex may play an important role in defining the efficiency and sequence of biosynthetic events. These "biophysical" processes, while critical for defining the activity and function of the synthetase, remain very challenging to study with existing methodologies. Herein, we show that native mass spectrometry coupled to ion mobility (native IM-MS) provides a powerful and sensitive means for investigating the conformational landscapes and intermolecular interactions of lanthipeptide synthetases. Namely, we demonstrate that the class II lanthipeptide synthetase (HalM2) and its noncovalent complex with the cognate HalA2 precursor peptide can be delivered into the gas phase in a manner that preserves native structures and intermolecular enzyme-peptide contacts. Moreover, gas phase ion mobility studies of the natively folded ions demonstrate that peptide binding and mutations to dynamic structural elements of HalM2 alter the conformational landscape of the enzyme. Cumulatively, these data support previous claims that lanthipeptide synthetases are structurally dynamic enzymes that undergo functionally relevant conformational changes in response to precursor peptide binding. This work establishes native IM-MS as a versatile approach for characterizing intermolecular interactions and for unraveling the relationships between protein structure and biochemical function in RiPP biosynthetic systems.
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Affiliation(s)
- Nuwani W Weerasinghe
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada
| | - Yeganeh Habibi
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada
| | - Kevin A Uggowitzer
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada
| | - Christopher J Thibodeaux
- Department of Chemistry and Centre de Recherche en Biologie Structurale, McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 0B8, Canada
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48
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Le ATH, Krylova SM, Beloborodov SS, Wang TY, Hili R, Johnson PE, Li F, Veedu RN, Belyanskaya S, Krylov SN. How to Develop and Prove High-Efficiency Selection of Ligands from Oligonucleotide Libraries: A Universal Framework for Aptamers and DNA-Encoded Small-Molecule Ligands. Anal Chem 2021; 93:5343-5354. [PMID: 33764056 DOI: 10.1021/acs.analchem.1c00601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Screening molecular libraries for ligands capable of binding proteins is widely used for hit identification in the early drug discovery process. Oligonucleotide libraries provide a very high diversity of compounds, while the combination of the polymerase chain reaction and DNA sequencing allow the identification of ligands in low copy numbers selected from such libraries. Ligand selection from oligonucleotide libraries requires mixing the library with the target followed by the physical separation of the ligand-target complexes from the unbound library. Cumulatively, the low abundance of ligands in the library and the low efficiency of available separation methods necessitate multiple consecutive rounds of partitioning. Multiple rounds of inefficient partitioning make the selection process ineffective and prone to failures. There are continuing efforts to develop a separation method capable of reliably generating a pure pool of ligands in a single round of partitioning; however, none of the proposed methods for single-round selection have been universally adopted. Our analysis revealed that the developers' efforts are disconnected from each other and hindered by the lack of quantitative criteria of selection quality assessment. Here, we present a formalism that describes single-round selection mathematically and provides parameters for quantitative characterization of selection quality. We use this formalism to define a universal strategy for development and validation of single-round selection methods. Finally, we analyze the existing partitioning methods, the published single-round selection reports, and some pertinent practical considerations through the prism of this formalism. This formalism is not an experimental protocol but a framework for correct development of experimental protocols. While single-round selection is not a goal by itself and may not always suffice selection of good-quality ligands, our work will help developers of highly efficient selection approaches to consolidate their efforts under an umbrella of universal quantitative criteria of method development and assessment.
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Affiliation(s)
- An T H Le
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Svetlana M Krylova
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Stanislav S Beloborodov
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Tong Y Wang
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Ryan Hili
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Philip E Johnson
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
| | - Feng Li
- Department of Chemistry and Centre for Biotechnology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Rakesh N Veedu
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University and Perron Institute for Neurological and Translational Science, Perth 6150, Australia
| | | | - Sergey N Krylov
- Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada
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49
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Báez Bolivar EG, Bui DT, Kitova EN, Han L, Zheng RB, Luber EJ, Sayed SY, Mahal LK, Klassen JS. Submicron Emitters Enable Reliable Quantification of Weak Protein-Glycan Interactions by ESI-MS. Anal Chem 2021; 93:4231-4239. [PMID: 33630563 DOI: 10.1021/acs.analchem.0c05003] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Interactions between carbohydrates (glycans) and glycan-binding proteins (GBPs) regulate a wide variety of important biological processes. However, the affinities of most monovalent glycan-GBP complexes are typically weak (dissociation constant (Kd) > μM) and difficult to reliably measure with conventional assays; consequently, the glycan specificities of most GBPs are not well established. Here, we demonstrate how electrospray ionization mass spectrometry (ESI-MS), implemented with nanoflow ESI emitters with inner diameters of ∼50 nm, allows for the facile quantification of low-affinity glycan-GBP interactions. The small size of the droplets produced from these submicron emitters effectively eliminates the formation of nonspecific glycan-GBP binding (false positives) during the ESI process up to ∼mM glycan concentrations. Thus, interactions with affinities as low as ∼5 mM can be measured directly from the mass spectrum. The general suppression of nonspecific adducts (including nonvolatile buffers and salts) achieved with these tips enables ESI-MS glycan affinity measurements to be performed on C-type lectins, a class of GBPs that bind glycans in a calcium-dependent manner and are important regulators of immune response. At physiologically relevant calcium ion concentrations (2-3 mM), the extent of Ca2+ nonspecific adduct formation observed using the submicron emitters is dramatically suppressed, allowing glycan affinities, and the influence of Ca2+ thereon, to be measured. Finally, we show how the use of submicron emitters and suppression of nonspecific binding enable the quantification of labile (prone to in-source dissociation) glycan-GBP interactions.
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Affiliation(s)
- Erick G Báez Bolivar
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Duong T Bui
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Ling Han
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Ruixiang B Zheng
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Erik J Luber
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Sayed Youssef Sayed
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Lara K Mahal
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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50
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Tian Y, Bao Q, Wang N, Wan N, Lv L, Hao H, He C, Ye H. Time-Resolved Acetaldehyde-Based Accessibility Profiling Maps Ligand-Target Interactions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:519-530. [PMID: 33382614 DOI: 10.1021/jasms.0c00382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Elucidating ligand-protein interactions is important in understanding the biochemical machinery for given proteins. Previously, formaldehyde (FH)-based labeling has been employed to obtain such structural knowledge, since reactive residues that participate in ligand-target interactions display reduced accessibility to FH-labeling reagents, and thus can be identified by quantitative proteomics. Although being rapid and efficient for probing proteinaceous lysine accessibility, here, we report an acetaldehyde (AcH)-labeling approach that complements with FH for probing ligand-target interactions. AcH labeling examines lysine accessibility at a more moderate reaction speed and hence delivers a cleaner reaction when compared to that of FH. The subsequent application of AcH to label RNase A without and with ligands has assisted to assign lysines involved in ligand-RNase A binding by detecting the time-dependent changes in accessibility profiles. We further employed multiple reaction monitoring (MRM) to quantify these ligand-binding-responsive sites when a variety of potential ligands were queried. We noted that the time-resolved abundance changes of these peptides can sensitively determine the ligand-binding sites and differentiate binding affinities among these ligands, which was confirmed by native mass spectrometry (MS) and molecular docking. Lastly, we demonstrated that the binding sites can be recognized by monitoring the chemical accessibility of these responsive peptides in cell lysates. Together, we believe that the proposed combined use of AcH-based lysine accessibility profiling, native MS, and MRM screening is a powerful toolbox in characterizing ligand-target interactions, mapping topography, and interrogating affinities and holds promise for future applications in a complex cellular environment.
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Affiliation(s)
- Yang Tian
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Qiuyu Bao
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Nian Wang
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Ning Wan
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Langlang Lv
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Haiping Hao
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Chaoyong He
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
| | - Hui Ye
- Jiangsu Provincial Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu 210009, China
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