1
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Rincon Pabon JP, Akbar Z, Politis A. MSe Collision Energy Optimization for the Analysis of Membrane Proteins Using HDX-cIMS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1383-1389. [PMID: 38842540 PMCID: PMC11228973 DOI: 10.1021/jasms.4c00093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/09/2024] [Accepted: 06/05/2024] [Indexed: 06/07/2024]
Abstract
Hydrogen/deuterium exchange mass spectrometry (HDX-MS) has evolved as an essential technique in structural proteomics. The use of ion mobility separation (IMS) coupled to HDX-MS has increased the applicability of the technique to more complex systems and has been shown to improve data quality and robustness. The first step when running any HDX-MS workflow is to confirm the sequence and retention time of the peptides resulting from the proteolytic digestion of the nondeuterated protein. Here, we optimized the collision energy ramp of HDMSE experiments for membrane proteins using a Waters SELECT SERIES cIMS-QTOF system following an HDX workflow using Phosphorylase B, XylE transporter, and Smoothened receptor (SMO) as model systems. Although collision energy (CE) ramp 10-50 eV gave the highest amount of positive identified peptides when using Phosphorylase B, XylE, and SMO, results suggest optimal CE ramps are protein specific, and different ramps can produce a unique set of peptides. We recommend cIMS users use different CE ramps in their HDMSE experiments and pool the results to ensure maximum peptide identifications. The results show how selecting an appropriate CE ramp can change the sequence coverage of proteins ranging from 4 to 94%.
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Affiliation(s)
- Juan Pablo Rincon Pabon
- Faculty of Biology, Medicine and Health, Division of Molecular and Cellular Function, The University of Manchester, Manchester M13 9PT, U.K
- Manchester Institute of Biotechnology, University of Manchester, Princess Street, Manchester M1 7DN, U.K
| | - Zulaikha Akbar
- Faculty of Biology, Medicine and Health, Division of Molecular and Cellular Function, The University of Manchester, Manchester M13 9PT, U.K
- Manchester Institute of Biotechnology, University of Manchester, Princess Street, Manchester M1 7DN, U.K
| | - Argyris Politis
- Faculty of Biology, Medicine and Health, Division of Molecular and Cellular Function, The University of Manchester, Manchester M13 9PT, U.K
- Manchester Institute of Biotechnology, University of Manchester, Princess Street, Manchester M1 7DN, U.K
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2
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Wagner WJ, Moyle AB, Wagner ND, Rempel DL, Gross ML. Evaluating Chemical Footprinting-Induced Perturbation of Protein Higher Order Structure. Anal Chem 2024; 96:9693-9703. [PMID: 38815160 PMCID: PMC11238718 DOI: 10.1021/acs.analchem.4c01735] [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: 06/01/2024]
Abstract
Specific amino acid footprinting mass spectrometry (MS) is an increasingly utilized method for elucidating protein higher order structure (HOS). It does this by adding to certain amino acid residues a mass tag, whose reaction extent depends on solvent accessibility and microenvironment of the protein. Unlike reactive free radicals and carbenes, these specific footprinters react slower than protein unfolding. Thus, their footprinting, under certain conditions, provokes structural changes to the protein, leading to labeling on non-native structures. It is critical to establish conditions (i.e., reagent concentrations, time of reaction) to ensure that the structure of the protein following footprinting remains native. Here, we compare the efficacy of five methods in assessing protein HOS following footprinting at the intact protein level and then further localize the perturbation at the peptide level. Three are MS-based methods that provide dose-response plot analysis, evaluation of Poisson distributions of precursor and products, and determination of the average number of modifications. These MS-based methods reliably and effectively indicate HOS perturbation at the intact protein level, whereas spectroscopic methods (circular dichroism (CD) and dynamic light scattering (DLS)) are less sensitive in monitoring subtle HOS perturbation caused by footprinting. Evaluation of HOS at the peptide level indicates regions that are sensitive to localized perturbations. Peptide-level analysis also provides higher resolution of the HOS perturbation, and we recommend using it for future footprinting studies. Overall, this work shows conclusive evidence for HOS perturbation caused by footprinting. Implementation of quality control workflows can identify conditions to avoid the perturbation, for footprinting, allowing accurate and reliable identification of protein structural changes that accompany, for example, ligand interactions, mutations, and changes in solution environment.
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Affiliation(s)
- Wesley J Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Don L Rempel
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130 United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130 United States
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3
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Heffernan JR, Wildenthal JA, Tran H, Katumba GL, McCoy WH, Henderson JP. Yersiniabactin is a quorum-sensing autoinducer and siderophore in uropathogenic Escherichia coli. mBio 2024; 15:e0027723. [PMID: 38236035 PMCID: PMC10865836 DOI: 10.1128/mbio.00277-23] [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: 02/08/2023] [Accepted: 12/07/2023] [Indexed: 01/19/2024] Open
Abstract
Siderophores are secreted ferric ion chelators used to obtain iron in nutrient-limited environmental niches, including human hosts. While all Escherichia coli express the enterobactin (Ent) siderophore system, isolates from patients with urinary tract infections additionally express the genetically distinct yersiniabactin (Ybt) siderophore system. To determine whether the Ent and Ybt systems are functionally redundant for iron uptake, we compared the growth of different isogenic siderophore biosynthetic mutants in the presence of transferrin, a human iron-binding protein. We observed that Ybt expression does not compensate for deficient Ent expression following low-density inoculation. Using transcriptional and product analysis, we found this non-redundancy to be attributable to a density-dependent transcriptional stimulation cycle in which Ybt functions as an autoinducer. These results distinguish the Ybt system as a combined quorum-sensing and siderophore system. These functions may reflect Ybt as a public good within bacterial communities or as an adaptation to confined, subcellular compartments in infected hosts. This combined functionality may contribute to the extraintestinal pathogenic potential of E. coli and related Enterobacterales.IMPORTANCEPatients with urinary tract infections are often infected with Escherichia coli strains carrying adaptations that increase their pathogenic potential. One of these adaptations is the accumulation of multiple siderophore systems, which scavenge iron for nutritional use. While iron uptake is important for bacterial growth, the increased metabolic costs of siderophore production could diminish bacterial fitness during infections. In a siderophore-dependent growth condition, we show that the virulence-associated yersiniabactin siderophore system in uropathogenic E. coli is not redundant with the ubiquitous E. coli enterobactin system. This arises not from differences in iron-scavenging activity but because yersiniabactin is preferentially expressed during bacterial crowding, leaving bacteria dependent upon enterobactin for growth at low cell density. Notably, this regulatory mode arises because yersiniabactin stimulates its own expression, acting as an autoinducer in a previously unappreciated quorum-sensing system. This unexpected result connects quorum-sensing with pathogenic potential in E. coli and related Enterobacterales.
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Affiliation(s)
- James R. Heffernan
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - John A. Wildenthal
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hung Tran
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - George L. Katumba
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - William H. McCoy
- Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jeffrey P. Henderson
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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4
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Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. J Biol Chem 2024; 300:105554. [PMID: 38072063 PMCID: PMC10788543 DOI: 10.1016/j.jbc.2023.105554] [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: 07/28/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
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Affiliation(s)
- Zongsen Zou
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John I Robinson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Lindsey K Steinberg
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Jeffrey P Henderson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
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5
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Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550588. [PMID: 37546885 PMCID: PMC10402112 DOI: 10.1101/2023.07.25.550588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Uropathogenic E. coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here we find the siderophore enterobactin and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined enterobactin biosynthesis and import mutants, we identify lower molecular weight, dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-enterobactin complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed enterobactin, we find that enterobactin and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
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Affiliation(s)
- Zongsen Zou
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - John I. Robinson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lindsey K. Steinberg
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jeffrey P. Henderson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
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6
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Moyle AB, Wagner ND, Wagner WJ, Cheng M, Gross ML. Workflow for Validating Specific Amino Acid Footprinting Reagents for Protein Higher Order Structure Elucidation. Anal Chem 2023; 95:10119-10126. [PMID: 37351860 PMCID: PMC10476636 DOI: 10.1021/acs.analchem.3c01919] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Protein footprinting mass spectrometry probes protein higher order structure and dynamics by labeling amino acid side-chains or backbone amides as a function of solvent accessibility. One category of footprinting uses residue-specific, irreversible covalent modifications, affording flexibility of sample processing for bottom-up analysis. Although several specific amino acid footprinting technologies are becoming established in structural proteomics, there remains a need to assess fundamental properties of new reagents before their application. Often, footprinting reagents are applied to complex or novel protein systems soon after their discovery and sometimes without a thorough investigation of potential downsides of the reagent. In this work, we assemble and test a validation workflow that utilizes cyclic peptides and a model protein to characterize benzoyl fluoride, a recently published, next-generation nucleophile footprinter. The workflow includes the characterization of potential side-chain reactive groups, reaction "quench" efficacies, reagent considerations and caveats (e.g., buffer pH), residue-specific kinetics compared to those of established reagents, and protein-wide characterization of modification sites with considerations for proteolysis. The proposed workflow serves as a starting point for improved footprinting reagent discovery, validation, and introduction, the aspects of which we recommend before applying to unknown protein systems.
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Affiliation(s)
- Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Wesley J. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Ming Cheng
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 United States
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7
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Heffernan JR, Katumba GL, McCoy WH, Henderson JP. Yersiniabactin is a quorum sensing autoinducer and siderophore in uropathogenic Escherichia coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.09.527953. [PMID: 36798367 PMCID: PMC9934619 DOI: 10.1101/2023.02.09.527953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Siderophores are secreted ferric ion chelators used to obtain iron in nutrient-limited environmental niches, including human hosts. While all E. coli encode the enterobactin (Ent) siderophore system, isolates from patients with urinary tract infections additionally encode the genetically distinct yersiniabactin (Ybt) siderophore system. To determine whether the Ent and Ybt systems are functionally redundant for iron uptake, we compared growth of different isogenic siderophore biosynthesis mutants in the presence of transferrin, a human iron-binding protein. We observed that the Ybt system does not compensate for loss of the Ent system during siderophore-dependent, low density growth. Using transcriptional and product analysis, we found that this non-redundancy is attributable to a density-dependent transcriptional stimulation cycle in which Ybt assume an additional autoinducer function. These results distinguish the Ybt system as a combined quorum-sensing and siderophore system. These functions may reflect Ybt as a public good within bacterial communities or as an adaptation to confined, subcellular compartments in infected hosts. The efficiency of this arrangement may contribute to the extraintestinal pathogenic potential of E. coli and related Enterobacterales. IMPORTANCE Urinary tract infections (UTIs) are one of the most common human bacterial infections encountered by physicians. Adaptations that increase the pathogenic potential of commensal microbes such as E.coli are of great interest. One potential adaptation observed in clinical isolates is accumulation of multiple siderophore systems, which scavenge iron for nutritional use. While iron uptake is important for bacterial growth, the increased metabolic costs of siderophore production could diminish bacterial fitness during infections. In a siderophore-dependent growth conditions, we show that the virulence-associated yersiniabactin siderophore system in uropathogenic E. coli is not redundant with the ubiquitous E. coli enterobactin system. This arises not from differences in iron scavenging activity but because yersiniabactin is preferentially expressed during bacterial crowding, leaving bacteria dependent upon enterobactin for growth at low cell density. Notably, this regulatory mode arises because yersiniabactin stimulates its own expression, acting as an autoinducer in a previously unappreciated quorum-sensing system. This unexpected result connects quorum-sensing with pathogenic potential in E. coli and related Enterobacterales.
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8
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Synthesis and study of new siderophore analog-ciprofloxacin conjugates with antibiotic activities against Pseudomonas aeruginosa and Burkholderia spp. Eur J Med Chem 2022; 245:114921. [DOI: 10.1016/j.ejmech.2022.114921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/14/2022]
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9
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Wagner ND, Moyle AB, Pabon JPR, Gross ML. Automated Specific Amino Acid Footprinting Mass Spectrometry: Repurposing an HDX Platform for Determining Reagent Feasibility. Anal Chem 2022; 94:10314-10319. [PMID: 35830607 PMCID: PMC10482561 DOI: 10.1021/acs.analchem.2c02073] [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: 11/30/2022]
Abstract
Protein footprinting is a mass spectrometry (MS)-based approach to measure protein conformational changes. One approach, specific amino acid labeling, imparts often an irreversible modification to protein side chains but requires careful selection of the reactive reagent and often time-consuming optimization of experimental parameters prior to submission to bottom-up MS analysis. In this work, we repurpose a hydrogen-deuterium exchange MS (HDX-MS) LEAP HDX system for automated specific amino acid footprinting MS, demonstrating its efficacy in reaction optimization and monitoring applicability to specific ligand binding systems. We screened reagent conditions for two model ligand-binding systems and demonstrate the method's efficacy for measuring differences induced by ligand binding. Our proof-of-concept experiments provide a platform for rapidly screening specific amino acid reagents and reaction conditions for protein systems to be studied by footprinting.
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Affiliation(s)
- Nicole D. Wagner
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Austin B. Moyle
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Juan P. Rincon Pabon
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
| | - Michael L. Gross
- Washington University in St. Louis, Department of Chemistry, St. Louis, MO 63130
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10
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Klahn P, Zscherp R, Jimidar CC. Advances in the Synthesis of Enterobactin, Artificial Analogues, and Enterobactin-Derived Antimicrobial Drug Conjugates and Imaging Tools for Infection Diagnosis. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1783-0751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
AbstractIron is an essential growth factor for bacteria, but although highly abundant in nature, its bioavailability during infection in the human host or the environment is limited. Therefore, bacteria produce and secrete siderophores to ensure their supply of iron. The triscatecholate siderophore enterobactin and its glycosylated derivatives, the salmochelins, play a crucial role for iron acquisition in several bacteria. As these compounds can serve as carrier molecules for the design of antimicrobial siderophore drug conjugates as well as siderophore-derived tool compounds for the detection of infections with bacteria, their synthesis and the design of artificial analogues is of interest. In this review, we give an overview on the synthesis of enterobactin, biomimetic as well as totally artificial analogues, and related drug-conjugates covering up to 12/2021.1 Introduction2 Antibiotic Crisis and Sideromycins as Natural Templates for New Antimicrobial Drugs3 Biosynthesis of Enterobactin, Salmochelins, and Microcins4 Total Synthesis of Enterobactin and Salmochelins5 Chemoenzymatic Semi-synthesis of Salmochelins and Microcin E492m Derivatives6 Synthesis of Biomimetic Enterobactin Derivatives with Natural Tris-lactone Backbone7 Synthesis of Artificial Enterobactin Derivatives without Tris-lactone Backbone8 Conclusions
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Affiliation(s)
- Philipp Klahn
- Institute of Organic Chemistry, Technische Universität Braunschweig
- Department for Chemistry and Molecular Biology, University of Gothenburg
| | - Robert Zscherp
- Institute of Organic Chemistry, Technische Universität Braunschweig
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11
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Moyle AB, Cheng M, Wagner ND, Gross ML. Benzoyl Transfer for Footprinting Alcohol-Containing Residues in Higher Order Structural Applications of Mass-Spectrometry-Based Proteomics. Anal Chem 2022; 94:1520-1524. [PMID: 35019278 PMCID: PMC10483880 DOI: 10.1021/acs.analchem.1c04659] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein footprinting mass spectrometry (MS), an emerging approach to elucidate higher-order structure (HOS) and binding, benefits from the iterative development of reaction strategies to expand the covalent labeling toolbox. Herein, we introduce a footprinting reagent for nucleophiles and demonstrate its efficacy for differential covalent labeling MS analysis. Benzoyl fluoride (BF), although reactive with water, is more practical for modifying nucleophilic functional groups than other acid halides and serves as an acyl-transfer reagent for proteins. BF is 10 times more reactive with phenolic Tyr than the current generation nucleophile footprinter. BF modifies, in addition to Tyr, Lys, His, and the N-terminus, weak nucleophiles Ser and Thr, for which few footprinters exist, imparting broad applicability with a range of nucleophiles. We applied benzoylation to a model Ser- and Thr-rich protein-ligand binding system without perturbing the protein HOS. This efficacious footprinting method expands the toolbox of reagents and provides promise for future reaction strategies including possibly membrane proteins.
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Affiliation(s)
- Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Ming Cheng
- Corresponding Authors Michael L. Gross - Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint. Louis, MO, 63130 USA. ; Ming Cheng - Department of Chemistry, Washington University in St. Louis, One Brookings Drive, Saint. Louis, MO, 63130 USA.
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
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12
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Lin Y, Gross ML. Mass Spectrometry-Based Structural Proteomics for Metal Ion/Protein Binding Studies. Biomolecules 2022; 12:135. [PMID: 35053283 PMCID: PMC8773722 DOI: 10.3390/biom12010135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Metal ions are critical for the biological and physiological functions of many proteins. Mass spectrometry (MS)-based structural proteomics is an ever-growing field that has been adopted to study protein and metal ion interactions. Native MS offers information on metal binding and its stoichiometry. Footprinting approaches coupled with MS, including hydrogen/deuterium exchange (HDX), "fast photochemical oxidation of proteins" (FPOP) and targeted amino-acid labeling, identify binding sites and regions undergoing conformational changes. MS-based titration methods, including "protein-ligand interactions by mass spectrometry, titration and HD exchange" (PLIMSTEX) and "ligand titration, fast photochemical oxidation of proteins and mass spectrometry" (LITPOMS), afford binding stoichiometry, binding affinity, and binding order. These MS-based structural proteomics approaches, their applications to answer questions regarding metal ion protein interactions, their limitations, and recent and potential improvements are discussed here. This review serves as a demonstration of the capabilities of these tools and as an introduction to wider applications to solve other questions.
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Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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13
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Sheff JG, Kelly JF, Robotham A, Sulea T, Malenfant F, L'Abbé D, Duchesne M, Pelletier A, Lefebvre J, Acel A, Parat M, Gosselin M, Wu C, Fortin Y, Baardsnes J, Van Faassen H, Awrey S, Chafe SC, McDonald PC, Dedhar S, Lenferink AEG. Hydrogen-deuterium exchange mass spectrometry reveals three unique binding responses of mAbs directed to the catalytic domain of hCAIX. MAbs 2021; 13:1997072. [PMID: 34812124 PMCID: PMC8632303 DOI: 10.1080/19420862.2021.1997072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human carbonic anhydrase (hCAIX), an extracellular enzyme that catalyzes the reversible hydration of CO2, is often overexpressed in solid tumors. This enzyme is instrumental in maintaining the survival of cancer cells in a hypoxic and acidic tumor microenvironment. Absent in most normal tissues, hCAIX is a promising therapeutic target for detection and treatment of solid tumors. Screening of a library of anti-hCAIX monoclonal antibodies (mAbs) previously identified three therapeutic candidates (mAb c2C7, m4A2 and m9B6) with distinct biophysical and functional characteristics. Selective binding to the catalytic domain was confirmed by yeast surface display and isothermal calorimetry, and deeper insight into the dynamic binding profiles of these mAbs upon binding were highlighted by bottom-up hydrogen-deuterium exchange mass spectrometry (HDX-MS). Here, a conformational and allosterically silent epitope was identified for the antibody-drug conjugate candidate c2C7. Unique binding profiles are described for both inhibitory antibodies, m4A2 and m9B6. M4A2 reduces the ability of the enzyme to hydrate CO2 by steric gating at the entrance of the catalytic cavity. Conversely, m9B6 disrupts the secondary structure that is necessary for substrate binding and hydration. The synergy of these two inhibitory mechanisms is demonstrated in in vitro activity assays and HDX-MS. Finally, the ability of m4A2 to modulate extracellular pH and intracellular metabolism is reported. By highlighting three unique modes by which hCAIX can be targeted, this study demonstrates both the utility of HDX-MS as an important tool in the characterization of anti-cancer biotherapeutics, and the underlying value of CAIX as a therapeutic target.
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Affiliation(s)
- Joey G Sheff
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - John F Kelly
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Anna Robotham
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Traian Sulea
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Félix Malenfant
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Denis L'Abbé
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Mélanie Duchesne
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Alex Pelletier
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Jean Lefebvre
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Andrea Acel
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Marie Parat
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Mylene Gosselin
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Cunle Wu
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Yves Fortin
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Jason Baardsnes
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
| | - Henk Van Faassen
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Shannon Awrey
- Department of Integrative Oncology, Bc Cancer Research Institute, Vancouver, BC, Canada
| | - Shawn C Chafe
- Department of Integrative Oncology, Bc Cancer Research Institute, Vancouver, BC, Canada
| | - Paul C McDonald
- Department of Integrative Oncology, Bc Cancer Research Institute, Vancouver, BC, Canada
| | - Shoukat Dedhar
- Department of Integrative Oncology, Bc Cancer Research Institute, Vancouver, BC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Anne E G Lenferink
- Human Health Therapeutics Research Centre, National Research Council Canada, Montreal, Quebec, Canada
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14
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Dekens DW, Eisel ULM, Gouweleeuw L, Schoemaker RG, De Deyn PP, Naudé PJW. Lipocalin 2 as a link between ageing, risk factor conditions and age-related brain diseases. Ageing Res Rev 2021; 70:101414. [PMID: 34325073 DOI: 10.1016/j.arr.2021.101414] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/12/2022]
Abstract
Chronic (neuro)inflammation plays an important role in many age-related central nervous system (CNS) diseases, including Alzheimer's disease, Parkinson's disease and vascular dementia. Inflammation also characterizes many conditions that form a risk factor for these CNS disorders, such as physical inactivity, obesity and cardiovascular disease. Lipocalin 2 (Lcn2) is an inflammatory protein shown to be involved in different age-related CNS diseases, as well as risk factor conditions thereof. Lcn2 expression is increased in the periphery and the brain in different age-related CNS diseases and also their risk factor conditions. Experimental studies indicate that Lcn2 contributes to various neuropathophysiological processes of age-related CNS diseases, including exacerbated neuroinflammation, cell death and iron dysregulation, which may negatively impact cognitive function. We hypothesize that increased Lcn2 levels as a result of age-related risk factor conditions may sensitize the brain and increase the risk to develop age-related CNS diseases. In this review we first provide a comprehensive overview of the known functions of Lcn2, and its effects in the CNS. Subsequently, this review explores Lcn2 as a potential (neuro)inflammatory link between different risk factor conditions and the development of age-related CNS disorders. Altogether, evidence convincingly indicates Lcn2 as a key constituent in ageing and age-related brain diseases.
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Affiliation(s)
- Doortje W Dekens
- Department of Neurology and Alzheimer Center Groningen, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands
| | - Leonie Gouweleeuw
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands
| | - Regien G Schoemaker
- Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands
| | - Peter P De Deyn
- Department of Neurology and Alzheimer Center Groningen, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Laboratory of Neurochemistry and Behaviour, Biobank, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Petrus J W Naudé
- Department of Neurology and Alzheimer Center Groningen, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands; Department of Psychiatry and Mental Health and Neuroscience Institute, Brain Behaviour Unit, University of Cape Town, Cape Town, South Africa.
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15
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Zscherp R, Coetzee J, Vornweg J, Grunenberg J, Herrmann J, Müller R, Klahn P. Biomimetic enterobactin analogue mediates iron-uptake and cargo transport into E. coli and P. aeruginosa. Chem Sci 2021; 12:10179-10190. [PMID: 34377407 PMCID: PMC8336463 DOI: 10.1039/d1sc02084f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/16/2021] [Indexed: 11/21/2022] Open
Abstract
The design, synthesis and biological evaluation of the artificial enterobactin analogue EntKL and several fluorophore-conjugates thereof are described. EntKL provides an attachment point for cargos such as fluorophores or antimicrobial payloads. Corresponding conjugates are recognized by outer membrane siderophore receptors of Gram-negative pathogens and retain the natural hydrolyzability of the tris-lactone backbone. Initial density-functional theory (DFT) calculations of the free energies of solvation (ΔG(sol)) and relaxed Fe–O force constants of the corresponding [Fe-EntKL]3− complexes indicated a similar iron binding constant compared to natural enterobactin (Ent). The synthesis of EntKL was achieved via an iterative assembly based on a 3-hydroxylysine building block over 14 steps with an overall yield of 3%. A series of growth recovery assays under iron-limiting conditions with Escherichia coli and Pseudomonas aeruginosa mutant strains that are defective in natural siderophore synthesis revealed a potent concentration-dependent growth promoting effect of EntKL similar to natural Ent. Additionally, four cargo-conjugates differing in molecular size were able to restore growth of E. coli indicating an uptake into the cytosol. P. aeruginosa displayed a stronger uptake promiscuity as six different cargo-conjugates were found to restore growth under iron-limiting conditions. Imaging studies utilizing BODIPYFL-conjugates, demonstrated the ability of EntKL to overcome the Gram-negative outer membrane permeability barrier and thus deliver molecular cargos via the bacterial iron transport machinery of E. coli and P. aeruginosa. The design, synthesis and evaluation of the enterobactin derivative (AcO)EntKL is reported, which mediates iron uptake and cargo transport into E. coli and P. aeruginosa and was able to compete with human enterobactin and iron binding proteins.![]()
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Affiliation(s)
- Robert Zscherp
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Janetta Coetzee
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Johannes Vornweg
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Jörg Grunenberg
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
| | - Jennifer Herrmann
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Rolf Müller
- Department for Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research and Department of Pharmacy at Universität des Saarlandes Campus Building E 8.1 D-66123 Saarbrücken Germany.,German Center for Infection Research (DZIF) Site Hannover-Braunschweig Germany
| | - Philipp Klahn
- Institute of Organic Chemistry, Technische Universität Braunschweig Hagenring 30 D-38106 Braunschweig Germany
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16
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Li D, Li H, Bauer C, Hu Y, Lewis JR, Xu A, Levinger I, Wang Y. Lipocalin-2 Variants and Their Relationship With Cardio-Renal Risk Factors. Front Endocrinol (Lausanne) 2021; 12:781763. [PMID: 34938273 PMCID: PMC8685543 DOI: 10.3389/fendo.2021.781763] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/09/2021] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To investigate the serum, plasma and urine levels of lipocalin-2 (LCN2) variants in healthy humans and their associations with risk factors for cardiometabolic (CMD) and chronic kidney (CKD) diseases. METHODS Fifty-nine males and 41 females participated in the study. Blood and urine were collected following an overnight fasting. LCN2 variants were analyzed using validated in-house ELISA kits. Heart rate, blood pressure, lipids profile, glucose, adiponectin, high-sensitivity C-reactive protein (hsCRP), creatinine, cystatin C, and biomarkers for kidney function were assessed. RESULTS The levels of hLcn2, C87A and R81E in serum and urine, but not plasma, were significantly higher in men than women. Increased levels of LCN2 variants, as well as their relative ratios, in serum and plasma were positively associated with body mass index, blood pressure, triglyceride and hsCRP (P<0.05). No significant correlations were found between these measures and hLcn2, C87A or R81E in urine. However, LCN2 variants in urine, but not plasma or serum, were correlated with biomarkers of kidney function (P<0.05). CONCLUSIONS Both the serum and plasma levels of LCN2 variants, as well as their ratios are associated with increased cardiometabolic risk, whereas those in urine are correlated with renal dysfunction. LCN2 variants represent promising biomarkers for CMD and CKD.
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Affiliation(s)
- Dahui Li
- The State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Haoyun Li
- The State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Carlie Bauer
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Yue Hu
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Joshua R. Lewis
- Medical School, University of Western Australia, Perth, WA, Australia
- Institute for Nutrition Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Centre for Kidney Research, Children’s Hospital at Westmead, School of Public Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Aimin Xu
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Itamar Levinger
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
- Australian Institute for Musculoskeletal Science, Victoria University, University of Melbourne, Western Health, St. Albans, VIC, Australia
| | - Yu Wang
- The State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- *Correspondence: Yu Wang,
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17
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Ozohanics O, Ambrus A. Hydrogen-Deuterium Exchange Mass Spectrometry: A Novel Structural Biology Approach to Structure, Dynamics and Interactions of Proteins and Their Complexes. Life (Basel) 2020; 10:E286. [PMID: 33203161 PMCID: PMC7696067 DOI: 10.3390/life10110286] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Accepted: 11/12/2020] [Indexed: 11/16/2022] Open
Abstract
Hydrogen/Deuterium eXchange Mass Spectrometry (HDX-MS) is a rapidly evolving technique for analyzing structural features and dynamic properties of proteins. It may stand alone or serve as a complementary method to cryo-electron-microscopy (EM) or other structural biology approaches. HDX-MS is capable of providing information on individual proteins as well as large protein complexes. Owing to recent methodological advancements and improving availability of instrumentation, HDX-MS is becoming a routine technique for some applications. When dealing with samples of low to medium complexity and sizes of less than 150 kDa, conformation and ligand interaction analyses by HDX-MS are already almost routine applications. This is also well supported by the rapid evolution of the computational (software) background that facilitates the analysis of the obtained experimental data. HDX-MS can cope at times with analytes that are difficult to tackle by any other approach. Large complexes like viral capsids as well as disordered proteins can also be analyzed by this method. HDX-MS has recently become an established tool in the drug discovery process and biopharmaceutical development, as it is now also capable of dissecting post-translational modifications and membrane proteins. This mini review provides the reader with an introduction to the technique and a brief overview of the most common applications. Furthermore, the most challenging likely applications, the analyses of glycosylated and membrane proteins, are also highlighted.
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Affiliation(s)
- Oliver Ozohanics
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, 37–47 Tuzolto Street, 1094 Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, 37–47 Tuzolto Street, 1094 Budapest, Hungary
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18
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Luo Y, Wan J, Luo C, Liu H, Zhou Y, Chen J, Duan Y, Ning X, Zhou Z, Wang K, Li J, Xu H, Chen Z. Higher Aqueous Levels of Resistin and Lipocalin-2 Indicated Worse Visual Improvement following anti-VEGF Therapy in Patients with Retinal Vein Occlusion. Curr Eye Res 2020; 46:845-854. [PMID: 33103481 DOI: 10.1080/02713683.2020.1842462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE The aim of this study was to investigate the aqueous humor levels of elastase-2, lactoferrin, lipocalin-2 (LCN-2), resistin, and thrombospondin-1 (TSP-1) in patients with retinal vein occlusion (RVO) and their relationship with visual prognosis following intravitreal anti-vascular endothelial growth factor (VEGF) therapy. MATERIALS AND METHODS 52 RVO patients (23 cases of central retinal vein occlusion (CRVO) and 29 cases of branch retinal vein occlusion (BRVO)) and 20 cases of senile cataract were enrolled in this study. All RVO patients underwent fundus examinations before and 6-8 months after intravitreal anti-VEGF treatment. Five milliliters of blood were collected from RVO patients before treatment for the measurement of lipids and coagulation factors. Sixty microliters of aqueous humor were collected during intravitreal injection of anti-VEGF or during cataract surgery. The levels of elastase-2, lactoferrin, LCN-2, resistin, and TSP-1 in aqueous humor were determined by Luminex xMAP multiple analysis. RESULTS The aqueous levels of resistin and LCN-2 were significantly higher but the level of TSP-1 was significantly lower in RVO patients compared to controls. Further, sub-group analysis showed that CRVO patients had significantly higher levels of resistin and LCN-2 than controls. The aqueous levels of resistin and LCN-2 were negatively correlated with visual improvement following anti-VEGF therapy in CRVO but not in BRVO patients. Visual improvement in RVO patients was not associated with blood lipid levels or any of the coagulation factors. CONCLUSION CRVO patients had significantly higher aqueous levels of resistin and LCN-2, which negatively impacted on visual improvement after anti-VEGF therapy.
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Affiliation(s)
- Yong Luo
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China.,Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Jianbo Wan
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Chang Luo
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China.,Aier Eye Institute, Changsha, Hunan, China
| | - HengWei Liu
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China
| | - YuFan Zhou
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China
| | - Juan Chen
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Yiqin Duan
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Xiangyan Ning
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Zengchao Zhou
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Kehua Wang
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Jun Li
- Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
| | - Heping Xu
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China.,Aier Institute of Optometry and Vision Science, Changsha, Hunan, China.,Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - ZhongPing Chen
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, China.,Aier Eye Hospital of Changsha, Changsha, Hunan Province, China
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19
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Guo C, Steinberg LK, Henderson JP, Gross ML. Organic Solvents for Enhanced Proteolysis of Stable Proteins for Hydrogen-Deuterium Exchange Mass Spectrometry. Anal Chem 2020; 92:11553-11557. [PMID: 32867496 DOI: 10.1021/acs.analchem.0c02194] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein digestion is a key challenge in mass spectrometry (MS)-based structural proteomics. Although using hydrogen-deuterium exchange kinetics with MS (HDX-MS) to interrogate the high-order structure of proteins is now established, it can be challenging for β-barrel proteins, which are important in cellular transport. These proteins contain a continuous chain of H-bonds that impart stability, causing difficulty in digestion for bottom-up measurements. To overcome this impediment, we tested organic solvents as denaturants during on-line pepsin digestion of soluble β-barrel proteins. We selected green fluorescent protein (GFP), siderocalin (Scn), and retinol-binding protein 4 (RBP4) as model proteins and screened six different polar-aprotic and polar-protic solvent combinations to disrupt the H-bonds and hydrophobic interactions holding together the β-sheets. The use of organic solvents improves digestion, generating more peptides from the rigid β-barrel regions, without compromising the ability to predict the retinol binding site on RBP4 when adopting this proteolysis with HDX.
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Affiliation(s)
- Chunyang Guo
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Lindsey K Steinberg
- Division of Infectious Diseases, Department of Medicine, Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Jeffrey P Henderson
- Division of Infectious Diseases, Department of Medicine, Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L Gross
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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20
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Zsila F, Beke-Somfai T. Human host-defense peptide LL-37 targets stealth siderophores. Biochem Biophys Res Commun 2020; 526:780-785. [PMID: 32265033 DOI: 10.1016/j.bbrc.2020.03.162] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/28/2020] [Indexed: 02/02/2023]
Abstract
A growing number of evidence shows that human-associated microbiota is an important contributor in health and disease. However, much of the complexity of host-microbiota interaction remains to be elucidated both at cellular and molecular levels. Siderophores are chemically diverse, ferric-specific chelators synthesized and secreted by microbes to secure their iron acquisition. The host defense peptide LL-37 is ubiquitously produced at epithelial surfaces modulating microbial communities and suppressing pathogenic strains. The present work demonstrates that LL-37 binds tightly siderocalin-resistant stealth siderophores which are important contributors to the virulence of several pathogens. As indicated by circular dichroism spectroscopic experiments, addition of aerobactin and rhizoferrin increases the membrane active α-helical conformation of the partially folded peptide. The cationic nature of LL-37 (+6 net charge at pH 7.4) and the multiple carboxylate groups present in siderophores refer to the dominant contribution of electrostatic interactions in the stabilization of peptide-chelator adducts. It is proposed that aside siderocalin proteins, LL-37 may be a complementary, less specific component of the siderophore scavenging repertoire of the innate immune system.
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Affiliation(s)
- Ferenc Zsila
- Biomolecular Self-Assembly Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, P.O. Box 286, H-1519, Budapest, Hungary.
| | - Tamás Beke-Somfai
- Biomolecular Self-Assembly Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, P.O. Box 286, H-1519, Budapest, Hungary
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