1
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Xu Y, Wagner GK. A cell-permeable probe for the labelling of a bacterial glycosyltransferase and virulence factor. RSC Chem Biol 2024; 5:55-62. [PMID: 38179196 PMCID: PMC10763556 DOI: 10.1039/d3cb00092c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/18/2023] [Indexed: 01/06/2024] Open
Abstract
Chemical probes for bacterial glycosyltransferases are of interest for applications such as tracking of expression levels, and strain profiling and identification. Existing probes for glycosyltransferases are typically based on sugar-nucleotides, whose charged nature limits their applicability in intact cells. We report the development of an uncharged covalent probe for the bacterial galactosyltransferase LgtC, and its application for the fluorescent labelling of this enzyme in recombinant form, cell lysates, and intact cells. The probe was designed by equipping a previously reported covalent LgtC inhibitor based on a pyrazol-3-one scaffold with a 7-hydroxycoumarin fluorophore. We show that this pyrazol-3-ones scaffold is surprisingly stable in aqueous media, which may have wider implications for the use of pyrazol-3-ones as chemical probes. We also show that the 7-hydroxycoumarin fluorophore leads to an unexpected improvement in activity, which could be exploited for the development of second generation analogues. These results will provide a basis for the development of LgtC-specific probes for the detection of LgtC-expressing bacterial strains.
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Affiliation(s)
- Yong Xu
- Department of Chemistry, King's College London UK
| | - Gerd K Wagner
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road Belfast BT9 7BL UK
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2
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Quintana ILL, Paul A, Chowdhury A, Moulton KD, Kulkarni SS, Dube DH. Thioglycosides Act as Metabolic Inhibitors of Bacterial Glycan Biosynthesis. ACS Infect Dis 2023; 9:2025-2035. [PMID: 37698279 PMCID: PMC10580310 DOI: 10.1021/acsinfecdis.3c00324] [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: 07/07/2023] [Indexed: 09/13/2023]
Abstract
Glycans that coat the surface of bacteria are compelling antibiotic targets because they contain distinct monosaccharides that are linked to pathogenesis and are absent in human cells. Disrupting glycan biosynthesis presents a path to inhibiting the ability of a bacterium to infect the host. We previously demonstrated that O-glycosides act as metabolic inhibitors and disrupt bacterial glycan biosynthesis. Inspired by a recent study which showed that thioglycosides (S-glycosides) are 10 times more effective than O-glycosides at inhibiting glycan biosynthesis in mammalian cells, we crafted a panel of S-glycosides based on rare bacterial monosaccharides. The novel thioglycosides altered glycan biosynthesis and fitness in pathogenic bacteria but had no notable effect on glycosylation or growth in beneficial bacteria or mammalian cells. In contrast to findings in mammalian cells, S-glycosides and O-glycosides exhibited comparable potency in bacteria. However, S-glycosides exhibited enhanced selectivity relative to O-glycosides. These novel metabolic inhibitors will allow selective perturbation of the bacterial glycocalyx for functional studies and set the stage to expand our antibiotic arsenal.
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Affiliation(s)
- Isabella
de la Luz Quintana
- Department
of Chemistry & Biochemistry, Bowdoin
College, 6600 College Station, Brunswick, Maine 04011, United States
| | - Ankita Paul
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400-076, India
| | - Aniqa Chowdhury
- Department
of Chemistry & Biochemistry, Bowdoin
College, 6600 College Station, Brunswick, Maine 04011, United States
| | - Karen D. Moulton
- Department
of Chemistry & Biochemistry, Bowdoin
College, 6600 College Station, Brunswick, Maine 04011, United States
| | - Suvarn S. Kulkarni
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400-076, India
| | - Danielle H. Dube
- Department
of Chemistry & Biochemistry, Bowdoin
College, 6600 College Station, Brunswick, Maine 04011, United States
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3
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Colombo E, Olla S, Minnelli C, Formato A, Veroni C, Corbisiero S, Pericolo M, Siguri C, Mobbili G, Agresti C, Seneci P. Synthesis and Characterization of Edaravone Analogues as Remyelinating Agents and Putative Mechanistic Probes. Molecules 2023; 28:6928. [PMID: 37836771 PMCID: PMC10574562 DOI: 10.3390/molecules28196928] [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: 09/09/2023] [Revised: 09/28/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023] Open
Abstract
Edaravone (EDA), an antioxidant drug approved for the treatment of ischemic stroke and amyotrophic lateral sclerosis, was recently proposed as a remyelinating candidate for the treatment of multiple sclerosis. Here, we synthesized twelve EDA analogues 2b-4c showing three substitution patterns A-C, searching for improved remyelinating agents and putative molecular targets responsible for their regenerative activity. We profiled them in three primary assays to determine their stimulation of oligodendrocyte progenitor cell metabolism (tetrazolium MTT assay), their antioxidant potential (2,2-diphenyl-1-picrylhydrazyl-DPPH assay) and to predict their bioavailability (virtual ADME profile). Active 4'-carboxylate 2b, 4'-ester 2c and N1-carbamate-4'-ester 4a were further characterized, justifying their in vitro effects and selecting 4a as a putative EDA 1 prodrug suitable for in vivo testing.
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Affiliation(s)
- Eleonora Colombo
- Chemistry Department, University of Milan, Via Golgi 19, 20133 Milan, Italy; (E.C.); (M.P.)
| | - Stefania Olla
- Biomedical and Genetic Research Institute (IRGB, National Research Council (CNR)), University Campus, Monserrato, 09042 Monserrato, Italy; (S.O.); (C.S.)
| | - Cristina Minnelli
- Department of Life and Environmental Sciences, Marche Polytechnic University, Via Brecce Bianche, 60131 Ancona, Italy; (C.M.); (G.M.)
| | - Alessia Formato
- Department of Neuroscience, National Institute of Health (ISS), Viale Regina Elena 299, 00161 Rome, Italy; (A.F.); (C.V.); (S.C.)
| | - Caterina Veroni
- Department of Neuroscience, National Institute of Health (ISS), Viale Regina Elena 299, 00161 Rome, Italy; (A.F.); (C.V.); (S.C.)
| | - Silvia Corbisiero
- Department of Neuroscience, National Institute of Health (ISS), Viale Regina Elena 299, 00161 Rome, Italy; (A.F.); (C.V.); (S.C.)
| | - Mattia Pericolo
- Chemistry Department, University of Milan, Via Golgi 19, 20133 Milan, Italy; (E.C.); (M.P.)
| | - Chiara Siguri
- Biomedical and Genetic Research Institute (IRGB, National Research Council (CNR)), University Campus, Monserrato, 09042 Monserrato, Italy; (S.O.); (C.S.)
| | - Giovanna Mobbili
- Department of Life and Environmental Sciences, Marche Polytechnic University, Via Brecce Bianche, 60131 Ancona, Italy; (C.M.); (G.M.)
| | - Cristina Agresti
- Department of Neuroscience, National Institute of Health (ISS), Viale Regina Elena 299, 00161 Rome, Italy; (A.F.); (C.V.); (S.C.)
| | - Pierfausto Seneci
- Chemistry Department, University of Milan, Via Golgi 19, 20133 Milan, Italy; (E.C.); (M.P.)
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4
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Green Synthesis of Spirooxindoles via Lipase-Catalyzed One-Pot Tandem Reaction in Aqueous Media. Catalysts 2023. [DOI: 10.3390/catal13010143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The development of non-natural enzymatic catalysis is important for multicomponent tandem organic transformations. However, the delicate acting environments of biological enzymes still present some challenges in the synthesis of spirooxindole skeleton via enzymatic catalysis. To address these issues, a lipase-catalyzed method was developed for the synthesis of spirooxindole frameworks. Using easily available isatins, cycloketones, and malononitriles as substrates, mild reaction conditions, and a reasonable reaction time, moderate to good yields (67–92%) and excellent functional group tolerance were accomplished via this protocol. The related mechanism explanation is also speculated in this paper.
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5
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Yakovlieva L, Fülleborn JA, Walvoort MTC. Opportunities and Challenges of Bacterial Glycosylation for the Development of Novel Antibacterial Strategies. Front Microbiol 2021; 12:745702. [PMID: 34630370 PMCID: PMC8498110 DOI: 10.3389/fmicb.2021.745702] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022] Open
Abstract
Glycosylation is a ubiquitous process that is universally conserved in nature. The various products of glycosylation, such as polysaccharides, glycoproteins, and glycolipids, perform a myriad of intra- and extracellular functions. The multitude of roles performed by these molecules is reflected in the significant diversity of glycan structures and linkages found in eukaryotes and prokaryotes. Importantly, glycosylation is highly relevant for the virulence of many bacterial pathogens. Various surface-associated glycoconjugates have been identified in bacteria that promote infectious behavior and survival in the host through motility, adhesion, molecular mimicry, and immune system manipulation. Interestingly, bacterial glycosylation systems that produce these virulence factors frequently feature rare monosaccharides and unusual glycosylation mechanisms. Owing to their marked difference from human glycosylation, bacterial glycosylation systems constitute promising antibacterial targets. With the rise of antibiotic resistance and depletion of the antibiotic pipeline, novel drug targets are urgently needed. Bacteria-specific glycosylation systems are especially promising for antivirulence therapies that do not eliminate a bacterial population, but rather alleviate its pathogenesis. In this review, we describe a selection of unique glycosylation systems in bacterial pathogens and their role in bacterial homeostasis and infection, with a focus on virulence factors. In addition, recent advances to inhibit the enzymes involved in these glycosylation systems and target the bacterial glycan structures directly will be highlighted. Together, this review provides an overview of the current status and promise for the future of using bacterial glycosylation to develop novel antibacterial strategies.
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Affiliation(s)
- Liubov Yakovlieva
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
| | - Julius A Fülleborn
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
| | - Marthe T C Walvoort
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
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6
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Preparative, mechanistic and tautomeric investigation of 1-phenyl and 1-methyl derivative of 3-methyl-5-pyrazolone. J CHEM SCI 2021. [DOI: 10.1007/s12039-021-01902-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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7
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Métier CC, Wagner GK. Novel disaccharide inhibitors for the bacterial galactosyltransferase LgtC: Design, synthesis via Heyns rearrangement, and biochemical evaluation. Carbohydr Res 2020; 492:108017. [PMID: 32402851 DOI: 10.1016/j.carres.2020.108017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/16/2020] [Accepted: 04/16/2020] [Indexed: 10/24/2022]
Abstract
Bacterial glycosyltransferases are potential targets for the development of novel antibiotics and anti-virulence agents. We report a novel inhibitor design for the retaining α-1,4-galactosyltransferase LgtC from Neisseria meningitidis. Our design is based on the installation of an electrophilic warhead on the LgtC acceptor substrate and targeted at a non-catalytic cysteine residue in the LgtC active site. We have successfully synthesised two prototype inhibitors in four steps from lactulose. The key step in our synthesis is a Heyns rearrangement, during which we observed the formation of a hitherto unknown side product. While both lactosamine derivatives behaved as moderate inhibitors of LgtC, they also retained residual substrate activity. These results suggest that in contrast to our original design, these inhibitors do not act via a covalent mode of action, but are most likely non-covalent inhibitors.
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Affiliation(s)
- Camille C Métier
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Gerd K Wagner
- King's College London, School of Basic & Medical Biosciences, St John's Institute of Dermatology, 9th Floor Tower Wing, Guy's Hospital, London, SE1 9RT, United Kingdom; Queen's University Belfast, School of Pharmacy, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, United Kingdom.
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8
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Sun JS, Wang YY, Liu M, Zhang J, Liu CF, Xu YJ, Dong L. Construction of pyrazolone analogues via rhodium-catalyzed C–H activation from pyrazolones and non-activated free allyl alcohols. Org Chem Front 2019. [DOI: 10.1039/c9qo00504h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly efficient rhodium(iii) catalysis was developed for obtaining structurally divergent pyrazolone analogues from pyrazolones and non-activated free allyl alcohols.
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Affiliation(s)
- Jun-Shu Sun
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
| | - Ying-Ying Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
| | - Man Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
| | - Jing Zhang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
| | - Chen-Fei Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
| | - Yan-Jun Xu
- College of Chemistry and Material Science
- Sichuan Normal University
- Chengdu
- China
| | - Lin Dong
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry
- West China School of Pharmacy
- Sichuan University
- Chengdu 610041
- China
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9
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He X, Ni D, Lu S, Zhang J. Characteristics of Allosteric Proteins, Sites, and Modulators. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1163:107-139. [DOI: 10.1007/978-981-13-8719-7_6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Liu CF, Liu M, Dong L. Iridium(III)-Catalyzed Tandem Annulation Synthesis of Pyrazolo[1,2-α]cinnolines from Pyrazolones and Sulfoxonium Ylides. J Org Chem 2018; 84:409-416. [PMID: 30521336 DOI: 10.1021/acs.joc.8b02582] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Chen-Fei Liu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Man Liu
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Lin Dong
- Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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11
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Stefaniak J, Lewis AM, Conole D, Galan SRG, Bataille CJR, Wynne GM, Castaldi MP, Lundbäck T, Russell AJ, Huber KVM. Chemical Instability and Promiscuity of Arylmethylidenepyrazolinone-Based MDMX Inhibitors. ACS Chem Biol 2018; 13:2849-2854. [PMID: 30216042 PMCID: PMC6198280 DOI: 10.1021/acschembio.8b00665] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Targeting the protein-protein interaction between p53 and MDM2/MDMX (MDM4) represents an attractive anticancer strategy for the treatment of p53-competent tumors. Several selective and potent MDM2 inhibitors have been developed and entered the clinic; however, the repertoire of MDMX antagonists is still limited. The arylmethylidenepyrazolinone SJ-172550 has been reported as a selective MDMX antagonist; yet, uncertainties about its mechanism of action have raised doubts about its use as a chemical probe. Here, we show that, in addition to its unclear mode of action, SJ-172550 is unstable in aqueous buffers, giving rise to side products of unknown biological activity. Using an SJ-172550-derived affinity probe, we observed promiscuous binding to cellular proteins whereas cellular thermal shift assays did not reveal a stabilizing effect on MDMX. Overall, our results raise further questions about the interpretation of data using SJ-172550 and related compounds to investigate cellular phenotypes.
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Affiliation(s)
- Jakub Stefaniak
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Andrew M. Lewis
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel Conole
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Sébastien R. G. Galan
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Carole J. R. Bataille
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Graham M. Wynne
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - M. Paola Castaldi
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Waltham, Massachusetts 02451, United States
| | - Thomas Lundbäck
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Angela J. Russell
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Kilian V. M. Huber
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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12
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Sharyan A, Gonzalez C, Ukaegbu O, Powell K, McCarthy PC. Determination of the binding affinities of Neisseria meningitidis serogroup W capsule polymerase with two nucleotide sugar substrates. BMC Res Notes 2018; 11:482. [PMID: 30012207 PMCID: PMC6048754 DOI: 10.1186/s13104-018-3596-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/12/2018] [Indexed: 01/22/2023] Open
Abstract
Objective Meningococcal meningitis is a public health burden. Immunization strategies have reduced global incidence of the disease. Glycoconjugate vaccines are the most effective type of vaccine to combat most causes of meningococcal meningitis. These vaccines contain capsular polysaccharide fragments from disease-causing serogroups of Neisseria meningitidis that are chemically attached to a carrier protein. The enzymes responsible for capsular polysaccharide synthesis can serve as tools to make these critical vaccine components. One such enzyme is the N. meningitidis serogroup W capsule polymerase. This enzyme is responsible for creating the galactose-sialic acid containing capsular polysaccharide of this serogroup. Our aim in this study was to determine the binding affinities of nucleotide sugar donors CMP-sialic acid and UDP-galactose using a coupled transferase assay to inform future work to modulate polysaccharide synthesis by this enzyme. Results We determined a Km of 66.8 µM for CMP-sialic acid and a Km for UDP-galactose of 3.9 µM. These values are lower than reported values for other retaining galactosyltransferases and inverting sialyltransferases respectively. There were difficulties obtaining reliable data for galactosyltransferase activity. An alternate strategy is needed to assess kinetic parameters of the separate transferase activities for this enzyme. Electronic supplementary material The online version of this article (10.1186/s13104-018-3596-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abeer Sharyan
- Department of Chemistry, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD, 21251, USA
| | - Cendy Gonzalez
- Department of Biology, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD, 21251, USA
| | - Ophelia Ukaegbu
- Department of Chemistry, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD, 21251, USA
| | - Kayla Powell
- Department of Chemistry, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD, 21251, USA
| | - Pumtiwitt C McCarthy
- Department of Chemistry, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD, 21251, USA.
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13
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Xu Y, Cuccui J, Denman C, Maharjan T, Wren BW, Wagner GK. Structure-activity relationships in a new class of non-substrate-like covalent inhibitors of the bacterial glycosyltransferase LgtC. Bioorg Med Chem 2018; 26:2973-2983. [PMID: 29602676 DOI: 10.1016/j.bmc.2018.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/03/2018] [Accepted: 03/04/2018] [Indexed: 02/07/2023]
Abstract
Lipooligosaccharide (LOS) structures in the outer core of Gram-negative mucosal pathogens such as Neisseria meningitidis and Haemophilus influenzae contain characteristic glycoepitopes that contribute significantly to bacterial virulence. An important example is the digalactoside epitope generated by the retaining α-1,4-galactosyltransferase LgtC. These digalactosides camouflage the pathogen from the host immune system and increase its serum resistance. Small molecular inhibitors of LgtC are therefore sought after as chemical tools to study bacterial virulence, and as potential candidates for anti-virulence drug discovery. We have recently discovered a new class of non-substrate-like inhibitors of LgtC. The new inhibitors act via a covalent mode of action, targeting a non-catalytic cysteine residue in the LgtC active site. Here, we describe, for the first time, structure-activity relationships for this new class of glycosyltransferase inhibitors. We have carried out a detailed analysis of the inhibition kinetics to establish the relative contribution of the non-covalent binding and the covalent inactivation steps for overall inhibitory activity. Selected inhibitors were also evaluated against a serum-resistant strain of Haemophilus influenzae, but did not enhance the killing effect of human serum.
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Affiliation(s)
- Yong Xu
- King's College London, Department of Chemistry, Faculty of Natural & Mathematical Sciences, Britannia House, 7 Trinity Street, London SE1 1DB, UK
| | - Jon Cuccui
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, UK
| | - Carmen Denman
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, UK
| | - Tripty Maharjan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, UK
| | - Brendan W Wren
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, UK
| | - Gerd K Wagner
- King's College London, Department of Chemistry, Faculty of Natural & Mathematical Sciences, Britannia House, 7 Trinity Street, London SE1 1DB, UK.
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14
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Xu Y, Uddin N, Wagner GK. Covalent Probes for Carbohydrate-Active Enzymes: From Glycosidases to Glycosyltransferases. Methods Enzymol 2018; 598:237-265. [DOI: 10.1016/bs.mie.2017.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Ema M, Xu Y, Gehrke S, Wagner GK. Identification of non-substrate-like glycosyltransferase inhibitors from library screening: pitfalls & hits. MEDCHEMCOMM 2017; 9:131-137. [PMID: 30108907 DOI: 10.1039/c7md00550d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 11/29/2017] [Indexed: 12/11/2022]
Abstract
Bacterial glycosyltransferases are potential targets for the development of novel antibiotics and anti-virulence agents. Most existing glycosyltransferase inhibitors are substrate analogues with limited potential for drug development. The identification of alternative inhibitor chemotypes is therefore of great interest for medicinal chemistry, drug discovery and chemical glycobiology. We describe the application of a biochemical glycosyltransferase assay to screen a small compound library containing three distinct chemical scaffolds (nucleosides, steroids and 5-methyl pyrazol-3-ones) against the retaining α-1,4-galactosyltransferase LgtC from Neisseria meningitidis. While no genuine LgtC inhibitory activity was observed in the nucleoside and steroid series, the best hit compounds in the 5-methyl pyrazol-3-one series showed low micromolar activity. We adapted our assay protocol to develop initial structure-activity relationships in this series, and to establish the target selectivity of the most potent inhibitor over two other glycosyltransferases. Our results provide insights into the activity of this class of non-substrate-like glycosyltransferase inhibitors, and highlight important general pitfalls for inhibitor screening against this enzyme family. Key elements of our experimental design, including a validated single-concentration protocol for inhibitor screening, and our process for elimination of false positives, are, in principle, directly transferable to many other sugar-nucleotide-dependent glycosyltransferases.
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Affiliation(s)
- Masaki Ema
- King's College London , Department of Chemistry , Faculty of Natural & Mathematical Sciences , Britannia House , 7 Trinity Street , London , SE1 1DB , UK . ; Tel: +44 (0)20 7848 1926
| | - Yong Xu
- King's College London , Department of Chemistry , Faculty of Natural & Mathematical Sciences , Britannia House , 7 Trinity Street , London , SE1 1DB , UK . ; Tel: +44 (0)20 7848 1926
| | - Sebastian Gehrke
- King's College London , Institute of Pharmaceutical Science , Faculty of Life Sciences & Medicine , UK
| | - Gerd K Wagner
- King's College London , Department of Chemistry , Faculty of Natural & Mathematical Sciences , Britannia House , 7 Trinity Street , London , SE1 1DB , UK . ; Tel: +44 (0)20 7848 1926
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