1
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Jekhmane S, Derks MGN, Maity S, Slingerland CJ, Tehrani KHME, Medeiros-Silva J, Charitou V, Ammerlaan D, Fetz C, Consoli NA, Cochrane RVK, Matheson EJ, van der Weijde M, Elenbaas BOW, Lavore F, Cox R, Lorent JH, Baldus M, Künzler M, Lelli M, Cochrane SA, Martin NI, Roos WH, Breukink E, Weingarth M. Host defence peptide plectasin targets bacterial cell wall precursor lipid II by a calcium-sensitive supramolecular mechanism. Nat Microbiol 2024:10.1038/s41564-024-01696-9. [PMID: 38783023 DOI: 10.1038/s41564-024-01696-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 04/04/2024] [Indexed: 05/25/2024]
Abstract
Antimicrobial resistance is a leading cause of mortality, calling for the development of new antibiotics. The fungal antibiotic plectasin is a eukaryotic host defence peptide that blocks bacterial cell wall synthesis. Here, using a combination of solid-state nuclear magnetic resonance, atomic force microscopy and activity assays, we show that plectasin uses a calcium-sensitive supramolecular killing mechanism. Efficient and selective binding of the target lipid II, a cell wall precursor with an irreplaceable pyrophosphate, is achieved by the oligomerization of plectasin into dense supra-structures that only form on bacterial membranes that comprise lipid II. Oligomerization and target binding of plectasin are interdependent and are enhanced by the coordination of calcium ions to plectasin's prominent anionic patch, causing allosteric changes that markedly improve the activity of the antibiotic. Structural knowledge of how host defence peptides impair cell wall synthesis will likely enable the development of superior drug candidates.
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Affiliation(s)
- Shehrazade Jekhmane
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Maik G N Derks
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
- Membrane Biochemistry and Biophysics, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Sourav Maity
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Kamaleddin H M E Tehrani
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - João Medeiros-Silva
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Vicky Charitou
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Danique Ammerlaan
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Céline Fetz
- Department of Biology, Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Naomi A Consoli
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, Italy
- Consorzio Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP), Sesto Fiorentino, Italy
| | - Rachel V K Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Eilidh J Matheson
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Mick van der Weijde
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Barend O W Elenbaas
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Francesca Lavore
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Ruud Cox
- Membrane Biochemistry and Biophysics, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Joseph H Lorent
- Membrane Biochemistry and Biophysics, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Markus Künzler
- Department of Biology, Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Moreno Lelli
- Magnetic Resonance Center (CERM) and Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, Italy
- Consorzio Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP), Sesto Fiorentino, Italy
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.
| | - Markus Weingarth
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Utrecht University, Utrecht, The Netherlands.
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2
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Machushynets N, Al Ayed K, Terlouw BR, Du C, Buijs NP, Willemse J, Elsayed SS, Schill J, Trebosc V, Pieren M, Alexander FM, Cochrane SA, Liles MR, Medema MH, Martin NI, van Wezel GP. Discovery and Derivatization of Tridecaptin Antibiotics with Altered Host Specificity and Enhanced Bioactivity. ACS Chem Biol 2024; 19:1106-1115. [PMID: 38602492 PMCID: PMC11106739 DOI: 10.1021/acschembio.4c00034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/13/2024] [Accepted: 03/25/2024] [Indexed: 04/12/2024]
Abstract
The prevalence of multidrug-resistant (MDR) pathogens combined with a decline in antibiotic discovery presents a major challenge for health care. To refill the discovery pipeline, we need to find new ways to uncover new chemical entities. Here, we report the global genome mining-guided discovery of new lipopeptide antibiotics tridecaptin A5 and tridecaptin D, which exhibit unusual bioactivities within their class. The change in the antibacterial spectrum of Oct-TriA5 was explained solely by a Phe to Trp substitution as compared to Oct-TriA1, while Oct-TriD contained 6 substitutions. Metabolomic analysis of producer Paenibacillus sp. JJ-21 validated the predicted amino acid sequence of tridecaptin A5. Screening of tridecaptin analogues substituted at position 9 identified Oct-His9 as a potent congener with exceptional efficacy against Pseudomonas aeruginosa and reduced hemolytic and cytotoxic properties. Our work highlights the promise of tridecaptin analogues to combat MDR pathogens.
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Affiliation(s)
- Nataliia
V. Machushynets
- Molecular
Biotechnology, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Karol Al Ayed
- Biological
Chemistry Group, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Barbara R. Terlouw
- Bioinformatics
Group, Wageningen University, Wageningen 6700 PB, The Netherlands
| | - Chao Du
- Molecular
Biotechnology, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Ned P. Buijs
- Biological
Chemistry Group, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Joost Willemse
- Molecular
Biotechnology, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Somayah S. Elsayed
- Molecular
Biotechnology, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Julian Schill
- BioVersys
AG, c/o Technologiepark, Basel CH-4057, Switzerland
| | - Vincent Trebosc
- BioVersys
AG, c/o Technologiepark, Basel CH-4057, Switzerland
| | - Michel Pieren
- BioVersys
AG, c/o Technologiepark, Basel CH-4057, Switzerland
| | - Francesca M. Alexander
- School of
Chemistry and Chemical Engineering, Queen’s
University of Belfast, Belfast BT9 5AG, United Kingdom
| | - Stephen A. Cochrane
- School of
Chemistry and Chemical Engineering, Queen’s
University of Belfast, Belfast BT9 5AG, United Kingdom
| | - Mark R. Liles
- Department
of Biological Sciences, Auburn University, Auburn, Alabama 36849, United States
| | - Marnix H. Medema
- Bioinformatics
Group, Wageningen University, Wageningen 6700 PB, The Netherlands
| | - Nathaniel I. Martin
- Biological
Chemistry Group, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
| | - Gilles P. van Wezel
- Molecular
Biotechnology, Institute of Biology, Leiden
University, Leiden 2333 BE, The Netherlands
- Department
of Microbial Ecology, Netherlands Institute
of Ecology, Wageningen 6700 PB, The Netherlands
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3
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Craven T, Nolan MD, Bailey J, Olatunji S, Bann SJ, Bowen K, Ostrovitsa N, Da Costa TM, Ballantine RD, Weichert D, Levine PM, Stewart LJ, Bhardwaj G, Geoghegan JA, Cochrane SA, Scanlan EM, Caffrey M, Baker D. Computational Design of Cyclic Peptide Inhibitors of a Bacterial Membrane Lipoprotein Peptidase. ACS Chem Biol 2024; 19:1125-1130. [PMID: 38712757 PMCID: PMC11106742 DOI: 10.1021/acschembio.4c00076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
There remains a critical need for new antibiotics against multi-drug-resistant Gram-negative bacteria, a major global threat that continues to impact mortality rates. Lipoprotein signal peptidase II is an essential enzyme in the lipoprotein biosynthetic pathway of Gram-negative bacteria, making it an attractive target for antibacterial drug discovery. Although natural inhibitors of LspA have been identified, such as the cyclic depsipeptide globomycin, poor stability and production difficulties limit their use in a clinical setting. We harness computational design to generate stable de novo cyclic peptide analogues of globomycin. Only 12 peptides needed to be synthesized and tested to yield potent inhibitors, avoiding costly preparation of large libraries and screening campaigns. The most potent analogues showed comparable or better antimicrobial activity than globomycin in microdilution assays against ESKAPE-E pathogens. This work highlights computational design as a general strategy to combat antibiotic resistance.
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Affiliation(s)
- Timothy
W. Craven
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Mark D. Nolan
- School
of Chemistry, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Jonathan Bailey
- School
of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin D02 R590, Ireland
- Biological
Inorganic Chemistry Laboratory, The Francis
Crick Institute, London NW1 1AT, U.K.
| | - Samir Olatunji
- School
of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Samantha J. Bann
- School
of
Chemistry and Chemical Engineering, Queen’s
University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, U.K.
| | - Katherine Bowen
- School
of Chemistry, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Nikita Ostrovitsa
- School
of Chemistry, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Thaina M. Da Costa
- Department
of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College
Dublin, Dublin D02 VF25, Ireland
| | - Ross D. Ballantine
- School
of
Chemistry and Chemical Engineering, Queen’s
University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, U.K.
| | - Dietmar Weichert
- School
of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Paul M. Levine
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Lance J. Stewart
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Gaurav Bhardwaj
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Joan A. Geoghegan
- Department
of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College
Dublin, Dublin D02 VF25, Ireland
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
| | - Stephen A. Cochrane
- School
of
Chemistry and Chemical Engineering, Queen’s
University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, U.K.
| | - Eoin M. Scanlan
- School
of Chemistry, Trinity College Dublin, Dublin D02 R590, Ireland
| | - Martin Caffrey
- School
of Medicine and School of Biochemistry and Immunology, Trinity College Dublin, Dublin D02 R590, Ireland
| | - David Baker
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
- Howard
Hughes Medical Institute, University of
Washington, Seattle, Washington 98195, United States
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4
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Karak M, Cloonan CR, Baker BR, Cochrane RVK, Cochrane SA. Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target. Beilstein J Org Chem 2024; 20:220-227. [PMID: 38352069 PMCID: PMC10862138 DOI: 10.3762/bjoc.20.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/26/2024] [Indexed: 02/16/2024] Open
Abstract
Lipid II is an essential glycolipid found in bacteria. Accessing this valuable cell wall precursor is important both for studying cell wall synthesis and for studying/identifying novel antimicrobial compounds. Herein, we describe optimizations to the modular chemical synthesis of lipid II and unnatural analogues. In particular, the glycosylation step, a critical step in the formation of the central disaccharide unit (GlcNAc-MurNAc), was optimized. This was achieved by employing the use of glycosyl donors with diverse leaving groups. The key advantage of this approach lies in its adaptability, allowing for the generation of a wide array of analogues through the incorporation of alternative building blocks at different stages of synthesis.
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Affiliation(s)
- Milandip Karak
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Cian R Cloonan
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Brad R Baker
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Rachel V K Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
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5
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Buijs NP, Matheson EJ, Cochrane SA, Martin NI. Targeting membrane-bound bacterial cell wall precursors: a tried and true antibiotic strategy in nature and the clinic. Chem Commun (Camb) 2023. [PMID: 37219335 DOI: 10.1039/d3cc01070h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Since Fleming's discovery of penicillin nearly a century ago, a bounty of natural product antibiotics have been discovered, many of which continue to be of clinical importance today. The structural diversity encountered among nature's repertoire of antibiotics is mirrored by the varying mechanisms of action by which they selectively target and kill bacterial cells. The ability for bacteria to construct and maintain a strong cell wall is essential for their robust growth and survival under a range of conditions. However, the need to maintain the cell wall also presents a vulnerability that is exploited by many natural antibiotics. Bacterial cell wall biosynthesis involves both the construction of complex membrane-bound precursor molecules and their subsequent crosslinking by dedicated enzymes. Interestingly, many naturally occurring antibiotics function not by directly inhibiting the enzymes associated with cell wall biosynthesis, but rather by binding tightly to their membrane-bound substrates. Such substrate sequestration mechanisms are comparatively rare outside of the antibiotics space with most small-molecule drug discovery programs instead aimed at developing inhibitors of target enzymes. In this feature article we provide the reader with an overview of the unique and ever increasing family of natural product antibiotics known to specifically function by binding to membrane-anchored bacterial cell wall precursors. In doing so, we highlight both our own contributions to the field as well as those made by other researchers engaged in exploring the potential offered by antibiotics that target bacterial cell wall precursors.
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Affiliation(s)
- Ned P Buijs
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.
| | - Eilidh J Matheson
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, UK.
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, UK.
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.
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6
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Ballantine RD, Al Ayed K, Bann SJ, Hoekstra M, Martin NI, Cochrane SA. Linearization of the Brevicidine and Laterocidine Lipopeptides Yields Analogues That Retain Full Antibacterial Activity. J Med Chem 2023; 66:6002-6009. [PMID: 37071814 PMCID: PMC10150354 DOI: 10.1021/acs.jmedchem.3c00308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Brevicidine and laterocidine are macrocyclic lipodepsipeptides with selective activity against Gram-negative bacteria, including colistin-resistant strains. Previously, the macrocyclic core of these peptides was thought essential for antibacterial activity. In this study, we show that C-terminal amidation of linear brevicidine and laterocidine scaffolds, and substitution of the native Thr9, yields linear analogues that retain the potent antibacterial activity and low hemolysis of the parent compounds. Furthermore, an alanine scan of both peptides revealed that the aromatic and basic amino acids within the common central scaffold are essential for antibacterial activity. This linearization strategy for modification of cyclic peptides is a highly effective way to reduce the time and cost of peptide synthesis and may be applicable to other non-ribosomal antibacterial peptides.
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Affiliation(s)
- Ross D Ballantine
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, U.K
| | - Karol Al Ayed
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Samantha J Bann
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, U.K
| | - Michael Hoekstra
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, U.K
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7
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Ballantine RD, Al Ayed K, Bann SJ, Hoekstra M, Martin NI, Cochrane SA. Synthesis and structure-activity relationship studies of N-terminal analogues of the lipopeptide antibiotics brevicidine and laterocidine. RSC Med Chem 2022; 13:1640-1643. [PMID: 36545437 PMCID: PMC9749936 DOI: 10.1039/d2md00281g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
The brevicidine and laterocidine family of lipopeptide antibiotics exhibit strong activity against multidrug-resistant Gram-negative bacteria, while showing low propensity to induce resistance. Both peptides feature a branched lipid tail on the N-terminal residue, which for brevicidine is chiral. Here, we report the synthesis and biological evaluation of a library of brevicidine and laterocidine analogues wherein the N-terminal lipid is replaced with linear achiral fatty acids. Optimal lipid chain lengths were determined and new analogues with strong activity against colistin-resistant E. coli produced.
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Affiliation(s)
- Ross D. Ballantine
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University BelfastStranmillis RoadBelfastBT9 5AGUK
| | - Karol Al Ayed
- Biological Chemistry Group, Institute of Biology, Leiden UniversitySylviusweg 722333 BELeidenThe Netherlands
| | - Samantha J. Bann
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University BelfastStranmillis RoadBelfastBT9 5AGUK
| | - Michael Hoekstra
- Biological Chemistry Group, Institute of Biology, Leiden UniversitySylviusweg 722333 BELeidenThe Netherlands
| | - Nathaniel I. Martin
- Biological Chemistry Group, Institute of Biology, Leiden UniversitySylviusweg 722333 BELeidenThe Netherlands
| | - Stephen A. Cochrane
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University BelfastStranmillis RoadBelfastBT9 5AGUK
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8
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Al Ayed K, Ballantine RD, Hoekstra M, Bann SJ, Wesseling CMJ, Bakker AT, Zhong Z, Li YX, Brüchle NC, van der Stelt M, Cochrane SA, Martin NI. Synthetic Studies with the Brevicidine and Laterocidine Lipopeptide Antibiotics Including Analogues with Enhanced Properties and in vivo Efficacy. Chem Sci 2022; 13:3563-3570. [PMID: 35432860 PMCID: PMC8943889 DOI: 10.1039/d2sc00143h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/09/2022] [Indexed: 12/01/2022] Open
Abstract
Brevicidine and laterocidine are two recently discovered lipopeptide antibiotics with promising antibacterial activity. Possessing a macrocyclic core, multiple positive charges, and a lipidated N-terminus, these lipopeptides exhibit potent and selective activity against Gram-negative pathogens, including polymyxin-resistant isolates. Given the low amounts of brevicidine and laterocidine accessible by fermentation of the producing microorganisms, synthetic routes to these lipopeptides present an attractive alternative. We here report the convenient solid-phase syntheses of both brevicidine and laterocidine and confirm their potent anti-Gram-negative activities. The synthetic routes developed also provide convenient access to novel structural analogues of both brevicidine and laterocidine that display improved hydrolytic stability while maintaining potent antibacterial activity in both in vitro assays and in vivo infection models. Convenient solid-phase approaches are described for the synthesis of brevicidine and laterocidine. Also reported are novel analogues including a laterocidine variant with enhanced hydrolytic stability and potent in vivo antibacterial activity.![]()
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Affiliation(s)
- Karol Al Ayed
- Biological Chemistry Group, Institute of Biology, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Ross D Ballantine
- School of Chemistry and Chemical Engineering, Queen's University Belfast David Keir Building, Stranmillis Road BT9 5AG Belfast UK
| | - Michael Hoekstra
- Biological Chemistry Group, Institute of Biology, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Samantha J Bann
- School of Chemistry and Chemical Engineering, Queen's University Belfast David Keir Building, Stranmillis Road BT9 5AG Belfast UK
| | - Charlotte M J Wesseling
- Biological Chemistry Group, Institute of Biology, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Alexander T Bakker
- Molecular Physiology Group, Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Zheng Zhong
- Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Yong-Xin Li
- Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Nora C Brüchle
- Biological Chemistry Group, Institute of Biology, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Mario van der Stelt
- Molecular Physiology Group, Leiden Institute of Chemistry, Leiden University Einsteinweg 55 2333 CC Leiden The Netherlands
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast David Keir Building, Stranmillis Road BT9 5AG Belfast UK
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
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9
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Kotsogianni I, Wood TM, Alexander FM, Cochrane SA, Martin NI. Binding Studies Reveal Phospholipid Specificity and Its Role in the Calcium-Dependent Mechanism of Action of Daptomycin. ACS Infect Dis 2021; 7:2612-2619. [PMID: 34406007 PMCID: PMC8438661 DOI: 10.1021/acsinfecdis.1c00316] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Multidrug-resistant bacteria pose a serious global health threat as antibiotics are increasingly losing their clinical efficacy. A molecular level understanding of the mechanism of action of antimicrobials plays a key role in developing new agents to combat the threat of antimicrobial resistance. Daptomycin, the only clinically used calcium-dependent lipopeptide antibiotic, selectively disrupts Gram-positive bacterial membranes to illicit its bactericidal effect. In this study, we use isothermal titration calorimetry to further characterize the structural features of the target bacterial phospholipids that drive daptomycin binding. Our studies reveal that daptomycin shows a clear preference for the phosphoglycerol headgroup. Furthermore, unlike other calcium-dependent lipopeptide antibiotics, calcium binding by daptomycin is strongly dependent on the presence of phosphatidylglycerol. These investigations provide new insights into daptomycin's phospholipid specificity and calcium binding behavior.
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Affiliation(s)
- Ioli Kotsogianni
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Thomas M. Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Francesca M. Alexander
- School of Chemistry and Chemical Engineering, David Keir Building, Stranmillis Road, Queen’s University Belfast, Belfast, BT9 5AG, United Kingdom
| | - Stephen A. Cochrane
- School of Chemistry and Chemical Engineering, David Keir Building, Stranmillis Road, Queen’s University Belfast, Belfast, BT9 5AG, United Kingdom
| | - Nathaniel I. Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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10
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Abstract
Tridecaptins are a re-emerging class of non-ribosomal antibacterial peptides (NRAPs) with potent activity against highly problematic strains of Gram-negative bacteria. An intricate mode of action has been reported to explain the bactericidal activity of these NRAPs, wherein they bind selectivity to the Gram-negative version of the peptidoglycan precursor lipid II on the outer leaflet of the inner membrane and disrupt the proton-motive force. Tridecaptins are highly amenable to synthetic modification owing to their linear structure, therefore, various synthetic analogues have been reported, several of which have enhanced antimicrobial activity, reduced cost of synthesis and/or improved stability towards d-peptidase mediated hydrolysis. It has also been demonstrated that unacylated tridecaptins can act synergistically with clinically relevant antibiotics by sensitizing the outer membrane. This review will summarize past literature on the development/discovery of novel tridecaptin analogues (up until the end of 2020), some of which may be useful therapeutic agents to treat insidious Gram-negative bacterial infections.
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Affiliation(s)
- Samantha J Bann
- School of Chemistry and Chemical Engineering, Queens University Belfast David Keir Building, Stranmillis Road Belfast BT9 5AG UK
| | - Ross D Ballantine
- School of Chemistry and Chemical Engineering, Queens University Belfast David Keir Building, Stranmillis Road Belfast BT9 5AG UK
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queens University Belfast David Keir Building, Stranmillis Road Belfast BT9 5AG UK
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11
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Baker BR, Ives CM, Bray A, Caffrey M, Cochrane SA. Undecaprenol kinase: Function, mechanism and substrate specificity of a potential antibiotic target. Eur J Med Chem 2020; 210:113062. [PMID: 33310291 DOI: 10.1016/j.ejmech.2020.113062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The bifunctional undecaprenol kinase/phosphatase (UdpK) is a small, prokaryotic, integral membrane kinase, homologous with Escherichia coli diacylglycerol kinase and expressed by the dgkA gene. In Gram-positive bacteria, UdpK is involved in the homeostasis of the bacterial undecaprenoid pool, where it converts undecaprenol to undecaprenyl phosphate (C55P) and also catalyses the reverse process. C55P is the universal lipid carrier and critical to numerous glycopolymer and glycoprotein biosynthetic pathways in bacteria. DgkA gene expression has been linked to facilitating bacterial growth and survival in response to environmental stressors, as well being implicated as a resistance mechanism to the topical antibiotic bacitracin, by providing an additional route to C55P. Therefore, identification of UdpK inhibitors could lead to novel antibiotic treatments. A combination of homology modelling and mutagenesis experiments on UdpK have been used to identify residues that may be involved in kinase/phosphatase activity. In this review, we will summarise recent work on the mechanism and substrate specificity of UdpK.
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Affiliation(s)
- Brad R Baker
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK
| | - Callum M Ives
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland; Division of Computational Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Ashley Bray
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland
| | - Martin Caffrey
- School of Medicine and School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160, Pearse Street, Dublin 2, D02 R590, Ireland.
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, UK.
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12
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Cochrane SA, Lohans CT. Breaking down the cell wall: Strategies for antibiotic discovery targeting bacterial transpeptidases. Eur J Med Chem 2020; 194:112262. [PMID: 32248005 DOI: 10.1016/j.ejmech.2020.112262] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/14/2022]
Abstract
The enzymes involved in bacterial cell wall synthesis are established antibiotic targets, and continue to be a central focus for antibiotic development. Bacterial penicillin-binding proteins (and, in some bacteria, l,d-transpeptidases) form essential peptide cross-links in the cell wall. Although the β-lactam class of antibiotics target these enzymes, bacterial resistance threatens their clinical use, and there is an urgent unmet need for new antibiotics. However, the search for new antibiotics targeting the bacterial cell wall is hindered by a number of obstacles associated with screening the enzymes involved in peptidoglycan synthesis. This review describes recent approaches for measuring the activity and inhibition of penicillin-binding proteins and l,d-transpeptidases, highlighting strategies that are poised to serve as valuable tools for high-throughput screening of transpeptidase inhibitors, supporting the development of new antibiotics.
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Affiliation(s)
- Stephen A Cochrane
- School of Chemistry and Chemical Engineering, David Keir Building, Stranmillis Road, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Christopher T Lohans
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, K7L 3N6, Canada.
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13
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Calabrese C, Uriarte I, Insausti A, Vallejo-López M, Basterretxea FJ, Cochrane SA, Davis BG, Corzana F, Cocinero EJ. Observation of the Unbiased Conformers of Putative DNA-Scaffold Ribosugars. ACS Cent Sci 2020; 6:293-303. [PMID: 32123748 PMCID: PMC7047431 DOI: 10.1021/acscentsci.9b01277] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Indexed: 06/10/2023]
Abstract
The constitution, configuration, and flexibility of the core sugars of DNA molecules alter their function in diverse roles. Conformational itineraries of the ribofuranosides (fs) have long been known to finely determine rates of processing, yet we also know that, strikingly, semifunctional DNAs containing pyranosides (ps) or other configurations can be created, suggesting sufficient but incompletely understood plasticity. The multiple conformers involved in such processes are necessarily influenced by context and environment: solvent, hosts, ligands. Notably, however, to date the unbiased, "naked" conformers have not been experimentally determined. Here, the inherent conformational biases of DNA scaffold deoxyribosides in unsolvated and solvated forms have now been defined using gas-phase microwave and solution-phase NMR spectroscopies coupled with computational analyses and exploitation of critical differences between natural-abundance isotopologues. Serial determination of precise, individual spectra for conformers of these 25 isotopologues in alpha (α-d) and beta (β-d); pyrano (p) and furano (f) methyl 2-deoxy-d-ribosides gave not only unprecedented atomic-level resolution structures of associated conformers but also their quantitative populations. Together these experiments revealed that typical 2E and 3E conformations of the sugar found in complex DNA structures are not inherently populated. Moreover, while both OH-5' and OH-3' are constrained by intramolecular hydrogen bonding in the unnatural αf scaffold, OH-3' is "born free" in the "naked" lowest lying energy conformer of natural βf. Consequently, upon solvation, unnatural αf is strikingly less perturbable (retaining 2T1 conformation in vacuo and water) than natural βf. Unnatural αp and βp ribosides also display low conformational perturbability. These first experimental data on inherent, unbiased conformers therefore suggest that it is the background of conformational flexibility of βf that may have led to its emergence out of multiple possibilities as the sugar scaffold for "life's code" and suggest a mechanism by which the resulting freedom of OH-3' (and hence accessibility as a nucleophile) in βf may drive preferential processing and complex structure formation, such as replicative propagation of DNA from 5'-to-3'.
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Affiliation(s)
- Camilla Calabrese
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
- Instituto
Biofisika (CSIC, UPV/EHU), 48080 Bilbao, Spain
| | - Iciar Uriarte
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
- Instituto
Biofisika (CSIC, UPV/EHU), 48080 Bilbao, Spain
| | - Aran Insausti
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
- Instituto
Biofisika (CSIC, UPV/EHU), 48080 Bilbao, Spain
| | - Montserrat Vallejo-López
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
| | - Francisco J. Basterretxea
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
| | - Stephen A. Cochrane
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Benjamin G. Davis
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
- The
Rosalind Franklin Institute, Oxfordshire, OX11 0FA, United Kingdom
| | - Francisco Corzana
- Departamento
de Química, Centro de Investigación en Síntesis
Química, Universidad de La
Rioja, 26006 Logroño, Spain
| | - Emilio J. Cocinero
- Departamento
de Química Física, Facultad de Ciencia y
Tecnología, Universidad del
País Vasco (UPV/EHU), Campus de Leioa, Ap. 644, 48080 Bilbao, Spain
- Instituto
Biofisika (CSIC, UPV/EHU), 48080 Bilbao, Spain
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14
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Cochrane RVK, Alexander FM, Boland C, Fetics SK, Caffrey M, Cochrane SA. From plant to probe: semi-synthesis of labelled undecaprenol analogues allows rapid access to probes for antibiotic targets. Chem Commun (Camb) 2020; 56:8603-8606. [DOI: 10.1039/d0cc03388j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Extraction of undecaprenol from bay leaves followed by synthetic modification is a convenient method to obtain novel chemical probes.
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Affiliation(s)
| | | | - Coilín Boland
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Susan K. Fetics
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Martin Caffrey
- School of Medicine and School of Biochemistry and Immunology
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Stephen A. Cochrane
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast
- UK
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15
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Chiorean S, Antwi I, Carney DW, Kotsogianni I, Giltrap AM, Alexander FM, Cochrane SA, Payne RJ, Martin NI, Henninot A, Vederas JC. Dissecting the Binding Interactions of Teixobactin with the Bacterial Cell-Wall Precursor Lipid II. Chembiochem 2019; 21:789-792. [PMID: 31552694 DOI: 10.1002/cbic.201900504] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Indexed: 12/11/2022]
Abstract
The prevalence of life-threatening, drug-resistant microbial infections has challenged researchers to consider alternatives to currently available antibiotics. Teixobactin is a recently discovered "resistance-proof" antimicrobial peptide that targets the bacterial cell wall precursor lipid II. In doing so, teixobactin exhibits potent antimicrobial activity against a wide range of Gram-positive organisms. Herein we demonstrate that teixobactin and several structural analogues are capable of binding lipid II from both Gram-positive and Gram-negative bacteria. Furthermore, we show that when combined with known outer membrane-disrupting peptides, teixobactin is active against Gram-negative organisms.
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Affiliation(s)
- Sorina Chiorean
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Isaac Antwi
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Daniel W Carney
- Ferring Research Institute, Inc., 4245 Sorrento Valley Boulevard, San Diego, CA, 92121, USA
| | - Ioli Kotsogianni
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, NL
| | - Andrew M Giltrap
- School of Chemistry, University of Sydney, Chemistry Building (F11) Eastern Avenue, Sydney, NSW, 2006, Australia
| | - Francesca M Alexander
- School of Chemistry and Chemical Engineering, Queen's University, 39 Stranmillis Road, Belfast, BT9 5AG, UK
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queen's University, 39 Stranmillis Road, Belfast, BT9 5AG, UK
| | - Richard J Payne
- School of Chemistry, University of Sydney, Chemistry Building (F11) Eastern Avenue, Sydney, NSW, 2006, Australia
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, NL
| | - Antoine Henninot
- Ferring Research Institute, Inc., 4245 Sorrento Valley Boulevard, San Diego, CA, 92121, USA
| | - John C Vederas
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
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16
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Bann SJ, Ballantine RD, McCallion CE, Qian PY, Li YX, Cochrane SA. A Chemical-Intervention Strategy To Circumvent Peptide Hydrolysis by d-Stereoselective Peptidases. J Med Chem 2019; 62:10466-10472. [PMID: 31657913 PMCID: PMC6887851 DOI: 10.1021/acs.jmedchem.9b01078] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
![]()
d-Stereoselective peptidases that degrade nonribosomal
peptides (NRPs) were recently discovered and could have serious implications
for the future of NRPs as antibiotics. Herein, we report chemical
modifications that can be used to impart resistance to the d-peptidases BogQ and TriF. New tridecaptin A analogues were synthesized
that retain strong antimicrobial activity and have significantly enhanced d-peptidase stability. Invitro assays confirmed that synthetic analogues retain the ability to
bind to their cellular receptor, peptidoglycan intermediate lipid
II.
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Affiliation(s)
- Samantha J Bann
- School of Chemistry and Chemical Engineering, Stranmillis Road , Queen's University Belfast , Belfast BT9 5AG , U.K
| | - Ross D Ballantine
- School of Chemistry and Chemical Engineering, Stranmillis Road , Queen's University Belfast , Belfast BT9 5AG , U.K
| | - Conor E McCallion
- School of Chemistry and Chemical Engineering, Stranmillis Road , Queen's University Belfast , Belfast BT9 5AG , U.K
| | - Pei-Yuan Qian
- Department of Ocean Science, Division of Life Science and Hong Kong Branch of Southern Marine Science & Engineering Guangdong Laboratory , Hong Kong University of Science and Technology , Clear Water Bay , Hong Kong
| | - Yong-Xin Li
- Department of Chemistry , Hong Kong University , Hong Kong
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Stranmillis Road , Queen's University Belfast , Belfast BT9 5AG , U.K
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17
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Dong YY, Wang H, Pike ACW, Cochrane SA, Hamedzadeh S, Wyszyński FJ, Bushell SR, Royer SF, Widdick DA, Sajid A, Boshoff HI, Park Y, Lucas R, Liu WM, Lee SS, Machida T, Minall L, Mehmood S, Belaya K, Liu WW, Chu A, Shrestha L, Mukhopadhyay SMM, Strain-Damerell C, Chalk R, Burgess-Brown NA, Bibb MJ, Barry Iii CE, Robinson CV, Beeson D, Davis BG, Carpenter EP. Structures of DPAGT1 Explain Glycosylation Disease Mechanisms and Advance TB Antibiotic Design. Cell 2019; 175:1045-1058.e16. [PMID: 30388443 PMCID: PMC6218659 DOI: 10.1016/j.cell.2018.10.037] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/01/2018] [Accepted: 10/15/2018] [Indexed: 12/24/2022]
Abstract
Protein N-glycosylation is a widespread post-translational modification. The first committed step in this process is catalysed by dolichyl-phosphate N-acetylglucosamine-phosphotransferase DPAGT1 (GPT/E.C. 2.7.8.15). Missense DPAGT1 variants cause congenital myasthenic syndrome and disorders of glycosylation. In addition, naturally-occurring bactericidal nucleoside analogues such as tunicamycin are toxic to eukaryotes due to DPAGT1 inhibition, preventing their clinical use. Our structures of DPAGT1 with the substrate UDP-GlcNAc and tunicamycin reveal substrate binding modes, suggest a mechanism of catalysis, provide an understanding of how mutations modulate activity (thus causing disease) and allow design of non-toxic “lipid-altered” tunicamycins. The structure-tuned activity of these analogues against several bacterial targets allowed the design of potent antibiotics for Mycobacterium tuberculosis, enabling treatment in vitro, in cellulo and in vivo, providing a promising new class of antimicrobial drug. Structures of DPAGT1 with UDP-GlcNAc and tunicamycin reveal mechanisms of catalysis DPAGT1 mutations in patients with glycosylation disorders modulate DPAGT1 activity Structures, kinetics and biosynthesis reveal role of lipid in tunicamycin Lipid-altered, tunicamycin analogues give non-toxic antibiotics against TB
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Affiliation(s)
- Yin Yao Dong
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Hua Wang
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Ashley C W Pike
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Stephen A Cochrane
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK; School of Chemistry and Chemical Engineering, Queen's University, Belfast, UK
| | - Sadra Hamedzadeh
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Filip J Wyszyński
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Simon R Bushell
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sylvain F Royer
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - David A Widdick
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Andaleeb Sajid
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Helena I Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Yumi Park
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ricardo Lucas
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Wei-Min Liu
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Seung Seo Lee
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Takuya Machida
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Leanne Minall
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | | | - Katsiaryna Belaya
- Neurosciences Group, Nuffield Department of Clinical Neuroscience, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Wei-Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neuroscience, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Amy Chu
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Leela Shrestha
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | | | | | - Rod Chalk
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | | | - Mervyn J Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Clifton E Barry Iii
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neuroscience, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Benjamin G Davis
- Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK.
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18
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Ballantine RD, McCallion CE, Nassour E, Tokajian S, Cochrane SA. Tridecaptin-inspired antimicrobial peptides with activity against multidrug-resistant Gram-negative bacteria. Medchemcomm 2019; 10:484-487. [PMID: 31015912 PMCID: PMC6457190 DOI: 10.1039/c9md00031c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 02/20/2019] [Indexed: 01/05/2023]
Abstract
New tridecaptin analogues are cheaper to make and retain strong Gram-negative activity.
Antimicrobial peptides are a rich source of potential antibiotic candidates. The tridecaptins, a family of linear lipo-tridecapeptides, are easily synthesized and show strong activity against Gram-negative bacteria. However, their composition includes several expensive amino acids, such as d/l diaminobutyric acid and d-allo-isoleucine, significantly increasing their cost of synthesis. Herein, we report a series of new tridecaptin derivatives that are much cheaper to synthesize and retain strong activity against multidrug-resistant Gram-negative bacteria.
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Affiliation(s)
- Ross D Ballantine
- School of Chemistry and Chemical Engineering , David Keir Building , Queen's University Belfast , Stranmillis Road , Belfast , BT9 5AG , UK .
| | - Conor E McCallion
- School of Chemistry and Chemical Engineering , David Keir Building , Queen's University Belfast , Stranmillis Road , Belfast , BT9 5AG , UK .
| | - Elie Nassour
- Department of Natural Sciences , School of Arts and Sciences , Lebanese American University , Byblos , Lebanon
| | - Sima Tokajian
- Department of Natural Sciences , School of Arts and Sciences , Lebanese American University , Byblos , Lebanon
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering , David Keir Building , Queen's University Belfast , Stranmillis Road , Belfast , BT9 5AG , UK .
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19
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Ballantine RD, Li YX, Qian PY, Cochrane SA. Rational design of new cyclic analogues of the antimicrobial lipopeptide tridecaptin A 1. Chem Commun (Camb) 2018; 54:10634-10637. [PMID: 30179243 PMCID: PMC6146376 DOI: 10.1039/c8cc05790g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cyclization of tridecaptin A1 imparts stability to the d-peptidase TriF.
Non-ribosomal peptides (NRPs) are a rich source of antibiotic candidates. However, it was recently discovered that resistance to NRPs can be mediated by d-stereoselective peptidases. The tridecaptins, a class of NRPs that selectively target Gram-negative bacteria, are degraded by the d-peptidase TriF. Through analysis of a solution NMR structure of tridecaptin A1, we have rationally synthesized new cyclic tridecaptin analogues that retain strong antimicrobial activity and are resistant to TriF.
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Affiliation(s)
- Ross D Ballantine
- School of Chemistry and Chemical Engineering, David Keir Building, Stranmillis Road, Queen's University Belfast, Belfast BT9 5AG, UK.
| | - Yong-Xin Li
- Department of Ocean Science and Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Pei-Yuan Qian
- Department of Ocean Science and Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, David Keir Building, Stranmillis Road, Queen's University Belfast, Belfast BT9 5AG, UK.
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20
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Bakhtiary A, Cochrane SA, Mercier P, McKay RT, Miskolzie M, Sit CS, Vederas JC. Insights into the Mechanism of Action of the Two-Peptide Lantibiotic Lacticin 3147. J Am Chem Soc 2017; 139:17803-17810. [PMID: 29164875 DOI: 10.1021/jacs.7b04728] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lacticin 3147 is a two peptide lantibiotc (LtnA1 and LtnA2) that displays nanomolar activity against many Gram-positive bacteria. Lacticin 3147 may exert its antimicrobial effect by several mechanisms. Isothermal titration calorimetry experiments show that only LtnA1 binds to the peptidoglycan precursor lipid II, which could inhibit peptidoglycan biosynthesis. An experimentally supported model of the resulting complex suggests that the key binding partners are the C-terminus of LtnA1 and pyrophosphate of lipid II. A combination of in vivo and in vitro assays indicates that LtnA1 and LtnA2 can induce rapid membrane lysis without the need for lipid II binding. However, the presence of lipid II substantially increases the activity of lacticin 3147. Furthermore, studies with synthetic LtnA2 analogues containing either desmethyl- or oxa-lanthionine rings confirm that the precise geometry of these rings is essential for this synergistic activity.
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Affiliation(s)
- Alireza Bakhtiary
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Stephen A Cochrane
- School of Chemistry and Chemical Engineering, Queens University Belfast , Belfast BT9 5AG, United Kingdom
| | - Pascal Mercier
- National High Field NMR Centre, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
| | - Ryan T McKay
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Mark Miskolzie
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Clarissa S Sit
- Department of Chemistry, Saint Mary's University , Halifax, Nova Scotia B3H 3C3, Canada
| | - John C Vederas
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
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21
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Cochrane SA, Lohans CT, van Belkum MJ, Bels MA, Vederas JC. Studies on tridecaptin B(1), a lipopeptide with activity against multidrug resistant Gram-negative bacteria. Org Biomol Chem 2016; 13:6073-81. [PMID: 25959079 DOI: 10.1039/c5ob00780a] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previously other groups had reported that Paenibacillus polymyxa NRRL B-30507 produces SRCAM 37, a type IIA bacteriocin with antimicrobial activity against Campylobacter jejuni. Genome sequencing and isolation of antimicrobial compounds from this P. polymyxa strain show that the antimicrobial activity is due to polymyxins and tridecaptin B1. The complete structural assignment, synthesis, and antimicrobial profile of tridecaptin B1 is reported, as well as the putative gene cluster responsible for its biosynthesis. This peptide displays strong activity against multidrug resistant Gram-negative bacteria, a finding that is timely to the current problem of antibiotic resistance.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6E 2M9, Canada.
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Cochrane SA, Li X, He S, Yu M, Wu M, Vederas JC. Synthesis of Tridecaptin-Antibiotic Conjugates with in Vivo Activity against Gram-Negative Bacteria. J Med Chem 2015; 58:9779-85. [PMID: 26636619 DOI: 10.1021/acs.jmedchem.5b01578] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A series of tridecaptin-antibiotic conjugates were synthesized and evaluated for in vitro and in vivo activity against Gram-negative bacteria. Covalently linking unacylated tridecaptin A1 (H-TriA1) to rifampicin, vancomycin, and erythromycin enhanced their activity in vitro but not by the same magnitude as coadministration of the peptide and these antibiotics. The antimicrobial activities of the conjugates were retained in vivo, with the H-TriA1-erythromycin conjugate proving a more effective treatment of Klebseilla pneumoniae infections in mice than erythromycin alone or in combination with H-TriA1.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Xuefeng Li
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota 58203-9037, United States
| | - Sisi He
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota 58203-9037, United States
| | - Min Yu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota 58203-9037, United States
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota 58203-9037, United States
| | - John C Vederas
- Department of Chemistry, University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
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Abstract
The isolation and total synthesis of the antimicrobial lipopeptide cerexin A1 is reported. This synthesis includes the preparation of orthogonally protected γ-hydroxylysine, utilizing a nitrile Reformatsky-type reaction as a key step to yield both diastereomers more efficiently than previously reported methods. The configuration of the β-hydroxyl in the lipid tail was determined by the use of a modified Ohrui-Akasaka approach. Furthermore, new cerexin analogues from Bacillus mycoides ATCC 21929 were isolated and characterized, revealing an ε-amino succinylation of a hydroxylysine residue that is unusual in a nonribosomal peptide synthetase product.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Richard R Surgenor
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Kevin M W Khey
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - John C Vederas
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
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Kwon M, Cochrane SA, Vederas JC, Ro DK. Molecular cloning and characterization of drimenol synthase from valerian plant (Valeriana officinalis). FEBS Lett 2014; 588:4597-603. [DOI: 10.1016/j.febslet.2014.10.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/25/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
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Cochrane SA, Vederas JC. Unacylated tridecaptin A₁ acts as an effective sensitiser of Gram-negative bacteria to other antibiotics. Int J Antimicrob Agents 2014; 44:493-9. [PMID: 25315408 DOI: 10.1016/j.ijantimicag.2014.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/14/2014] [Accepted: 08/13/2014] [Indexed: 11/29/2022]
Abstract
A derivative of the linear cationic lipopeptide tridecaptin A₁missing the N-terminal lipophilic acyl group, termed H-TriA₁, is devoid of antimicrobial activity but is extremely effective at sensitising Gram-negative bacteria to certain antibiotics. H-TriA₁has low cytotoxicity compared with the natural peptide and in low concentrations it can substantially lower the minimum inhibitory concentration (MIC) of some antibiotics against strains of Escherichia coli, Campylobacter jejuni and Klebsiella pneumoniae. In particular, the MIC of rifampicin was lowered 256-512-fold against K. pneumoniae strains using low concentrations of H-TriA₁. H-TriA₁does not exert its synergistic effect through partial membrane lysis, but does bind to model bacterial membranes in a manner akin to the natural peptide. Formation of this stable secondary structure on the outer membrane may account for the observed synergistic activity.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta, 30 University Campus NW, Edmonton, AB, Canada T6G 2G2
| | - John C Vederas
- Department of Chemistry, University of Alberta, 30 University Campus NW, Edmonton, AB, Canada T6G 2G2.
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Affiliation(s)
| | - John C. Vederas
- Department of Chemistry; University of Alberta; Alberta Canada
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Cochrane SA, Findlay B, Vederas JC, Ratemi ES. Key residues in octyl-tridecaptin A1 analogues linked to stable secondary structures in the membrane. Chembiochem 2014; 15:1295-9. [PMID: 24816483 DOI: 10.1002/cbic.201402024] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Indexed: 11/07/2022]
Abstract
Tridecaptin A1 is a linear antimicrobial lipopeptide comprised of 13 amino acids, including three diaminobutyric acid (Dab) residues. It displays potent activity against Gram-negative bacteria, including multidrug-resistant strains. Using solid-phase peptide synthesis, we performed an alanine scan of a fully active analogue, octyl-tridecaptin A1 , to determine key residues responsible for activity. The synthetic analogues were tested against ten organisms, both Gram-positive and Gram-negative bacteria. Modification of D-Dab8 abolished activity, and marked decreases were observed with substitution of D-allo-Ile12 and D-Trp5. Circular dichroism showed that octyl-tridecaptin A1 adopts a secondary structure in the presence of model phospholipid membranes, which was weakened by D-Dab8-D-Ala, D-allo-Ile12-D-Ala, and D-Trp5-D-Ala substitutions. The antimicrobial activity of the analogues is directly correlated to their ability to adopt a stable secondary structure in a membrane environment.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2 (Canada)
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Cochrane SA, Lohans CT, Brandelli JR, Mulvey G, Armstrong GD, Vederas JC. Synthesis and structure-activity relationship studies of N-terminal analogues of the antimicrobial peptide tridecaptin A(1). J Med Chem 2014; 57:1127-31. [PMID: 24479847 DOI: 10.1021/jm401779d] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chemical synthesis was used to increase the potency of the antimicrobial lipopeptide tridecaptin A1. Lipid tail modification proved to be an ideal platform for synthesizing structurally simpler analogues that are not readily accessible by isolation. The stereochemical elements of the tridecaptin A1 lipid tail are not essential for antimicrobial activity and could be replaced with hydrophobic aliphatic or aromatic groups. Some simpler analogues displayed potent antimicrobial activity against Gram-negative bacteria, including Campylobacter jejuni, Escherichia coli O157:H7, and multidrug resistant Klebsiella pneumoniae.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
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Lohans CT, van Belkum MJ, Cochrane SA, Huang Z, Sit CS, McMullen LM, Vederas JC. Biochemical, Structural, and Genetic Characterization of Tridecaptin A1, an Antagonist ofCampylobacter jejuni. Chembiochem 2013; 15:243-9. [DOI: 10.1002/cbic.201300595] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Indexed: 11/09/2022]
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Mann ER, McCarthy NE, Peake STC, Milestone AN, Al-Hassi HO, Bernardo D, Tee CT, Landy J, Pitcher MC, Cochrane SA, Hart AL, Stagg AJ, Knight SC. Skin- and gut-homing molecules on human circulating γδ T cells and their dysregulation in inflammatory bowel disease. Clin Exp Immunol 2013; 170:122-30. [PMID: 23039882 DOI: 10.1111/j.1365-2249.2012.04649.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Changes in phenotype and function of γδ T cells have been reported in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Dysregulation of lymphocyte migration plays a key role in IBD pathogenesis; however, data on migratory properties of γδ T cells are scarce. Human circulating γδ T cells from healthy controls (n = 27), patients with active CD (n = 15), active UC (n = 14) or cutaneous manifestations of IBD (n = 2) were characterized by flow cytometry. Circulating γδ T cells in healthy controls were CD3(hi) and expressed CD45RO. They expressed gut-homing molecule β7 but not gut-homing molecule corresponding chemokine receptors (CCR)9, or skin-homing molecules cutaneous lymphocyte-associated antigen (CLA) and CCR4, despite conventional T cells containing populations expressing these molecules. CCR9 expression was increased on γδ T cells in CD and UC, while skin-homing CLA was expressed aberrantly on γδ T cells in patients with cutaneous manifestations of IBD. Lower levels of CD3 expression were found on γδ T cells in CD but not in UC, and a lower proportion of γδ T cells expressed CD45RO in CD and UC. Enhanced expression of gut-homing molecules on circulating γδ T cells in IBD and skin-homing molecules in cutaneous manifestations of IBD may be of clinical relevance.
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Affiliation(s)
- E R Mann
- Antigen Presentation Research Group, Imperial College London, Northwick Park and St Mark’s Campus, Level 7W, St Mark’s Hospital,Watford Road, Harrow HA1 3UJ, UK
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Abstract
A systematic study of the ring-closing metathesis (RCM) of unprotected oxytocin and crotalphine peptide analogues in water is reported. The replacement of cysteine with S-allyl cysteine enables RCM to proceed readily in water containing excess MgCl(2) with 30% t-BuOH as a co-solvent. The presence of the sulfur atom is vital for efficient aqueous RCM to occur, with non-sulfur containing analogues undergoing RCM in low yields.
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Affiliation(s)
- Stephen A Cochrane
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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Cochrane SA, Salt LJ, Wantling E, Rogers A, Coutts J, Ballmer-Weber BK, Fritsche P, Fernández-Rivas M, Reig I, Knulst A, Le TM, Asero R, Beyer K, Golding M, Crevel R, Clare Mills EN, Mackie AR. Development of a standardized low-dose double-blind placebo-controlled challenge vehicle for the EuroPrevall project. Allergy 2012; 67:107-13. [PMID: 22092081 DOI: 10.1111/j.1398-9995.2011.02715.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for diagnosing food allergy. Standardized materials and protocols are essential for comparing DBPCFC results for multicentre studies such as EuroPrevall. This required the development and piloting of a standardized vehicle and low-dose protocol for confirming food allergy and determination of minimum eliciting doses (MEDs). METHODS A low-dose DBPCFC protocol was developed, with eight titrated protein doses from 3 μg to 1 g. This was delivered using a simple, microbiologically stable food base incorporating allergenic food ingredients manufactured at three sites and centrally distributed to clinical centres. Allergen blinding was assessed by a professional sensory testing panel using a triangle test. Homogeneity and allergen content were confirmed by ELISA and clinical efficacy was assessed in a pilot study, using celeriac and hazelnut as exemplars. RESULTS Celeriac and hazelnut ingredients were sufficiently blinded in the dessert. The dessert meals were successfully piloted with hazelnut in allergy clinics in Spain, the Netherlands and Italy and with celeriac and hazelnut in Zurich. The challenges elicited a range of subjective and objective reactions ranging in severity from mild itching of the oral mucosa to bronchospasm. CONCLUSIONS A standardized challenge vehicle proven to sufficiently blind processed, powdered hazelnut and celeriac ingredients and that can be reproducibly manufactured has been developed. This pilot study shows that the vehicle is promising for the confirmation of food allergy and determination of MEDs in adults and children with body weight >28.8 kg (approximately 7-11 years old).
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Affiliation(s)
- S A Cochrane
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, UK.
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Liu W, Chan ASH, Liu H, Cochrane SA, Vederas JC. Solid supported chemical syntheses of both components of the lantibiotic lacticin 3147. J Am Chem Soc 2011; 133:14216-9. [PMID: 21848315 DOI: 10.1021/ja206017p] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lantibiotics are antimicrobial peptides produced by bacteria. Some are employed for food preservation, whereas others have therapeutic potential due to their activity against organisms resistant to current antibiotics. They are ribosomally synthesized and posttranslationally modified by dehydration of serine and threonine residues followed by attack of thiols of cysteines to form monosulfide lanthionine and methyllanthionine rings, respectively. Chemical synthesis of peptide analogues is a powerful method to verify stereochemistry and access structure-activity relationships. However, solid supported synthesis of lantibiotics has been difficult due to problems in generating lanthionines and methyllanthionines with orthogonal protection and good stereochemical control. We report the solid-phase syntheses of both peptides of a two-component lantibiotic, lacticin 3147. Both successive and interlocking ring systems were synthesized on-resin, thereby providing a general methodology for this family of natural products.
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Affiliation(s)
- Wei Liu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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Lucas JSA, Nieuwenhuizen NJ, Atkinson RG, Macrae EA, Cochrane SA, Warner JO, Hourihane JO. Kiwifruit allergy: actinidin is not a major allergen in the United Kingdom. Clin Exp Allergy 2007; 37:1340-8. [PMID: 17845415 DOI: 10.1111/j.1365-2222.2007.02776.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Actinidin has previously been reported as the major allergen in kiwifruit. Objectives To investigate the relevance of actinidin in a well-characterized population of UK patients with kiwifruit allergy. METHODS To identify the allergens in kiwifruit, using Western blots, we examined the IgE-binding patterns of 76 patients with a history of kiwifruit allergy, 23 of who had had a positive double-blind, placebo-controlled food challenge. In addition, IgE binding to purified native actinidin was studied in 30 patients, and to acidic and basic isoforms of recombinant actinidin in five patients. Inhibition of IgE binding to kiwifruit protein extract by purified native actinidin was investigated by both inhibition immunoblots and inhibition ELISAs using pooled sera. RESULTS Twelve protein bands in kiwifruit protein extract were bound by IgE. A protein band with a molecular weight of 38 kDa was the major allergen recognized by 59% of the population. IgE did not bind to actinidin in the kiwifruit protein extract, or to purified native or recombinant forms of actinidin during Western blotting. Pooled sera bound to kiwifruit protein extract but not purified actinidin on ELISA, and pre-incubating sera with actinidin did not inhibit IgE binding to kiwifruit protein extract on immunoblot or ELISA. CONCLUSION A novel 38 kDa protein, not actinidin, is the major allergen in this large study population. Identification of major allergens in one patient group is therefore not necessarily reproducible in another; therefore, major allergens should not be defined until there is a sufficient body of data from diverse geographical and cultural populations.
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Affiliation(s)
- J S A Lucas
- Division of Infection Inflammation and Repair, University of Southampton, Southampton, UK.
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