1
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van der Meij A, Elsayed SS, Du C, Willemse J, Wood TM, Martin NI, Raaijmakers JM, van Wezel GP. The plant stress hormone jasmonic acid evokes defensive responses in streptomycetes. Appl Environ Microbiol 2023; 89:e0123923. [PMID: 37902333 PMCID: PMC10686085 DOI: 10.1128/aem.01239-23] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/21/2023] [Indexed: 10/31/2023] Open
Abstract
IMPORTANCE Microorganisms that live on or inside plants can influence plant growth and health. Among the plant-associated bacteria, streptomycetes play an important role in defense against plant diseases, but the underlying mechanisms are not well understood. Here, we demonstrate that the plant hormones jasmonic acid (JA) and methyl jasmonate directly affect the life cycle of streptomycetes by modulating antibiotic synthesis and promoting faster development. Moreover, the plant hormones specifically stimulate the synthesis of the polyketide antibiotic actinorhodin in Streptomyces coelicolor. JA is then modified in the cell by amino acid conjugation, thereby quenching toxicity. Collectively, these results provide new insight into the impact of a key plant hormone on diverse phenotypic responses of streptomycetes.
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Affiliation(s)
- Anne van der Meij
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Somayah S. Elsayed
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Chao Du
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Joost Willemse
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Thomas M. Wood
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Nathaniel I. Martin
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
| | - Jos M. Raaijmakers
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands
| | - Gilles P. van Wezel
- Molecular Biotechnology, Institute of Biology, Leiden University, the Netherlands, Leiden
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands
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2
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Javed A, Slingerland CJ, Wood TM, Martin NI, Broere F, Weingarth MH, Veldhuizen EJA. Chimeric Peptidomimetic Antibiotic Efficiently Neutralizes Lipopolysaccharides (LPS) and Bacteria-Induced Activation of RAW Macrophages. ACS Infect Dis 2023; 9:518-526. [PMID: 36790385 PMCID: PMC10012172 DOI: 10.1021/acsinfecdis.2c00518] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Peptide antibiotics have gathered attention given the urgent need to discover antimicrobials with new mechanisms of action. Their extended role as immunomodulators makes them interesting candidates for the development of compounds with dual mode of action. The objective of this study was to test the anti-inflammatory capacity of a recently reported chimeric peptidomimetic antibiotic (CPA) composed of polymyxin B nonapeptide (PMBN) and a macrocyclic β-hairpin motif (MHM). We investigated the potential of CPA to inhibit lipopolysaccharide (LPS)-induced activation of RAW264.7 macrophages. In addition, we elucidated which structural motif was responsible for this activity by testing CPA, its building blocks, and their parent compounds separately. CPA showed excellent LPS neutralizing activity for both smooth and rough LPSs. At nanomolar concentrations, CPA completely inhibited LPS-induced nitric oxide, TNF-α, and IL-10 secretion. Murepavadin, MHM, and PMBN were incapable of neutralizing LPS in this assay, while PMB was less active compared to CPA. Isothermal titration calorimetry showed strong binding between the CPA and LPS with similar binding characteristics also found for the other compounds, indicating that binding does not necessarily correlate with neutralization of LPS. Finally, we showed that CPA-killed bacteria caused significantly less macrophage activation than bacteria killed with gentamicin, heat, or any of the other compounds. This indicates that the combined killing activity and LPS neutralization of CPA can prevent unwanted inflammation, which could be a major advantage over conventional antibiotics. Our data suggests that immunomodulatory activity can further strengthen the therapeutic potential of peptide antibiotics and should be included in the characterization of novel compounds.
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Affiliation(s)
- Ali Javed
- Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Division Infectious Diseases & Immunology, Section Immunology, Utrecht University, 3584 CL Utrecht, The Netherlands.,NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CS Utrecht, The Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Femke Broere
- Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Division Infectious Diseases & Immunology, Section Immunology, Utrecht University, 3584 CL Utrecht, The Netherlands
| | - Markus H Weingarth
- NMR Spectroscopy, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CS Utrecht, The Netherlands
| | - Edwin J A Veldhuizen
- Faculty of Veterinary Medicine, Department of Biomolecular Health Sciences, Division Infectious Diseases & Immunology, Section Immunology, Utrecht University, 3584 CL Utrecht, The Netherlands
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3
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Versloot RA, Lucas FL, Yakovlieva L, Tadema MJ, Zhang Y, Wood TM, Martin NI, Marrink SJ, Walvoort MTC, Maglia G. Quantification of Protein Glycosylation Using Nanopores. Nano Lett 2022; 22:5357-5364. [PMID: 35766994 PMCID: PMC9284675 DOI: 10.1021/acs.nanolett.2c01338] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Although nanopores can be used for single-molecule sequencing of nucleic acids using low-cost portable devices, the characterization of proteins and their modifications has yet to be established. Here, we show that hydrophilic or glycosylated peptides translocate too quickly across FraC nanopores to be recognized. However, high ionic strengths (i.e., 3 M LiCl) and low pH (i.e., pH 3) together with using a nanopore with a phenylalanine at its constriction allows the recognition of hydrophilic peptides, and to distinguish between mono- and diglycosylated peptides. Using these conditions, we devise a nanopore method to detect, characterize, and quantify post-translational modifications in generic proteins, which is one of the pressing challenges in proteomic analysis.
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Affiliation(s)
| | | | - Liubov Yakovlieva
- Chemical
Biology Division, Stratingh Institute for Chemistry, University of Groningen, 9747AG Groningen, The Netherlands
| | - Matthijs Jonathan Tadema
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, The Netherlands
| | - Yurui Zhang
- Biological
Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Thomas M. Wood
- Biological
Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Nathaniel I. Martin
- Biological
Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 BE Leiden, The Netherlands
| | - Siewert J. Marrink
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, The Netherlands
| | - Marthe T. C. Walvoort
- Chemical
Biology Division, Stratingh Institute for Chemistry, University of Groningen, 9747AG Groningen, The Netherlands
| | - Giovanni Maglia
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, The Netherlands
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4
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Wood TM, Zeronian MR, Buijs N, Bertheussen K, Abedian HK, Johnson AV, Pearce NM, Lutz M, Kemmink J, Seirsma T, Hamoen LW, Janssen BJC, Martin NI. Mechanistic insights into the C 55-P targeting lipopeptide antibiotics revealed by structure-activity studies and high-resolution crystal structures. Chem Sci 2022; 13:2985-2991. [PMID: 35382464 PMCID: PMC8905900 DOI: 10.1039/d1sc07190d] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 01/18/2022] [Indexed: 12/27/2022] Open
Abstract
The continued rise of antibiotic resistance is a global concern that threatens to undermine many aspects of modern medical practice. Key to addressing this threat is the discovery and development of new antibiotics that operate by unexploited modes of action. The so-called calcium-dependent lipopeptide antibiotics (CDAs) are an important emerging class of natural products that provides a source of new antibiotic agents rich in structural and mechanistic diversity. Notable in this regard is the subset of CDAs comprising the laspartomycins and amphomycins/friulimicins that specifically target the bacterial cell wall precursor undecaprenyl phosphate (C55-P). In this study we describe the design and synthesis of new C55-P-targeting CDAs with structural features drawn from both the laspartomycin and amphomycin/friulimicin classes. Assessment of these lipopeptides revealed previously unknown and surprisingly subtle structural features that are required for antibacterial activity. High-resolution crystal structures further indicate that the amphomycin/friulimicin-like lipopeptides adopt a unique crystal packing that governs their interaction with C55-P and provides an explanation for their antibacterial effect. In addition, live-cell microscopy studies provide further insights into the biological activity of the C55-P targeting CDAs highlighting their unique mechanism of action relative to the clinically used CDA daptomycin. Structural and mechanistic studies give new insights into calcium-dependent lipopeptide antibiotics that target C55-P.![]()
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Affiliation(s)
- Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands .,Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Matthieu R Zeronian
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Ned Buijs
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Kristine Bertheussen
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Hanieh K Abedian
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Aidan V Johnson
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
| | - Nicholas M Pearce
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Martin Lutz
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Johan Kemmink
- Faculty of Science and Engineering, University of Groningen 9747 AG Groningen The Netherlands
| | - Tjalling Seirsma
- Bacterial Cell Biology and Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands
| | - Leendert W Hamoen
- Bacterial Cell Biology and Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands
| | - Bert J C Janssen
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Sylviusweg 72 2333 BE Leiden The Netherlands
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5
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Cioce A, Bineva-Todd G, Agbay AJ, Choi J, Wood TM, Debets MF, Browne WM, Douglas HL, Roustan C, Tastan OY, Kjaer S, Bush JT, Bertozzi CR, Schumann B. Optimization of Metabolic Oligosaccharide Engineering with Ac 4GalNAlk and Ac 4GlcNAlk by an Engineered Pyrophosphorylase. ACS Chem Biol 2021. [PMID: 33835779 DOI: 10.1021/acschem-bio.1c00034] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Metabolic oligosaccharide engineering (MOE) has fundamentally contributed to our understanding of protein glycosylation. Efficient MOE reagents are activated into nucleotide-sugars by cellular biosynthetic machineries, introduced into glycoproteins and traceable by bioorthogonal chemistry. Despite their widespread use, the metabolic fate of many MOE reagents is only beginning to be mapped. While metabolic interconnectivity can affect probe specificity, poor uptake by biosynthetic salvage pathways may impact probe sensitivity and trigger side reactions. Here, we use metabolic engineering to turn the weak alkyne-tagged MOE reagents Ac4GalNAlk and Ac4GlcNAlk into efficient chemical tools to probe protein glycosylation. We find that bypassing a metabolic bottleneck with an engineered version of the pyrophosphorylase AGX1 boosts nucleotide-sugar biosynthesis and increases bioorthogonal cell surface labeling by up to two orders of magnitude. A comparison with known azide-tagged MOE reagents reveals major differences in glycoprotein labeling, substantially expanding the toolbox of chemical glycobiology.
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Affiliation(s)
- Anna Cioce
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Ganka Bineva-Todd
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Anthony J Agbay
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Junwon Choi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Thomas M Wood
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Marjoke F Debets
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - William M Browne
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Holly L Douglas
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Chloe Roustan
- Structural Biology Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Omur Y Tastan
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Svend Kjaer
- Structural Biology Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Jacob T Bush
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY United Kingdom
| | - Carolyn R Bertozzi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Howard Hughes Medical Institute, 380 Roth Way, Stanford, California 94305, United States
| | - Benjamin Schumann
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
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6
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Cioce A, Bineva-Todd G, Agbay AJ, Choi J, Wood TM, Debets MF, Browne WM, Douglas HL, Roustan C, Tastan OY, Kjaer S, Bush JT, Bertozzi CR, Schumann B. Optimization of Metabolic Oligosaccharide Engineering with Ac 4GalNAlk and Ac 4GlcNAlk by an Engineered Pyrophosphorylase. ACS Chem Biol 2021; 16:1961-1967. [PMID: 33835779 PMCID: PMC8501146 DOI: 10.1021/acschembio.1c00034] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
Metabolic oligosaccharide
engineering (MOE) has fundamentally contributed
to our understanding of protein glycosylation. Efficient MOE reagents
are activated into nucleotide-sugars by cellular biosynthetic machineries,
introduced into glycoproteins and traceable by bioorthogonal chemistry.
Despite their widespread use, the metabolic fate of many MOE reagents
is only beginning to be mapped. While metabolic interconnectivity
can affect probe specificity, poor uptake by biosynthetic salvage
pathways may impact probe sensitivity and trigger side reactions.
Here, we use metabolic engineering to turn the weak alkyne-tagged
MOE reagents Ac4GalNAlk and Ac4GlcNAlk into
efficient chemical tools to probe protein glycosylation. We find that
bypassing a metabolic bottleneck with an engineered version of the
pyrophosphorylase AGX1 boosts nucleotide-sugar biosynthesis and increases
bioorthogonal cell surface labeling by up to two orders of magnitude.
A comparison with known azide-tagged MOE reagents reveals major differences
in glycoprotein labeling, substantially expanding the toolbox of chemical
glycobiology.
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Affiliation(s)
- Anna Cioce
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Ganka Bineva-Todd
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Anthony J. Agbay
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Junwon Choi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Thomas M. Wood
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Marjoke F. Debets
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - William M. Browne
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Holly L. Douglas
- Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Chloe Roustan
- Structural Biology Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Omur Y. Tastan
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
| | - Svend Kjaer
- Structural Biology Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Jacob T. Bush
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY United Kingdom
| | - Carolyn R. Bertozzi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Howard Hughes Medical Institute, 380 Roth Way, Stanford, California 94305, United States
| | - Benjamin Schumann
- Department of Chemistry, Imperial College London, 80 Wood Lane, W12 0BZ London, United Kingdom
- The Chemical Glycobiology Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, United Kingdom
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7
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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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8
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Wood TM, Slingerland CJ, Martin NI. A Convenient Chemoenzymatic Preparation of Chimeric Macrocyclic Peptide Antibiotics with Potent Activity against Gram-Negative Pathogens. J Med Chem 2021; 64:10890-10899. [PMID: 34283589 PMCID: PMC8365600 DOI: 10.1021/acs.jmedchem.1c00176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
The continuing rise
of antibiotic resistance, particularly among
Gram-negative pathogens, threatens to undermine many aspects of modern
medical practice. To address this threat, novel antibiotics that utilize
unexploited bacterial targets are urgently needed. Over the past decade,
a number of studies have highlighted the antibacterial potential of
macrocyclic peptides that target Gram-negative outer membrane proteins
(OMPs). Recently, it was reported that the antibacterial activities
of OMP-targeting macrocyclic peptidomimetics of the antimicrobial
peptide protegrin-1 are dramatically enhanced upon linking to polymyxin
E nonapeptide (PMEN). In this study, we describe a convergent, chemoenzymatic
route for the convenient preparation of such conjugates. Specifically,
we investigated the use of both amide bond formation and azide-alkyne
ligation for connecting an OMP-targeting macrocyclic peptide to a
PMEN building block (obtained by enzymatic degradation of polymyxin
E). The conjugates obtained via both approaches display potent antibacterial
activity against a range of Gram-negative pathogens including multi-drug-resistant
isolates.
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Affiliation(s)
- Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands.,Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, Leiden 2333 BE, The Netherlands
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9
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Wesseling CMJ, Wood TM, Slingerland CJ, Bertheussen K, Lok S, Martin NI. Thrombin-Derived Peptides Potentiate the Activity of Gram-Positive-Specific Antibiotics against Gram-Negative Bacteria. Molecules 2021; 26:molecules26071954. [PMID: 33808488 PMCID: PMC8037310 DOI: 10.3390/molecules26071954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022] Open
Abstract
The continued rise of antibiotic resistance threatens to undermine the utility of the world’s current antibiotic arsenal. This problem is particularly troubling when it comes to Gram-negative pathogens for which there are inherently fewer antibiotics available. To address this challenge, recent attention has been focused on finding compounds capable of disrupting the Gram-negative outer membrane as a means of potentiating otherwise Gram-positive-specific antibiotics. In this regard, agents capable of binding to the lipopolysaccharide (LPS) present in the Gram-negative outer membrane are of particular interest as synergists. Recently, thrombin-derived C-terminal peptides (TCPs) were reported to exhibit unique LPS-binding properties. We here describe investigations establishing the capacity of TCPs to act as synergists with the antibiotics erythromycin, rifampicin, novobiocin, and vancomycin against multiple Gram-negative strains including polymyxin-resistant clinical isolates. We further assessed the structural features most important for the observed synergy and characterized the outer membrane permeabilizing activity of the most potent synergists. Our investigations highlight the potential for such peptides in expanding the therapeutic range of antibiotics typically only used to treat Gram-positive infections.
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Affiliation(s)
- Charlotte M. J. Wesseling
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
| | - Thomas M. Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
| | - Cornelis J. Slingerland
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
| | - Kristine Bertheussen
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
- Bio-Organic Synthesis Group, Leiden Institute of Chemistry, Leiden University, 2333 Leiden, The Netherlands
| | - Samantha Lok
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
| | - Nathaniel I. Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, 2333 Leiden, The Netherlands; (C.M.J.W.); (T.M.W.); (C.J.S.); (K.B.); (S.L.)
- Correspondence:
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10
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Yakovlieva L, Wood TM, Kemmink J, Kotsogianni I, Koller F, Lassak J, Martin NI, Walvoort MTC. A β-hairpin epitope as novel structural requirement for protein arginine rhamnosylation. Chem Sci 2020; 12:1560-1567. [PMID: 34163919 PMCID: PMC8179230 DOI: 10.1039/d0sc05823h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
For canonical asparagine glycosylation, the primary amino acid sequence that directs glycosylation at specific asparagine residues is well-established. Here we reveal that a recently discovered bacterial enzyme EarP, that transfers rhamnose to a specific arginine residue in its acceptor protein EF-P, specifically recognizes a β-hairpin loop. Notably, while the in vitro rhamnosyltransferase activity of EarP is abolished when presented with linear substrate peptide sequences derived from EF-P, the enzyme readily glycosylates the same sequence in a cyclized β-hairpin mimic. Additional studies with other substrate-mimicking cyclic peptides revealed that EarP activity is sensitive to the method used to induce cyclization and in some cases is tolerant to amino acid sequence variation. Using detailed NMR approaches, we established that the active peptide substrates all share some degree of β-hairpin formation, and therefore conclude that the β-hairpin epitope is the major determinant of arginine-rhamnosylation by EarP. Our findings add a novel recognition motif to the existing knowledge on substrate specificity of protein glycosylation, and are expected to guide future identifications of rhamnosylation sites in other protein substrates.
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Affiliation(s)
- Liubov Yakovlieva
- Chemical Biology Group, Stratingh Institute for Chemistry, University of Groningen Groningen The Netherlands
| | - Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Leiden The Netherlands .,Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University Utrecht The Netherlands
| | - Johan Kemmink
- Chemical Biology Group, Stratingh Institute for Chemistry, University of Groningen Groningen The Netherlands
| | - Ioli Kotsogianni
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Leiden The Netherlands
| | - Franziska Koller
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München Planegg/Martinsried Germany
| | - Jürgen Lassak
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München Planegg/Martinsried Germany
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University Leiden The Netherlands
| | - Marthe T C Walvoort
- Chemical Biology Group, Stratingh Institute for Chemistry, University of Groningen Groningen The Netherlands
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Wood TM, Bertheussen K, Martin NI. The contribution of achiral residues in the laspartomycin family of calcium-dependent lipopeptide antibiotics. Org Biomol Chem 2020; 18:514-517. [PMID: 31854417 DOI: 10.1039/c9ob02534k] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The growing threat of antibacterial resistance is a global concern. The so-called calcium-dependent lipopeptide antibiotics (CDAs) have emerged as a promising source of new antibiotic agents that are rich in structural and mechanistic diversity. Over forty unique CDAs have been identified to date and share a number of common features. Recent efforts in our group have provided new mechanistic and structural insights into the laspartomycin family of CDAs. We here describe investigations aimed at probing the role of the three glycine residues found in the laspartomycin peptide macrocycle. In doing so laspartomycin analogues containing the achiral 2-aminoisobutyric acid (AIB) as well as l- or d-alanine in place of glycine were prepared and their antibacterial activities evaluated.
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Affiliation(s)
- Thomas M Wood
- Biological Chemistry Group, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.
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12
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Wood TM, Martin NI. The calcium-dependent lipopeptide antibiotics: structure, mechanism, & medicinal chemistry. Medchemcomm 2019; 10:634-646. [PMID: 31191855 DOI: 10.1039/c9md00126c] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 03/20/2019] [Indexed: 12/19/2022]
Abstract
To push back the growing tide of antibacterial resistance the discovery and development of new antibiotics is a must. In recent years the calcium-dependent lipopeptide antibiotics (CDAs) have emerged as a potential source of new antibacterial agents rich in structural and mechanistic diversity. All CDAs share a common lipidated cyclic peptide motif containing amino acid side chains that specifically chelate calcium. It is only in the calcium bound state that the CDAs achieve their potent antibacterial activities. Interestingly, despite their common structural features, the mechanisms by which different CDAs target bacteria can vary dramatically. This review provides both a historic context for the CDAs while also addressing the state of the art with regards to their discovery, optimization, and antibacterial mechanisms.
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Affiliation(s)
- Thomas M Wood
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands.,Biological Chemistry Group , Institute of Biology Leiden , Leiden University , Sylvius Laboratories , Sylviusweg 72 , 2333 BE Leiden , The Netherlands . ; Tel: +31 (0)6 1878 5274
| | - Nathaniel I Martin
- Biological Chemistry Group , Institute of Biology Leiden , Leiden University , Sylvius Laboratories , Sylviusweg 72 , 2333 BE Leiden , The Netherlands . ; Tel: +31 (0)6 1878 5274
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13
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Kleijn LHJ, Vlieg HC, Wood TM, Sastre Toraño J, Janssen BJC, Martin NI. A High-Resolution Crystal Structure that Reveals Molecular Details of Target Recognition by the Calcium-Dependent Lipopeptide Antibiotic Laspartomycin C. Angew Chem Int Ed Engl 2017; 56:16546-16549. [PMID: 29108098 PMCID: PMC5767759 DOI: 10.1002/anie.201709240] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [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] [Received: 09/06/2017] [Revised: 10/21/2017] [Indexed: 12/15/2022]
Abstract
The calcium‐dependent antibiotics (CDAs) are an important emerging class of antibiotics. The crystal structure of the CDA laspartomycin C in complex with calcium and the ligand geranyl‐phosphate at a resolution of 1.28 Å is reported. This is the first crystal structure of a CDA bound to its bacterial target. The structure is also the first to be reported for an antibiotic that binds the essential bacterial phospholipid undecaprenyl phosphate (C55‐P). These structural insights are of great value in the design of antibiotics capable of exploiting this unique bacterial target.
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Affiliation(s)
- Laurens H J Kleijn
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Hedwich C Vlieg
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Thomas M Wood
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Javier Sastre Toraño
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Bert J C Janssen
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Nathaniel I Martin
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
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Kleijn LHJ, Vlieg HC, Wood TM, Sastre Toraño J, Janssen BJC, Martin NI. A High-Resolution Crystal Structure that Reveals Molecular Details of Target Recognition by the Calcium-Dependent Lipopeptide Antibiotic Laspartomycin C. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Laurens H. J. Kleijn
- Department of Chemical Biology & Drug Discovery; Utrecht Institute for Pharmaceutical Sciences; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Hedwich C. Vlieg
- Crystal and Structural Chemistry; Bijvoet Center for Biomolecular Research; Utrecht University; Padualaan 8 3584 CH Utrecht The Netherlands
| | - Thomas M. Wood
- Department of Chemical Biology & Drug Discovery; Utrecht Institute for Pharmaceutical Sciences; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Javier Sastre Toraño
- Department of Chemical Biology & Drug Discovery; Utrecht Institute for Pharmaceutical Sciences; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Bert J. C. Janssen
- Crystal and Structural Chemistry; Bijvoet Center for Biomolecular Research; Utrecht University; Padualaan 8 3584 CH Utrecht The Netherlands
| | - Nathaniel I. Martin
- Department of Chemical Biology & Drug Discovery; Utrecht Institute for Pharmaceutical Sciences; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
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't Hart P, Wood TM, Tehrani KHME, van Harten RM, Śleszyńska M, Rentero Rebollo I, Hendrickx APA, Willems RJL, Breukink E, Martin NI. De novo identification of lipid II binding lipopeptides with antibacterial activity against vancomycin-resistant bacteria. Chem Sci 2017; 8:7991-7997. [PMID: 29568446 PMCID: PMC5853558 DOI: 10.1039/c7sc03413j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/29/2017] [Indexed: 12/20/2022] Open
Abstract
Lipid II binding lipopeptides discovered via bicyclic peptide phage display exhibit promising antibacterial activity.
Creative strategies for identifying new antibiotics are essential to addressing the looming threat of a post-antibiotic era. We here report the use of a targeted peptide phage display screen as a means of generating novel antimicrobial lipopeptides. Specifically, a library of phage displayed bicyclic peptides was screened against a biomolecular target based on the bacterial cell wall precursor lipid II. In doing so we identified unique lipid II binding peptides that upon lipidation were found to be active against a range of Gram-positive bacteria including clinically relevant strains of vancomycin resistant bacteria. Optimization of the peptide sequence led to variants with enhanced antibacterial activity and reduced hemolytic activity. Biochemical experiments further confirm a lipid II mediated mode of action for these new-to-nature antibacterial lipopeptides.
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Affiliation(s)
- Peter 't Hart
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
| | - Thomas M Wood
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
| | - Kamaleddin Haj Mohammad Ebrahim Tehrani
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
| | - Roel M van Harten
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
| | - Małgorzata Śleszyńska
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
| | - Inmaculada Rentero Rebollo
- Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne , Lausanne , Switzerland
| | - Antoni P A Hendrickx
- Department of Medical Microbiology , University Medical Center , Utrecht , The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology , University Medical Center , Utrecht , The Netherlands
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics Group , Department of Chemistry , Utrecht University , The Netherlands
| | - Nathaniel I Martin
- Department of Chemical Biology & Drug Discovery , Utrecht Institute for Pharmaceutical Sciences , Utrecht University , Universiteitsweg 99 , 3584 CG Utrecht , The Netherlands .
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Koopmans T, Wood TM, 't Hart P, Kleijn LHJ, Hendrickx APA, Willems RJL, Breukink E, Martin NI. Semisynthetic Lipopeptides Derived from Nisin Display Antibacterial Activity and Lipid II Binding on Par with That of the Parent Compound. J Am Chem Soc 2015; 137:9382-9. [PMID: 26122963 DOI: 10.1021/jacs.5b04501] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The lipid II-binding N-terminus of nisin, comprising the so-called A/B ring system, was synthetically modified to provide antibacterially active and proteolytically stable derivatives. A variety of lipids were coupled to the C-terminus of the nisin A/B ring system to generate semisynthetic constructs that display potent inhibition of bacterial growth, with activities approaching that of nisin itself. Most notable was the activity observed against clinically relevant bacterial strains including MRSA and VRE. Experiments with membrane models indicate that these constructs operate via a lipid II-mediated mode of action without causing pore formation. A lipid II-dependent mechanism of action is further supported by antagonization assays wherein the addition of lipid II was found to effectively block the antibacterial activity of the nisin-derived lipopeptides.
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Affiliation(s)
| | | | | | | | - Antoni P A Hendrickx
- ‡Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Rob J L Willems
- ‡Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Eefjan Breukink
- §Membrane Biochemistry and Biophysics Group, Department of Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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Chandel NS, McClintock DS, Feliciano CE, Wood TM, Melendez JA, Rodriguez AM, Schumacker PT. Reactive oxygen species generated at mitochondrial complex III stabilize hypoxia-inducible factor-1alpha during hypoxia: a mechanism of O2 sensing. J Biol Chem 2000; 275:25130-8. [PMID: 10833514 DOI: 10.1074/jbc.m001914200] [Citation(s) in RCA: 1462] [Impact Index Per Article: 60.9] [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: 01/06/2023] Open
Abstract
During hypoxia, hypoxia-inducible factor-1alpha (HIF-1alpha) is required for induction of a variety of genes including erythropoietin and vascular endothelial growth factor. Hypoxia increases mitochondrial reactive oxygen species (ROS) generation at Complex III, which causes accumulation of HIF-1alpha protein responsible for initiating expression of a luciferase reporter construct under the control of a hypoxic response element. This response is lost in cells depleted of mitochondrial DNA (rho(0) cells). Overexpression of catalase abolishes hypoxic response element-luciferase expression during hypoxia. Exogenous H(2)O(2) stabilizes HIF-1alpha protein during normoxia and activates luciferase expression in wild-type and rho(0) cells. Isolated mitochondria increase ROS generation during hypoxia, as does the bacterium Paracoccus denitrificans. These findings reveal that mitochondria-derived ROS are both required and sufficient to initiate HIF-1alpha stabilization during hypoxia.
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Affiliation(s)
- N S Chandel
- Department of Medicine, The University of Chicago, IL 60637, USA
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Wood TM. Issues and future directions in assessing physical activity: an introduction to the conference proceedings. Res Q Exerc Sport 2000; 71 Suppl 2:ii-vii. [PMID: 25680026 DOI: 10.1080/02701367.2000.11082779] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Abstract
The Royal Canadian Mounted Police use the Physical Ability Requirement Evaluation (PARE) for screening applicants. The purposes of this investigation were to identify those field tests of physical fitness that were associated with PARE performance and determine which most accurately classified successful and unsuccessful PARE performers. The participants were 27 female and 21 male volunteers. Testing included measures of aerobic power, anaerobic power, agility, muscular strength, muscular endurance, and body composition. Multiple regression analysis revealed a three-variable model for males (70-lb bench press, standing long jump, and agility) explaining 79% of the variability in PARE time, whereas a one-variable model (agility) explained 43% of the variability for females. Analysis of the classification accuracy of the males' data was prohibited because 91% of the males passed the PARE. Classification accuracy of the females' data, using logistic regression, produced a two-variable model (agility, 1.5-mile endurance run) with 93% overall classification accuracy.
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Affiliation(s)
- H I Stanish
- School of Health and Human Performance, Dalhousie University, Halifax, Nova Scotia, Canada
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Wood TM, McCrae SI. Arabinoxylan-degrading enzyme system of the fungus Aspergillus awamori: purification and properties of an alpha-L-arabinofuranosidase. Appl Microbiol Biotechnol 1996; 45:538-45. [PMID: 8737575 DOI: 10.1007/bf00578468] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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: 02/01/2023]
Abstract
An alpha-L-arabinofuranosidase produced by the fungus Aspergillus awamori had a molecular mass of approximately 64 kDa on sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and was optimally active at pH 4.6 and 50 degrees C. The enzyme, which chromatographed as a single component on SDS-PAGE, appeared to consist of two isoenzymes of pI 3.6 and 3.2. Acting in isolation, the alpha-L-arabinofuranosidase had only a very limited capacity to release L-arabinose (less than 11%) directly from arabinoxylans that had been extracted from a number of plant cell wall preparations using 18% alkali, but a much higher proportion of the L-arabinose (46%) was released from a wheat straw arabinoxylan that had been isolated by steam treatment. There was a marked synergistic effect between the alpha-L-arabinofuranosidase and an endo-(1 --> 4)-beta-D-xylanase produced by A. awamori in both the rate and extent of the release of L-arabinose from both oat straw and wheat straw arabinoxylans, suggesting that L-arabinose-substituted oligosaccharides generated by the endoxylanase action were better substrates for enzyme action. A novel property of the alpha-L-arabinofuranosidase was its capacity to release a substantial proportion (42%) of feruloyl L-arabinose from intact wheat straw arabinoxylan. The concerted action of the alpha-L-arabinofuranosidase and endoxylanase released 71% of the feruloyl L-arabinose and 69% of the p-coumaroyl L-arabinose substituents from wheat straw arabinoxylan.
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Castanares A, Hay AJ, Gordon AH, McCrae SI, Wood TM. D-xylan-degrading enzyme system from the fungus Phanerochaete chrysosporium: isolation and partial characterisation of an alpha-(4-O-methyl)-D-glucuronidase. J Biotechnol 1995; 43:183-94. [PMID: 8590644 DOI: 10.1016/0168-1656(95)00128-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [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: 01/31/2023]
Abstract
A number of fungi were screened for their capacities to produce extracellular alpha-(4-O-methyl)-D-glucuronidase. Of those tested, Phanerochaete chrysosporium ATCC 24725 produced the enzyme in greatest yield. The single alpha-(4-O-methyl)-D-glucuronidase produced by this fungus was purified by a series of chromatographic methods involving anion exchange, hydrophobic interaction and chromatofocusing. Isolated in this way, the enzyme had an apparent molecular mass of 112 kDa in sodium dodecyl sulphate polyacrylamide gels, and a pI of 4.6 when determined by isoelectric focusing in polyacrylamide gels. The enzyme was optimally active at pH 3.5, but showed significant activity over the pH range 3-5. In the absence of substrate the enzyme was inactivated at pH 3.5 in 2 h at 50 degree C: at pH 5.0 it retained 42% of its activity for 24 h at this temperature. The enzyme showed little activity on glucuronoxylan polysaccharides, but some short-chain xylo-oligosaccharides which were substituted with alpha-linked 4-O-methyl-D-glucopyranosyl uronic acid attached to the 2-position of the non-reducing D-xylopyranosyl residue were readily hydrolysed. There were marked synergistic effects apparent in the release of 4-O-methyl-D-glucopyranosyl uronic acid from various glucuronoxylans when the alpha-(4-O-methyl)-D-glucuronidase was acting in concert with endo-(1-->4)-beta-D-xylanase, and with beta-D-xylosidase and/or an alpha-L-arabinofuranosidase.
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Affiliation(s)
- A Castanares
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Wood TM, Wilson CA, McCrae SI. The cellulase system of the anaerobic rumen fungus Neocallimastix frontalis: studies on the properties of fractions rich in endo-(1-->4)-beta-D-glucanase activity. Appl Microbiol Biotechnol 1995; 44:177-84. [PMID: 8579830 DOI: 10.1007/bf00164499] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 01/31/2023]
Abstract
Seven fractions rich in endoglucanase activity were separated from the extracellular cellulase system of the anaerobic rumen fungus Neocallimastix frontalis. The fractions (ES1, ES3, ES2U1, ES2U2, ES2U4, ES2U3C1 and ES2U3C2) were separated from each other and from a fraction that could solubilize crystalline cellulose (the so-called crystalline-cellulose-solubilizing component, CCSC) by the sequential use of differential adsorption on the microcrystalline cellulose Avicel, gel filtration and affinity chromatography on concanavalin-A-Sepharose. The molecular masses of the endoglucanase fractions, when determined by gel filtration, were 64, 30, 61, 113, 17, 38 and 93 kDa respectively. Each enzyme degraded carboxymethylcellulose and was rich in activity to cellulose swollen in phosphoric acid to break the hydrogen bonding: cellobiose, cellotriose and cellotetraose were released in differing proportions. Each fraction showed a characteristic gradient when the capacity of each enzyme to increase the fluidity of a solution of carboxymethylcellulose was plotted against the increase in reducing power of the solution. Although neither endoglucanase fraction, acting in isolation, could degrade crystalline cellulose, three of the fractions (ES1, ES3 and ES2U1) could act synergistically with the CCSC fraction in this regard. Remarkably, the same three fractions also acted in synergism with the cellobiohydrolases (CBH I and CBH II) of the aerobic fungus Penicillium pinophilum in degrading crystalline cellulose, but only when both cellobiohydrolase enzymes were present in the solution along with any one of the three endoglucanases. These observations support the conclusion that the mechanism of action of the cellulase system of N. frontalis in degrading crystalline cellulose may be similar to that operating in the aerobic fungi.
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Wood TM, Wilson CA. Alpha-(4-O-methyl)-D-glucuronidase activity produced by the rumen anaerobic fungus Piromonas communis: a study of selected properties. Appl Microbiol Biotechnol 1995; 43:893-900. [PMID: 7576556 DOI: 10.1007/bf02431925] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [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: 01/26/2023]
Abstract
The rumen anaerobic fungus Piromonas communis, unlike the rumen anaerobic fungi Neocallimastix frontalis and Neocallimastix patriciarum, produced extracellular alpha-(4-O-methyl)-D-glucuronidase when grown in cultures containing filter-paper, barley straw, birchwood xylan or birchwood sawdust as carbon source. The highest concentration of enzyme was produced in cultures containing birchwood sawdust. The aldobiouronic acid O-alpha-(4-O-methyl-D-glucopyranosyluronic acid)-(1-->2)-D-xylopyranose (MeGlcAXyl) was the best substrate of those tested: the aldotriouronic acid O-alpha-(4-O-methyl-D-glucopyranosyluronic acid (1-->2)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (MeGlcAXyl2) and the aldotetraouronic acid O-alpha-(4-O-methyl-D-glucopyranosyluronic acid)-(1-->2)-O-beta-D- xylopyranosyl-(1-->4)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (MeGlcAXyl3) were also attacked but the rate fell as the degree of polymerisation increased. When the same substituted xylo-oligosaccharides were reduced to the corresponding alditols the enzyme activity disappeared. Similarly, p-nitrophenyl-alpha-D-glucuronide was not a substrate. Remarkably, the relative rates of attack shown by the alpha-(4-O-methyl)-D-glucuronidase on the aldouronic acids and on xylans extracted from birchwood, oat spelts and oat straw differed according to the carbon source used to produce the enzyme. The alpha-(4-O-methyl)-D-glucuronidase had a pH optimum of 5.5 and a temperature optimum of 50 degrees C. On gel filtration the enzyme was shown to be associated with proteins covering the range 100-300 kDa, but a major peak of activity in the column effluent appeared to have a molecular mass of 103 kDa.
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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25
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Wood TM, Wilson CA. Studies on the capacity of the cellulase of the anaerobic rumen fungus Piromonas communis P to degrade hydrogen bond-ordered cellulose. Appl Microbiol Biotechnol 1995; 43:572-8. [PMID: 7632404 DOI: 10.1007/bf00218468] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [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: 01/26/2023]
Abstract
The anaerobic rumen fungus Piromonas communis, when cultured on cotton fibre as the carbon source, produces an extracellular cellulase that is capable of solubilizing "crystalline" hydrogen-bond-ordered cellulose, in the form of the cotton fibre, at a rate that is greater than that of any other cellulases reported in the literature hitherto. The cell-free culture fluid is also very rich in xylan-degrading enzymes. The activity towards crystalline cellulose resides in a high-molecular-mass (approximately 700-1000 kDa) component (so-called crystalline-cellulose-solubilizing component, CCSC) that comprises endo (1-->4)-beta-D-glucanase (carboxymethylcellulase), beta-D-glucosidase and another enzyme that appears to be important for the breakdown of hydrogen-bond-ordered cellulose. The CCSC is associated with only a small amount of the endo(1-->4)-beta-D-glucanase (1.9%), beta-D-glucosidase (0.7%) and protein (0.5%) found in the crude cell-free cellulase preparation. The CCSC, unlike the bulk of the endo(1-->4)-beta-D-glucanase and beta-D-glucosidase, is very strongly absorbed on the microcrystalline cellulose, Avicel.
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Wilson CA, McCrae SI, Wood TM. Characterisation of a β-d-glucosidase from the anaerobic rumen fungus Neocallimastix frontalis with particular reference to attack on cello-oligosaccharides. J Biotechnol 1994. [DOI: 10.1016/0168-1656(94)90129-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Beattie L, Mahalingeswara Bhat K, Wood TM. The effect of cations on reassociation of the components of the cellulosome cellulase complex synthesized by the bacterium Clostridium thermocellum. Appl Microbiol Biotechnol 1994. [DOI: 10.1007/bf00173338] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Garcia-Campayo V, McCrae SI, Zhang JX, Flint HJ, Wood TM. Mode of action, kinetic properties and physicochemical characterization of two different domains of a bifunctional (1-->4)-beta-D-xylanase from Ruminococcus flavefaciens expressed separately in Escherichia coli. Biochem J 1993; 296 ( Pt 1):235-43. [PMID: 8250849 PMCID: PMC1137679 DOI: 10.1042/bj2960235] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [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: 01/29/2023]
Abstract
Two catalytic domains, A and C, of xylanase A (XYLA) from Ruminococcus flavefaciens were expressed separately as truncated gene products from lacZ fusions in Escherichia coli. The fusion products, referred to respectively as XYLA-A1 and XYLA-C2, were purified to homogeneity by anion-exchange chromatography and chromatofocusing. XYLA-A1 was isoelectric at pH 5.0 and had a molecular mass of 30 kDa, whereas XYLA-C2 had a pI of 5.4 and a molecular mass of 44 kDa. The catalytic activity shown by both domains was optimal at 50 degrees C, but XYLA-A1 was more sensitive than XYLA-C2 to temperatures higher than the optimum. XYLA-A1 showed a higher sensitivity to pH than XYLA-C2. The enzyme activity of both domains was completely inactivated in the presence of copper or silver ions and partially inactivated by iron or zinc ions. Neither domain was active on xylo-oligosaccharides shorter than xylopentaose: the rate of degradation of longer xylo-oligosaccharides (degree of polymerization 5-10) increased as the chain length increased. Analysis of the products of hydrolysis of xylo-oligosaccharides and xylan (arabinoxylan) polysaccharide showed that the two domains differed in their modes of action: xylobiose was the shortest product of the hydrolysis. With oat spelt xylan as substrate, XYLA-A1 activity was apparently restricted to regions where xylopyranosyl residues did not carry arabinofuranosyl substituents, whereas XYLA-C2 was able to release hetero-oligosaccharides carrying arabinofuranosyl residues. Neither domain was able to release arabinose from oat spelt xylan.
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Ferreira LM, Wood TM, Williamson G, Faulds C, Hazlewood GP, Black GW, Gilbert HJ. A modular esterase from Pseudomonas fluorescens subsp. cellulosa contains a non-catalytic cellulose-binding domain. Biochem J 1993; 294 ( Pt 2):349-55. [PMID: 8373350 PMCID: PMC1134461 DOI: 10.1042/bj2940349] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.8] [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: 01/30/2023]
Abstract
The 5' regions of genes xynB and xynC, coding for a xylanase and arabinofuranosidase respectively, are identical and are reiterated four times within the Pseudomonas fluorescens subsp. cellulosa genome. To isolate further copies of the reiterated xynB/C 5' region, a genomic library of Ps. fluorescens subsp. cellulosa DNA was screened with a probe constructed from the conserved region of xynB. DNA from one phage which hybridized to the probe, but not to sequences upstream or downstream of the reiterated xynB/C locus, was subcloned into pMTL22p to construct pFG1. The recombinant plasmid expressed a protein in Escherichia coli, designated esterase XYLD, of M(r) 58,500 which bound to cellulose but not to xylan. XYLD hydrolysed aryl esters, released acetate groups from acetylxylan and liberated 4-hydroxy-3-methoxycinnamic acid from destarched wheat bran. The nucleotide sequence of the XYLD-encoding gene, xynD, revealed an open reading frame of 1752 bp which directed the synthesis of a protein of M(r) 60,589. The 5' 817 bp of xynD and the amino acid sequence between residues 37 and 311 of XYLD were almost identical with the corresponding regions of xynB and xynC and their encoded proteins XYLB and XYLC. Truncated derivatives of XYLD lacking the N-terminal conserved sequence retained the capacity to hydrolyse ester linkages, but did not bind cellulose. Expression of truncated derivatives of xynD, comprising the 5' 817 bp sequence, encoded a non-catalytic polypeptide that bound cellulose. These data indicate that XYLD has a modular structure comprising of a N-terminal cellulose-binding domain and a C-terminal catalytic domain.
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Affiliation(s)
- L M Ferreira
- Department of Biological and Nutritional Sciences, University of Newcastle upon Tyne, U.K
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Abstract
A beta-D-xylosidase from the anaerobic rumen fungus Neocallimastix frontalis was purified by anion-exchange and gel filtration chromatography. The enzyme was isoelectrically homogeneous and had an isoelectric point of pH 4.6. The apparent molecular mass calculated by gel filtration was 150,000 Da. Under denaturing conditions, the enzyme appeared as a dimer composed of two polypeptides with molecular masses of 83,000 and 53,000 Da. The pH and temperature optimum were 6.4 and 37 degrees C, respectively: the activity was very sensitive to temperature. The enzyme was inhibited by copper, silver and zinc ions, EDTA and SDS, and was stimulated by calcium and magnesium ions. It was competitively inhibited by D-xylose with an apparent Ki of 3.98 mM. The beta-D-xylosidase exhibited hydrolytic activity on xylobiose and xylo-oligosaccharides of dp up to 7: the specific activities and maximum velocities decreased as the chain length increased. Analysis of the products of hydrolysis by HPLC indicated a typical exo-action. A mixture of beta-D-xylosidase and a xylanase acted synergistically in producing high reducing sugar values, using a xylan from oat spelts.
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Castanares A, Wood TM. Purification and characterization of a feruloyl/p-coumaroyl esterase from solid-state cultures of the aerobic fungus Penicillium pinophilum. Biochem Soc Trans 1992; 20:275S. [PMID: 1426561 DOI: 10.1042/bst020275s] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- A Castanares
- Rowett Research Institute, Bucksburn, Aberdeen, U.K
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Garcia-Campayo V, Wood TM. Hydrolysis of xylo-oligosaccharides by a beta-xylosidase from the rumen anaerobic fungus Neocallimastix frontalis. Biochem Soc Trans 1992; 20:274S. [PMID: 1426560 DOI: 10.1042/bst020274s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Wilson CA, Wood TM. Studies on the cellulase of the rumen anaerobic fungus Neocallimastix frontalis, with special reference to the capacity of the enzyme to degrade crystalline cellulose. Enzyme Microb Technol 1992. [DOI: 10.1016/0141-0229(92)90148-h] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Mahalingeswara Bhat K, Wood TM. The cellulase of the anaerobic bacterium Clostridium thermocellum: Isolation, dissociation, and reassociation of the cellulosome. Carbohydr Res 1992. [DOI: 10.1016/0008-6215(92)85079-f] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, U.K
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Smith DC, Wood TM. Xylanase production byAspergillus awamori. Development of a medium and optimization of the fermentation parameters for the production of extracellular xylanase and ?-xylosidase while maintaining low protease production. Biotechnol Bioeng 1991; 38:883-90. [DOI: 10.1002/bit.260380810] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bhat KM, Hay AJ, Wood TM, Claeyssens M. Comparison of the mode of action and site specificity of endo-(1,4)-beta-D-glucanases of Penicillium pinophilum using normal, 1-3H-labelled, reduced and chromogenic cello-oligosaccharides. Biochem Soc Trans 1990; 18:638-9. [PMID: 2276486 DOI: 10.1042/bst0180638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- K M Bhat
- Rowett Research Institute, Bucksburn, Aberdeen, U.K
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Bhat KM, Hay AJ, Claeyssens M, Wood TM. Study of the mode of action and site-specificity of the endo-(1----4)-beta-D-glucanases of the fungus Penicillium pinophilum with normal, 1-3H-labelled, reduced and chromogenic cello-oligosaccharides. Biochem J 1990; 266:371-8. [PMID: 2317193 PMCID: PMC1131141 DOI: 10.1042/bj2660371] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [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: 12/31/2022]
Abstract
The modes of action of the five major endo-(1----4)-beta-D-glucanases (I, II, III, IV and V) purified from Penicillium pinophilum cellulase were compared by h.p.l.c. analysis, with normal, 1-3H-labelled and reduced cello-oligosaccharides and 4-methylumbelliferyl glycosides as substrates. Significant differences were observed in the preferred site of cleavage even when substrates with the same number of glycosidic bonds were compared. Thus, although endoglucanase I was unable to attack normal cello-oligosaccharides shorter than degree of polymerization 6, it hydrolysed reduced cellopentaose to yield cellotriose and cellobi-itol, and it produced cellotriose and 4-methylumbelliferyl glucoside from 4-methylumbelliferyl cellotetraoside. Endoglucanase IV hydrolysed [1-3H]cellotriose but did not attack either cellotri-itol or 4-methylumbelliferyl cellobioside. These and other anomalous results indicated clearly that modification of the reducing glycosyl residue on the cello-oligosaccharides induces in an apparent change in the mode of action of the endoglucanases. It is suggested that, although cello-oligosaccharide derivatives are useful for differentiating and classifying endoglucanases, conclusions on the mechanism of cellulase action resulting from these measurements should be treated cautiously. Unequivocal information on the mode of endoglucanase action on cello-oligosaccharides was obtained with radiolabelled cello-oligosaccharides of degree of polymerization 3 to 5. Indications that transglycosylation was a property of the endoglucanases were particularly evident with the 4-methylumbelliferyl cello-oligosaccharides. Turnover numbers for hydrolysis of the umbelliferyl cello-oligosaccharides were calculated, and these, along with the other analytical data collected on the products of hydrolysis of the normal, reduced and radiolabelled cello-oligosaccharides, suggested that the various endoglucanases had different roles to play in the overall hydrolysis of cellulose to sugars small enough to be transported through the cell membrane.
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Affiliation(s)
- K M Bhat
- Rowett Research Institute, Bucksburn, Aberdeen, U.K
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Brooks DA, Williams RN, Dean RS, Wood TM, Krug D. The predictive validity of a neuropsychological screening measure. Int J Neurosci 1990; 51:83-8. [PMID: 2265912 DOI: 10.3109/00207459009000512] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This study examined the efficacy of a neuropsychological screening measure in discriminating between neurologically impaired and nonimpaired subjects. It also examined the ability of this screening measure correctly to classify impaired subjects according to right and left hemisphere involvement. The results showed that some 96% of subjects could be correctly classified as impaired or nonimpaired. The measure was also found correctly to identify the hemisphere involved in 95% of the impaired cases. The value and limitations of neuropsychological screening instruments was discussed in terms of portability and ease of administration.
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Affiliation(s)
- D A Brooks
- Learning Services Corporation-Bear Creek, Lakewood, Colorado
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Chauvaux S, Beguin P, Aubert JP, Bhat KM, Gow LA, Wood TM, Bairoch A. Calcium-binding affinity and calcium-enhanced activity of Clostridium thermocellum endoglucanase D. Biochem J 1990; 265:261-5. [PMID: 2302168 PMCID: PMC1136638 DOI: 10.1042/bj2650261] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.5] [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: 12/31/2022]
Abstract
Clostridium thermocellum endoglucanase D (EC 3.2.1.4: EGD), which is encoded by the celD gene, was found to bind Ca2+ with an association constant of 2.03 x 10(6) M-1. Ca2+ stimulated the activity of EGD towards swollen Avicel by 2-fold. In the presence of Ca2+, the Kd of the enzyme towards p-nitrophenyl-beta-D-cellobioside and carboxymethylcellulose was decreased by 4-fold. Furthermore, Ca2+ increased the half-life of the enzyme at 75 degrees C from 13 to 47 min. Since the 3' sequence of celD encodes a duplicated region sharing similarities with the Ca2+-binding site of several Ca2+-binding proteins, a deleted clone was constructed and used to purify a truncated form of the enzyme which no longer contained the duplicated region. The truncated enzyme was very similar to EGD expressed from the intact gene with respect to activity, Ca2(+)-binding kinetics and Ca2+ effects on substrate binding and thermostability. Thus the latter parameters do not appear to be mediated through the duplicated conserved region.
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Affiliation(s)
- S Chauvaux
- Unité de Physiologie Cellulaire and URA 1300 CNRS, Départment des Biotechnologies, Institut Pasteur, Paris, France
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Claeyssens M, Van Tilbeurgh H, Tomme P, Wood TM, McRae SI. Fungal cellulase systems. Comparison of the specificities of the cellobiohydrolases isolated from Penicillium pinophilum and Trichoderma reesei. Biochem J 1989; 261:819-25. [PMID: 2803246 PMCID: PMC1138904 DOI: 10.1042/bj2610819] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [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: 01/02/2023]
Abstract
Reaction patterns for the hydrolysis of chromophoric glycosides from cello-oligosaccharides and lactose by the cellobiohydrolases (CBH I and CBH II) purified from Trichoderma reesei and Penicillium pinophilum were determined. They coincide with those found for the parent unsubstituted sugars. CBH I enzyme from both organisms attacks these substrates in a random manner. Turnover numbers are, however, low and do not increase appreciably as a function of the degree of polymerization of the substrates. The active-site topology of the CBH I from T. reesei was further probed by equilibrium binding experiments with cellobiose, cellotriose, lactose and some of their derivatives. These point to a single interaction site (ABC), spatially restricted as deduced from the apparent independency of the thermodynamic parameters. It appears that the putative subsite A can accommodate a galactopyranosyl or glucopyranosyl group, and subsite B a glucopyranosyl group, whereas in subsite C either a glucopyranosyl or a chromophoric group can be bound, scission occurring between subsites B and C. The apparent kinetic parameters (turnover numbers) for the hydrolysis of cello-oligosaccharides (and their derivatives) by the CBH II type enzyme increase as a function of chain length, indicative of an extended binding site (A-F). Its architecture allows for specific binding of beta-(1----4)-glucopyranosyl groups in subsites A, B and C. Binding of a chromophore in subsite C produces a non-hydrolysable complex. The thermodynamic interaction parameters of some ligands common to both type of enzyme were compared: these substantiate the conclusions reached above.
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Affiliation(s)
- M Claeyssens
- Laboratorium voor Bichemie, Rijksuniversiteit Gent, Belgium
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Bhat K, McCrae SI, Wood TM. The endo-(1→4)-β-d-glucanase system of Penicillium pinophilum cellulase: Isolation, purification, and characterization of five major endoglucanase components. Carbohydr Res 1989. [DOI: 10.1016/0008-6215(89)84131-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wood TM, McCrae SI, Bhat KM. The mechanism of fungal cellulase action. Synergism between enzyme components of Penicillium pinophilum cellulase in solubilizing hydrogen bond-ordered cellulose. Biochem J 1989; 260:37-43. [PMID: 2549957 PMCID: PMC1138622 DOI: 10.1042/bj2600037] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.5] [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: 01/01/2023]
Abstract
Studies on reconstituted mixtures of extensively purified cellobiohydrolases I and II and the five major endoglucanases of the fungus Penicillium pinophilum have provided some new information on the mechanism by which crystalline cellulose in the form of the cotton fibre is rendered soluble. It was observed that there was little or no synergistic activity either between purified cellobiohydrolases I and II, or, contrary to previous findings, between the individual cellobiohydrolases and the endoglucanases. Cotton fibre was degraded to a significant degree only when three enzymes were present in the reconstituted enzyme mixture: these were cellobiohydrolases I and II and some specific endoglucanases. The optimum ratio of the cellobiohydrolases was 1:1. Only a trace of endoglucanase activity was required to make the mixture of cellobiohydrolases I and II effective. The addition of cellobiohydrolases I and II individually to endoglucanases from other cellulolytic fungi resulted in little synergistic activity; however, a mixture of endoglucanases and both cellobiohydrolases was effective. It is suggested that current concepts of the mechanism of cellulase action may be the result of incompletely resolved complexes between cellobiohydrolase and endoglucanase activities. It was found that such complexes in filtrates of P. pinophilium or Trichoderma reesei were easily resolved using affinity chromatography on a column of p-aminobenzyl-1-thio-beta-D-cellobioside.
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Affiliation(s)
- T M Wood
- Rowett Research Institute, Bucksburn, Aberdeen, Scotland, U.K
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Bhat KM, Wood TM. Multiple forms of endo-1,4-?-D-glucanase in the extracellular cellulase ofPenicillium pinophilum. Biotechnol Bioeng 1989; 33:1242-8. [DOI: 10.1002/bit.260331004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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McCrae SI, Falconer DJ, Wood TM. Hydrolysis of the polysaccharides of straw by enzymes produced by a mutant strain of the fungusPenicillium pinophilum. Biotechnol Bioeng 1989; 33:422-7. [DOI: 10.1002/bit.260330407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gow LA, Wood TM. Breakdown of crystalline cellulose by synergistic action between cellulase components fromClostridium thermocellumandTrichoderma koningii. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb02946.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Brown J, Collin SA, Wood TM. Development of a medium for high cellulase, xylanase and β-glucosidase production by a mutant strain (NTG III/6) of the cellulolytic fungus Penicillium pinophilum. Enzyme Microb Technol 1987. [DOI: 10.1016/0141-0229(87)90059-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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