101
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Wan SJ, Sullivan AB, Shieh P, Metruccio MME, Evans DJ, Bertozzi CR, Fleiszig SMJ. IL-1R and MyD88 Contribute to the Absence of a Bacterial Microbiome on the Healthy Murine Cornea. Front Microbiol 2018; 9:1117. [PMID: 29896179 PMCID: PMC5986933 DOI: 10.3389/fmicb.2018.01117] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 05/11/2018] [Indexed: 01/09/2023] Open
Abstract
Microbial communities are important for the health of mucosal tissues. Traditional culture and gene sequencing have demonstrated bacterial populations on the conjunctiva. However, it remains unclear if the cornea, a transparent tissue critical for vision, also hosts a microbiome. Corneas of wild-type, IL-1R (-/-) and MyD88 (-/-) C57BL/6 mice were imaged after labeling with alkyne-functionalized D-alanine (alkDala), a probe that only incorporates into the peptidoglycan of metabolically active bacteria. Fluorescence in situ hybridization (FISH) was also used to detect viable bacteria. AlkDala labeling was rarely observed on healthy corneas. In contrast, adjacent conjunctivae harbored filamentous alkDala-positive forms, that also labeled with DMN-Tre, a Corynebacterineae-specific probe. FISH confirmed the absence of viable bacteria on healthy corneas, which also cleared deliberately inoculated bacteria within 24 h. Differing from wild-type, both IL-1R (-/-) and MyD88 (-/-) corneas harbored numerous alkDala-labeled bacteria, a result abrogated by topical antibiotics. IL-1R (-/-) corneas were impermeable to fluorescein suggesting that bacterial colonization did not reflect decreased epithelial integrity. Thus, in contrast to the conjunctiva and other mucosal surfaces, healthy murine corneas host very few viable bacteria, and this constitutive state requires the IL-1R and MyD88. While this study cannot exclude the presence of fungi, viruses, or non-viable or dormant bacteria, the data suggest that healthy murine corneas do not host a resident viable bacterial community, or microbiome, the absence of which could have important implications for understanding the homeostasis of this tissue.
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Affiliation(s)
- Stephanie J Wan
- Vision Science Program, University of California, Berkeley, Berkeley, CA, United States
| | - Aaron B Sullivan
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - Peyton Shieh
- College of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Matteo M E Metruccio
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - David J Evans
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- College of Pharmacy, Touro University California, Vallejo, CA, United States
| | - Carolyn R Bertozzi
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- Graduate Groups in Vision Sciences, Microbiology, and Infectious Diseases & Immunity, University of California, Berkeley, Berkeley, CA, United States
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102
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Bakkum T, van Leeuwen T, Sarris AJC, van Elsland DM, Poulcharidis D, Overkleeft HS, van Kasteren SI. Quantification of Bioorthogonal Stability in Immune Phagocytes Using Flow Cytometry Reveals Rapid Degradation of Strained Alkynes. ACS Chem Biol 2018; 13:1173-1179. [PMID: 29693370 PMCID: PMC5962927 DOI: 10.1021/acschembio.8b00355] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
One of the areas
in which bioorthogonal chemistry—chemistry
performed inside a cell or organism—has become of pivotal importance
is in the study of host–pathogen interactions. The incorporation
of bioorthogonal groups into the cell wall or proteome of intracellular
pathogens has allowed study within the endolysosomal system. However,
for the approach to be successful, the incorporated bioorthogonal
groups must be stable to chemical conditions found within these organelles,
which are some of the harshest found in metazoans: the groups are
exposed to oxidizing species, acidic conditions, and reactive thiols.
Here we present an assay that allows the assessment of the stability
of bioorthogonal groups within host cell phagosomes. Using a flow
cytometry-based assay, we have quantified the relative label stability
inside dendritic cell phagosomes of strained and unstrained alkynes.
We show that groups that were shown to be stable in other systems
were degraded by as much as 79% after maturation of the phagosome.
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Affiliation(s)
- Thomas Bakkum
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Tyrza van Leeuwen
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Alexi J. C. Sarris
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Daphne M. van Elsland
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Dimitrios Poulcharidis
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Herman S. Overkleeft
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Sander I. van Kasteren
- Leiden Institute of Chemistry and The Institute for Chemical Immunology, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
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103
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Feigman MJS, Pires MM. Synthetic Immunobiotics: A Future Success Story in Small Molecule-Based Immunotherapy? ACS Infect Dis 2018; 4:664-672. [PMID: 29431421 DOI: 10.1021/acsinfecdis.7b00261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Drug resistance to our current stock of antibiotics is projected to increase to levels that threaten our ability to reduce and eliminate bacterial infections, which is now considered one of the primary health care crises of the 21st century. Traditional antibiotic agents (e.g., penicillin) paved the way for massive advances in human health, but we need novel strategies to maintain the upper hand in the battle against pathogenic bacteria. Nontraditional strategies, such as targeted immunotherapies, could prove fruitful in complementing our antibiotic arsenal.
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Affiliation(s)
- Mary J. Sabulski Feigman
- Department of Chemistry, Lehigh University, 6 E. Packer Ave., Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, Lehigh University, 6 E. Packer Ave., Bethlehem, Pennsylvania 18015, United States
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104
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Rodriguez-Rivera FP, Zhou X, Theriot JA, Bertozzi CR. Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front-Line Tuberculosis Drugs. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Frances P. Rodriguez-Rivera
- Department of Chemistry; University of California; Berkeley CA 94720 USA
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Xiaoxue Zhou
- Department of Biochemistry; Stanford University School of Medicine; Stanford CA 94305 USA
| | - Julie A. Theriot
- Department of Biochemistry; Stanford University School of Medicine; Stanford CA 94305 USA
- Department of Microbiology and Immunology; Stanford University School of Medicine; Stanford CA 94305 USA
- Howard Hughes Medical Institute; Stanford University; Stanford CA 94305 USA
| | - Carolyn R. Bertozzi
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
- Howard Hughes Medical Institute; Stanford University; Stanford CA 94305 USA
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105
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Rodriguez-Rivera FP, Zhou X, Theriot JA, Bertozzi CR. Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front-Line Tuberculosis Drugs. Angew Chem Int Ed Engl 2018; 57:5267-5272. [PMID: 29392891 DOI: 10.1002/anie.201712020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/28/2018] [Indexed: 02/06/2023]
Abstract
Front-line tuberculosis (TB) drugs have been characterized extensively in vitro and in vivo with respect to gene expression and cell viability. However, little work has been devoted to understanding their effects on the physiology of the cell envelope, one of the main targets of this clinical regimen. Herein, we use metabolic labeling methods to visualize the effects of TB drugs on cell envelope dynamics in mycobacterial species. We developed a new fluorophore-trehalose conjugate to visualize trehalose monomycolates of the mycomembrane using super-resolution microscopy. We also probed the relationship between mycomembrane and peptidoglycan dynamics using a dual metabolic labeling strategy. Finally, we found that metabolic labeling of both cell envelope structures reports on drug effects on cell physiology in two hours, far faster than a genetic sensor of cell envelope stress. Our work provides insight into acute drug effects on cell envelope biogenesis in live mycobacteria.
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Affiliation(s)
- Frances P Rodriguez-Rivera
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.,Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Xiaoxue Zhou
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Julie A Theriot
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA
| | - Carolyn R Bertozzi
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA
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106
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Kolbe K, Veleti SK, Johnson EE, Cho YW, Oh S, Barry CE. Role of Chemical Biology in Tuberculosis Drug Discovery and Diagnosis. ACS Infect Dis 2018; 4:458-466. [PMID: 29364647 DOI: 10.1021/acsinfecdis.7b00242] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The use of chemical techniques to study biological systems (often referred to currently as chemical biology) has become a powerful tool for both drug discovery and the development of novel diagnostic strategies. In tuberculosis, such tools have been applied to identifying drug targets from hit compounds, matching high-throughput screening hits against large numbers of isolated protein targets and identifying classes of enzymes with important functions. Metabolites unique to mycobacteria have provided important starting points for the development of innovative tools. For example, the unique biology of trehalose has provided both novel diagnostic strategies as well as probes of in vivo biological processes that are difficult to study any other way. Other mycobacterial metabolites are potentially valuable starting points and have the potential to illuminate new aspects of mycobacterial pathogenesis.
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Affiliation(s)
- Katharina Kolbe
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
| | - Sri Kumar Veleti
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
| | - Emma E. Johnson
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
| | - Young-Woo Cho
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
| | - Sangmi Oh
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland 20892, United States
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107
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Di Guilmi AM, Bonnet J, Peiβert S, Durmort C, Gallet B, Vernet T, Gisch N, Wong YS. Specific and spatial labeling of choline-containing teichoic acids in Streptococcus pneumoniae by click chemistry. Chem Commun (Camb) 2018; 53:10572-10575. [PMID: 28894874 DOI: 10.1039/c7cc05646j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Propargyl-choline was efficiently incorporated into teichoic acid (TA) polymers on the surface of Streptococcus pneumoniae. The introduction of a fluorophore by click chemistry enabled sufficient labeling of the pneumococcus, as well as its specific detection when mixed with other bacterial species. The labeling is localized at the septal site, suggesting a similar location of the TA and peptidoglycan (PG) synthetic machineries. This method is a unique opportunity to improve our understanding of the spatial location of pneumococcal TA biosynthesis.
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Affiliation(s)
- A M Di Guilmi
- Univ. Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
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108
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Abstract
Peptidoglycan is an essential component of the cell wall that protects bacteria from environmental stress. A carefully coordinated biosynthesis of peptidoglycan during cell elongation and division is required for cell viability. This biosynthesis involves sophisticated enzyme machineries that dynamically synthesize, remodel, and degrade peptidoglycan. However, when and where bacteria build peptidoglycan, and how this is coordinated with cell growth, have been long-standing questions in the field. The improvement of microscopy techniques has provided powerful approaches to study peptidoglycan biosynthesis with high spatiotemporal resolution. Recent development of molecular probes further accelerated the growth of the field, which has advanced our knowledge of peptidoglycan biosynthesis dynamics and mechanisms. Here, we review the technologies for imaging the bacterial cell wall and its biosynthesis activity. We focus on the applications of fluorescent d-amino acids, a newly developed type of probe, to visualize and study peptidoglycan synthesis and dynamics, and we provide direction for prospective research.
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Affiliation(s)
- Atanas D Radkov
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.,Current affiliation: Biophysics and Biochemistry Department, University of California, San Francisco, California 94158, USA;
| | - Yen-Pang Hsu
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
| | - Garrett Booher
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
| | - Michael S VanNieuwenhze
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA; , ,
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109
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Puffal J, García-Heredia A, Rahlwes KC, Siegrist MS, Morita YS. Spatial control of cell envelope biosynthesis in mycobacteria. Pathog Dis 2018; 76:4953754. [DOI: 10.1093/femspd/fty027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/25/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Julia Puffal
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alam García-Heredia
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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110
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Logsdon MM, Aldridge BB. Stable Regulation of Cell Cycle Events in Mycobacteria: Insights From Inherently Heterogeneous Bacterial Populations. Front Microbiol 2018; 9:514. [PMID: 29619019 PMCID: PMC5871693 DOI: 10.3389/fmicb.2018.00514] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/06/2018] [Indexed: 11/24/2022] Open
Abstract
Model bacteria, such as E. coli and B. subtilis, tightly regulate cell cycle progression to achieve consistent cell size distributions and replication dynamics. Many of the hallmark features of these model bacteria, including lateral cell wall elongation and symmetric growth and division, do not occur in mycobacteria. Instead, mycobacterial growth is characterized by asymmetric polar growth and division. This innate asymmetry creates unequal birth sizes and growth rates for daughter cells with each division, generating a phenotypically heterogeneous population. Although the asymmetric growth patterns of mycobacteria lead to a larger variation in birth size than typically seen in model bacterial populations, the cell size distribution is stable over time. Here, we review the cellular mechanisms of growth, division, and cell cycle progression in mycobacteria in the face of asymmetry and inherent heterogeneity. These processes coalesce to control cell size. Although Mycobacterium smegmatis and Mycobacterium bovis Bacillus Calmette-Guérin (BCG) utilize a novel model of cell size control, they are similar to previously studied bacteria in that initiation of DNA replication is a key checkpoint for cell division. We compare the regulation of DNA replication initiation and strategies used for cell size homeostasis in mycobacteria and model bacteria. Finally, we review the importance of cellular organization and chromosome segregation relating to the physiology of mycobacteria and consider how new frameworks could be applied across the wide spectrum of bacterial diversity.
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Affiliation(s)
- Michelle M Logsdon
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States.,Department of Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, United States
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States.,Department of Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, United States.,Department of Biomedical Engineering, Tufts University School of Engineering, Medford, MA, United States
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111
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Cambray S, Bandyopadhyay A, Gao J. Fluorogenic diazaborine formation of semicarbazide with designed coumarin derivatives. Chem Commun (Camb) 2018; 53:12532-12535. [PMID: 29085929 DOI: 10.1039/c7cc07389e] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bioorthogonal fluorogenic reactions serve as enabling tools in research and biotechnology. Herein we describe fluorogenic conjugations of semicarbazide with coumarin derivatives that incorporate a 2-acetylphenylboronic acid motif. These designed coumarins rapidly conjugate with semicarbazide to give diazaborine products with significantly enhanced fluorescence. To demonstrate potential applications of this fluorogenic reaction, we synthesized a semicarbazide-presenting amino acid d-Dap-Scz, which readily incorporates into the cell wall of Staphalococcus aureus and serves as a handle for conjugation with the coumarins. The fluorogenic conjugation of the coumarins to cell surface semicarbazide enables facile visualization of d-Dap-Scz treated bacteria.
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Affiliation(s)
- Samantha Cambray
- Department of Chemistry, Merkert Chemistry Center, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02461, USA.
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112
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Ordonez AA, Jain SK. Pathogen-Specific Bacterial Imaging in Nuclear Medicine. Semin Nucl Med 2018. [DOI: 10.1053/j.semnuclmed.2017.11.003
expr 890398765 + 809902709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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113
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Abstract
When serious infections are suspected, patients are often treated empirically with broad-spectrum antibiotics while awaiting results that provide information on the bacterial class and species causing the infection, as well as drug susceptibilities. For deep-seated infections, these traditional diagnostic techniques often rely on tissue biopsies to obtain clinical samples which can be expensive, dangerous, and has the potential of sampling bias. Moreover, these procedures and results can take several days and may not always provide reliable information. This combination of time and effort required for proper antibiotic selection has become a barrier leading to indiscriminate broad-spectrum antibiotic use. Exposure to nosocomial infections and indiscriminate use of broad-spectrum antibiotics are responsible for promoting bacterial drug-resistance leading to substantial morbidity and mortality, especially in hospitalized and immunosuppressed patients. Therefore, early diagnosis of infection and targeted antibiotic treatments are urgently needed to reduce morbidity and mortality caused by bacterial infections worldwide. Reliable pathogen-specific bacterial imaging techniques have the potential to provide early diagnosis and guide antibiotic treatments.
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Affiliation(s)
- Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.
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114
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Kerschgens IP, Gademann K. Antibiotic Algae by Chemical Surface Engineering. Chembiochem 2018; 19:439-443. [DOI: 10.1002/cbic.201700553] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Indexed: 02/01/2023]
Affiliation(s)
- Isabel P. Kerschgens
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 8057 Zürich Switzerland
| | - Karl Gademann
- Department of Chemistry; University of Zürich; Winterthurerstrasse 190 8057 Zürich Switzerland
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115
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Siegl SJ, Vázquez A, Dzijak R, Dračínský M, Galeta J, Rampmaier R, Klepetářová B, Vrabel M. Design and Synthesis of Aza-Bicyclononene Dienophiles for Rapid Fluorogenic Ligations. Chemistry 2018; 24:2426-2432. [PMID: 29243853 DOI: 10.1002/chem.201705188] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Indexed: 12/15/2022]
Abstract
Fluorogenic bioorthogonal reactions enable visualization of biomolecules under native conditions with excellent signal-to-noise ratio. Here, we present the design and synthesis of conformationally-strained aziridine-fused trans-cyclooctene (aza-TCO) dienophiles, which lead to the formation of fluorescent products in tetrazine ligations without the need for attachment of an extra fluorophore moiety. The presented aza-TCOs adopt the highly strained "half-chair" conformation, which was predicted computationally and confirmed by NMR measurements and X-ray crystallography. Kinetic studies revealed that the aza-TCOs belong to the most reactive dienophiles known to date. The potential of the newly developed aza-TCO probes for bioimaging applications is demonstrated by protein labeling experiments, imaging of cellular glycoconjugates and peptidoglycan imaging of live bacteria.
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Affiliation(s)
- Sebastian J Siegl
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Arcadio Vázquez
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Rastislav Dzijak
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Juraj Galeta
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Robert Rampmaier
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Blanka Klepetářová
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Milan Vrabel
- Institute of Organic Chemistry and Biochemistry of the, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
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116
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Welsh MA, Taguchi A, Schaefer K, Van Tyne D, Lebre-ton F, Gilmore MS, Kahne D, Walker S. Identification of a Functionally Unique Family of Penicillin-Binding Proteins. J Am Chem Soc 2017; 139:17727-17730. [PMID: 29182854 PMCID: PMC5729098 DOI: 10.1021/jacs.7b10170] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Penicillin-binding proteins (PBPs) are enzymes involved in the assembly of the bacterial cell wall, a major target for antibiotics. These proteins are classified by mass into high-molecular-weight PBPs, which are transpeptidases that form peptidoglycan cross-links, and low-molecular-weight PBPs, which are typically hydrolases. We report a functionally unique family of low-molecular-weight PBPs that act as transpeptidases rather than hydrolases, but they do not cross-link peptidoglycan. We show that these PBPs can exchange d-amino acids bearing chemical tags or affinity handles into peptidoglycan precursors, including Lipid II, enabling biochemical studies of proteins involved in cell wall assembly. We report that, in two organisms, the PBPs incorporate lysine into cellular peptidoglycan and that, further, the PBPs have the unprecedented ability to transfer the primary ε-amine of lysine to peptidoglycan.
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Affiliation(s)
- Michael A. Welsh
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Atsushi Taguchi
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Kaitlin Schaefer
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
- Dept. of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Daria Van Tyne
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - François Lebre-ton
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - Michael S. Gilmore
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - Daniel Kahne
- Dept. of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Suzanne Walker
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
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117
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Howell M, Daniel JJ, Brown PJB. Live Cell Fluorescence Microscopy to Observe Essential Processes During Microbial Cell Growth. J Vis Exp 2017. [PMID: 29286454 DOI: 10.3791/56497] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Core cellular processes such as DNA replication and segregation, protein synthesis, cell wall biosynthesis, and cell division rely on the function of proteins which are essential for bacterial survival. A series of target-specific dyes can be used as probes to better understand these processes. Staining with lipophilic dyes enables the observation of membrane structure, visualization of lipid microdomains, and detection of membrane blebs. Use of fluorescent-d-amino acids (FDAAs) to probe the sites of peptidoglycan biosynthesis can indicate potential defects in cell wall biogenesis or cell growth patterning. Finally, nucleic acid stains can indicate possible defects in DNA replication or chromosome segregation. Cyanine DNA stains label living cells and are suitable for time-lapse microscopy enabling real-time observations of nucleoid morphology during cell growth. Protocols for cell labeling can be applied to protein depletion mutants to identify defects in membrane structure, cell wall biogenesis, or chromosome segregation. Furthermore, time-lapse microscopy can be used to monitor morphological changes as an essential protein is removed and can provide additional insights into protein function. For example, the depletion of essential cell division proteins results in filamentation or branching, whereas the depletion of cell growth proteins may cause cells to become shorter or rounder. Here, protocols for cell growth, target-specific labeling, and time-lapse microscopy are provided for the bacterial plant pathogen Agrobacterium tumefaciens. Together, target-specific dyes and time-lapse microscopy enable characterization of essential processes in A. tumefaciens. Finally, the protocols provided can be readily modified to probe essential processes in other bacteria.
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Sharifzadeh S, Boersma MJ, Kocaoglu O, Shokri A, Brown CL, Shirley JD, Winkler ME, Carlson EE. Novel Electrophilic Scaffold for Imaging of Essential Penicillin-Binding Proteins in Streptococcus pneumoniae. ACS Chem Biol 2017; 12:2849-2857. [PMID: 28990753 DOI: 10.1021/acschembio.7b00614] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptidoglycan (PG) is a mesh-like heteropolymer made up of glycan chains cross-linked by short peptides and is the major scaffold of eubacterial cell walls, determining cell shape, size, and chaining. This structure, which is required for growth and survival, is located outside of the cytoplasmic membrane of bacterial cells, making it highly accessible to antibiotics. Penicillin-binding proteins (PBPs) are essential for construction of PG and perform transglycosylase activities to generate the glycan strands and transpeptidation to cross-link the appended peptides. The β-lactam antibiotics, which are among the most clinically effective antibiotics for the treatment of bacterial infections, inhibit PBP transpeptidation, ultimately leading to cell lysis. Despite this importance, the discrete functions of individual PBP homologues have been difficult to determine. These major gaps in understanding of PBP activation and macromolecular interactions largely result from a lack of tools to assess the functional state of specific PBPs in bacterial cells. We have identified β-lactones as a privileged scaffold for the generation of PBP-selective probes and utilized these compounds for imaging of the essential proteins, PBP2x and PBP2b, in Streptococcus pneumoniae. We demonstrated that while PBP2b activity is restricted to a ring surrounding the division sites, PBP2x activity is present both at the septal center and at the surrounding ring. These spatially separate regions of PBP2x activity could not be detected by previous activity-based approaches, which highlights a critical strength of our PBP-selective imaging strategy.
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Affiliation(s)
- Shabnam Sharifzadeh
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Michael J. Boersma
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Ozden Kocaoglu
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Alireza Shokri
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Clayton L. Brown
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Joshua D. Shirley
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Malcolm E. Winkler
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Erin E. Carlson
- Departments
of Chemistry, ‡Medicinal Chemistry, and Biochemistry, §Molecular Biology
and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Departments of Biology, ⊥Molecular and Cellular Biochemistry,
and #Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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Wang Y, Lazor KM, DeMeester KE, Liang H, Heiss TK, Grimes CL. Postsynthetic Modification of Bacterial Peptidoglycan Using Bioorthogonal N-Acetylcysteamine Analogs and Peptidoglycan O-Acetyltransferase B. J Am Chem Soc 2017; 139:13596-13599. [PMID: 28898061 PMCID: PMC5837961 DOI: 10.1021/jacs.7b06820] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Bacteria have the natural ability to install protective postsynthetic modifications onto its bacterial peptidoglycan (PG), the coat woven into bacterial cell wall. Peptidoglycan O-acetyltransferase B (PatB) catalyzes the O-acetylation of PG in Gram (-) bacteria, which aids in bacterial survival, as it prevents autolysins such as lysozyme from cleaving the PG. We explored the mechanistic details of PatB's acetylation function and determined that PatB has substrate specificity for bioorthgonal short N-acetyl cysteamine (SNAc) donors. A variety of functionality including azides and alkynes were installed on tri-N-acetylglucosamine (NAG)3, a PG mimic, as well as PG isolated from various Gram (+) and Gram (-) bacterial species. The bioorthogonal modifications protect the isolated PG against lysozyme degradation in vitro. We further demonstrate that this postsynthetic modification of PG can be extended to use click chemistry to fluorescently label the mature PG in whole bacterial cells of Bacillus subtilis. Modifying PG postsynthetically can aid in the development of antibiotics and immune modulators by expanding the understanding of how PG is processed by lytic enzymes.
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Affiliation(s)
- Yiben Wang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Klare M. Lazor
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Kristen E. DeMeester
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Hai Liang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Tyler K. Heiss
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Catherine L. Grimes
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Biological Chemistry, University of Delaware, Newark, DE 19716, USA
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Distinct Spatiotemporal Dynamics of Peptidoglycan Synthesis between Mycobacterium smegmatis and Mycobacterium tuberculosis. mBio 2017; 8:mBio.01183-17. [PMID: 28900018 PMCID: PMC5596344 DOI: 10.1128/mbio.01183-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peptidoglycan (PG), a polymer cross-linked by d-amino acid-containing peptides, is an essential component of the bacterial cell wall. We found that a fluorescent d-alanine analog (FDAA) incorporates chiefly at one of the two poles in Mycobacterium smegmatis but that polar dominance varies as a function of the cell cycle in Mycobacterium tuberculosis: immediately after cytokinesis, FDAAs are incorporated chiefly at one of the two poles, but just before cytokinesis, FDAAs are incorporated comparably at both. These observations suggest that mycobacterial PG-synthesizing enzymes are localized in functional compartments at the poles and septum and that the capacity for PG synthesis matures at the new pole in M. tuberculosis Deeper knowledge of the biology of mycobacterial PG synthesis may help in discovering drugs that disable previously unappreciated steps in the process.IMPORTANCE People are dying all over the world because of the rise of antimicrobial resistance to medicines that could previously treat bacterial infections, including tuberculosis. Here, we used fluorescent d-alanine analogs (FDAAs) that incorporate into peptidoglycan (PG)-the synthesis of which is an attractive drug target-combined with high- and super-resolution microscopy to investigate the spatiotemporal dynamics of PG synthesis in M. smegmatis and M. tuberculosis FDAA incorporation predominates at one of the two poles in M. smegmatis In contrast, while FDAA incorporation into M. tuberculosis is also polar, there are striking variations in polar dominance as a function of the cell cycle. This suggests that enzymes involved in PG synthesis are localized in functional compartments in mycobacteria and that M. tuberculosis possesses a mechanism for maturation of the capacity for PG synthesis at the new pole. This may help in discovering drugs that cripple previously unappreciated steps in the process.
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121
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Imaging Active Infection in vivo Using D-Amino Acid Derived PET Radiotracers. Sci Rep 2017; 7:7903. [PMID: 28801560 PMCID: PMC5554133 DOI: 10.1038/s41598-017-08415-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/10/2017] [Indexed: 12/21/2022] Open
Abstract
Occult bacterial infections represent a worldwide health problem. Differentiating active bacterial infection from sterile inflammation can be difficult using current imaging tools. Present clinically viable methodologies either detect morphologic changes (CT/ MR), recruitment of immune cells (111In-WBC SPECT), or enhanced glycolytic flux seen in inflammatory cells (18F-FDG PET). However, these strategies are often inadequate to detect bacterial infection and are not specific for living bacteria. Recent approaches have taken advantage of key metabolic differences between prokaryotic and eukaryotic organisms, allowing easier distinction between bacteria and their host. In this report, we exploited one key difference, bacterial cell wall biosynthesis, to detect living bacteria using a positron-labeled D-amino acid. After screening several 14C D-amino acids for their incorporation into E. coli in culture, we identified D-methionine as a probe with outstanding radiopharmaceutical potential. Based on an analogous procedure to that used for L-[methyl-11C]methionine ([11C] L-Met), we developed an enhanced asymmetric synthesis of D-[methyl-11C]methionine ([11C] D-Met), and showed that it can rapidly and selectively differentiate both E. coli and S. aureus infections from sterile inflammation in vivo. We believe that the ease of [11C] D-Met radiosynthesis, coupled with its rapid and specific in vivo bacterial accumulation, make it an attractive radiotracer for infection imaging in clinical practice.
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122
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Pidgeon SE, Pires MM. Cell Wall Remodeling of Staphylococcus aureus in Live Caenorhabditis elegans. Bioconjug Chem 2017; 28:2310-2315. [DOI: 10.1021/acs.bioconjchem.7b00363] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sean E. Pidgeon
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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123
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Atwal S, Giengkam S, Chaemchuen S, Dorling J, Kosaisawe N, VanNieuwenhze M, Sampattavanich S, Schumann P, Salje J. Evidence for a peptidoglycan-like structure in Orientia tsutsugamushi. Mol Microbiol 2017; 105:440-452. [PMID: 28513097 PMCID: PMC5523937 DOI: 10.1111/mmi.13709] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2017] [Indexed: 01/04/2023]
Abstract
Bacterial cell walls are composed of the large cross-linked macromolecule peptidoglycan, which maintains cell shape and is responsible for resisting osmotic stresses. This is a highly conserved structure and the target of numerous antibiotics. Obligate intracellular bacteria are an unusual group of organisms that have evolved to replicate exclusively within the cytoplasm or vacuole of a eukaryotic cell. They tend to have reduced amounts of peptidoglycan, likely due to the fact that their growth and division takes place within an osmotically protected environment, and also due to a drive to reduce activation of the host immune response. Of the two major groups of obligate intracellular bacteria, the cell wall has been much more extensively studied in the Chlamydiales than the Rickettsiales. Here, we present the first detailed analysis of the cell envelope of an important but neglected member of the Rickettsiales, Orientia tsutsugamushi. This bacterium was previously reported to completely lack peptidoglycan, but here we present evidence supporting the existence of a peptidoglycan-like structure in Orientia, as well as an outer membrane containing a network of cross-linked proteins, which together confer cell envelope stability. We find striking similarities to the unrelated Chlamydiales, suggesting convergent adaptation to an obligate intracellular lifestyle.
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Affiliation(s)
- Sharanjeet Atwal
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand
| | - Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand
| | - Suwittra Chaemchuen
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand
| | - Jack Dorling
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Nont Kosaisawe
- Siriraj Laboratory for Systems Pharmacology, Faculty of Medicine, Siriraj Hospital, Bangkok, Thailand
| | | | - Somponnat Sampattavanich
- Siriraj Laboratory for Systems Pharmacology, Faculty of Medicine, Siriraj Hospital, Bangkok, Thailand
| | - Peter Schumann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand
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124
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Sherratt AR, Rouleau Y, Luebbert C, Strmiskova M, Veres T, Bidawid S, Corneau N, Pezacki JP. Rapid Screening and Identification of Living Pathogenic Organisms via Optimized Bioorthogonal Non-canonical Amino Acid Tagging. Cell Chem Biol 2017; 24:1048-1055.e3. [PMID: 28757183 DOI: 10.1016/j.chembiol.2017.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/19/2017] [Accepted: 06/27/2017] [Indexed: 10/19/2022]
Abstract
Pathogenic bacteria can be a major cause of illness from environmental sources as well as the consumption of contaminated products, giving rise to public health concerns globally. The surveillance of such living organisms in food and water supplies remains an important challenge in mitigating their deleterious societal effects. Here, we have developed an optimized bioorthogonal non-canonical amino acid tagging approach to the imaging, capture, and interrogation of shigatoxigenic/verotoxigenic Escherichia coli (VTEC) and Listeria that enables the distinction between living wild-type pathogenic bacteria. The approaches utilize homopropargylglycine (HPG), as well as optimized growth media, that restricts endogenous methionine biosynthesis in a variety of species of public health concern. Endogenous methionine residues are then replaced with HPG, which can then be modified using a myriad of compatible bioorthogonal reactions for tagging of exclusively live bacteria. The methods reported allow for the very rapid screening and identification of living pathogenic organisms.
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Affiliation(s)
- Allison Rae Sherratt
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, 10 Marie-Curie Private, Ottawa K1N 6N5, Canada; Life Sciences Division, National Research Council of Canada, 100 Sussex Drive, Ottawa K1A 0R6, Canada
| | - Yanouchka Rouleau
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, 10 Marie-Curie Private, Ottawa K1N 6N5, Canada; Life Sciences Division, National Research Council of Canada, 100 Sussex Drive, Ottawa K1A 0R6, Canada
| | | | - Miroslava Strmiskova
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, 10 Marie-Curie Private, Ottawa K1N 6N5, Canada
| | - Teodor Veres
- Life Sciences Division, National Research Council of Canada, 100 Sussex Drive, Ottawa K1A 0R6, Canada
| | - Sabah Bidawid
- Health Canada, Bureau of Microbial Hazards, Ottawa K1A 0K9, Canada
| | - Nathalie Corneau
- Health Canada, Bureau of Microbial Hazards, Ottawa K1A 0K9, Canada
| | - John Paul Pezacki
- Department of Chemistry and Biomolecular Sciences, Centre for Chemical and Synthetic Biology, University of Ottawa, 10 Marie-Curie Private, Ottawa K1N 6N5, Canada; Life Sciences Division, National Research Council of Canada, 100 Sussex Drive, Ottawa K1A 0R6, Canada.
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125
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Pidgeon SE, Pires MM. Cell Wall Remodeling by a Synthetic Analog Reveals Metabolic Adaptation in Vancomycin Resistant Enterococci. ACS Chem Biol 2017; 12:1913-1918. [PMID: 28574692 DOI: 10.1021/acschembio.7b00412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.
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Affiliation(s)
- Sean E. Pidgeon
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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126
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Pidgeon SE, Pires MM. Vancomycin-Dependent Response in Live Drug-Resistant Bacteria by Metabolic Labeling. Angew Chem Int Ed Engl 2017; 56:8839-8843. [DOI: 10.1002/anie.201704851] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Sean E. Pidgeon
- Department of Chemistry; Lehigh University; 6 E. Packer Avenue Bethlehem PA 18015 USA
| | - Marcos M. Pires
- Department of Chemistry; Lehigh University; 6 E. Packer Avenue Bethlehem PA 18015 USA
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127
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Pidgeon SE, Pires MM. Vancomycin-Dependent Response in Live Drug-Resistant Bacteria by Metabolic Labeling. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201704851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Sean E. Pidgeon
- Department of Chemistry; Lehigh University; 6 E. Packer Avenue Bethlehem PA 18015 USA
| | - Marcos M. Pires
- Department of Chemistry; Lehigh University; 6 E. Packer Avenue Bethlehem PA 18015 USA
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128
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Bi X, Yin J, Nguyen GKT, Rao C, Halim NBA, Hemu X, Tam JP, Liu CF. Enzymatic Engineering of Live Bacterial Cell Surfaces Using Butelase 1. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703317] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xiaobao Bi
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Juan Yin
- Lee Kong Chian School of Medicine; Nanyang Technological University; 59 Nanyang Drive Singapore 636921 Singapore
| | - Giang K. T. Nguyen
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Chang Rao
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Nurashikin Bte Abdul Halim
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Xinya Hemu
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - James P. Tam
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Chuan-Fa Liu
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
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129
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Bi X, Yin J, Nguyen GKT, Rao C, Halim NBA, Hemu X, Tam JP, Liu CF. Enzymatic Engineering of Live Bacterial Cell Surfaces Using Butelase 1. Angew Chem Int Ed Engl 2017; 56:7822-7825. [DOI: 10.1002/anie.201703317] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Xiaobao Bi
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Juan Yin
- Lee Kong Chian School of Medicine; Nanyang Technological University; 59 Nanyang Drive Singapore 636921 Singapore
| | - Giang K. T. Nguyen
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Chang Rao
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Nurashikin Bte Abdul Halim
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Xinya Hemu
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - James P. Tam
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | - Chuan-Fa Liu
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
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130
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Row RD, Shih HW, Alexander AT, Mehl RA, Prescher JA. Cyclopropenones for Metabolic Targeting and Sequential Bioorthogonal Labeling. J Am Chem Soc 2017; 139:7370-7375. [DOI: 10.1021/jacs.7b03010] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | - Austin T. Alexander
- Department
of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Ryan A. Mehl
- Department
of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
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131
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Progress and prospects for small-molecule probes of bacterial imaging. Nat Chem Biol 2017; 12:472-8. [PMID: 27315537 DOI: 10.1038/nchembio.2109] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 05/13/2016] [Indexed: 11/09/2022]
Abstract
Fluorescence microscopy is an essential tool for the exploration of cell growth, division, transcription and translation in eukaryotes and prokaryotes alike. Despite the rapid development of techniques to study bacteria, the size of these organisms (1-10 μm) and their robust and largely impenetrable cell envelope present major challenges in imaging experiments. Fusion-based strategies, such as attachment of the protein of interest to a fluorescent protein or epitope tag, are by far the most common means for examining protein localization and expression in prokaryotes. While valuable, the use of genetically encoded tags can result in mislocalization or altered activity of the desired protein, does not provide a readout of the catalytic state of enzymes and cannot enable visualization of many other important cellular components, such as peptidoglycan, lipids, nucleic acids or glycans. Here, we highlight the use of biomolecule-specific small-molecule probes for imaging in bacteria.
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132
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Liang H, DeMeester KE, Hou CW, Parent MA, Caplan JL, Grimes CL. Metabolic labelling of the carbohydrate core in bacterial peptidoglycan and its applications. Nat Commun 2017; 8:15015. [PMID: 28425464 PMCID: PMC5411481 DOI: 10.1038/ncomms15015] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 02/20/2017] [Indexed: 02/07/2023] Open
Abstract
Bacterial cells are surrounded by a polymer known as peptidoglycan (PG), which protects the cell from changes in osmotic pressure and small molecule insults. A component of this material, N-acetyl-muramic acid (NAM), serves as a core structural element for innate immune recognition of PG fragments. We report the synthesis of modifiable NAM carbohydrate derivatives and the installation of these building blocks into the backbone of Gram-positive and Gram-negative bacterial PG utilizing metabolic cell wall recycling and biosynthetic machineries. Whole cells are labelled via click chemistry and visualized using super-resolution microscopy, revealing higher resolution PG structural details and allowing the cell wall biosynthesis, as well as its destruction in immune cells, to be tracked. This study will assist in the future identification of mechanisms that the immune system uses to recognize bacteria, glean information about fundamental cell wall architecture and aid in the design of novel antibiotics. N-acetyl-muramic acid (NAM) is a core component of the bacterial peptidoglycan (PG) cell wall, and is recognised by the innate immune system. Here the authors engineer Gram-negative and Gram-positive bacteria to incorporate a modified NAM into the backbone of PG, which can be labelled with click chemistry for imaging and tracking.
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Affiliation(s)
- Hai Liang
- Department of Chemistry and Biochemistry, University of Delaware, 134 Brown Lab, Newark, Delaware 19716, USA
| | - Kristen E DeMeester
- Department of Chemistry and Biochemistry, University of Delaware, 134 Brown Lab, Newark, Delaware 19716, USA
| | - Ching-Wen Hou
- Department of Chemistry and Biochemistry, University of Delaware, 134 Brown Lab, Newark, Delaware 19716, USA
| | - Michelle A Parent
- Department of Medical Laboratory Sciences, University of Delaware, Newark, Delaware 19716, USA.,Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Jeffrey L Caplan
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, USA.,Bioimaging Center, Delaware Biotechnology Institute, Newark, Delaware 19716, USA
| | - Catherine L Grimes
- Department of Chemistry and Biochemistry, University of Delaware, 134 Brown Lab, Newark, Delaware 19716, USA.,Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, USA
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133
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Lauro ML, D’Ambrosio EA, Bahnson BJ, Grimes CL. Molecular Recognition of Muramyl Dipeptide Occurs in the Leucine-rich Repeat Domain of Nod2. ACS Infect Dis 2017; 3:264-270. [PMID: 27748583 DOI: 10.1021/acsinfecdis.6b00154] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Genetic mutations in the innate immune receptor nucleotide-binding oligomerization domain-containing 2 (Nod2) have demonstrated increased susceptibility to Crohn's disease, an inflammatory bowel disease that is hypothesized to be accompanied by changes in the gut microbiota. Nod2 responds to the presence of bacteria, specifically a fragment of the bacterial cell wall, muramyl dipeptide (MDP). The proposed site of this interaction is the leucine-rich repeat (LRR) domain. Surface plasmon resonance and molecular modeling were used to investigate the interaction of the LRR domain with MDP. A functional and pure LRR domain was obtained from Escherichia coli expression in high yield. The LRR domain binds to MDP with high affinity, with a KD of 212 ± 24 nM. Critical portions of the receptor were determined by mutagenesis of putative binding residues. Fragment analysis of MDP revealed that both the peptide and carbohydrate portion contribute to the binding interaction.
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Affiliation(s)
- Mackenzie L. Lauro
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Elizabeth A. D’Ambrosio
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Brian J. Bahnson
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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134
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Abstract
Members of the genus Mycobacterium are the most prevalent cause of infectious diseases. Mycobacteria have a complex cell envelope containing a peptidoglycan layer and an additional arabinogalactan polymer to which a mycolic acid bilayer is linked; this complex, multilayered cell wall composition (mAGP) is conserved among all CMN group bacteria. The arabinogalactan and mycolic acid synthesis pathways constitute effective drug targets for tuberculosis treatment. Ethambutol (EMB), a classical antituberculosis drug, inhibits the synthesis of the arabinose polymer. Although EMB acts bacteriostatically, its underlying molecular mechanism remains unclear. Here, we used Corynebacterium glutamicum and Mycobacterium phlei as model organisms to study the effects of EMB at the single-cell level. Our results demonstrate that EMB specifically blocks apical cell wall synthesis, but not cell division, explaining the bacteriostatic effect of EMB. Furthermore, the data suggest that members of the family Corynebacterineae have two dedicated machineries for cell elongation (elongasome) and cytokinesis (divisome). Antibiotic treatment of bacterial pathogens has contributed enormously to the increase in human health. Despite the apparent importance of antibiotic treatment of bacterial infections, surprisingly little is known about the molecular functions of antibiotic actions in the bacterial cell. Here, we analyzed the molecular effects of ethambutol, a first-line antibiotic against infections caused by members of the genus Mycobacterium. We find that this drug selectively blocks apical cell growth but still allows for effective cytokinesis. As a consequence, cells survive ethambutol treatment and adopt a pneumococcal cell growth mode with cell wall synthesis only at the site of cell division. However, combined treatment of ethambutol and beta-lactam antibiotics acts synergistically and effectively stops cell proliferation.
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135
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Bacillus subtilis Swarmer Cells Lead the Swarm, Multiply, and Generate a Trail of Quiescent Descendants. mBio 2017; 8:mBio.02102-16. [PMID: 28174308 PMCID: PMC5296600 DOI: 10.1128/mbio.02102-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Bacteria adopt social behavior to expand into new territory, led by specialized swarmers, before forming a biofilm. Such mass migration of Bacillus subtilis on a synthetic medium produces hyperbranching dendrites that transiently (equivalent to 4 to 5 generations of growth) maintain a cellular monolayer over long distances, greatly facilitating single-cell gene expression analysis. Paradoxically, while cells in the dendrites (nonswarmers) might be expected to grow exponentially, the rate of swarm expansion is constant, suggesting that some cells are not multiplying. Little attention has been paid to which cells in a swarm are actually multiplying and contributing to the overall biomass. Here, we show in situ that DNA replication, protein translation and peptidoglycan synthesis are primarily restricted to the swarmer cells at dendrite tips. Thus, these specialized cells not only lead the population forward but are apparently the source of all cells in the stems of early dendrites. We developed a simple mathematical model that supports this conclusion. Swarming motility enables rapid coordinated surface translocation of a microbial community, preceding the formation of a biofilm. This movement occurs in thin films and involves specialized swarmer cells localized to a narrow zone at the extreme swarm edge. In the B. subtilis system, using a synthetic medium, the swarm front remains as a cellular monolayer for up to 1.5 cm. Swarmers display high-velocity whirls and vortexing and are often assumed to drive community expansion at the expense of cell growth. Surprisingly, little attention has been paid to which cells in a swarm are actually growing and contributing to the overall biomass. Here, we show that swarmers not only lead the population forward but continue to multiply as a source of all cells in the community. We present a model that explains how exponential growth of only a few cells is compatible with the linear expansion rate of the swarm.
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136
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Bandyopadhyay A, Cambray S, Gao J. Fast Diazaborine Formation of Semicarbazide Enables Facile Labeling of Bacterial Pathogens. J Am Chem Soc 2017; 139:871-878. [PMID: 27992180 PMCID: PMC6191850 DOI: 10.1021/jacs.6b11115] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bioorthogonal conjugation chemistry has enabled the development of tools for the interrogation of complex biological systems. Although a number of bioorthogonal reactions have been documented in literature, they are less ideal for one or several reasons including slow kinetics, low stability of the conjugated product, requirement of toxic catalysts, and side reactions with unintended biomolecules. Herein we report a fast (>103 M-1 s-1) and bioorthogonal conjugation reaction that joins semicarbazide to an aryl ketone or aldehyde with an ortho-boronic acid substituent. The boronic acid moiety greatly accelerates the initial formation of a semicarbazone conjugate, which rearranges into a stable diazaborine. The diazaborine formation can be performed in blood serum or cell lysates with minimal interference from biomolecules. We further demonstrate that application of this conjugation chemistry enables facile labeling of bacteria. A synthetic amino acid D-AB3, which presents a 2-acetylphenylboronic acid moiety as its side chain, was found to incorporate into several bacterial species through cell wall remodeling, with particularly high efficiency for Escherichia coli. Subsequent D-AB3 conjugation to a fluorophore-labeled semicarbazide allows robust detection of this bacterial pathogen in blood serum.
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Affiliation(s)
- Anupam Bandyopadhyay
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02461
| | - Samantha Cambray
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02461
| | - Jianmin Gao
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02461
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137
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Pawlak JB, Hos BJ, van de Graaff MJ, Megantari OA, Meeuwenoord N, Overkleeft HS, Filippov DV, Ossendorp F, van Kasteren SI. The Optimization of Bioorthogonal Epitope Ligation within MHC-I Complexes. ACS Chem Biol 2016; 11:3172-3178. [PMID: 27704768 DOI: 10.1021/acschembio.6b00498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Antigen recognition followed by the activation of cytotoxic T-cells (CTLs) is a key step in adaptive immunity, resulting in clearance of viruses and cancers. The repertoire of peptides that have the ability to bind to the major histocompatibility type-I (MHC-I) is enormous, but the approaches available for studying the diversity of the peptide repertoire on a cell are limited. Here, we explore the use of bioorthogonal chemistry to quantify specific peptide-MHC-I complexes (pMHC-I) on cells. We show that modifying epitope peptides with bioorthogonal groups in surface accessible positions allows wild-type-like MHC-I binding and bioorthogonal ligation using fluorogenic chromophores in combination with a Cu(I)-catalyzed Huisgen cycloaddition reaction. We expect that this approach will make a powerful addition to the antigen presentation toolkit as for the first time it allows quantification of antigenic peptides for which no detection tools exist.
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Affiliation(s)
- Joanna B. Pawlak
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Brett J. Hos
- Department
of Immunohematology and Blood Transfusion, Leiden University Medical Center and The Institute for Chemical Immunology, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - Michel J. van de Graaff
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Otty A. Megantari
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Nico Meeuwenoord
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Herman S. Overkleeft
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Dmitri V. Filippov
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Ferry Ossendorp
- Department
of Immunohematology and Blood Transfusion, Leiden University Medical Center and The Institute for Chemical Immunology, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - Sander I. van Kasteren
- Leiden
Institute of Chemistry and The Institute for Chemical Immunology, Leiden University Einsteinweg 55, 2333 CC Leiden, The Netherlands
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138
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Baumgart M, Schubert K, Bramkamp M, Frunzke J. Impact of LytR-CpsA-Psr Proteins on Cell Wall Biosynthesis in Corynebacterium glutamicum. J Bacteriol 2016; 198:3045-3059. [PMID: 27551018 PMCID: PMC5075034 DOI: 10.1128/jb.00406-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/17/2016] [Indexed: 12/28/2022] Open
Abstract
Proteins of the LCP (LytR, CpsA, Psr) family have been shown to inherit important roles in bacterial cell wall biosynthesis. However, their exact function in the formation of the complex cell wall structures of the Corynebacteriales, including the prominent pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae, remains unclear. Here, we analyzed the role of the LCP proteins LcpA and LcpB of Corynebacterium glutamicum, both of which localize at regions of nascent cell wall biosynthesis. A strain lacking lcpB did not show any growth-related or morphological phenotype under the tested conditions. In contrast, conditional silencing of the essential lcpA gene resulted in severe growth defects and drastic morphological changes. Compared to the wild-type cell wall, the cell wall of this mutant contained significantly less mycolic acids and a reduced amount of arabinogalactan. In particular, rhamnose, a specific sugar component of the linker that connects arabinogalactan and peptidoglycan, was decreased. Complementation studies of the lcpA-silencing strain with several mutated and truncated LcpA variants suggested that both periplasmic domains are essential for function whereas the cytoplasmic N-terminal part is dispensable. Successful complementation experiments with proteins of M. tuberculosis and C. diphtheriae revealed a conserved function of LCP proteins in these species. Finally, pyrophosphatase activity of LcpA was shown in an in vitro assay. Taken together, our results suggest that LCP proteins are responsible for the transfer of arabinogalactan onto peptidoglycan in actinobacterial species and support a crucial function of a so-far-uncharacterized C-terminal domain (LytR_C domain) which is frequently found at the C terminus of the LCP domain in this prokaryotic phylum. IMPORTANCE About one-third of the world's population is infected with Mycobacterium tuberculosis, and multiple-antibiotic resistance provokes the demand for novel antibiotics. The special cell wall architecture of Corynebacteriales is critical for treatments because it is either a direct target or a barrier that the drug has to cross. Here, we present the analysis of LcpA and LcpB of the closely related Corynebacterium glutamicum, the first of which is an essential protein involved in cell wall biogenesis. Our work provides a comprehensive characterization of the impact of LCP proteins on cell wall biogenesis in this medically and biotechnologically important class of bacteria. Special focus is set on the two periplasmic LcpA domains and their contributions to physiological function.
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Affiliation(s)
- Meike Baumgart
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, Jülich, Germany
| | - Karin Schubert
- Ludwig-Maximilians-Universität München, Fakultät Biologie, Planegg-Martinsried, Germany
| | - Marc Bramkamp
- Ludwig-Maximilians-Universität München, Fakultät Biologie, Planegg-Martinsried, Germany
| | - Julia Frunzke
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, Jülich, Germany
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139
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Howell M, Brown PJ. Building the bacterial cell wall at the pole. Curr Opin Microbiol 2016; 34:53-59. [PMID: 27504539 DOI: 10.1016/j.mib.2016.07.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 01/06/2023]
Abstract
Polar growth is the predominant mode of cell wall extension in the Actinobacteria and the alphaproteobacterial clade Rhizobiales. The observation of polar elongation in taxonomically diverse bacteria suggests that polar growth may have evolved independently. Indeed, the regulatory mechanisms governing the assembly of cell wall biosynthesis machinery at the pole are distinct in the Actinobacteria and Rhizobiales. Here we highlight recent advances in our understanding of polar growth mechanisms in bacteria, with an emphasis on Streptomyces and Agrobacterium. This review illustrates that common themes are emerging in the regulation of polar growth in diverse bacteria. Emerging themes include the use of landmark proteins to direct growth to the pole and coordination of polar growth with cell-cycle progression.
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Affiliation(s)
- Matthew Howell
- Division of Biological Sciences, 423 Tucker Hall, 612 Hitt St., University of Missouri, Columbia, MO 65211, USA
| | - Pamela Jb Brown
- Division of Biological Sciences, 423 Tucker Hall, 612 Hitt St., University of Missouri, Columbia, MO 65211, USA.
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140
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Ngo JT, Adams SR, Deerinck TJ, Boassa D, Rodriguez-Rivera F, Palida SF, Bertozzi CR, Ellisman MH, Tsien RY. Click-EM for imaging metabolically tagged nonprotein biomolecules. Nat Chem Biol 2016; 12:459-65. [PMID: 27110681 PMCID: PMC4871776 DOI: 10.1038/nchembio.2076] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 03/08/2016] [Indexed: 12/14/2022]
Abstract
EM has long been the main technique for imaging cell structures with nanometer resolution but has lagged behind light microscopy in the crucial ability to make specific molecules stand out. Here we introduce click-EM, a labeling technique for correlative light microscopy and EM imaging of nonprotein biomolecules. In this approach, metabolic labeling substrates containing bioorthogonal functional groups are provided to cells for incorporation into biopolymers by endogenous biosynthetic machinery. The unique chemical functionality of these analogs is exploited for selective attachment of singlet oxygen-generating fluorescent dyes via bioorthogonal 'click chemistry' ligations. Illumination of dye-labeled structures generates singlet oxygen to locally catalyze the polymerization of diaminobenzidine into an osmiophilic reaction product that is readily imaged by EM. We describe the application of click-EM in imaging metabolically tagged DNA, RNA and lipids in cultured cells and neurons and highlight its use in tracking peptidoglycan synthesis in the Gram-positive bacterium Listeria monocytogenes.
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Affiliation(s)
- John T. Ngo
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093
| | - Stephen R. Adams
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093
| | - Thomas J. Deerinck
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093
| | | | - Sakina F. Palida
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093
| | - Carolyn R. Bertozzi
- Howard Hughes Medical Institute
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Mark H. Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093
| | - Roger Y. Tsien
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093
- Howard Hughes Medical Institute
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141
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Sarkar S, Libby EA, Pidgeon SE, Dworkin J, Pires MM. In Vivo Probe of Lipid II-Interacting Proteins. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603441] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sourav Sarkar
- Department of Chemistry; Lehigh University; Bethlehem PA 18015 USA
| | - Elizabeth A. Libby
- Department of Microbiology & Immunology; Columbia University; New York NY 10032 USA
| | - Sean E. Pidgeon
- Department of Chemistry; Lehigh University; Bethlehem PA 18015 USA
| | - Jonathan Dworkin
- Department of Microbiology & Immunology; Columbia University; New York NY 10032 USA
| | - Marcos M. Pires
- Department of Chemistry; Lehigh University; Bethlehem PA 18015 USA
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142
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Sarkar S, Libby EA, Pidgeon SE, Dworkin J, Pires MM. In Vivo Probe of Lipid II-Interacting Proteins. Angew Chem Int Ed Engl 2016; 55:8401-4. [PMID: 27225706 DOI: 10.1002/anie.201603441] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 04/25/2016] [Indexed: 11/11/2022]
Abstract
β-Lactams represent one of the most important classes of antibiotics discovered to date. These agents block Lipid II processing and cell wall biosynthesis through inactivation of penicillin-binding proteins (PBPs). PBPs enzymatically load cell wall building blocks from Lipid II carrier molecules onto the growing cell wall scaffold during growth and division. Lipid II, a bottleneck in cell wall biosynthesis, is the target of some of the most potent antibiotics in clinical use. Despite the immense therapeutic value of this biosynthetic pathway, the PBP-Lipid II association has not been established in live cells. To determine this key interaction, we designed an unnatural d-amino acid dipeptide that is metabolically incorporated into Lipid II molecules. By hijacking the peptidoglycan biosynthetic machinery, photoaffinity probes were installed in combination with click partners within Lipid II, thereby allowing, for the first time, demonstration of PBP interactions in vivo with Lipid II.
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Affiliation(s)
- Sourav Sarkar
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Elizabeth A Libby
- Department of Microbiology & Immunology, Columbia University, New York, NY, 10032, USA
| | - Sean E Pidgeon
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Jonathan Dworkin
- Department of Microbiology & Immunology, Columbia University, New York, NY, 10032, USA
| | - Marcos M Pires
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA.
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143
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Komatsu T, Virdee S. ICBS and ECBS Chemical Biology Meeting 2015 - Let Them Come to Berlin! ACS Chem Biol 2016; 11:1159-66. [PMID: 27198933 DOI: 10.1021/acschembio.6b00268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Toru Komatsu
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- JST PRESTO, Tokyo, Japan
| | - Satpal Virdee
- MRC
Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
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144
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Liechti G, Kuru E, Packiam M, Hsu YP, Tekkam S, Hall E, Rittichier JT, VanNieuwenhze M, Brun YV, Maurelli AT. Pathogenic Chlamydia Lack a Classical Sacculus but Synthesize a Narrow, Mid-cell Peptidoglycan Ring, Regulated by MreB, for Cell Division. PLoS Pathog 2016; 12:e1005590. [PMID: 27144308 PMCID: PMC4856321 DOI: 10.1371/journal.ppat.1005590] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 04/01/2016] [Indexed: 01/28/2023] Open
Abstract
The peptidoglycan (PG) cell wall is a peptide cross-linked glycan polymer essential for bacterial division and maintenance of cell shape and hydrostatic pressure. Bacteria in the Chlamydiales were long thought to lack PG until recent advances in PG labeling technologies revealed the presence of this critical cell wall component in Chlamydia trachomatis. In this study, we utilize bio-orthogonal D-amino acid dipeptide probes combined with super-resolution microscopy to demonstrate that four pathogenic Chlamydiae species each possess a ≤ 140 nm wide PG ring limited to the division plane during the replicative phase of their developmental cycles. Assembly of this PG ring is rapid, processive, and linked to the bacterial actin-like protein, MreB. Both MreB polymerization and PG biosynthesis occur only in the intracellular form of pathogenic Chlamydia and are required for cell enlargement, division, and transition between the microbe’s developmental forms. Our kinetic, molecular, and biochemical analyses suggest that the development of this limited, transient, PG ring structure is the result of pathoadaptation by Chlamydia to an intracellular niche within its vertebrate host. Pathogenic Chlamydia do not assemble their peptidoglycan (PG) cell wall in a classical, mesh-like sacculus, but instead apparently confine it to the mid-cell in the actively dividing, non-infectious form. We characterize the assembly and aging of this PG-ring and link its synthesis to MreB, an actin-like protein associated with lateral cell wall synthesis in bacteria. As PG is recognized by the host innate immune system, we hypothesize that the limited amount of PG synthesized by Chlamydia is an adaptation to the microbe’s intracellular lifestyle.
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Affiliation(s)
- George Liechti
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Erkin Kuru
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Mathanraj Packiam
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Yen-Pang Hsu
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Srinivas Tekkam
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Edward Hall
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Jonathan T Rittichier
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Michael VanNieuwenhze
- Department of Chemistry, Indiana University, Bloomington, Indiana, United States of America
| | - Yves V Brun
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Anthony T Maurelli
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
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145
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Sherratt AR, Chigrinova M, MacKenzie DA, Rastogi NK, Ouattara MTM, Pezacki AT, Pezacki JP. Dual Strain-Promoted Alkyne–Nitrone Cycloadditions for Simultaneous Labeling of Bacterial Peptidoglycans. Bioconjug Chem 2016; 27:1222-6. [DOI: 10.1021/acs.bioconjchem.6b00063] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Allison R. Sherratt
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
| | - Mariya Chigrinova
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
| | - Douglas A. MacKenzie
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
- Department
of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa K1N 6N5, Canada
| | - Neelabh K. Rastogi
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
- Department
of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa K1N 6N5, Canada
| | - Myriam T. M. Ouattara
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
| | - Aidan T. Pezacki
- Department
of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa K1N 6N5, Canada
| | - John P. Pezacki
- Life
Sciences Division, National Research Council of Canada, 100 Sussex
Drive, Ottawa K1A 0R6, Canada
- Department
of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa K1N 6N5, Canada
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146
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Spatially distinct and metabolically active membrane domain in mycobacteria. Proc Natl Acad Sci U S A 2016; 113:5400-5. [PMID: 27114527 DOI: 10.1073/pnas.1525165113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protected from host immune attack and antibiotic penetration by their unique cell envelope, mycobacterial pathogens cause devastating human diseases such as tuberculosis. Seamless coordination of cell growth with cell envelope elongation at the pole maintains this barrier. Unraveling this spatiotemporal regulation is a potential strategy for controlling mycobacterial infections. Our biochemical analysis previously revealed two functionally distinct membrane fractions in Mycobacterium smegmatis cell lysates: plasma membrane tightly associated with the cell wall (PM-CW) and a distinct fraction of pure membrane free of cell wall components (PMf). To provide further insight into the functions of these membrane fractions, we took the approach of comparative proteomics and identified more than 300 proteins specifically associated with the PMf, including essential enzymes involved in cell envelope synthesis such as a mannosyltransferase, Ppm1, and a galactosyltransferase, GlfT2. Furthermore, comparative lipidomics revealed the distinct lipid composition of the PMf, with specific association of key cell envelope biosynthetic precursors. Live-imaging fluorescence microscopy visualized the PMf as patches of membrane spatially distinct from the PM-CW and notably enriched in the pole of the growing cells. Taken together, our study provides the basis for assigning the PMf as a spatiotemporally distinct and metabolically active membrane domain involved in cell envelope biogenesis.
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147
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Abstract
Bacteria have traditionally been studied as single-cell organisms. In laboratory settings, aerobic bacteria are usually cultured in aerated flasks, where the cells are considered essentially homogenous. However, in many natural environments, bacteria and other microorganisms grow in mixed communities, often associated with surfaces. Biofilms are comprised of surface-associated microorganisms, their extracellular matrix material, and environmental chemicals that have adsorbed to the bacteria or their matrix material. While this definition of a biofilm is fairly simple, biofilms are complex and dynamic. Our understanding of the activities of individual biofilm cells and whole biofilm systems has developed rapidly, due in part to advances in molecular, analytical, and imaging tools and the miniaturization of tools designed to characterize biofilms at the enzyme level, cellular level, and systems level.
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148
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Fura JM, Pidgeon SE, Birabaharan M, Pires MM. Dipeptide-Based Metabolic Labeling of Bacterial Cells for Endogenous Antibody Recruitment. ACS Infect Dis 2016; 2:302-309. [PMID: 27294199 PMCID: PMC4898660 DOI: 10.1021/acsinfecdis.6b00007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Indexed: 02/06/2023]
Abstract
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The number of antibiotic-resistant
bacterial infections has increased
dramatically over the past decade. To combat these pathogens, novel
antimicrobial strategies must be explored and developed. We previously
reported a strategy based on hapten-modified cell wall analogues to
induce recruitment of endogenous antibodies to bacterial cell surfaces.
Cell surface remodeling using unnatural single d-amino acid
cell wall analogues led to modification at the C-terminus of the peptidoglycan
stem peptide. During peptidoglycan processing, installed hapten-displaying
amino acids can be subsequently removed by cell wall enzymes. Herein,
we disclose a two-step dipeptide peptidoglycan remodeling strategy
aimed at introducing haptens at an alternative site within the stem
peptide to improve retention and diminish removal by cell wall enzymes.
Through this redesigned strategy, we determined size constraints of
peptidoglycan remodeling and applied these constraints to attain hapten–linker
conjugates that produced high levels of antibody recruitment to bacterial
cell surfaces.
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Affiliation(s)
- Jonathan M. Fura
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Sean E. Pidgeon
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Morgan Birabaharan
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Marcos M. Pires
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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149
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Varon Silva D. ECBS & ICBS 2015 Joint Meeting: Bringing Chemistry to Life. Chembiochem 2016; 17:447-52. [PMID: 26710339 DOI: 10.1002/cbic.201500684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 01/11/2023]
Abstract
The European Chemical Biology Society (ECBS) and the International Chemical Biology Society (ICBS) recently organized a joint meeting in Berlin. This meeting had more than 250 participants. Four keynote lectures were given by Timothy Mitchison, David Tirrell, Carolyn Bertozzi and Jason Chin; in addition there were 13 invited speakers, 20 selected oral talks and 30 talks selected from 90 posters. The meeting was divided into six topics: chemoproteomics, epigenetics, conjugates for target delivering, anti-infectives, molecular imaging and probing the structure, and function of post-translational modifications. The highlights of the meeting are presented in this report.
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Affiliation(s)
- Daniel Varon Silva
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Muehlenberg 01, 14476, Potsdam, Germany.
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150
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Pidgeon SE, Pires MM. Metabolic remodeling of bacterial surfaces via tetrazine ligations. Chem Commun (Camb) 2016; 51:10330-3. [PMID: 26027845 DOI: 10.1039/c5cc01693b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Bioorthogonal click ligations are extensively used for the introduction of functional groups in biological systems. Tetrazine ligations are attractive in that they are catalyst-free and display favorable kinetics. We describe the efficient remodeling of bacterial cell surfaces using unnatural d-amino acids derivatized with tetrazine ligation handles. The metabolic incorporation of these unnatural d-amino acids onto bacterial cell surfaces resulted in a site-selective installation of fluorophores.
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Affiliation(s)
- S E Pidgeon
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
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