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Savková K, Danchenko M, Fabianová V, Bellová J, Bencúrová M, Huszár S, Korduláková J, Siváková B, Baráth P, Mikušová K. Compartmentalization of galactan biosynthesis in mycobacteria. J Biol Chem 2024; 300:105768. [PMID: 38367664 PMCID: PMC10951656 DOI: 10.1016/j.jbc.2024.105768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/31/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024] Open
Abstract
Galactan polymer is a prominent component of the mycobacterial cell wall core. Its biogenesis starts at the cytoplasmic side of the plasma membrane by a build-up of the linker disaccharide [rhamnosyl (Rha) - N-acetyl-glucosaminyl (GlcNAc) phosphate] on the decaprenyl-phosphate carrier. This decaprenyl-P-P-GlcNAc-Rha intermediate is extended by two bifunctional galactosyl transferases, GlfT1 and GlfT2, and then it is translocated to the periplasmic space by an ABC transporter Wzm-Wzt. The cell wall core synthesis is finalized by the action of an array of arabinosyl transferases, mycolyl transferases, and ligases that catalyze an attachment of the arabinogalactan polymer to peptidoglycan through the linker region. Based on visualization of the GlfT2 enzyme fused with fluorescent tags it was proposed that galactan polymerization takes place in a specific compartment of the mycobacterial cell envelope, the intracellular membrane domain, representing pure plasma membrane free of cell wall components (previously denoted as the "PMf" domain), which localizes to the polar region of mycobacteria. In this work, we examined the activity of the galactan-producing cellular machine in the cell-wall containing cell envelope fraction and in the cell wall-free plasma membrane fraction prepared from Mycobacterium smegmatis by the enzyme assays using radioactively labeled substrate UDP-[14C]-galactose as a tracer. We found that despite a high abundance of GlfT2 in both of these fractions as confirmed by their thorough proteomic analyses, galactan is produced only in the reaction mixtures containing the cell wall components. Our findings open the discussion about the distribution of GlfT2 and the regulation of its activity in mycobacteria.
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Affiliation(s)
- Karin Savková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Maksym Danchenko
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Viktória Fabianová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jana Bellová
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Mária Bencúrová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Stanislav Huszár
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jana Korduláková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Barbara Siváková
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Baráth
- Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarína Mikušová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia.
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Wen Z, Fang C, Liu X, Liu Y, Li M, Yuan Y, Han Z, Wang C, Zhang T, Sun C. A recombinant Mycobacterium smegmatis-based surface display system for developing the T cell-based COVID-19 vaccine. Hum Vaccin Immunother 2023; 19:2171233. [PMID: 36785935 PMCID: PMC10012901 DOI: 10.1080/21645515.2023.2171233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
The immune escape mutations of SARS-CoV-2 variants emerged frequently, posing a new challenge to weaken the protective efficacy of current vaccines. Thus, the development of novel SARS-CoV-2 vaccines is of great significance for future epidemic prevention and control. We herein reported constructing the attenuated Mycobacterium smegmatis (M. smegmatis) as a bacterial surface display system to carry the spike (S) and nucleocapsid (N) of SARS-CoV-2. To mimic the native localization on the surface of viral particles, the S or N antigen was fused with truncated PE_PGRS33 protein, which is a transportation component onto the cell wall of Mycobacterium tuberculosis (M.tb). The sub-cellular fraction analysis demonstrated that S or N protein was exactly expressed onto the surface (cell wall) of the recombinant M. smegmatis. After the immunization of the M. smegmatis-based COVID-19 vaccine candidate in mice, S or N antigen-specific T cell immune responses were effectively elicited, and the subsets of central memory CD4+ T cells and CD8+ T cells were significantly induced. Further analysis showed that there were some potential cross-reactive CTL epitopes between SARS-CoV-2 and M.smegmatis. Overall, our data provided insights that M. smegmatis-based bacterial surface display system could be a suitable vector for developing T cell-based vaccines against SARS-CoV-2 and other infectious diseases.
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Affiliation(s)
- Ziyu Wen
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Cuiting Fang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China.,University of Chinese Academy of Sciences (UCAS), Beijing, China.,Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China.,China-New Zealand Joint Laboratory on Biomedicine and Health, Guangzhou, China
| | - Xinglai Liu
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Yan Liu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China.,University of Chinese Academy of Sciences (UCAS), Beijing, China.,Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China
| | - Minchao Li
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Yue Yuan
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Zirong Han
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Congcong Wang
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China
| | - Tianyu Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China.,University of Chinese Academy of Sciences (UCAS), Beijing, China.,Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China.,China-New Zealand Joint Laboratory on Biomedicine and Health, Guangzhou, China
| | - Caijun Sun
- School of Public Health (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, China.,Ministry of Education, Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Guangzhou, China
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3
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Boradia V, Frando A, Grundner C. The Mycobacterium tuberculosis PE15/PPE20 complex transports calcium across the outer membrane. PLoS Biol 2022; 20:e3001906. [PMID: 36441815 PMCID: PMC9731449 DOI: 10.1371/journal.pbio.3001906] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/08/2022] [Accepted: 11/04/2022] [Indexed: 11/29/2022] Open
Abstract
The mechanisms by which nutrients traverse the Mycobacterium tuberculosis (Mtb) outer membrane remain mostly unknown and, in the absence of classical porins, likely involve specialized transport systems. Calcium ions (Ca2+) are an important nutrient and serve as a second messenger in eukaryotes, but whether bacteria have similar Ca2+ signaling systems is not well understood. To understand the basis for Ca2+ transport and signaling in Mtb, we determined Mtb's transcriptional response to Ca2+. Overall, only few genes changed expression, suggesting a limited role of Ca2+ as a transcriptional regulator. However, 2 of the most strongly down-regulated genes were the pe15 and ppe20 genes that code for members of a large family of proteins that localize to the outer membrane and comprise many intrinsically disordered proteins. PE15 and PPE20 formed a complex and PPE20 directly bound Ca2+. Ca2+-associated phenotypes such as increased ATP consumption and biofilm formation were reversed in a pe15/ppe20 knockout (KO) strain, suggesting a direct role in Ca2+ homeostasis. To test whether the PE15/PPE20 complex has a role in Ca2+ transport across the outer membrane, we created a fluorescence resonance energy transfer (FRET)-based Ca2+ reporter strain. A pe15/ppe20 KO in the FRET background showed a specific and selective loss of Ca2+ influx that was dependent on the presence of an intact outer cell wall. These data show that PE15/PPE20 form a Ca2+-binding protein complex that selectively imports Ca2+, show a distinct transport function for an intrinsically disordered protein, and support the emerging idea of a general family-wide role of PE/PPE proteins as idiosyncratic transporters across the outer membrane.
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Affiliation(s)
- Vishant Boradia
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Andrew Frando
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Christoph Grundner
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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4
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Direct Interaction of Polar Scaffolding Protein Wag31 with Nucleoid-Associated Protein Rv3852 Regulates Its Polar Localization. Cells 2021; 10:cells10061558. [PMID: 34203111 PMCID: PMC8233713 DOI: 10.3390/cells10061558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/12/2021] [Accepted: 06/16/2021] [Indexed: 11/25/2022] Open
Abstract
Rv3852 is a unique nucleoid-associated protein (NAP) found exclusively in Mycobacterium tuberculosis (Mtb) and closely related species. Although annotated as H-NS, we showed previously that it is very different from H-NS in its properties and is distinct from other NAPs, anchoring to cell membrane by virtue of possessing a C-terminal transmembrane helix. Here, we investigated the role of Rv3852 in Mtb in organizing architecture or synthesis machinery of cell wall by protein–protein interaction approach. We demonstrated a direct physical interaction of Rv3852 with Wag31, an important cell shape and cell wall integrity determinant essential in Mtb. Wag31 localizes to the cell poles and possibly acts as a scaffold for cell wall synthesis proteins, resulting in polar cell growth in Mtb. Ectopic expression of Rv3852 in M. smegmatis resulted in its interaction with Wag31 orthologue DivIVAMsm. Binding of the NAP to Wag31 appears to be necessary for fine-tuning Wag31 localization to the cell poles, enabling complex cell wall synthesis in Mtb. In Rv3852 knockout background, Wag31 is mislocalized resulting in disturbed nascent peptidoglycan synthesis, suggesting that the NAP acts as a driver for localization of Wag31 to the cell poles. While this novel association between these two proteins presents one of the mechanisms to structure the elaborate multi-layered cell envelope of Mtb, it also exemplifies a new function for a NAP in mycobacteria.
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5
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Levine SR, Beatty KE. Investigating β-Lactam Drug Targets in Mycobacterium tuberculosis Using Chemical Probes. ACS Infect Dis 2021; 7:461-470. [PMID: 33470787 DOI: 10.1021/acsinfecdis.0c00809] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb), infects 10 million people a year. An estimated 25% of humans harbor latent TB infections, an asymptomatic form of the disease. In both active and latent infections, Mtb relies on cell wall peptidoglycan for viability. In the current work, we synthesized fluorescent analogues of β-lactam antibiotics to study two classes of enzymes that maintain Mtb's peptidoglycan: penicillin-binding proteins (PBPs) and l,d-transpeptidases (LDTs). This set of activity-based probes included analogues of three classes of β-lactams: a monobactam (aztreonam-Cy5), a cephalosporin (cephalexin-Cy5), and a carbapenem (meropenem-Cy5). We used these probes to profile enzyme activity in protein gel-resolved lysates of Mtb. All three out-performed the commercial reagent Bocillin-FL, a penam. Meropenem-Cy5 was used to identify β-lactam targets by mass spectrometry, including PBPs, LDTs, and the β-lactamase BlaC. New probes were also used to compare PBP and LDT activity in two metabolic states: dormancy and active replication. We provide the first direct evidence that Mtb dynamically regulates the enzymes responsible for maintaining peptidoglycan in dormancy. Lastly, we profiled drug susceptibility in lysates and found that meropenem inhibits PBPs, LDTs, and BlaC.
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Affiliation(s)
- Samantha R. Levine
- Department of Pharmaceutical Sciences, University of California-Irvine, Irvine, California 92617, United States
| | - Kimberly E. Beatty
- Department of Pharmaceutical Sciences, University of California-Irvine, Irvine, California 92617, United States
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Mosavari N, Karimi A, Tadayon K, Shahhosseini G, Zavaran Hosseini A, Babaie M. Evaluation of Heating and Irradiation Methods for Production of Purified Protein Derivative (PPD) of Mycobacterium Tuberculosis. ARCHIVES OF RAZI INSTITUTE 2021; 75:439-449. [PMID: 33403839 DOI: 10.22092/ari.2019.123082.1238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 12/10/2019] [Indexed: 09/30/2022]
Abstract
Tuberculin skin test, also known as the tuberculin or purified protein derivative (PPD) test, is an extensively applied diagnostic test for the detection of primary infection with Mycobacterium tuberculosis (Mtb). The production of PPD is accompanied by some difficulties that require a series of modifications in the production and purification processes. The present study aimed to determine the facilitation level of the manufacturing process by modifying evaluation methods for the production of PPD tuberculin. Mtb strains were cultured in Lowenstein-Jensen media, and the cultured strains were inoculated into the Dorset-Henley liquid medium by the biphasic medium of potato-Dorset-Henley. After incubation, flasks containing cultured strain were selected for bacterial inactivation, and the optimal gamma radiation dose(s) was determined. Tuberculoproteins were precipitated by ammonium sulfate (AS) and Trichloroacetic acid (TCA). Protein concentration was determined using the Bradford and Kjeldahl protein assay methods. Finally, the lymphocyte transformation test and potency test were performed. Based on the results, the Dorset-Henley liquid medium is suitable for the massive growth of the bacterium. The transferal of Mtb from solid to liquid medium was directly carried out without intermediate culture. It was found that during tuberculoprotein production, heating at 100°C for 3 h would be safe for killing mycobacterium. Furthermore, the simultaneous use of heating and gamma irradiation (8 kGgy) killed all of the mycobacteria, while doses of 1, 1.5, and 7 kGy decreased a significant number of bacterial cells. The results also indicated that the concentration of tuberculoprotein extracted by TCA precipitation method was higher than that obtained by AS precipitation. The tuberculoproteins which were produced by these two methods in the lymphocyte transformation test were not significantly different in terms of potency (P>0.05). Moreover, due to the high volume of produced protein, the protein measurement was more efficiently carried out by the Kjeldahl method, compared to the Bradford method. Finally, the results of the present study demonstrated that in addition to the novel approach of gamma irradiation, optimum methods are efficient and applicable in the production of PPD tuberculin.
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Affiliation(s)
- N Mosavari
- . Reference Laboratory of Bovine Tuberculosis, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - A Karimi
- Department of Molecular Medicine, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - K Tadayon
- . Reference Laboratory of Bovine Tuberculosis, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Gh Shahhosseini
- Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute, Karaj, Iran.,Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute, Karaj, Iran
| | | | - M Babaie
- . Reference Laboratory of Bovine Tuberculosis, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
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7
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Abstract
This chapter covers the various methods of mechanical cell disruption and tissue homogenization that are currently commercially available for processing small samples s < 1 mL) to larger multikilogram production quantities. These mechanical methods of lysing do not introduce chemicals or enzymes to the system. However, the energies required when using these "harsh," high mechanical energy methods can be enough to damage the very components being sought.The destruction of cell membranes and walls is effected by subjecting the cells (a) to shearing by liquid flow, (b) to exploding by pressure differences between inside and outside of cell, (c) to collision forces by impact of beads or paddles, or (d) a combination of these forces.Practical suggestions to optimize each method, where to acquire such equipment, and links to reference sources are included. Several novel technologies are presented.
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8
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Strong EJ, Jurcic Smith KL, Saini NK, Ng TW, Porcelli SA, Lee S. Identification of Autophagy-Inhibiting Factors of Mycobacterium tuberculosis by High-Throughput Loss-of-Function Screening. Infect Immun 2020; 88:e00269-20. [PMID: 32989037 PMCID: PMC7671894 DOI: 10.1128/iai.00269-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/23/2020] [Indexed: 12/19/2022] Open
Abstract
The interaction of host cells with mycobacteria is complex and can lead to multiple outcomes ranging from bacterial clearance to progressive or latent infection. Autophagy is recognized as one component of host cell responses that has an essential role in innate and adaptive immunity to intracellular bacteria. Many microbes, including Mycobacterium tuberculosis, have evolved to evade or exploit autophagy, but the precise mechanisms and virulence factors are mostly unknown. Through a loss-of-function screening of an M. tuberculosis transposon mutant library, we identified 16 genes that contribute to autophagy inhibition, six of which encoded the PE/PPE protein family. Their expression in Mycobacterium smegmatis confirmed that these PE/PPE proteins inhibit autophagy and increase intracellular bacterial persistence or replication in infected cells. These effects were associated with increased mammalian target of rapamycin (mTOR) activity and also with decreased production of tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β). We also confirmed that the targeted deletion of the pe/ppe genes in M. tuberculosis resulted in enhanced autophagy and improved intracellular survival rates compared to those of wild-type bacteria in the infected macrophages. Differential expression of these PE/PPE proteins was observed in response to various stress conditions, suggesting that they may confer advantages to M. tuberculosis by modulating its interactions with host cells under various conditions. Our findings demonstrated that multiple M. tuberculosis PE/PPE proteins are involved in inhibiting autophagy during infection of host phagocytes and may provide strategic targets in developing therapeutics or vaccines against tuberculosis.
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Affiliation(s)
- Emily J Strong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | - Neeraj K Saini
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tony W Ng
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Steven A Porcelli
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Sunhee Lee
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Human Vaccine Institute, Duke University, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
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9
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Hermann C, Karamchand L, Blackburn JM, Soares NC. Cell Envelope Proteomics of Mycobacteria. J Proteome Res 2020; 20:94-109. [PMID: 33140963 DOI: 10.1021/acs.jproteome.0c00650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The World Health Organization (WHO) estimates that Mycobacterium tuberculosis, the most pathogenic mycobacterium species to humans, has infected up to a quarter of the world's population, with the occurrence of multidrug-resistant strains on the rise. Research into the detailed composition of the cell envelope proteome in mycobacteria over the last 20 years has formed a key part of the efforts to understand host-pathogen interactions and to control the current tuberculosis epidemic. This is due to the great importance of the cell envelope proteome during infection and during the development of antibiotic resistance as well as the search of surface-exposed proteins that could be targeted by therapeutics and vaccines. A variety of experimental approaches and mycobacterial species have been used in proteomic studies thus far. Here we provide for the first time an extensive summary of the different approaches to isolate the mycobacterial cell envelope, highlight some of the limitations of the studies performed thus far, and comment on how the recent advances in membrane proteomics in other fields might be translated into the field of mycobacteria to provide deeper coverage.
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Affiliation(s)
- Clemens Hermann
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Leshern Karamchand
- National Research Council Canada, Nanotechnology Research Centre, Biomedical Nanotechnologies, 11421 Saskatchewan Drive NW, Edmonton, Alberta T6G 2M9, Canada
| | - Jonathan M Blackburn
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
| | - Nelson C Soares
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates.,College of Pharmacy, Department of Medicinal Chemistry, University of Sharjah, Sharjah 27272, United Arab Emirates
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Garg R, Borbora SM, Bansia H, Rao S, Singh P, Verma R, Balaji KN, Nagaraja V. Mycobacterium tuberculosis Calcium Pump CtpF Modulates the Autophagosome in an mTOR-Dependent Manner. Front Cell Infect Microbiol 2020; 10:461. [PMID: 33042857 PMCID: PMC7525011 DOI: 10.3389/fcimb.2020.00461] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022] Open
Abstract
Calcium is a very important second messenger, whose concentration in various cellular compartments is under tight regulation. A disturbance in the levels of calcium in these compartments can play havoc in the cell, as it regulates various cellular processes by direct or indirect mechanisms. Here, we have investigated the functional importance of a calcium transporting P2A ATPase, CtpF of Mycobacterium tuberculosis (Mtb) in the pathogen's interaction with the host. Among its uncanny ways of dealing with the host with umpteen strategies for survival and persistence in humans, CtpF is identified as a new player. The levels of ctpF are upregulated in macrophage stresses like hypoxia, high nitric oxide levels and acidic pH. Using confocal microscopy and fluorimetry, we show that CtpF effluxes calcium in macrophages in early stages of Mtb infection. Downregulation of ctpF expression by conditional knockdown resulted in perturbation of host calcium levels and consequent decreased activation of mTOR. We present a mechanism how calcium efflux by the pathogen inhibits mTOR-dependent autophagy and enhances bacterial survival. Our work highlights how Mtb engages its metal efflux pumps to exploit host autophagic process for its proliferation.
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Affiliation(s)
- Rajni Garg
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Salik Miskat Borbora
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Harsh Bansia
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Sandhya Rao
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Prakruti Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Rinkee Verma
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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11
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Espinosa-Cueto P, Magallanes-Puebla A, Mancilla R. Phosphate starvation enhances phagocytosis of Mycobacterium bovis/BCG by macrophages. BMC Immunol 2020; 21:34. [PMID: 32517651 PMCID: PMC7282091 DOI: 10.1186/s12865-020-00364-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 06/04/2020] [Indexed: 01/07/2023] Open
Abstract
Background Tuberculosis is an important health problem worldwide. The only available vaccine is M. bovis/BCG, an attenuated mycobacterium that activates the innate and the acquired immune system after being phagocytosed by macrophages and dendritic cells. Vaccination fails to prevent adult pulmonary tuberculosis although it may have a protective effect in childhood infection. Understanding how BCG interacts with macrophages and other immunocompetent cells is crucial to develop new vaccines. Results In this study we showed that macrophages phagocytose M. bovis/BCG bacilli with higher efficiency when they are cultured without phosphate. We isolated mycobacterial membranes to search for mycobacterial molecules that could be involved in these processes; by immunoblot, it was found that the plasma membranes of phosphate-deprived bacilli express the adhesins PstS-1, LpqH, LprG, and the APA antigen. These proteins are not detected in membranes of bacilli grown with usual amounts of phosphate. Conclusions The interest of our observations is to show that under the metabolic stress implied in phosphate deprivation, mycobacteria respond upregulating adhesins that could improve their capacity to infect macrophages. These observations are relevant to understand how M. bovis/BCG induces protective immunity.
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Affiliation(s)
- Patricia Espinosa-Cueto
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, 04510, México City, Mexico
| | - Alejandro Magallanes-Puebla
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, 04510, México City, Mexico
| | - Raul Mancilla
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Escolar S/N, Ciudad Universitaria, 04510, México City, Mexico.
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12
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Rv2037c, a stress induced conserved hypothetical protein of Mycobacterium tuberculosis, is a phospholipase: Role in cell wall modulation and intracellular survival. Int J Biol Macromol 2020; 153:817-835. [DOI: 10.1016/j.ijbiomac.2020.03.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 02/08/2023]
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13
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Kavunja HW, Biegas KJ, Banahene N, Stewart JA, Piligian BF, Groenevelt JM, Sein CE, Morita YS, Niederweis M, Siegrist MS, Swarts BM. Photoactivatable Glycolipid Probes for Identifying Mycolate-Protein Interactions in Live Mycobacteria. J Am Chem Soc 2020; 142:7725-7731. [PMID: 32293873 PMCID: PMC7949286 DOI: 10.1021/jacs.0c01065] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycobacteria have a distinctive glycolipid-rich outer membrane, the mycomembrane, which is a critical target for tuberculosis drug development. However, proteins that associate with the mycomembrane, or that are involved in its metabolism and host interactions, are not well-characterized. To facilitate the study of mycomembrane-related proteins, we developed photoactivatable trehalose monomycolate analogues that metabolically incorporate into the mycomembrane in live mycobacteria, enabling in vivo photo-cross-linking and click-chemistry-mediated analysis of mycolate-interacting proteins. When deployed in Mycobacterium smegmatis with quantitative proteomics, this strategy enriched over 100 proteins, including the mycomembrane porin (MspA), several proteins with known mycomembrane synthesis or remodeling functions (CmrA, MmpL3, Ag85, Tdmh), and numerous candidate mycolate-interacting proteins. Our approach is highly versatile, as it (i) enlists click chemistry for flexible protein functionalization; (ii) in principle can be applied to any mycobacterial species to identify endogenous bacterial proteins or host proteins that interact with mycolates; and (iii) can potentially be expanded to investigate protein interactions with other mycobacterial lipids. This tool is expected to help elucidate fundamental physiological and pathological processes related to the mycomembrane and may reveal novel diagnostic and therapeutic targets.
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Affiliation(s)
- Herbert W Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Kyle J Biegas
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Jessica A Stewart
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Brent F Piligian
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Jessica M Groenevelt
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Caralyn E Sein
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
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Maan P, Kaur J. Rv2223c, an acid inducible carboxyl-esterase of Mycobacterium tuberculosis enhanced the growth and survival of Mycobacterium smegmatis. Future Microbiol 2019; 14:1397-1415. [DOI: 10.2217/fmb-2019-0162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To elucidate the role of Rv2223c in Mycobacterium tuberculosis. Methods: Purified recombinant Rv2223c protein was characterized. Expression of rv2223c in the presence of different stress environment and subcellular localization were performed in M. tuberculosis H37Ra and Mycobacterium smegmatis ( MS_2223c). Effect of its overexpression on growth rate, infection and intracellular survival in THP-1/PBMC cells were studied. Results: rRv2223c demonstrated esterase activity with preference for pNP-octanoate and hydrolyzed trioctanoate to di- and mono-octanoate. Expression of rv2223c was upregulated in acidic and nutritive stress conditions. rRv2223c was identified in extracellular and cell wall fractions. MS_2223c exhibited enhanced growth, survival during in vitro stress, infection and intracellular survival. Conclusions: Rv2223c is a secretary, carboxyl-esterase, with enhanced expression under acidic and nutritive stress condition and might help in intracellular survival of bacteria.
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Affiliation(s)
- Pratibha Maan
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, India
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Kaur J, Kaur J. Rv0518, a nutritive stress inducible GDSL lipase of Mycobacterium tuberculosis, enhanced intracellular survival of bacteria by cell wall modulation. Int J Biol Macromol 2019; 135:180-195. [DOI: 10.1016/j.ijbiomac.2019.05.121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022]
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Kamariah N, Huber RG, Nartey W, Bhushan S, Bond PJ, Grüber G. Structure and subunit arrangement of Mycobacterial F1FO ATP synthase and novel features of the unique mycobacterial subunit δ. J Struct Biol 2019; 207:199-208. [DOI: 10.1016/j.jsb.2019.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/21/2019] [Accepted: 05/23/2019] [Indexed: 02/08/2023]
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Daffé M, Marrakchi H. Unraveling the Structure of the Mycobacterial Envelope. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0027-2018. [PMID: 31267927 PMCID: PMC10957186 DOI: 10.1128/microbiolspec.gpp3-0027-2018] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Indexed: 12/28/2022] Open
Abstract
The mycobacterial cell envelope consists of a typical plasma membrane of lipid and protein surrounded by a complex cell wall composed of carbohydrate and lipid. In pathogenic species, such as Mycobacterium tuberculosis, an outermost "capsule" layer surrounds the cell wall. This wall embraces a fundamental, covalently linked "cell-wall skeleton" composed of peptidoglycan, solidly attached to arabinogalactan, whose penta-saccharide termini are esterified by very-long-chain fatty acids (mycolic acids). These fatty acids form the inner leaflet of an outer membrane, called the mycomembrane, whose outer leaflet consists of a great variety of non-covalently linked lipids and glycolipids. The thickness of the mycomembrane, which is similar to that of the plasma membrane, is surprising in view of the length of mycoloyl residues, suggesting dedicated conformations of these fatty acids. Finally, a periplasmic space also exists in mycobacteria, between the plasma membrane and the peptidoglycan. This article provides a comprehensive overview of this biologically important and structurally unique mycobacterial cell compartment.
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Affiliation(s)
- Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Department of Tuberculosis and Infection Biology, Toulouse, France
| | - Hedia Marrakchi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Department of Tuberculosis and Infection Biology, Toulouse, France
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18
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Saleem I, Coombes AGA, Chambers MA. In Vitro Evaluation of Eudragit Matrices for Oral Delivery of BCG Vaccine to Animals. Pharmaceutics 2019; 11:pharmaceutics11060270. [PMID: 31185612 PMCID: PMC6630751 DOI: 10.3390/pharmaceutics11060270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022] Open
Abstract
Bacillus Calmette–Guérin (BCG) vaccine is the only licensed vaccine against tuberculosis (TB) in humans and animals. It is most commonly administered parenterally, but oral delivery is highly advantageous for the immunisation of cattle and wildlife hosts of TB in particular. Since BCG is susceptible to inactivation in the gut, vaccine formulations were prepared from suspensions of Eudragit L100 copolymer powder and BCG in phosphate-buffered saline (PBS), containing Tween® 80, with and without the addition of mannitol or trehalose. Samples were frozen at −20 °C, freeze-dried and the lyophilised powders were compressed to produce BCG–Eudragit matrices. Production of the dried powders resulted in a reduction in BCG viability. Substantial losses in viability occurred at the initial formulation stage and at the stage of powder compaction. Data indicated that the Eudragit matrix protected BCG against simulated gastric fluid (SGF). The matrices remained intact in SGF and dissolved completely in simulated intestinal fluid (SIF) within three hours. The inclusion of mannitol or trehalose in the matrix provided additional protection to BCG during freeze-drying. Control needs to be exercised over BCG aggregation, freeze-drying and powder compaction conditions to minimise physical damage of the bacterial cell wall and maximise the viability of oral BCG vaccines prepared by dry powder compaction.
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Affiliation(s)
- Imran Saleem
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
| | - Allan G A Coombes
- Pharmacy Australia Centre of Excellence, University of Queensland, School of Pharmacy, 20 Cornwall Street, Woolloongaba, QLD 4102, Australia.
| | - Mark A Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
- School of Veterinary Medicine, University of Surrey, VSM Building, Daphne Jackson Rd, Guildford GU2 7AL, UK.
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Fiolek TJ, Banahene N, Kavunja HW, Holmes NJ, Rylski AK, Pohane AA, Siegrist MS, Swarts BM. Engineering the Mycomembrane of Live Mycobacteria with an Expanded Set of Trehalose Monomycolate Analogues. Chembiochem 2019; 20:1282-1291. [PMID: 30589191 PMCID: PMC6614877 DOI: 10.1002/cbic.201800687] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Indexed: 01/20/2023]
Abstract
Mycobacteria and related organisms in the Corynebacterineae suborder are characterized by a distinctive outer membrane referred to as the mycomembrane. Biosynthesis of the mycomembrane occurs through an essential process called mycoloylation, which involves antigen 85 (Ag85)-catalyzed transfer of mycolic acids from the mycoloyl donor trehalose monomycolate (TMM) to acceptor carbohydrates and, in some organisms, proteins. We recently described an alkyne-modified TMM analogue (O-AlkTMM-C7) which, in conjunction with click chemistry, acted as a chemical reporter for mycoloylation in intact cells and allowed metabolic labeling of mycoloylated components of the mycomembrane. Here, we describe the synthesis and evaluation of a toolbox of TMM-based reporters bearing alkyne, azide, trans-cyclooctene, and fluorescent tags. These compounds gave further insight into the substrate tolerance of mycoloyltransferases (e.g., Ag85s) in a cellular context and they provide significantly expanded experimental versatility by allowing one- or two-step cell labeling, live cell labeling, and rapid cell labeling via tetrazine ligation. Such capabilities will facilitate research on mycomembrane composition, biosynthesis, and dynamics. Moreover, because TMM is exclusively metabolized by Corynebacterineae, the described probes may be valuable for the specific detection and cell-surface engineering of Mycobacterium tuberculosis and related pathogens. We also performed experiments to establish the dependence of probe incorporation on mycoloyltransferase activity, results from which suggested that cellular labeling is a function not only of metabolic incorporation (and likely removal) pathway(s), but also accessibility across the envelope. Thus, whole-cell labeling experiments with TMM reporters should be carefully designed and interpreted when envelope permeability may be compromised. On the other hand, this property of TMM reporters can potentially be exploited as a convenient way to probe changes in envelope integrity and permeability, facilitating drug development studies.
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Affiliation(s)
- Taylor J Fiolek
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Herbert W Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Nathan J Holmes
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Adrian K Rylski
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
| | - Amol Arunrao Pohane
- Department of Microbiology, University of Massachusetts, 639 N. Pleasant Street, Amherst, MA, 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, 639 N. Pleasant Street, Amherst, MA, 01003, USA
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI, 48859, USA
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Sicairos-Ruelas EE, Gerba CP, Bright KR. Efficacy of copper and silver as residual disinfectants in drinking water. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2019; 54:146-155. [PMID: 30686111 DOI: 10.1080/10934529.2018.1535160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/02/2018] [Accepted: 10/05/2018] [Indexed: 06/09/2023]
Abstract
Contamination events and biofilms can decrease the amount of free chlorine available in drinking water systems. The efficacy of 100 μg/L silver and 400 μg/L copper, individually and combined, were evaluated as secondary, longer-lasting residual disinfectants against Salmonella enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Mycobacterium fortuitum at 24 °C and 4 °C. A >5.0-log10 reduction was observed in E. coli and L. monocytogenes after three hours and S. Typhimurium following seven hours of exposure to silver. M. fortuitum was the most resistant species to silver (1.11-log10 after seven hours). Copper did not significantly reduce S. Typhimurium and E. coli at 24 °C; ≥2.80-log10 reductions were observed in the Gram-positive L. monocytogenes and M. fortuitum. Longer exposure times were required at 4 °C to achieve significant reductions in all species. A synergistic effect was observed when silver and copper were combined at 24 °C. In addition, silver was not affected by the presence of organic matter at concentrations that completely inhibited 0.2 mg/L chlorine. The results of this study suggest that combinations of silver and copper show promise as secondary residual disinfectants. They may also be used in conjunction with low chlorine levels or other disinfectants to provide additional, long-lasting residuals in distribution systems.
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Affiliation(s)
- Enue E Sicairos-Ruelas
- a Water and Energy Sustainable Technology Center , The University of Arizona , Tucson , Arizona , USA
| | - Charles P Gerba
- a Water and Energy Sustainable Technology Center , The University of Arizona , Tucson , Arizona , USA
| | - Kelly R Bright
- a Water and Energy Sustainable Technology Center , The University of Arizona , Tucson , Arizona , USA
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LipG a bifunctional phospholipase/thioesterase involved in mycobacterial envelope remodeling. Biosci Rep 2018; 38:BSR20181953. [PMID: 30487163 PMCID: PMC6435540 DOI: 10.1042/bsr20181953] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/27/2018] [Accepted: 11/27/2018] [Indexed: 12/28/2022] Open
Abstract
Tuberculosis caused by Mycobacterium tuberculosis is currently one of the leading causes of death from an infectious agent. The main difficulties encountered in eradicating this bacteria are mainly related to (i) a very complex lipid composition of the bacillus cell wall, (ii) its ability to hide from the immune system inside the granulomas, and (iii) the increasing number of resistant strains. In this context, we were interested in the Rv0646c (lipGMTB ) gene located upstream to the mmaA cluster which is described as being crucial for the production of cell wall components and required for the bacilli adaptation and survival in mouse macrophages. Using biochemical experiments combined with the construction of deletion and overexpression mutant strains in Mycobacterium smegmatis, we found that LipGMTB is a cytoplasmic membrane-associated enzyme that displays both phospholipase and thioesterase activities. Overproduction of LipGMTB decreases the glycopeptidolipids (GPL) level concomitantly to an increase in phosphatidylinositol (PI) which is the precursor of the PI mannoside (PIM), an essential lipid component of the bacterial cell wall. Conversely, deletion of the lipGMS gene in M. smegmatis leads to an overproduction of GPL, and subsequently decreases the strain susceptibility to various antibiotics. All these findings demonstrate that LipG is involved in cell envelope biosynthesis/remodeling, and consequently this enzyme may thus play an important role in mycobacterial physiology.
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22
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Maan P, Kumar A, Kaur J, Kaur J. Rv1288, a Two Domain, Cell Wall Anchored, Nutrient Stress Inducible Carboxyl-Esterase of Mycobacterium tuberculosis, Modulates Cell Wall Lipid. Front Cell Infect Microbiol 2018; 8:421. [PMID: 30560095 PMCID: PMC6287010 DOI: 10.3389/fcimb.2018.00421] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 11/16/2018] [Indexed: 01/29/2023] Open
Abstract
Rv1288, a conserved hypothetical protein of M. tuberculosis (M.tb), was recently characterized as two-domain esterase enzyme by in silico study. In the present study, Rv1288 and its domains (Est and Lyt) were cloned individually from M.tb into E. coli for expression and purification. The purified rRv1288 and rEst proteins exhibited lipolytic activity with medium chain length esters as optimum substrates, while Lyt domain did not show enzymatic activity. However, presence of Lyt domain resulted in enhanced rate of protein aggregation at higher temperature. Both rRv1288 and rEst followed the similar patterns of substrate specificity, temperature and pH activity. Site directed mutagenesis confirmed the Ser-294, Asp-391 and His-425 as catalytic site residues. Rv1288 was found to be present in cell wall fraction of M.tb H37Ra. Peptidoglycan binding activity of Rv1288 and its domains demonstrated that the Lyt domain is essential for anchoring protein to the cell wall. Expression of rv1288 was up regulated in M.tb under nutrient starved condition. Over expression of rv1288 in surrogate host M. smegmatis led to change in colony morphology, enhanced pellicle and aggregate formation that might be linked with the changed lipid composition of bacterial cell wall. Cell wall of M. smegmatis expressing rv1288 had higher amount of lipids, with a significant increase in trehalose dimycolate content. Rv1288 also leads to increase in drug resistance of M. smegmatis. Rv1288 also enhanced the intracellular survival of M. smegmatis in Raw264.7 cell line. Overall, this study suggested that Rv1288, a cell wall localized carboxyl hydrolase with mycolyl-transferase activity, modulated the cell wall lipids to favor the survival of bacteria under stress condition.
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Affiliation(s)
- Pratibha Maan
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Arbind Kumar
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Jashandeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, India
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Feng G, Flanagan BM, Mikkelsen D, Williams BA, Yu W, Gilbert RG, Gidley MJ. Mechanisms of utilisation of arabinoxylans by a porcine faecal inoculum: competition and co-operation. Sci Rep 2018. [PMID: 29540852 PMCID: PMC5852058 DOI: 10.1038/s41598-018-22818-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Recent studies show that a single or small number of intestinal microbes can completely degrade complex carbohydrates. This suggests a drive towards competitive utilisation of dietary complex carbohydrates resulting in limited microbial diversity, at odds with the health benefits associated with a diverse microbiome. This study investigates the enzymatic metabolism of wheat and rye arabinoxylans (AX) using in vitro fermentation, with a porcine faecal inoculum. Through studying the activity of AX-degrading enzymes and the structural changes of residual AX during fermentation, we show that the AX-degrading enzymes are mainly cell-associated, which enables the microbes to utilise the AX competitively. However, potential for cross-feeding is also demonstrated to occur by two distinct mechanisms: (1) release of AX after partial degradation by cell-associated enzymes, and (2) release of enzymes during biomass turnover, indicative of co-operative AX degradation. This study provides a model for the combined competitive-co-operative utilisation of complex dietary carbohydrates by gut microorganisms.
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Affiliation(s)
- Guangli Feng
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Bernadine M Flanagan
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Deirdre Mikkelsen
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Barbara A Williams
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Wenwen Yu
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Robert G Gilbert
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, College of Agriculture, Yangzhou University, Yangzhou, Jiangsu Province, 225009, China
| | - Michael J Gidley
- ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia.
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Chownk M, Kaur J, Singh K, Kaur J. mbtJ: an iron stress-induced acetyl hydrolase/esterase of Mycobacterium tuberculosis helps bacteria to survive during iron stress. Future Microbiol 2018. [PMID: 29519132 DOI: 10.2217/fmb-2017-0194] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AIM mbtJ from Mycobacterium tuberculosis H37Rv is a member of mbt A-J operon required for mycobactin biogenesis. MATERIALS & METHODS The esterase/acetyl-hydrolase activity of mbtJ was determined by pNP-esters/native-PAGE and expression under iron stress by quantitative-PCR. Effect of gene on growth/survival of Mycobacterium was studied using antisense. Its effect on morphology, growth/infection was studied in Mycobacterium smegmatis. RESULTS It showed acetyl hydrolase/esterase activity at pH 8.0 and 50°C with pNP-butyrate. Its expression was upregulated under iron stress. The antisense inhibited the survival of bacterium during iron stress. Expression of mbtJ changed colony morphology and enhanced the growth/infection in M. smegmatis. CONCLUSION mbtJ, an acetyl-hydrolase/esterase, enhanced the survival of M. tuberculosis under iron stress, affected the growth/infection efficiency in M. smegmatis, suggesting its pivotal role in the intracellular survival of bacterium.
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Affiliation(s)
- Manisha Chownk
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Jashandeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Kashmir Singh
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
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Mycobacterium tuberculosis H37Rv LpqG Protein Peptides Can Inhibit Mycobacterial Entry through Specific Interactions. Molecules 2018; 23:molecules23030526. [PMID: 29495456 PMCID: PMC6017924 DOI: 10.3390/molecules23030526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/14/2018] [Accepted: 02/21/2018] [Indexed: 01/08/2023] Open
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis, a disease causing major mortality worldwide. As part of a systematic methodology for studying M. tuberculosis surface proteins which might be involved in host-pathogen interactions, our group found that LpqG surface protein (Rv3623) found in M. tuberculosis complex strains was located on the mycobacterial envelope and that peptide 16661 (21SGCDSHNSGSLGADPRQVTVY40) had high specific binding to U937 monocyte-derived macrophages and inhibited mycobacterial entry to such cells in a concentration-dependent way. A region having high specific binding to A549 alveolar epithelial cells was found which had low mycobacterial entry inhibition. As suggested in previous studies, relevant sequences in the host-pathogen interaction do not induce an immune response and peptides characterised as HABPs are poorly recognised by sera from individuals regardless of whether they have been in contact with M. tuberculosis. Our approach to designing a synthetic, multi-epitope anti-tuberculosis vaccine has been based on identifying sequences involved in different proteins’ mycobacteria-target cell interaction and modifying their sequence to improve their immunogenic characteristics, meaning that peptide 16661 sequence should be considered in such design.
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Kaur G, Sharma A, Narang T, Dogra S, Kaur J. Characterization of ML0314c of Mycobacterium leprae and deciphering its role in the immune response in leprosy patients. Gene 2018; 643:26-34. [DOI: 10.1016/j.gene.2017.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 11/30/2017] [Accepted: 12/01/2017] [Indexed: 11/15/2022]
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Dissecting the mycobacterial cell envelope and defining the composition of the native mycomembrane. Sci Rep 2017; 7:12807. [PMID: 28993692 PMCID: PMC5634507 DOI: 10.1038/s41598-017-12718-4] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 09/18/2017] [Indexed: 11/20/2022] Open
Abstract
The mycobacterial envelope is unique, containing the so-called mycomembrane (MM) composed of very-long chain fatty acids, mycolic acids (MA). Presently, the molecular composition of the MM remains unproven, due to the diversity of methods used for determining its composition. The plasma membranes (PM) and the native MM-containing cell walls (MMCW) of two rapid-growing mycobacterial species, Mycobacterium aurum and M. smegmatis, were isolated from their cell lysates by differential ultracentrifugation. Transmission electron microscopy and biochemical analyses demonstrated that the two membranes were virtually pure. Bottom-up quantitative proteomics study indicated a different distribution of more than 2,100 proteins between the PM and MMCW. Among these, the mannosyltransferase PimB, galactofuranosyltransferase GlfT2, Cytochrome p450 and ABC transporter YjfF, were most abundant in the PM, which also contain lipoglycans, phospholipids, including phosphatidylinositol mannosides, and only a tiny amount of other glycolipids. Antigen85 complex proteins, porins and the putative transporters MCE protein family were mostly found in MMCW fraction that contains MA esterifying arabinogalactan, constituting the inner leaflet of MM. Glycolipids, phospholipids and lipoglycans, together with proteins, presumably composed the outer leaflet of the MM, a lipid composition that differs from that deduced from the widely used extraction method of mycobacterial cells with dioctylsulfosuccinate sodium.
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Tripathy A, Sen P, Su B, Briscoe WH. Natural and bioinspired nanostructured bactericidal surfaces. Adv Colloid Interface Sci 2017; 248:85-104. [PMID: 28780961 PMCID: PMC6643001 DOI: 10.1016/j.cis.2017.07.030] [Citation(s) in RCA: 257] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 07/25/2017] [Accepted: 07/25/2017] [Indexed: 01/22/2023]
Abstract
Bacterial antibiotic resistance is becoming more widespread due to excessive use of antibiotics in healthcare and agriculture. At the same time the development of new antibiotics has effectively ground to a hold. Chemical modifications of material surfaces have poor long-term performance in preventing bacterial build-up and hence approaches for realising bactericidal action through physical surface topography have become increasingly important in recent years. The complex nature of the bacteria cell wall interactions with nanostructured surfaces represents many challenges while the design of nanostructured bactericidal surfaces is considered. Here we present a brief overview of the bactericidal behaviour of naturally occurring and bio-inspired nanostructured surfaces against different bacteria through the physico-mechanical rupture of the cell wall. Many parameters affect this process including the size, shape, density, rigidity/flexibility and surface chemistry of the surface nanotextures as well as factors such as bacteria specificity (e.g. gram positive and gram negative) and motility. Different fabrication methods for such bactericidal nanostructured surfaces are summarised.
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Affiliation(s)
- Abinash Tripathy
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Prosenjit Sen
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Bo Su
- School of Oral and Dental Sciences, University of Bristol, Bristol BS1 2LY, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Bhat ZS, Rather MA, Maqbool M, Lah HU, Yousuf SK, Ahmad Z. Cell wall: A versatile fountain of drug targets in Mycobacterium tuberculosis. Biomed Pharmacother 2017; 95:1520-1534. [PMID: 28946393 DOI: 10.1016/j.biopha.2017.09.036] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 09/07/2017] [Accepted: 09/10/2017] [Indexed: 12/18/2022] Open
Abstract
Tuberculosis is the leading infectious disease responsible for an estimated one and a half million human deaths each year around the globe. HIV-TB coinfection and rapid increase in the emergence of drug resistant forms of TB is a dangerous scenario. This underlines the urgent need for new drugs with novel mechanism of action. A plethora of literature exist that highlight the importance of enzymes involved in the biosynthesis of mycobacterial cell wall responsible for its survival, growth, permeability, virulence and resistance to antibiotics. Therefore, assembly of cell wall components is an attractive target for the development of chemotherapeutics against Mycobacterium tuberculosis. The aim of this review is to highlight novel sets of enzyme inhibitors that disrupt its cell wall biosynthetic pathway. These include the currently approved first and second line drugs, candidates in clinical trials and current structure activity guided endeavors of scientific community to identify new potent inhibitors with least cytotoxicity and better efficacy against emergence of drug resistance till date.
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Affiliation(s)
- Zubair Shanib Bhat
- Clinical Microbiology and PK/PD Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India.
| | - Muzafar Ahmad Rather
- Clinical Microbiology and PK/PD Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India; Department of Biochemistry, University of Kashmir, Srinagar, Jammu & Kashmir 190006, India
| | - Mubashir Maqbool
- Clinical Microbiology and PK/PD Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India; Department of Zoology, University of Kashmir, Srinagar, Jammu & Kashmir 190006, India
| | - Hafiz Ul Lah
- Medicinal Chemistry Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India
| | - Syed Khalid Yousuf
- Academy of Scientific and Innovative Research (AcSIR), CSIR- Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India; Medicinal Chemistry Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India
| | - Zahoor Ahmad
- Clinical Microbiology and PK/PD Division, Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Indian Institute of Integrative Medicine (IIIM), Campus, Sanat Nagar, Srinagar, Jammu & Kashmir 190005, India.
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30
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Singh KH, Jha B, Dwivedy A, Choudhary E, N AG, Ashraf A, Arora D, Agarwal N, Biswal BK. Characterization of a secretory hydrolase from Mycobacterium tuberculosis sheds critical insight into host lipid utilization by M. tuberculosis. J Biol Chem 2017; 292:11326-11335. [PMID: 28515317 DOI: 10.1074/jbc.m117.794297] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/15/2017] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis causes tuberculosis in humans and predominantly infects alveolar macrophages. To survive inside host lesions and to evade immune surveillance, this pathogen has developed many strategies. For example, M. tuberculosis uses host-derived lipids/fatty acids as nutrients for prolonged persistence within hypoxic host microenvironments. M. tuberculosis imports these metabolites through its respective transporters, and in the case of host fatty acids, a pertinent question arises: does M. tuberculosis have the enzyme(s) for cleavage of fatty acids from host lipids? We show herein that a previously uncharacterized membrane-associated M. tuberculosis protein encoded by Rv2672 is conserved exclusively in actinomycetes, exhibits both lipase and protease activities, is secreted into macrophages, and catalyzes host lipid hydrolysis. In light of these functions, we annotated Rv2672 as mycobacterial secreted hydrolase 1 (Msh1). Furthermore, we found that this enzyme is up-regulated both in an in vitro model of hypoxic stress and in a mouse model of M. tuberculosis infection, suggesting that the pathogen requires Msh1 under hypoxic conditions. Silencing Msh1 expression compromised the ability of M. tuberculosis to proliferate inside lipid-rich foamy macrophages but not under regular culture conditions in vitro, underscoring Msh1's importance for M. tuberculosis persistence in lipid-rich microenvironments. Of note, this is the first report providing insight into the mechanism of host lipid catabolism by an M. tuberculosis enzyme, augmenting our current understanding of how M. tuberculosis meets its nutrient requirements under hypoxic conditions.
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Affiliation(s)
| | - Bhavya Jha
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India
| | - Abhisek Dwivedy
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India
| | - Eira Choudhary
- Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Faridabad, Haryana 121001, India, and.,Symbiosis School of Biomedical Sciences, Symbiosis International University, Lavale, Pune, Maharashtra 412115, India
| | - Arpitha G N
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India
| | - Anam Ashraf
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India
| | - Divya Arora
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India
| | - Nisheeth Agarwal
- Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, Faridabad, Haryana 121001, India, and
| | - Bichitra Kumar Biswal
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi 110067, India,
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31
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Belardinelli JM, Jackson M. Green Fluorescent Protein as a protein localization and topological reporter in mycobacteria. Tuberculosis (Edinb) 2017; 105:13-17. [PMID: 28610783 DOI: 10.1016/j.tube.2017.04.001] [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: 11/29/2016] [Revised: 04/04/2017] [Accepted: 04/07/2017] [Indexed: 11/29/2022]
Abstract
The cell envelope-associated proteins of Mycobacterium species play critical functions in the physiology and pathogenicity of these microorganisms. Because the determination of their subcellular localization and transmembrane topology is often critical to the understanding of their function, we investigated whether the Green Fluorescent Protein (GFP) could be used as a reporter to probe protein localization and map the topology of inner membrane proteins directly in intact mycobacterial cells. To this end, two GFP-based mycobacterial reporter plasmids were engineered and their functionality validated using a variety of membrane-associated, exported and cytosolic proteins.
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Affiliation(s)
- Juan Manuel Belardinelli
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA.
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32
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Jadeja D, Dogra N, Arya S, Singh G, Singh G, Kaur J. Characterization of LipN (Rv2970c) of Mycobacterium Tuberculosis H37Rv and its Probable Role in Xenobiotic Degradation. J Cell Biochem 2016. [PMID: 26212120 DOI: 10.1002/jcb.25285] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
LipN (Rv2970c) belongs to the Lip family of M. tuberculosis H37Rv and is homologous to the human Hormone Sensitive Lipase. The enzyme demonstrated preference for short carbon chain substrates with optimal activity at 45°C/pH 8.0 and stability between pH 6.0-9.0. The specific activity of the enzyme was 217 U/mg protein with pNP-butyrate as substrate. It hydrolyzed tributyrin to di- and monobutyrin. The active-site residues of the enzyme were confirmed to be Ser216, Asp316, and His346. Tetrahydrolipstatin, RHC-80267 and N-bromosuccinimide inhibited LipN enzyme activity completely. Interestingly, Trp145, a non active-site residue, demonstrated functional role to retain enzyme activity. The enzyme was localized in cytosolic fraction of M. tuberculosis H37Rv. The enzyme was able to synthesize ester of butyric acid, methyl butyrate, in presence of methanol. LipN was able to hydrolyze 4-hydroxyphenylacetate to hydroquinone. The gene was not expressed in in-vitro growth conditions while the expression of rv2970c gene was observed post 6h of macrophage infection by M. tuberculosis H37Ra. Under individual in-vitro stress conditions, the gene was expressed during acidic stress condition only. These findings suggested that LipN is a cytosolic, acid inducible carboxylesterase with no positional specificity in demonstrating activity with short carbon chain substrates. It requires Trp145, a non active site residue, for it's enzyme activity.
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Affiliation(s)
| | - Nandita Dogra
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Stuti Arya
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Gurpreet Singh
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Gurdyal Singh
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, India
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33
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Mitachi K, Siricilla S, Yang D, Kong Y, Skorupinska-Tudek K, Swiezewska E, Franzblau SG, Kurosu M. Fluorescence-based assay for polyprenyl phosphate-GlcNAc-1-phosphate transferase (WecA) and identification of novel antimycobacterial WecA inhibitors. Anal Biochem 2016; 512:78-90. [PMID: 27530653 DOI: 10.1016/j.ab.2016.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 07/18/2016] [Accepted: 08/08/2016] [Indexed: 11/26/2022]
Abstract
Polyprenyl phosphate-GlcNAc-1-phosphate transferase (WecA) is an essential enzyme for the growth of Mycobacterium tuberculosis (Mtb) and some other bacteria. Mtb WecA catalyzes the transformation from UDP-GlcNAc to decaprenyl-P-P-GlcNAc, the first membrane-anchored glycophospholipid that is responsible for the biosynthesis of mycolylarabinogalactan in Mtb. Inhibition of WecA will block the entire biosynthesis of essential cell wall components of Mtb in both replicating and non-replicating states, making this enzyme a target for development of novel drugs. Here, we report a fluorescence-based method for the assay of WecA using a modified UDP-GlcNAc, UDP-Glucosamine-C6-FITC (1), a membrane fraction prepared from an M. smegmatis strain, and the E. coli B21WecA. Under the optimized conditions, UDP-Glucosamine-C6-FITC (1) can be converted to the corresponding decaprenyl-P-P-Glucosamine-C6-FITC (3) in 61.5% yield. Decaprenyl-P-P-Glucosamine-C6-FITC is readily extracted with n-butanol and can be quantified by ultraviolet-visible (UV-vis) spectrometry. Screening of the compound libraries designed for bacterial phosphotransferases resulted in the discovery of a selective WecA inhibitor, UT-01320 (12) that kills both replicating and non-replicating Mtb at low concentration. UT-01320 (12) also kills the intracellular Mtb in macrophages. We conclude that the WecA assay reported here is amenable to medium- and high-throughput screening, thus facilitating the discovery of novel WecA inhibitors.
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Affiliation(s)
- Katsuhiko Mitachi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States
| | - Shajila Siricilla
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States
| | - Dong Yang
- Department of Microbiology, Immunology & Biochemistry, University of Tennessee Health Science Center, 858 Madison Avenue, Memphis, TN 38163-0001, United Sates
| | - Ying Kong
- Department of Microbiology, Immunology & Biochemistry, University of Tennessee Health Science Center, 858 Madison Avenue, Memphis, TN 38163-0001, United Sates
| | - Karolina Skorupinska-Tudek
- Department of Lipid Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland
| | - Ewa Swiezewska
- Department of Lipid Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland
| | - Scott G Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612, United States
| | - Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States.
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34
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Potgieter MG, Nakedi KC, Ambler JM, Nel AJM, Garnett S, Soares NC, Mulder N, Blackburn JM. Proteogenomic Analysis of Mycobacterium smegmatis Using High Resolution Mass Spectrometry. Front Microbiol 2016; 7:427. [PMID: 27092112 PMCID: PMC4821088 DOI: 10.3389/fmicb.2016.00427] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 03/16/2016] [Indexed: 11/30/2022] Open
Abstract
Biochemical evidence is vital for accurate genome annotation. The integration of experimental data collected at the proteome level using high resolution mass spectrometry allows for improvements in genome annotation by providing evidence for novel gene models, while validating or modifying others. Here, we report the results of a proteogenomic analysis of a reference strain of Mycobacterium smegmatis (mc2155), a fast growing model organism for the pathogenic Mycobacterium tuberculosis—the causative agent for Tuberculosis. By integrating high throughput LC/MS/MS proteomic data with genomic six frame translation and ab initio gene prediction databases, a total of 2887 ORFs were identified, including 2810 ORFs annotated to a Reference protein, and 63 ORFs not previously annotated to a Reference protein. Further, the translational start site (TSS) was validated for 558 Reference proteome gene models, while upstream translational evidence was identified for 81. In addition, N-terminus derived peptide identifications allowed for downstream TSS modification of a further 24 gene models. We validated the existence of six previously described interrupted coding sequences at the peptide level, and provide evidence for four novel frameshift positions. Analysis of peptide posterior error probability (PEP) scores indicates high-confidence novel peptide identifications and shows that the genome of M. smegmatis mc2155 is not yet fully annotated. Data are available via ProteomeXchange with identifier PXD003500.
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Affiliation(s)
- Matthys G Potgieter
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Kehilwe C Nakedi
- Division of Chemical and Systems Biology, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Jon M Ambler
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Andrew J M Nel
- Division of Chemical and Systems Biology, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Shaun Garnett
- Division of Chemical and Systems Biology, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Nelson C Soares
- Division of Chemical and Systems Biology, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Nicola Mulder
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
| | - Jonathan M Blackburn
- Division of Chemical and Systems Biology, Department of Integrative Biomedical Sciences, IDM, University of Cape Town Cape Town, South Africa
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35
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Rabadi SM, Sanchez BC, Varanat M, Ma Z, Catlett SV, Melendez JA, Malik M, Bakshi CS. Antioxidant Defenses of Francisella tularensis Modulate Macrophage Function and Production of Proinflammatory Cytokines. J Biol Chem 2015; 291:5009-21. [PMID: 26644475 DOI: 10.1074/jbc.m115.681478] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 11/06/2022] Open
Abstract
Francisella tularensis, the causative agent of a fatal human disease known as tularemia, has been used in the bioweapon programs of several countries in the past, and now it is considered a potential bioterror agent. Extreme infectivity and virulence of F. tularensis is due to its ability to evade immune detection and to suppress the host's innate immune responses. However, Francisella-encoded factors and mechanisms responsible for causing immune suppression are not completely understood. Macrophages and neutrophils generate reactive oxygen species (ROS)/reactive nitrogen species as a defense mechanism for the clearance of phagocytosed microorganisms. ROS serve a dual role; at high concentrations they act as microbicidal effector molecules that destroy intracellular pathogens, and at low concentrations they serve as secondary signaling messengers that regulate the expression of various inflammatory mediators. We hypothesized that the antioxidant defenses of F. tularensis maintain redox homeostasis in infected macrophages to prevent activation of redox-sensitive signaling components that ultimately result in suppression of pro-inflammatory cytokine production and macrophage microbicidal activity. We demonstrate that antioxidant enzymes of F. tularensis prevent the activation of redox-sensitive MAPK signaling components, NF-κB signaling, and the production of pro-inflammatory cytokines by inhibiting the accumulation of ROS in infected macrophages. We also report that F. tularensis inhibits ROS-dependent autophagy to promote its intramacrophage survival. Collectively, this study reveals novel pathogenic mechanisms adopted by F. tularensis to modulate macrophage innate immune functions to create an environment permissive for its intracellular survival and growth.
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Affiliation(s)
- Seham M Rabadi
- From the Department of Microbiology and Immunology, New York Medical College, Valhalla, New York 10595
| | - Belkys C Sanchez
- From the Department of Microbiology and Immunology, New York Medical College, Valhalla, New York 10595
| | - Mrudula Varanat
- From the Department of Microbiology and Immunology, New York Medical College, Valhalla, New York 10595
| | - Zhuo Ma
- the Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208, and
| | - Sally V Catlett
- the Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208, and
| | - Juan Andres Melendez
- the Colleges of Nanoscale Science and Engineering, State University of New York Polytechnic Institute, Albany, New York 12203
| | - Meenakshi Malik
- the Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208, and
| | - Chandra Shekhar Bakshi
- From the Department of Microbiology and Immunology, New York Medical College, Valhalla, New York 10595,
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36
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Brecik M, Centárová I, Mukherjee R, Kolly GS, Huszár S, Bobovská A, Kilacsková E, Mokošová V, Svetlíková Z, Šarkan M, Neres J, Korduláková J, Cole ST, Mikušová K. DprE1 Is a Vulnerable Tuberculosis Drug Target Due to Its Cell Wall Localization. ACS Chem Biol 2015; 10:1631-6. [PMID: 25906160 DOI: 10.1021/acschembio.5b00237] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The flavo-enzyme DprE1 catalyzes a key epimerization step in the decaprenyl-phosphoryl d-arabinose (DPA) pathway, which is essential for mycobacterial cell wall biogenesis and targeted by several new tuberculosis drug candidates. Here, using differential radiolabeling with DPA precursors and high-resolution fluorescence microscopy, we disclose the unexpected extracytoplasmic localization of DprE1 and periplasmic synthesis of DPA. Collectively, this explains the vulnerability of DprE1 and the remarkable potency of the best inhibitors.
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Affiliation(s)
- Miroslav Brecik
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Ivana Centárová
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Raju Mukherjee
- Global
Health Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Gaëlle S. Kolly
- Global
Health Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Stanislav Huszár
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Adela Bobovská
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Emöke Kilacsková
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Veronika Mokošová
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Zuzana Svetlíková
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Michal Šarkan
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - João Neres
- Global
Health Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jana Korduláková
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
| | - Stewart T. Cole
- Global
Health Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Katarína Mikušová
- Department
of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
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37
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Mitachi K, Siricilla S, Klaic L, Clemons WM, Kurosu M. Chemoenzymatic syntheses of water-soluble lipid I fluorescent probes. Tetrahedron Lett 2015; 56:3441-3446. [PMID: 26190869 PMCID: PMC4505380 DOI: 10.1016/j.tetlet.2015.01.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Peptidoglycan (PG) is unique to bacteria, and thus, the enzymes responsible for its biosynthesis are promising antibacterial drug targets. The membrane-embedded enzymes in PG remain significant challenges in studying their mechanisms due to the fact that preparations of suitable enzymatic substrates require time-consuming biological transformations or chemical synthesis. Lipid I (prenyl diphosphoryl-MurNAc-pentapeptide) is an important PG biosynthesis intermediate to study the central enzymes, translocase I (MraY/MurX) and MurG. Lipid I isolated from nature contains the C50-or C55-prenyl unit that shows extremely poor water-solubility that renders studies of translocase I and MurG enzymes difficult. We have studied biological transformation of water soluble lipid I fluorescent probes using bacterial membrane fractions and purified MraY enzymes. In our investigation of the minimum structural requirements of the prenyl phosphates in MraY-catalyzed lipid I synthesis, we found that (2Z,6E)-farnesyl phosphate (C15-phosphate) can be recognized by E. coli MraY to generate the water-soluble lipid I fluorescent probes in high-yield. Under the optimized conditions, the same reaction was performed by using the purified MraY from Hydrogenivirga spp. to afford the lipid I analog with high-yield in a short reaction time.
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Affiliation(s)
- Katsuhiko Mitachi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163, USA
| | - Shajila Siricilla
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163, USA
| | - Lada Klaic
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Bld. Pasadena, CA 91125, USA
| | - William M. Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Bld. Pasadena, CA 91125, USA
| | - Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163, USA
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39
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The Mycobacterium tuberculosis outer membrane channel protein CpnT confers susceptibility to toxic molecules. Antimicrob Agents Chemother 2015; 59:2328-36. [PMID: 25645841 DOI: 10.1128/aac.04222-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is protected from toxic solutes by an effective outer membrane permeability barrier. Recently, we showed that the outer membrane channel protein CpnT is required for efficient nutrient uptake by M. tuberculosis and Mycobacterium bovis BCG. In this study, we found that the cpnT mutant of M. bovis BCG is more resistant than the wild type to a large number of drugs and antibiotics, including rifampin, ethambutol, clarithromycin, tetracycline, and ampicillin, by 8- to 32-fold. Furthermore, the cpnT mutant of M. bovis BCG was 100-fold more resistant to nitric oxide, a major bactericidal agent required to control M. tuberculosis infections in mice. Thus, CpnT constitutes the first outer membrane susceptibility factor in slow-growing mycobacteria. The dual functions of CpnT in uptake of nutrients and mediating susceptibility to toxic molecules are reflected in macrophage infection experiments: while loss of CpnT was detrimental for M. bovis BCG in macrophages that enable bacterial replication, presumably due to inadequate nutrient uptake, it conferred a survival advantage in macrophages that mount a strong bactericidal response. Importantly, the cpnT gene showed a significantly higher density of nonsynonymous mutations in drug-resistant clinical M. tuberculosis strains, indicating that CpnT is under selective pressure in human tuberculosis and/or during chemotherapy. Our results indicate that the CpnT channel constitutes an outer membrane gateway controlling the influx of nutrients and toxic molecules into slow-growing mycobacteria. This study revealed that reducing protein-mediated outer membrane permeability might constitute a new drug resistance mechanism in slow-growing mycobacteria.
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Goldberg S. Mechanical/physical methods of cell distribution and tissue homogenization. Methods Mol Biol 2015; 1295:1-20. [PMID: 25820709 DOI: 10.1007/978-1-4939-2550-6_1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This chapter covers the various methods of Mechanical Cell Disruption and Tissue Homogenization that are currently commercially available for processing minute samples (<1 mL) to larger production quantities. These mechanical methods of lysing do not introduce chemicals or enzymes to the system. However, the energies needed when using these "harsh" methods can be high and destroy the very proteins being sought.The destruction of cell membranes and walls by these "harsh" methods is effected by subjecting the cells (1) to shearing by liquid flow, (2) to exploding by pressure differences between inside and outside of cell, (3) to collision forces by impact of beads or paddles, or (4) a combination of these forces. Practical suggestions to optimize each method, where to acquire such equipment, and links to reference sources are included.
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Belardinelli JM, Larrouy-Maumus G, Jones V, Sorio de Carvalho LP, McNeil MR, Jackson M. Biosynthesis and translocation of unsulfated acyltrehaloses in Mycobacterium tuberculosis. J Biol Chem 2014; 289:27952-65. [PMID: 25124040 PMCID: PMC4183827 DOI: 10.1074/jbc.m114.581199] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/12/2014] [Indexed: 11/25/2022] Open
Abstract
A number of species-specific polymethyl-branched fatty acid-containing trehalose esters populate the outer membrane of Mycobacterium tuberculosis. Among them, 2,3-diacyltrehaloses (DAT) and penta-acyltrehaloses (PAT) not only play a structural role in the cell envelope but also contribute to the ability of M. tuberculosis to multiply and persist in the infected host, promoting the intracellular survival of the bacterium and modulating host immune responses. The nature of the machinery, topology, and sequential order of the reactions leading to the biosynthesis, assembly, and export of these complex glycolipids to the cell surface are the object of the present study. Our genetic and biochemical evidence corroborates a model wherein the biosynthesis and translocation of DAT and PAT to the periplasmic space are coupled and topologically split across the plasma membrane. The formation of DAT occurs on the cytosolic face of the plasma membrane through the action of PapA3, FadD21, and Pks3/4; that of PAT occurs on the periplasmic face via transesterification reactions between DAT substrates catalyzed by the acyltransferase Chp2 (Rv1184c). The integral membrane transporter MmpL10 is essential for DAT to reach the cell surface, and its presence in the membrane is required for Chp2 to be active. Disruption of mmpL10 or chp2 leads to an important build-up of DAT inside the cells and to the formation of a novel form of unsulfated acyltrehalose esterified with polymethyl-branched fatty acids normally found in sulfolipids that is translocated to the cell surface.
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Affiliation(s)
- Juan Manuel Belardinelli
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682 and
| | - Gérald Larrouy-Maumus
- the Division of Mycobacterial Research, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Victoria Jones
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682 and
| | - Luiz Pedro Sorio de Carvalho
- the Division of Mycobacterial Research, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Michael R McNeil
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682 and
| | - Mary Jackson
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682 and
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Siricilla S, Mitachi K, Wan B, Franzblau SG, Kurosu M. Discovery of a capuramycin analog that kills nonreplicating Mycobacterium tuberculosis and its synergistic effects with translocase I inhibitors. J Antibiot (Tokyo) 2014; 68:271-8. [PMID: 25269459 PMCID: PMC4382465 DOI: 10.1038/ja.2014.133] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/02/2014] [Accepted: 09/07/2014] [Indexed: 11/20/2022]
Abstract
Capuramycin (1) and its analogs are strong translocase I (MurX/MraY) inhibitors. In our SAR studies of capuramycin analogs against M. tuberculosis (Mtb), we observed for the first time that a capuramycin analog, UT-01320 (3) killed non-replicating (dormant) Mtb at low concentrations under low-oxygen conditions, whereas selective MurX inhibitors killed only replicating Mtb under aerobic conditions. Interestingly, 3 did not exhibit MurX enzyme inhibitory activity even at high concentrations, however, 3 inhibited bacterial RNA polymerases with the IC50 values of 100-150 nM range. A new RNA polymerase inhibitor 3 displayed strong synergistic effects with a MurX inhibitor SQ 641 (2), a promising preclinical TB drug.
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Affiliation(s)
- Shajila Siricilla
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Katsuhiko Mitachi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bajoie Wan
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Scott G Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
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Mycobacterial membrane vesicles administered systemically in mice induce a protective immune response to surface compartments of Mycobacterium tuberculosis. mBio 2014; 5:e01921-14. [PMID: 25271291 PMCID: PMC4196239 DOI: 10.1128/mbio.01921-14] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Pathogenic and nonpathogenic species of bacteria and fungi release membrane vesicles (MV), containing proteins, polysaccharides, and lipids, into the extracellular milieu. Previously, we demonstrated that several mycobacterial species, including bacillus Calmette-Guerin (BCG) and Mycobacterium tuberculosis, release MV containing lipids and proteins that subvert host immune response in a Toll-like receptor 2 (TLR2)-dependent manner (R. Prados-Rosales et al., J. Clin. Invest. 121:1471–1483, 2011, doi:10.1172/JCI44261). In this work, we analyzed the vaccine potential of MV in a mouse model and compared the effects of immunization with MV to those of standard BCG vaccination. Immunization with MV from BCG or M. tuberculosis elicited a mixed humoral and cellular response directed to both membrane and cell wall components, such as lipoproteins. However, only vaccination with M. tuberculosis MV was able to protect as well as live BCG immunization. M. tuberculosis MV boosted BCG vaccine efficacy. In summary, MV are highly immunogenic without adjuvants and elicit immune responses comparable to those achieved with BCG in protection against M. tuberculosis. This work offers a new vaccine approach against tuberculosis using mycobacterial MV. Mycobacterium MV are a naturally released product combining immunogenic antigens in the context of a lipid structure. The fact that MV do not need adjuvants and elicit protection comparable to that elicited by the BCG vaccine encourages vaccine approaches that combine protein antigens and lipids. Consequently, mycobacterium MV establish a new type of vaccine formulation.
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Boradia VM, Malhotra H, Thakkar JS, Tillu VA, Vuppala B, Patil P, Sheokand N, Sharma P, Chauhan AS, Raje M, Raje CI. Mycobacterium tuberculosis acquires iron by cell-surface sequestration and internalization of human holo-transferrin. Nat Commun 2014; 5:4730. [DOI: 10.1038/ncomms5730] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 07/17/2014] [Indexed: 11/09/2022] Open
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Sharma IM, Prakash S, Dhanaraman T, Chatterji D. Characterization of a dual-active enzyme, DcpA, involved in cyclic diguanosine monophosphate turnover in Mycobacterium smegmatis. MICROBIOLOGY-SGM 2014; 160:2304-2318. [PMID: 25037163 DOI: 10.1099/mic.0.080200-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have reported previously that the long-term survival of Mycobacterium smegmatis is facilitated by a dual-active enzyme MSDGC-1 (renamed DcpA), which controls the cellular turnover of cyclic diguanosine monophosphate (c-di-GMP). Most mycobacterial species possess at least a single copy of a DcpA orthologue that is highly conserved in terms of sequence similarity and domain architecture. Here, we show that DcpA exists in monomeric and dimeric forms. The dimerization of DcpA is due to non-covalent interactions between two protomers that are arranged in a parallel orientation. The dimer shows both synthesis and hydrolysis activities, whereas the monomer shows only hydrolysis activity. In addition, we have shown that DcpA is associated with the cytoplasmic membrane and exhibits heterogeneous cellular localization with a predominance at the cell poles. Finally, we have also shown that DcpA is involved in the change in cell length and colony morphology of M. smegmatis. Taken together, our study provides additional evidence about the role of the bifunctional protein involved in c-di-GMP signalling in M. smegmatis.
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Affiliation(s)
- Indra Mani Sharma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Sunita Prakash
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Thillaivillalan Dhanaraman
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal H3C 3J7, Québec, Canada
| | - Dipankar Chatterji
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
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Matange N, Podobnik M, Visweswariah SS. The non-catalytic "cap domain" of a mycobacterial metallophosphoesterase regulates its expression and localization in the cell. J Biol Chem 2014; 289:22470-81. [PMID: 24970891 DOI: 10.1074/jbc.m114.578328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Despite highly conserved core catalytic domains, members of the metallophosphoesterase (MPE) superfamily perform diverse and crucial functions ranging from nucleotide and nucleic acid metabolism to phospholipid hydrolysis. Unique structural elements outside of the catalytic core called "cap domains" are thought to provide specialization to these enzymes; however, no directed study has been performed to substantiate this. The cap domain of Rv0805, an MPE from Mycobacterium tuberculosis, is located C-terminal to its catalytic domain and is dispensable for the catalytic activity of this enzyme in vitro. We show here that this C-terminal extension (CTE) mediates in vivo localization of the protein to the cell membrane and cell wall as well as modulates expression levels of Rv0805 in mycobacteria. We also demonstrate that Rv0805 interacts with the cell wall of mycobacteria, possibly with the mycolyl-arabinogalactan-peptidoglycan complex, by virtue of its C terminus, a hitherto unknown property of this MPE. Using a panel of mutant proteins, we identify interactions between active site residues of Rv0805 and the CTE that determine its association with the cell wall. Finally, we show that Rv0805 and a truncated mutant devoid of the CTE produce different phenotypic effects when expressed in mycobacteria. Our study thus provides a detailed dissection of the functions of the cap domain of an MPE and suggests that the repertoire of cellular functions of MPEs cannot be understood without exploring the modulatory effects of these subdomains.
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Affiliation(s)
- Nishad Matange
- From the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore, India 560012 and
| | - Marjetka Podobnik
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Sandhya S Visweswariah
- From the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore, India 560012 and
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Siricilla S, Mitachi K, Skorupinska-Tudek K, Swiezewska E, Kurosu M. Biosynthesis of a water-soluble lipid I analogue and a convenient assay for translocase I. Anal Biochem 2014; 461:36-45. [PMID: 24939461 DOI: 10.1016/j.ab.2014.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 05/08/2014] [Accepted: 05/22/2014] [Indexed: 02/07/2023]
Abstract
Translocase I (MraY/MurX) is an essential enzyme in growth of the vast majority of bacteria that catalyzes the transformation from UDP-MurNAc-pentapeptide (Park's nucleotide) to prenyl-MurNAc-pentapeptide (lipid I), the first membrane-anchored peptidoglycan precursor. MurX has received considerable attention in the development of new tuberculosis (TB) drugs due to the fact that the MurX inhibitors kill exponentially growing Mycobacterium tuberculosis (Mtb) much faster than clinically used TB drugs. Lipid I isolated from Mtb contains the C50-prenyl unit that shows very poor water solubility; thus, this chemical characteristic of lipid I renders MurX enzyme assays impractical for screening and lacks reproducibility of the enzyme assays. We have established a scalable chemical synthesis of Park's nucleotide-N(ε)-dansylthiourea 2 that can be used as a MurX enzymatic substrate to form lipid I analogues. In our investigation of the minimum structure requirement of the prenyl phosphate in the MraY/MurX-catalyzed lipid I analogue synthesis with 2, we found that neryl phosphate (C10 phosphate) can be recognized by MraY/MurX to generate the water-soluble lipid I analogue in quantitative yield under the optimized conditions. Here, we report a rapid and robust analytical method for quantifying MraY/MurX inhibitory activity of library molecules.
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Affiliation(s)
- Shajila Siricilla
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States
| | - Katsuhiko Mitachi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States
| | - Karolina Skorupinska-Tudek
- Department of Lipid Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland
| | - Ewa Swiezewska
- Department of Lipid Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland
| | - Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163-0001, United States
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Rana A, Rub A, Akhter Y. Proteome-scale identification of outer membrane proteins in Mycobacterium avium subspecies paratuberculosis using a structure based combined hierarchical approach. ACTA ACUST UNITED AC 2014; 10:2329-37. [DOI: 10.1039/c4mb00234b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The overall strategy used for the proteome-wide comprehensive computational investigation to identify outer membrane proteins fromMycobacterium aviumsubsp.paratuberculosis.
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Affiliation(s)
- Aarti Rana
- School of Life Sciences
- Central University of Himachal Pradesh
- District-Kangra, India
| | - Abdur Rub
- Infection and Immunity Lab
- Department of Biotechnology
- Jamia Millia Islamia (A Central University)
- New Delhi, India-110025
| | - Yusuf Akhter
- School of Life Sciences
- Central University of Himachal Pradesh
- District-Kangra, India
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van der Woude AD, Stoop EJM, Stiess M, Wang S, Ummels R, van Stempvoort G, Piersma SR, Cascioferro A, Jiménez CR, Houben ENG, Luirink J, Pieters J, van der Sar AM, Bitter W. Analysis of SecA2-dependent substrates in Mycobacterium marinum identifies protein kinase G (PknG) as a virulence effector. Cell Microbiol 2013; 16:280-95. [PMID: 24119166 DOI: 10.1111/cmi.12221] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 09/14/2013] [Accepted: 09/24/2013] [Indexed: 02/03/2023]
Abstract
The pathogenicity of mycobacteria is closely associated with their ability to export virulence factors. For this purpose, mycobacteria possess different protein secretion systems, including the accessory Sec translocation pathway, SecA2. Although this pathway is associated with intracellular survival and virulence, the SecA2-dependent effector proteins remain largely undefined. In this work, we studied a Mycobacterium marinum secA2 mutant with an impaired capacity to initiate granuloma formation in zebrafish embryos. By comparing the proteomic profile of cell envelope fractions from the secA2 mutant with wild type M. marinum, we identified putative SecA2-dependent substrates. Immunoblotting procedures confirmed SecA2-dependent membrane localization for several of these proteins, including the virulence factor protein kinase G (PknG). Interestingly, phenotypical defects of the secA2 mutant are similar to those described for ΔpknG, including phagosomal maturation. Overexpression of PknG in the secA2 mutant restored its localization to the cell envelope. Importantly, PknG-overexpression also partially restored the virulence of the secA2 mutant, as indicated by enhanced infectivity in zebrafish embryos and restored inhibition of phagosomal maturation. These results suggest that SecA2-dependent membrane localization of PknG is an important determinant for M. marinum virulence.
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Affiliation(s)
- Aniek D van der Woude
- Department of Medical Microbiology and Infection Control, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands; Department of Molecular Microbiology, Institute of Molecular Cell Biology, VU University, de Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
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Gunawardena HP, Feltcher ME, Wrobel JA, Gu S, Braunstein M, Chen X. Comparison of the membrane proteome of virulent Mycobacterium tuberculosis and the attenuated Mycobacterium bovis BCG vaccine strain by label-free quantitative proteomics. J Proteome Res 2013; 12:5463-74. [PMID: 24093440 DOI: 10.1021/pr400334k] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Mycobacterium tuberculosis membrane is rich in antigens that are potential targets for diagnostics and the development of new vaccines. To better understand the mechanisms underlying MTB virulence and identify new targets for therapeutic intervention, we investigated the differential composition of membrane proteomes between virulent M. tuberculosis H37Rv (MTB) and the Mycobacterium bovis BCG vaccine strain. To compare the membrane proteomes, we used LC-MS/MS analysis in combination with label-free quantitative proteomics, utilizing the area under the curve of the extracted ion chromatograms of peptides obtained from m/z and retention time alignment of MS1 features. With this approach, we obtained relative abundance ratios for 2203 identified membrane-associated proteins in high confidence. Of these proteins, 294 showed statistically significant differences of at least two fold in relative abundance between MTB and BCG membrane fractions. Our comparative analysis detected several proteins associated with known genomic regions of difference between MTB and BCG as being absent, which validated the accuracy of our approach. In further support of our label-free quantitative data, we verified select protein differences by immunoblotting. To our knowledge, we have generated the first comprehensive and high-coverage profile of comparative membrane proteome changes between virulent MTB and its attenuated relative BCG, which helps elucidate the proteomic basis of the intrinsic virulence of the MTB pathogen.
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Affiliation(s)
- Harsha P Gunawardena
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill , 120 Mason Farm Road, Campus Box 7260 3rd Floor, Genetic Medicine Building, Chapel Hill, North Carolina 27599, United States
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