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Shih KY, Chang YT, Wang YJ, Huang JM. Ouabain, ATPase inhibitor, potentially enhances the effect of polyhexamethylene biguanide on Acanthamoeba castellanii. Int J Parasitol Drugs Drug Resist 2024; 25:100550. [PMID: 38821038 PMCID: PMC11177127 DOI: 10.1016/j.ijpddr.2024.100550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 06/02/2024]
Abstract
Acanthamoeba, a free-living amoeba, is commonly found in various natural environments, such as rivers and soil, as well as in public baths, swimming pools, and sewers. Acanthamoeba can cause severe illness such as granulomatous amoebic encephalitis and Acanthamoeba keratitis (AK) in humans. AK, the most recognized disease, can cause permanent visual impairment or blindness by affecting the cornea. AK commonly affects contact lens wearers who neglect proper cleaning habits. The symptoms of AK include epithelial and stromal destruction, corneal infiltrate, and intense ocular pain, occasionally necessitating surgical removal of the entire eyeball. Current AK treatment involves the hourly application of eye drops containing polyhexamethylene biocide (PHMB). However, studies have revealed their ineffectiveness against drug-resistant strains. Acanthamoeba can form cysts as a survival mechanism in adverse environments, though the exact mechanism remains unknown. Our experiments revealed that sodium P-type ATPase (ACA1_065450) is closely linked to encystation. In addition, various encystation buffers, such as MgCl2 or NaCl, induced the expression of P-type ATPase. Furthermore, we used ouabain, an ATPase inhibitor, to inhibit the Na+/K+ ion pump, consequently decreasing the encystation rate of Acanthamoeba. Our primary objective is to develop an advanced treatment for AK. We anticipate that the combination of ouabain and PHMB may serve as an effective therapeutic approach against AK in the future.
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Affiliation(s)
- Kuang-Yi Shih
- Department of Life Science, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, Taiwan.
| | - Yao-Tsung Chang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
| | - Yu-Jen Wang
- Department of Parasitology, School of Medicine, China Medical University, Taichung, Taiwan.
| | - Jian-Ming Huang
- School of Medicine, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, Taiwan; Department of Medical Science, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, Taiwan; Institute of Molecular and Cellular Biology, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, Taiwan.
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2
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Xu X, Moreno S, Boye S, Wang P, Voit B, Appelhans D. Artificial Organelles with Digesting Characteristics: Imitating Simplified Lysosome- and Macrophage-Like Functions by Trypsin-Loaded Polymersomes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2207214. [PMID: 37076948 DOI: 10.1002/advs.202207214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/12/2023] [Indexed: 05/03/2023]
Abstract
Defects in cellular protein/enzyme encoding or even in organelles are responsible for many diseases. For instance, dysfunctional lysosome or macrophage activity results in the unwanted accumulation of biomolecules and pathogens implicated in autoimmune, neurodegenerative, and metabolic disorders. Enzyme replacement therapy (ERT) is a medical treatment that replaces an enzyme that is deficient or absent in the body but suffers from short lifetime of the enzymes. Here, this work proposes the fabrication of two different pH-responsive and crosslinked trypsin-loaded polymersomes as protecting enzyme carriers mimicking artificial organelles (AOs). They allow the enzymatic degradation of biomolecules to mimic simplified lysosomal function at acidic pH and macrophage functions at physiological pH. For optimal working of digesting AOs in different environments, pH and salt composition are considered the key parameters, since they define the permeability of the membrane of the polymersomes and the access of model pathogens to the loaded trypsin. Thus, this work demonstrates environmentally controlled biomolecule digestion by trypsin-loaded polymersomes also under simulated physiological fluids, allowing a prolonged therapeutic window due to protection of the enzyme in the AOs. This enables the application of AOs in the fields of biomimetic therapeutics, specifically in ERT for dysfunctional lysosomal diseases.
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Affiliation(s)
- Xiaoying Xu
- Deaprtment Bioactive and Responsive Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
- Organic Chemistry of Polymers, Technische Universität Dresden, D-01062, Dresden, Germany
| | - Silvia Moreno
- Deaprtment Bioactive and Responsive Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
| | - Susanne Boye
- Center Macromolecular Structure Analysis, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
| | - Peng Wang
- Deaprtment Bioactive and Responsive Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
| | - Brigitte Voit
- Deaprtment Bioactive and Responsive Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
- Organic Chemistry of Polymers, Technische Universität Dresden, D-01062, Dresden, Germany
| | - Dietmar Appelhans
- Deaprtment Bioactive and Responsive Polymers, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069, Dresden, Germany
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3
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Non-pyrogenic highly pure magnetosomes for efficient hyperthermia treatment of prostate cancer. Appl Microbiol Biotechnol 2023; 107:1159-1176. [PMID: 36633624 DOI: 10.1007/s00253-022-12247-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 01/13/2023]
Abstract
We report the fabrication of highly pure magnetosomes that are synthesized by magnetotactic bacteria (MTB) using pharmaceutically compatible growth media, i.e., without compounds of animal origin (yeast extracts), carcinogenic, mutagenic, or toxic for reproduction (CMR) products, and other heavy metals than iron. To enable magnetosome medical applications, these growth media are reduced and amended compared with media commonly used to grow these bacteria. Furthermore, magnetosomes are made non-pyrogenic by being extracted from these micro-organisms and heated above 400 °C to remove and denature bacterial organic material and produce inorganic magnetosome minerals. To be stabilized, these minerals are further coated with citric acid to yield M-CA, leading to fully reconstructed chains of magnetosomes. The heating properties and anti-tumor activity of highly pure M-CA are then studied by bringing M-CA into contact with PC3-Luc tumor cells and by exposing such assembly to an alternating magnetic field (AMF) of 42 mT and 195 kHz during 30 min. While in the absence of AMF, M-CA are observed to be non-cytotoxic, they result in a 35% decrease in cell viability following AMF application. The treatment efficacy can be associated with a specific absorption rate (SAR) value of M-CA, which is relatively high in cellular environment, i.e., SARcell = 253 ± 11 W/gFe, while being lower than the M-CA SAR value measured in water, i.e., SARwater = 1025 ± 194 W/gFe, highlighting that a reduction in the Brownian contribution to the SAR value in cellular environment does not prevent efficient tumor cell destruction with these nanoparticles. KEY POINTS : • Highly pure magnetosomes were produced in pharmaceutically compatible growth media • Non-pyrogenic and stable magnetosomes were prepared for human injection • Magnetosomes efficiently destroyed prostate tumor cells in magnetic hyperthermia.
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4
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Yin L, Liang C, Wei W, Huang S, Ren Y, Geng Y, Huang X, Chen D, Guo H, Fang J, Deng H, Lai W, Yu S, Ouyang P. The Antibacterial Activity of Thymol Against Drug-Resistant Streptococcus iniae and Its Protective Effect on Channel Catfish (Ictalurus punctatus). Front Microbiol 2022; 13:914868. [PMID: 35733967 PMCID: PMC9207766 DOI: 10.3389/fmicb.2022.914868] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/02/2022] [Indexed: 12/30/2022] Open
Abstract
Streptococcus iniae is a zoonotic pathogen, which seriously threatens aquaculture and human health worldwide. Antibiotics are the preferred way to treat S. iniae infection. However, the unreasonable use of antibiotics leads to the enhancement of bacterial resistance, which is not conducive to the prevention and treatment of this disease. Therefore, it is urgent to find new efficient and environmentally friendly antibacterial agents to replace traditional antibiotics. In this study, the antibacterial activity and potential mechanism of thymol against S. iniae were evaluated by electron microscopy, lactate dehydrogenase, DNA and protein leakage and transcriptomic analysis. Thymol exhibited potent antibacterial activity against S. iniae in vitro, and the MIC and MBC were 128 and 256μg/mL, respectively. SEM and TEM images showed that the cell membrane and cell wall were damaged, and the cells were abnormally enlarged and divided. 2MIC thymol disrupted the integrity of cell walls and membranes, resulting in the release of intracellular macromolecules including nucleotides, proteins and inorganic ions. The results of transcriptomic analysis indicated that thymol interfered with energy metabolism and membrane transport, affected DNA replication, repair and transcription in S. iniae. In vivo studies showed that thymol had a protective effect on experimental S. iniae infection in channel catfish. It could reduce the cumulative mortality of channel catfish and the number of S. iniae colonization in tissues, and increase the activities of non-specific immune enzymes in serum, including catalase, superoxide dismutase, lysozyme and acid phosphatase. Taken together, these findings suggested that thymol may be a candidate plant agent to replace traditional antibiotics for the prevention and treatment of S. iniae infection.
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Affiliation(s)
- Lizi Yin
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Chao Liang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Wenyan Wei
- Aquaculture Research Institute, Chengdu Academy of Agriculture and Forestry Sciences, Chengdu, China
| | - Shuanghui Huang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yongqiang Ren
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yi Geng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaoli Huang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hongrui Guo
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Jing Fang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Huidan Deng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Weimin Lai
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shumin Yu
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ping Ouyang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- *Correspondence: Ping Ouyang
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5
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Ramya D, Thatheyus AJ, Juliana SJB, Kiruba NJM, Selvam A DG. Physical characterization and kinetic studies of Zn (II) biosorption by Morganella morganii ACZ05. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 85:970-986. [PMID: 35228348 DOI: 10.2166/wst.2022.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Through this investigation, we establish the mechanism and physical characterization of zinc (II) sequestration by Morganella morganii ACZ05 strain, which was isolated and characterized from soil polluted by effluents from electroplating industries. As far as we know, there is very little literature concerning zinc biosorption using an environmental strain of M. morganii. The SEM analysis shows the dark porous gaps in the aggregated cell-matrix of test bacterial biomass which is inferred as water channels usually seen in biofilms, as compared to metal-unexposed control. M. morganii is not known to produce biofilms unless in the rare nosocomial conditions. Here, SEM analysis shows the production of biofilms after exposure to zinc (II) at 500 ppm, which has not been previously reported. EDX analysis of bacterial biomass also specified the sorption of zinc (II) by the bacterial cells and the presence of new peaks for zinc in contrast to control. Both XRD and FTIR analysis observations strongly implicate the potential of physical adsorption as a mechanism for heavy metal resistance. Analysis of the cell surface by Atomic force microscopy and examination of the topography revealed cell aggregation occurs during biofilm production after zinc biosorption. Unlike other reports, regular models such as Langmuir isotherm and Freundlich isotherm were found insufficient to explain the physisorption of zinc (II) metal ions on complex multicomponent adsorbents such as the exopolymeric surface of the bacterial cells. However, adsorption kinetics of zinc (II) to the bacterial biomass was most effectively elucidated by a pseudo-second-order kinetic model, suggesting a certain kind of chemisorption that requires further study.
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Affiliation(s)
- D Ramya
- Department of Microbiology, The American College, Madurai 625 002, Tamil Nadu, India E-mail:
| | - A Joseph Thatheyus
- Postgraduate & Research Department of Zoology, The American College, Madurai 625 002, Tamil Nadu, India
| | - S Jemima Balaselvi Juliana
- Postgraduate & Research Department of Chemistry, The American College, Madurai 625 002, Tamil Nadu, India
| | | | - Deborah Gnana Selvam A
- Department of Microbiology, The American College, Madurai 625 002, Tamil Nadu, India E-mail:
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6
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Xu T, Zhang C, Xia K, Li W, Cao Y, Gu H. Small DNAs that Bind Nickel(II) Specifically and Tightly. Anal Chem 2021; 93:14912-14917. [PMID: 34734709 DOI: 10.1021/acs.analchem.1c04034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal recognition by nucleic acids provides an intriguing route for biosensing of metal. Toward this goal, a key prerequisite is the acquisition of nucleic acids that can selectively respond to specific metals. Herein, we report for the first time the discovery of two small DNAs that can specifically bind Ni2+ and discriminate against similar ions, particularly, Co2+. Their minimal effective constructs are 60-70 nucleotides (nt) in length with Ni2+ binding even at harsh denaturing conditions of 8 M urea and 50 mM EDTA. Using isothermal titration calorimetry (ITC), we estimated the dissociation constant (KD) of a representative DNA to be 24.0 ± 4.5 μM, with a 9:1 stoichiometry of Ni2+ bound to DNA. As being engineered into nanosized particles, these DNAs can act like nanosponges to specifically adsorb Ni2+ from artificial wastewater, demonstrating their potential as a novel molecular tool for high-quality nickel enrichment and detection.
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Affiliation(s)
- Tianbin Xu
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
| | - Canyu Zhang
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
| | - Kai Xia
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
| | - Wei Li
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
| | - Yichun Cao
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
| | - Hongzhou Gu
- Fudan University Shanghai Cancer Center, and the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Shanghai Stomatological Hospital, Fudan University, Shanghai 200032, China.,Center for Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 200433, China
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7
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Elhakim YA, Ali AE, Hosny AEDMS, Abdeltawab NF. Zinc Deprivation as a Promising Approach for Combating Methicillin-Resistant Staphylococcus aureus: A Pilot Study. Pathogens 2021; 10:1228. [PMID: 34684179 PMCID: PMC8540720 DOI: 10.3390/pathogens10101228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/06/2021] [Accepted: 09/15/2021] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global health burden with an urgent need for antimicrobial agents. Studies have shown that host immune responses limit essential metals such as zinc during infection, leading to the limitation of bacterial virulence. Thus, the deprivation of zinc as an important co-factor for the activity of many S. aureus enzymes can be a potential antimicrobial approach. However, the effect of zinc deprivation on S. aureus and MRSA is not fully understood. Therefore, the current study aimed to dissect the effects of zinc deprivation on S. aureus hemolytic activity and biofilm formation through employing biochemical and genetic approaches to study the effect of zinc deprivation on S. aureus growth and virulence. Chemically defined media (CDM) with and without ZnCl2, was used to assess the effect of zinc deprivation on growth, biofilm formation, and hemolytic activity in methicillin-susceptible S. aureus (MSSA) RN6390 and MRSA N315 strains. Zinc deprivation decreased the growth of RN6390 and N315 S. aureus strains significantly by 1.5-2 folds, respectively compared to the zinc physiological range encountered by the bacteria in the human body (7-20 µM) (p < 0.05). Zinc deprivation significantly reduced biofilm formation by 1.5 folds compared to physiological levels (p < 0.05). Moreover, the hemolytic activity of RN6390 and N315 S. aureus strains was significantly decreased by 20 and 30 percent, respectively compared to physiological zinc levels (p < 0.05). Expression of biofilm-associated transcripts levels at late stage of biofilm formation (20 h) murein hydrolase activator A (cidA) and cidB were downregulated by 3 and 5 folds, respectively (p < 0.05) suggested an effect on extracellular DNA production. Expression of hemolysins-associated genes (hld, hlb, hla) was downregulated by 3, 5, and 10 folds, respectively, in absence of zinc (p < 0.001). Collectively the current study showed that zinc deprivation in vitro affected growth, biofilm formation, and hemolytic activity of S. aureus. Our in vitro findings suggested that zinc deprivation can be a potential supportive anti-biofilm formation and antihemolytic approach to contain MRSA topical infections.
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Affiliation(s)
- Yomna A. Elhakim
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
| | - Amal E. Ali
- Department of Microbiology and Immunology, Faculty of Pharmacy, Future University in Egypt, New Cairo 12311, Egypt;
| | - Alaa El-Dien M. S. Hosny
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
- Department of Microbiology and Immunology, Faculty of Pharmacy, Modern University for Technology and Information (MTI), Cairo 12055, Egypt
| | - Nourtan F. Abdeltawab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
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8
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Ahad RIA, Syiem MB. Analyzing dose dependency of antioxidant defense system in the cyanobacterium Nostoc muscorum Meg 1 chronically exposed to Cd 2. Comp Biochem Physiol C Toxicol Pharmacol 2021; 242:108950. [PMID: 33310062 DOI: 10.1016/j.cbpc.2020.108950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/02/2020] [Accepted: 12/06/2020] [Indexed: 12/20/2022]
Abstract
The aim of the present study was to analyze the dose dependency of oxidant-antioxidant homeostasis in Cd2+ exposed Nostoc muscorum Meg 1 cells. Quantification of percent DNA loss, protein oxidation and lipid peroxidation was carried out to assess Cd2+ induced ROS mediated damages to the organism. The countermeasures adopted by the cyanobacterium were also evaluated by computing various components of both enzymatic and non-enzymatic antioxidants. Exposure to different Cd2+ (0.1, 0.2, 0.3, 0.5, 1, 1.5, 2, 2.5, 3 ppm) doses showed substantial increase in ROS content in the ranges of 20-181% and 116-323% at the end of first and seventh day. The DNA damage, protein oxidation and lipid peroxidation were increased by 11-62%, 7-143% and 13-183% with increasing Cd2+ concentrations at the end of seven days. TEM images clearly showed damages to the cell wall, cell membrane and thylakoid organization at higher Cd2+ (0.5-3 ppm) concentrations. Cd2+ exposure up to 0.5 ppm registered increase in contents of antioxidative enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR)) and in non-enzymatic antioxidants (glutathione, total thiol, phytochelatin and proline) indicating stimulation of ROS mitigating machinery. However, toxicity of Cd2+ was evident as at higher concentrations the cellular morphology and ultra-structures were negatively affected and the capacities of the cells to generate various antioxidant measures were highly compromised. The organism registered 96-98% sorption ability from a solution supplemented with 0.3 ppm Cd2+ and thus show realistic potential as Cd2+ bioremediator in wastewater treatment.
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Affiliation(s)
- Rabbul Ibne A Ahad
- Department of Biochemistry, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Mayashree B Syiem
- Department of Biochemistry, North-Eastern Hill University, Shillong, Meghalaya, 793022, India.
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9
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Abstract
Labeling of nucleic acids is required for many studies aiming to elucidate their functions and dynamics in vitro and in cells. Out of the numerous labeling concepts that have been devised, covalent labeling provides the most stable linkage, an unrivaled choice of small and highly fluorescent labels and - thanks to recent advances in click chemistry - an incredible versatility. Depending on the approach, site-, sequence- and cell-specificity can be achieved. DNA and RNA labeling are rapidly developing fields that bring together multiple areas of research: on the one hand, synthetic and biophysical chemists develop new fluorescent labels and isomorphic nucleobases as well as faster and more selective bioorthogonal reactions. On the other hand, the number of enzymes that can be harnessed for post-synthetic and site-specific labeling of nucleic acids has increased significantly. Together with protein engineering and genetic manipulation of cells, intracellular and cell-specific labeling has become possible. In this review, we provide a structured overview of covalent labeling approaches for nucleic acids and highlight notable developments, in particular recent examples. The majority of this review will focus on fluorescent labeling; however, the principles can often be readily applied to other labels. We will start with entirely chemical approaches, followed by chemo-enzymatic strategies and ribozymes, and finish with metabolic labeling of nucleic acids. Each section is subdivided into direct (or one-step) and two-step labeling approaches and will start with DNA before treating RNA.
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Affiliation(s)
- Nils Klöcker
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, D-48149 Münster, Germany.
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10
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Berny C, Le Fèvre R, Guyot F, Blondeau K, Guizonne C, Rousseau E, Bayan N, Alphandéry E. A Method for Producing Highly Pure Magnetosomes in Large Quantity for Medical Applications Using Magnetospirillum gryphiswaldense MSR-1 Magnetotactic Bacteria Amplified in Minimal Growth Media. Front Bioeng Biotechnol 2020; 8:16. [PMID: 32133346 PMCID: PMC7041420 DOI: 10.3389/fbioe.2020.00016] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/09/2020] [Indexed: 12/12/2022] Open
Abstract
We report the synthesis in large quantity of highly pure magnetosomes for medical applications. For that, magnetosomes are produced by MSR-1 Magnetospirillum gryphiswaldense magnetotactic bacteria using minimal growth media devoid of uncharacterized and toxic products prohibited by pharmaceutical regulation, i.e., yeast extract, heavy metals different from iron, and carcinogenic, mutagenic and reprotoxic agents. This method follows two steps, during which bacteria are first pre-amplified without producing magnetosomes and are then fed with an iron source to synthesize magnetosomes, yielding, after 50 h of growth, an equivalent OD565 of ~8 and 10 mg of magnetosomes in iron per liter of growth media. Compared with magnetosomes produced in non-minimal growth media, those particles have lower concentrations in metals other than iron. Very significant reduction or disappearance in magnetosome composition of zinc, manganese, barium, and aluminum are observed. This new synthesis method paves the way towards the production of magnetosomes for medical applications.
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Affiliation(s)
- Clément Berny
- Nanobacterie SARL, Paris, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | | | - François Guyot
- Paris Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France.,Institut Universitaire de France (IUF), Paris, France
| | - Karine Blondeau
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | | | | | - Nicolas Bayan
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Edouard Alphandéry
- Nanobacterie SARL, Paris, France.,Paris Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France
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11
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Pessanha de Carvalho L, Held J, de Melo EJT. Essential and nonessential metal effects on extracellular Leishmania amazonensis in vitro. Exp Parasitol 2019; 209:107826. [PMID: 31881207 DOI: 10.1016/j.exppara.2019.107826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/26/2019] [Accepted: 12/20/2019] [Indexed: 10/25/2022]
Abstract
Protozoan parasites like Leishmania amazonensis are excellent models to test the effects of new drugs against a functional molecular arsenal used to establish successfully an infection in the vertebrate host, where they invade the cells of the monocytic system. However, little is known about the influence of metal ions on the cellular functionality of the infective forms of L. amazonensis. In the present work, we show that ZnCl2 (an essential metal to cellular metabolism) did not induce drastic effects on the survival of the promastigote under the conditions tested. However, incubation of ZnCl2 prior to subsequent treatment with CdCl2 and HgCl2 led to a drastic toxic effect on parasite survival in vitro. Nonessential metals such as CdCl2 and HgCl2 promoted a drastic effect on parasite survival progressively with increasing dose and time of exposure. Notably, HgCl2 produced an effective elimination of the parasite in doses/time smaller than the CdCl2. This toxic action induced in the parasite a high condensation of the nuclear heterochromatin, besides the absence or de-structuring of functional organelles such as glycosomes, acidocalcisomes, and mitochondria in the cytoplasm. Our results suggest that promastigotes of L. amazonensis are sensitive to the toxic activity of nonessential metals, and that this activity increases when parasites are previously exposed to Zn. To summarize, toxic effects of the tested metals are dose and time dependent and can be used as a study model to better understand the functionality of the molecular arsenal responsible for the parasitism.
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Affiliation(s)
- Laís Pessanha de Carvalho
- Laboratory of Tissue and Cell Biology, Center for Bioscience and Biotechnology, State University of Northern Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000 - Parque California, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil; Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.
| | - Jana Held
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.
| | - Edésio José Tenório de Melo
- Laboratory of Tissue and Cell Biology, Center for Bioscience and Biotechnology, State University of Northern Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000 - Parque California, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil.
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12
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Extreme Environments and High-Level Bacterial Tellurite Resistance. Microorganisms 2019; 7:microorganisms7120601. [PMID: 31766694 PMCID: PMC6955997 DOI: 10.3390/microorganisms7120601] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 01/10/2023] Open
Abstract
Bacteria have long been known to possess resistance to the highly toxic oxyanion tellurite, most commonly though reduction to elemental tellurium. However, the majority of research has focused on the impact of this compound on microbes, namely E. coli, which have a very low level of resistance. Very little has been done regarding bacteria on the other end of the spectrum, with three to four orders of magnitude greater resistance than E. coli. With more focus on ecologically-friendly methods of pollutant removal, the use of bacteria for tellurite remediation, and possibly recovery, further highlights the importance of better understanding the effect on microbes, and approaches for resistance/reduction. The goal of this review is to compile current research on bacterial tellurite resistance, with a focus on high-level resistance by bacteria inhabiting extreme environments.
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De Novo Iron Oxide Hydroxide, Ferrihydrite Produced by Comamonas testosteroni Exhibiting Intrinsic Peroxidase-Like Activity and Their Analytical Applications. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7127869. [PMID: 31032360 PMCID: PMC6458858 DOI: 10.1155/2019/7127869] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/04/2019] [Indexed: 11/17/2022]
Abstract
Natural enzyme mimics have attracted considerable attention due to leakage of enzymes and their easy denaturation during their storage and immobilization procedure. Here in this study, for the first time, a new iron oxide hydroxide, ferrihydrite - Fe1.44O0.32 (OH) 3.68 magnetic nanoparticles were synthesized by bacterial strain named Comamonas testosteroni. The characterization of the produced magnetic nanoparticles was confirmed by transmission electron microscopy (TEM), Fourier-transform spectroscopy (FTIR), X-ray diffraction (XRD), and magnetization hysteresis loops. Further, these extracted nanoparticles were proven to have biogenic magnetic behavior and to exhibit enhanced peroxidase-like activity. It is capable of catalyzing the oxidation of 3, 3', 5, 5'-Tetramethylbenzidine (TMB) by H2O2 to produce blue color (typical color reactions). Catalysis was examined to follow Michaelis-Menton kinetics and the good affinity to both H2O2 and TMB. The K m value of the Fe1.44O0.32 (OH) 3.68 with H2O2 and TMB as the substrate was 0.0775 and 0.0155 mM, respectively, which were lower than that of the natural enzyme (HRP). Experiments of electron spin resonance (ESR) spectroscopy proved that the BMNPs could catalyze H2O2 to produce hydroxyl radicals. As a new peroxidase mimetic, the BMNPs were exhibited to offer a simple, sensitive, and selective colorimetric method for determination of H2O2 and glucose and efficiently catalyze the detection of glucose in real blood samples.
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14
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Pan Y, Wang Y, Fan X, Wang W, Yang X, Cui D, Zhao M. Bacterial intracellular nanoparticles exhibiting antioxidant properties and the significance of their formation in ROS detoxification. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:140-146. [PMID: 30623592 DOI: 10.1111/1758-2229.12733] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/05/2019] [Indexed: 06/09/2023]
Abstract
Biogenic magnetic nanoparticles (BMNPs) can be formed by numerous microorganisms. However, the significance of their formation and their possible functions have not been explored in detail. To explore a possible function of Fe3 O4 NPs in Burkholderia sp. strain YN01, we investigated their catalytic abilities in the elimination of intracellular reactive oxygen species (ROS). Changes in ROS content under different conditions were assessed and showed that low oxygen and high iron concentrations in the growth medium promoted ROS production. However, the levels of ROS gradually decreased with BMNP formation, suggesting that these particles possess intrinsic superoxide dismutase (SOD)-like activity and catalase (CAT)-like activity, as proven in this study. To ensure that the observed ROS decrease was not due to antioxidase overexpression caused by the oxidative stress response, SOD and CAT were inhibited in vivo to analyse the ROS variation and BMNP yield under microoxic and high-iron conditions respectively. The results demonstrated that the formation of these intracellular iron nanoparticles was required for the efficient scavenging of excess ROS, which was dependent on their antioxidase-like properties. This result reveals a novel physiological function of biogenic intracellular Fe3 O4 nanoparticles.
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Affiliation(s)
- Yu Pan
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China
| | - Yongming Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Xingyuan Fan
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Wenbin Wang
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Xiumin Yang
- School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China
| | - Daizong Cui
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
| | - Min Zhao
- College of Life Science, Northeast Forestry University, Harbin, 150040, China
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15
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Nandi SK, Chakraborty A, Panda AK, Kar RK, Bhunia A, Biswas A. Evidences for zinc (II) and copper (II) ion interactions with Mycobacterium leprae HSP18: Effect on its structure and chaperone function. J Inorg Biochem 2018; 188:62-75. [DOI: 10.1016/j.jinorgbio.2018.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/01/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
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16
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Witkowska E, Korsak D, Kowalska A, Janeczek A, Kamińska A. Strain-level typing and identification of bacteria - a novel approach for SERS active plasmonic nanostructures. Anal Bioanal Chem 2018; 410:5019-5031. [PMID: 29907950 PMCID: PMC6061775 DOI: 10.1007/s00216-018-1153-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/16/2018] [Accepted: 05/18/2018] [Indexed: 10/24/2022]
Abstract
One of the potential applications of surface-enhanced Raman spectroscopy (SERS) is the detection of biological compounds and microorganisms. Here we demonstrate that SERS coupled with principal component analysis (PCA) serves as a perfect method for determining the taxonomic affiliation of bacteria at the strain level. We demonstrate for the first time that it is possible to distinguish different genoserogroups within a single species, Listeria monocytogenes, which is one of the most virulent foodborne pathogens and in some cases contact with which may be fatal. We also postulate that it is possible to detect additional proteins in the L. monocytogenes cell envelope, which provide resistance to benzalkonium chloride and cadmium. A better understanding of this infectious agent could help in selecting the appropriate pharmaceutical product for enhanced treatment. Graphical abstract ᅟ.
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Affiliation(s)
- Evelin Witkowska
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Dorota Korsak
- Faculty of Biology, Institute of Microbiology, Department of Applied Microbiology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Aneta Kowalska
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Anna Janeczek
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Agnieszka Kamińska
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
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17
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Yeole SD, Khire SS, Sarode CH, Patil KD. On the cation– $$\uppi $$ π interactions in 1,2-dihydro-1,2-azaborine. J CHEM SCI 2018. [DOI: 10.1007/s12039-018-1500-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Lopez-Ezquerra A, Mitschke A, Bornberg-Bauer E, Joop G. Tribolium castaneum gene expression changes after Paranosema whitei infection. J Invertebr Pathol 2018; 153:92-98. [DOI: 10.1016/j.jip.2018.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/10/2018] [Accepted: 02/12/2018] [Indexed: 12/24/2022]
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19
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López M, Quitian LV, Calderón MN, Soto CY. The P-type ATPase CtpG preferentially transports Cd2+ across the Mycobacterium tuberculosis plasma membrane. Arch Microbiol 2017; 200:483-492. [DOI: 10.1007/s00203-017-1465-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 12/31/2022]
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20
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Clauss-Lendzian E, Vaishampayan A, de Jong A, Landau U, Meyer C, Kok J, Grohmann E. Stress response of a clinical Enterococcus faecalis isolate subjected to a novel antimicrobial surface coating. Microbiol Res 2017; 207:53-64. [PMID: 29458868 DOI: 10.1016/j.micres.2017.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 04/21/2017] [Accepted: 11/07/2017] [Indexed: 12/17/2022]
Abstract
Emerging antibiotic resistance among pathogenic bacteria, paired with their ability to form biofilms on medical and technical devices, represents a serious problem for effective and long-term decontamination in health-care environments and gives rise to an urgent need for new antimicrobial materials. Here we present the impact of AGXX®, a novel broad-spectrum antimicrobial surface coating consisting of micro-galvanic elements formed by silver and ruthenium, on the transcriptome of Enterococcus faecalis. A clinical E. faecalis isolate was subjected to metal stress by growing it for different periods in presence of the antimicrobial coating or silver-coated steel meshes. Subsequently, total RNA was isolated and next-generation RNA sequencing was performed to analyze variations in gene expression in presence of the antimicrobial materials with focus on known stress genes. Exposure to the antimicrobial coating had a large impact on the transcriptome of E. faecalis. After 24min almost 1/5 of the E. faecalis genome displayed differential expression. At each time-point the cop operon was strongly up-regulated, providing indirect evidence for the presence of free Ag+-ions. Moreover, exposure to the antimicrobial coating induced a broad general stress response in E. faecalis. Genes coding for the chaperones GroEL and GroES and the Clp proteases, ClpE and ClpB, were among the top up-regulated heat shock genes. Differential expression of thioredoxin, superoxide dismutase and glutathione synthetase genes indicates a high level of oxidative stress. We postulate a mechanism of action where the combination of Ag+-ions and reactive oxygen species generated by AGXX® results in a synergistic antimicrobial effect, superior to that of conventional silver coatings.
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Affiliation(s)
- Emanuel Clauss-Lendzian
- Division of Infectious Diseases, University Medical Center Freiburg, Hugstetter Straße 55, 79106 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Ankita Vaishampayan
- School of Life Sciences and Technology, Beuth University of Applied Sciences, Seestrasse 64, 13347 Berlin, Germany
| | - Anne de Jong
- Department of Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 Groningen, The Netherlands
| | - Uwe Landau
- Largentec GmbH, Am Waldhaus 32, 14129 Berlin, Germany
| | - Carsten Meyer
- Largentec GmbH, Am Waldhaus 32, 14129 Berlin, Germany
| | - Jan Kok
- Department of Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 Groningen, The Netherlands
| | - Elisabeth Grohmann
- Division of Infectious Diseases, University Medical Center Freiburg, Hugstetter Straße 55, 79106 Freiburg im Breisgau, Baden-Württemberg, Germany; School of Life Sciences and Technology, Beuth University of Applied Sciences, Seestrasse 64, 13347 Berlin, Germany.
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21
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Furukawa K, Ramesh A, Zhou Z, Weinberg Z, Vallery T, Winkler WC, Breaker RR. Bacterial riboswitches cooperatively bind Ni(2+) or Co(2+) ions and control expression of heavy metal transporters. Mol Cell 2016; 57:1088-1098. [PMID: 25794617 DOI: 10.1016/j.molcel.2015.02.009] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/17/2014] [Accepted: 02/03/2015] [Indexed: 11/19/2022]
Abstract
Bacteria regularly encounter widely varying metal concentrations in their surrounding environment. As metals become depleted or, conversely, accrue to toxicity, microbes will activate cellular responses that act to maintain metal homeostasis. A suite of metal-sensing regulatory ("metalloregulatory") proteins orchestrate these responses by allosterically coupling the selective binding of target metals to the activity of DNA-binding domains. However, we report here the discovery, validation, and structural details of a widespread class of riboswitch RNAs, whose members selectively and tightly bind the low-abundance transition metals, Ni(2+) and Co(2+). These riboswitches bind metal cooperatively, and with affinities in the low micromolar range. The structure of a Co(2+)-bound RNA reveals a network of molecular contacts that explains how it achieves cooperative binding between adjacent sites. These findings reveal that bacteria have evolved to utilize highly selective metalloregulatory riboswitches, in addition to metalloregulatory proteins, for detecting and responding to toxic levels of heavy metals.
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Affiliation(s)
- Kazuhiro Furukawa
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
| | - Arati Ramesh
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Zhiyuan Zhou
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
| | - Zasha Weinberg
- Howard Hughes Medical Institute, New Haven, CT 06520, USA
| | - Tenaya Vallery
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Wade C Winkler
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
| | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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22
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Darwin KH. Mycobacterium tuberculosis and Copper: A Newly Appreciated Defense against an Old Foe? J Biol Chem 2015; 290:18962-6. [PMID: 26055711 DOI: 10.1074/jbc.r115.640193] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several independent studies have recently converged upon the conclusion that the human bacterial pathogen Mycobacterium tuberculosis encounters copper during infections. At least three independently regulated pathways respond to excess copper and are required for the full virulence of M. tuberculosis in animals. In this review, I will discuss the functions of the best-characterized copper-responsive proteins in M. tuberculosis, the potential sources of copper during an infection, and remaining questions about the interface between copper and tuberculosis.
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Affiliation(s)
- K Heran Darwin
- From the Department of Microbiology, New York University School of Medicine New York, New York 10016
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23
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CtpA, a putative Mycobacterium tuberculosis P-type ATPase, is stimulated by copper (I) in the mycobacterial plasma membrane. Biometals 2015; 28:713-24. [PMID: 25967101 DOI: 10.1007/s10534-015-9860-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/01/2015] [Indexed: 12/24/2022]
Abstract
The transport of heavy-metal ions across the plasma membrane is essential for mycobacterial intracellular survival; in this context, P-type ATPases are pivotal for maintenance of ionic gradients and the plasma membrane homeostasis of mycobacteria. To date, the copper ion transport that is mediated by P-type ATPases in mycobacteria is poorly understood. In this work, the ion-specific activation of CtpA, a putative plasma membrane Mycobacterium tuberculosis P-type ATPase, with different heavy-metal cations was assessed. Mycobacterium smegmatis mc(2)155 cells heterologously expressing the M. tuberculosis ctpA gene displayed an increased tolerance to toxic levels of the Cu(2+) ion (4 mM) compared to control cells, suggesting that CtpA is possibly involved in the copper detoxification of mycobacterial cells. In contrast, the tolerance of M. smegmatis recombinant cells against other heavy-metal divalent cations, such as Co(2+), Mn(2+), Ni(2+) and Zn(2+), was not detected. In addition, the ATPase activity of plasma membrane vesicles that were obtained from M. smegmatis cells expressing CtpA was stimulated by Cu(+) (4.9 nmol of Pi released/mg of protein.min) but not by Cu(2+) ions; therefore, Cu(2+) reduction to Cu(+) inside mycobacterial cells is suggested. Finally, the plasma membrane vesicles of M. smegmatis that were enriched with CtpA exhibited an optimal activity at 37 °C and pH 7.9; the apparent kinetic parameters of the enzyme were a K(1/2) of 4.68 × 10(-2) µM for Cu(+), a Vmax of 10.3 U/mg of protein, and an h value of 1.91.
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24
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Rosenberg J, Dickmanns A, Neumann P, Gunka K, Arens J, Kaever V, Stülke J, Ficner R, Commichau FM. Structural and biochemical analysis of the essential diadenylate cyclase CdaA from Listeria monocytogenes. J Biol Chem 2015; 290:6596-606. [PMID: 25605729 DOI: 10.1074/jbc.m114.630418] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The recently identified second messenger cyclic di-AMP (c-di-AMP) is involved in several important cellular processes, such as cell wall metabolism, maintenance of DNA integrity, ion transport, transcription regulation, and allosteric regulation of enzyme function. Interestingly, c-di-AMP is essential for growth of the Gram-positive model bacterium Bacillus subtilis. Although the genome of B. subtilis encodes three c-di-AMP-producing diadenlyate cyclases that can functionally replace each other, the phylogenetically related human pathogens like Listeria monocytogenes and Staphylococcus aureus possess only one enzyme, the diadenlyate cyclase CdaA. Because CdaA is also essential for growth of these bacteria, the enzyme is a promising target for the development of novel antibiotics. Here we present the first crystal structure of the L. monocytogenes CdaA diadenylate cyclase domain that is conserved in many human pathogens. Moreover, biochemical characterization of the cyclase revealed an unusual metal cofactor requirement.
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Affiliation(s)
| | - Achim Dickmanns
- Molecular Structural Biology, Institute for Microbiology and Genetics, Georg-August University Göttingen, D-37077 Göttingen, Germany and
| | - Piotr Neumann
- Molecular Structural Biology, Institute for Microbiology and Genetics, Georg-August University Göttingen, D-37077 Göttingen, Germany and
| | - Katrin Gunka
- From the Departments of General Microbiology and
| | - Johannes Arens
- Molecular Structural Biology, Institute for Microbiology and Genetics, Georg-August University Göttingen, D-37077 Göttingen, Germany and
| | - Volkhard Kaever
- the Research Core Unit Metabolomics, Hannover Medical School, D-30625 Hannover, Germany
| | - Jörg Stülke
- From the Departments of General Microbiology and
| | - Ralf Ficner
- Molecular Structural Biology, Institute for Microbiology and Genetics, Georg-August University Göttingen, D-37077 Göttingen, Germany and
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25
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26
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Biogenic magnetic nanoparticles from Burkholderia sp. YN01 exhibiting intrinsic peroxidase-like activity and their applications. Appl Microbiol Biotechnol 2014; 99:703-15. [DOI: 10.1007/s00253-014-5938-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/02/2014] [Accepted: 07/05/2014] [Indexed: 12/19/2022]
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27
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Pulido PA, Novoa-Aponte L, Villamil N, Soto CY. The DosR Dormancy Regulator of Mycobacterium tuberculosis Stimulates the Na+/K+ and Ca2+ ATPase Activities in Plasma Membrane Vesicles of Mycobacteria. Curr Microbiol 2014; 69:604-10. [DOI: 10.1007/s00284-014-0632-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 04/30/2014] [Indexed: 01/14/2023]
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28
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Al-Shanawa M, Nabok A, Hashim A, Smith T, Forder S. Optical Study of the Effect of Gamma Radiation and Heavy Metals on Microorganisms (Bacteria). BIONANOSCIENCE 2014. [DOI: 10.1007/s12668-014-0133-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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29
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Shi Y, Zhao G, Kong W. Genetic analysis of riboswitch-mediated transcriptional regulation responding to Mn2+ in Salmonella. J Biol Chem 2014; 289:11353-11366. [PMID: 24596096 DOI: 10.1074/jbc.m113.517516] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Riboswitches are a class of cis-acting regulatory RNAs normally characterized from the 5'-UTR of bacterial transcripts that bind a specific ligand to regulate expression of associated genes by forming alternative conformations. Here, we present a riboswitch that contributes to transcriptional regulation through sensing Mn(2+) in Salmonella typhimurium. We characterized a 5'-UTR (UTR1) from the mntH locus encoding a Mn(2+) transporter, which forms a Rho-independent terminator to implement transcription termination with a high Mn(2+) selectivity both in vivo and in vitro. Nucleotide substitutions that cause disruption of the terminator interfere with the regulatory function of UTR1. RNA probing analyses outlined a specific UTR1 conformation that favors the terminator structure in Mn(2+)-replete condition. Switch sequence GCUAUG can alternatively base pair duplicated hexanucleotide CAUAGC to form either a pseudoknot or terminator stem. Mn(2+), but not Mg(2+), and Ca(2+), can enhance cleavage at specific nucleotides in UTR1. We conclude that UTR1 is a riboswitch that senses cytoplasmic Mn(2+) and therefore participates in Mn(2+)-responsive mntH regulation in Salmonella. This riboswitch domain is also conserved in several Gram-negative enteric bacteria, indicating that this Mn(2+)-responsive mechanism could have broader implications in bacterial gene expression. Additionally, a high level of cytoplasmic Mn(2+) can down-regulate transcription of the Salmonella Mg(2+) transporter mgtA locus in a Mg(2+) riboswitch-dependent manner. On the other hand, these two types of cation riboswitches do not share similarity at the primary or secondary structural levels. Taken together, characterization of Mn(2+)-responsive riboswitches should expand the scope of RNA regulatory elements in response to inorganic ions.
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Affiliation(s)
- Yixin Shi
- Center for Infectious Diseases and Vaccinology, Biodesign Institute, and Arizona State University, Tempe, Arizona 85287-4501; School of Life Sciences, Arizona State University, Tempe, Arizona 85287-4501.
| | - Guang Zhao
- Center for Infectious Diseases and Vaccinology, Biodesign Institute, and Arizona State University, Tempe, Arizona 85287-4501
| | - Wei Kong
- Center for Infectious Diseases and Vaccinology, Biodesign Institute, and Arizona State University, Tempe, Arizona 85287-4501
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30
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Xiao YM, Zhao GY, Fang XX, Zhao YX, Wang GH, Yang W, Xu JW. A smart copper(ii)-responsive binuclear gadolinium(iii) complex-based magnetic resonance imaging contrast agent. RSC Adv 2014. [DOI: 10.1039/c4ra04526b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The relaxivity of the complex was modulated by Cu2+, that is, in the absence of Cu2+ the complex exhibited a relatively low relaxivity value of 6.40 mM−1 s−1, while the addition of Cu2+ triggered the relaxivity to 11.28 mM−1 s−1, an enhancement of approximately 76%.
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Affiliation(s)
- Yan-meng Xiao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
- University of Chinese Academy of Sciences
- Beijing, P. R. China
| | - Gui-yan Zhao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
- University of Chinese Academy of Sciences
- Beijing, P. R. China
| | - Xin-xiu Fang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
- University of Chinese Academy of Sciences
- Beijing, P. R. China
| | - Yong-xia Zhao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
- University of Chinese Academy of Sciences
- Beijing, P. R. China
| | - Guan-hua Wang
- Guangdong Provincial Public Laboratory of Analysis and Testing Technology
- Guangdong Institute of Analysis
- Guangzhou 510070, P. R. China
| | - Wei Yang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
| | - Jing-wei Xu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Changchun 130022, P. R. China
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31
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Merchant AT, Spatafora GA. A role for the DtxR family of metalloregulators in gram-positive pathogenesis. Mol Oral Microbiol 2013; 29:1-10. [PMID: 24034418 DOI: 10.1111/omi.12039] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2013] [Indexed: 11/28/2022]
Abstract
Given the central role of transition metal ions in a variety of biochemical processes, the colonization, survival, and proliferation of a bacterium within a host hinges upon its ability to overcome the metal ion deprivation that characterizes nutritional immunity. Metalloregulatory, or 'metal-sensing' proteins have evolved in bacteria to mediate metal ion homeostasis by activating or repressing the expression of genes encoding metal ion transport systems upon binding their cognate metal ion. Yet increasing evidence in the literature supports an additional role for these metalloregulatory proteins in pathogenesis. Herein, we survey studies on the DtxR family of metalloregulators, namely DtxR (Cornyebacterium diphtheriae), SloR (Streptococcus mutans), MtsR (Streptococcus pyogenes), and MntR (Staphylococcus aureus) to describe how metalloregulation enables adaptive virulence gene expression within the mammalian host. This research has important implications for drug design, as the generation of hyper-repressive metalloregulatory proteins may represent a mechanism by which to attenuate bacterial pathogenicity. The fact that metalloregulators are unique to prokaryotes makes these proteins especially attractive therapeutic targets.
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Affiliation(s)
- A T Merchant
- Department of Biology, Middlebury College, Middlebury, VT, USA
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EfaR is a major regulator of Enterococcus faecalis manganese transporters and influences processes involved in host colonization and infection. Infect Immun 2013; 81:935-44. [PMID: 23297382 DOI: 10.1128/iai.06377-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Metal ions, in particular manganese, are important modulators of bacterial pathogenicity. However, little is known about the role of manganese-dependent proteins in the nosocomial pathogen Enterococcus faecalis, a major cause of bacterial endocarditis. The present study demonstrates that the DtxR/MntR family metalloregulator EfaR of E. faecalis controls the expression of several of its regulon members in a manganese-dependent way. We also show that efaR inactivation impairs the ability of E. faecalis to form biofilms, to survive inside macrophages, and to tolerate oxidative stress. Our results reveal that EfaR is an important modulator of E. faecalis virulence and link manganese homeostasis to enterococcal pathogenicity.
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Santos P, Gordillo A, Osses L, Salazar LM, Soto CY. Effect of antimicrobial peptides on ATPase activity and proton pumping in plasma membrane vesicles obtained from mycobacteria. Peptides 2012; 36:121-8. [PMID: 22569076 DOI: 10.1016/j.peptides.2012.04.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 04/23/2012] [Accepted: 04/23/2012] [Indexed: 12/29/2022]
Abstract
The potential usefulness of antimicrobial peptides (AMPs) as antimycobacterial compounds has not been extensively explored. Although a myriad of studies on AMPs from different sources have been done, some of its mechanisms of action are still unknown. Maganins are of particular interest since they do not lyse non-dividing mammalian cells. In this work, AMPs with well-recognized activity against bacteria were synthesized, characterized, purified and their antimycobacterial activity and influence on ATPase activity in mycobacterial plasma membrane vesicles were assessed. Using bioinformatics tools, a magainin-I analog peptide (MIAP) with improved antimicrobial activity was designed. The influence of MIAP on proton (H(+)) pumping mediated by F(1)F(0)-ATPase in plasma membrane vesicles obtained from Mycobacterium tuberculosis was evaluated. We observed that the antimycobacterial activity of AMPs was low and variable. However, the activity of the designed peptide MIAP against M. tuberculosis was 2-fold higher in comparison to magainin-I. The basal ATPase activity of mycobacterial plasma membrane vesicles decreased approximately 24-30% in the presence of AMPs. On the other hand, the MIAP peptide completely abolished the F(1)F(0)-ATPase activity involved in H(+) pumping across M. tuberculosis plasma membranes vesicles at levels similar to the specific inhibitor N,N' dicyclohexylcarbodiimide. These finding suggest that AMPs can inhibit the H(+) pumping F(1)F(0)-ATPase of mycobacterial plasma membrane that potentially interferes the internal pH and viability of mycobacteria.
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Affiliation(s)
- Paola Santos
- Chemistry Department, Faculty of Sciences, Universidad Nacional de Colombia, Bogotá, Colombia
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Ward SK, Heintz JA, Albrecht RM, Talaat AM. Single-cell elemental analysis of bacteria: quantitative analysis of polyphosphates in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2012; 2:63. [PMID: 22919654 PMCID: PMC3417655 DOI: 10.3389/fcimb.2012.00063] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 04/20/2012] [Indexed: 12/31/2022] Open
Abstract
More than 1.8 million people die annually from infection with Mycobacterium tuberculosis, the causative agent of tuberculosis. The ability of M. tuberculosis to obtain and distribute micronutrients, including biometals, is known to play a role in its intracellular survival and virulence within a host. Techniques to detect elemental distributions within M. tuberculosis cells have previously been limited to bulk detection methods or low-resolution analyses. Here, we present a method for determining the elemental distribution within M. tuberculosis on a single-cell level, at high (individual nanometer) resolution, using scanning transmission electron microscopy (STEM) in concert with energy-dispersive X-ray spectroscopy (EDS). Results revealed the presence of large polyphosphate granules in all strains of Mycobacteria tested. These persisted even through starvation conditions, and might play a role connected to elemental homeostasis in M. tuberculosis. Associated with the polyphosphate granules were micronutrients such as calcium and magnesium. In addition, we expanded the technique beyond Mycobacteria to show that STEM and EDS could be used as a simple screen to detect the presence or absence of concentrated elements on a single-cell level within all six other bacterial types tested, with minimal processing to the bacteria. Overall, we believe that this technique represents a first step in developing a better understanding of the role that components of the intracellular milieu, including polyphosphates and biometals, play in the pathogenesis of M. tuberculosis, with potential future applications for in vivo analysis.
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Affiliation(s)
- Sarah K Ward
- Department of Pathobiological Sciences, University of Wisconsin-Madison Madison, WI, USA
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Guo FF, Yang W, Jiang W, Geng S, Peng T, Li JL. Magnetosomes eliminate intracellular reactive oxygen species in Magnetospirillum gryphiswaldense MSR-1. Environ Microbiol 2012; 14:1722-9. [DOI: 10.1111/j.1462-2920.2012.02707.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Impact of manganese, copper and zinc ions on the transcriptome of the nosocomial pathogen Enterococcus faecalis V583. PLoS One 2011; 6:e26519. [PMID: 22053193 PMCID: PMC3203883 DOI: 10.1371/journal.pone.0026519] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 09/28/2011] [Indexed: 11/19/2022] Open
Abstract
Mechanisms that enable Enterococcus to cope with different environmental stresses and their contribution to the switch from commensalism to pathogenicity of this organism are still poorly understood. Maintenance of intracellular homeostasis of metal ions is crucial for survival of these bacteria. In particular Zn(2+), Mn(2+) and Cu(2+) are very important metal ions as they are co-factors of many enzymes, are involved in oxidative stress defense and have a role in the immune system of the host. Their concentrations inside the human body vary hugely, which makes it imperative for Enterococcus to fine-tune metal ion homeostasis in order to survive inside the host and colonize it. Little is known about metal regulation in Enterococcus faecalis. Here we present the first genome-wide description of gene expression of E. faecalis V583 growing in the presence of high concentrations of zinc, manganese or copper ions. The DNA microarray experiments revealed that mostly transporters are involved in the responses of E. faecalis to prolonged exposure to high metal concentrations although genes involved in cellular processes, in energy and amino acid metabolisms and genes related to the cell envelope also seem to play important roles.
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Reyes-Caballero H, Lee CW, Giedroc DP. Mycobacterium tuberculosis NmtR harbors a nickel sensing site with parallels to Escherichia coli RcnR. Biochemistry 2011; 50:7941-52. [PMID: 21819125 DOI: 10.1021/bi200737a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis NmtR is a Ni(II)/Co(II)-sensing metalloregulatory protein from the extensively studied ArsR/SmtB family. Two Ni(II) ions bind to the NmtR dimer to form octahedral coordination complexes with the following stepwise binding affinities: K(Ni1) = (1.2 ± 0.1) × 10(10) M(-1), and K(Ni2) = (0.7 ± 0.4) × 10(10) M(-1) (pH 7.0). A glutamine scanning mutagenesis approach reveals that Asp91, His93, His104, and His107, all contained within the C-terminal α5 helix, and His3 as part of the conserved α-NH(2)-Gly2-His3-Gly4 motif at the N-terminus make significant contributions to the magnitude of K(Ni). In contrast, substitution of residues from the C-terminal region, His109, Asp114, and His116, previously implicated in Ni(II) binding and metalloregulation in cells, gives rise to wild-type K(Ni) and Ni(II)-dependent allosteric coupling free energies. Interestingly, deletion of residues 112-120 from the C-terminal region (Δ111 NmtR) reduces the Ni(II) binding stoichiometry to one per dimer and greatly reduces Ni(II) responsiveness. H3Q and Δ111 NmtRs also show clear perturbations in the rank order of metal responsiveness to Ni(II), Co(II), and Zn(II) that is distinct from that of wild-type NmtR. (15)N relaxation experiments with apo-NmtR reveal that both N-terminal (residues 2-14) and C- terminal (residues 110-120) regions are unstructured in solution, and this property likely dictates the metal specificity profile characteristic of the Ni(II) sensor NmtR relative to other ArsR family regulators.
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Ogura M. ZnuABC and ZosA zinc transporters are differently involved in competence development in Bacillus subtilis. ACTA ACUST UNITED AC 2011; 150:615-25. [DOI: 10.1093/jb/mvr098] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Vetrivel U, Subramanian G, Dorairaj S. A novel in silico approach to identify potential therapeutic targets in human bacterial pathogens. THE HUGO JOURNAL 2011. [PMID: 23205162 DOI: 10.1007/s11568-011-9152-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED In recent years, genome-sequencing projects of pathogens and humans have revolutionized microbial drug target identification. Of the several known genomic strategies, subtractive genomics has been successfully utilized for identifying microbial drug targets. The present work demonstrates a novel genomics approach in which codon adaptation index (CAI), a measure used to predict the translational efficiency of a gene based on synonymous codon usage, is coupled with subtractive genomics approach for mining potential drug targets. The strategy adopted is demonstrated using respiratory pathogens, namely, Streptococcus pneumoniae and Haemophilus influenzae as examples. Our approach identified 8 potent target genes (Streptococcus pneumoniae-2, H. influenzae-6), which are functionally significant and also play key role in host-pathogen interactions. This approach facilitates swift identification of potential drug targets, thereby enabling the search for new inhibitors. These results underscore the utility of CAI for enhanced in silico drug target identification. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (doi:10.1007/s11568-011-9152-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Umashankar Vetrivel
- Center of Bioinformatics, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamilnadu 600 006 India
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Fadda A, Fierro AC, Lemmens K, Monsieurs P, Engelen K, Marchal K. Inferring the transcriptional network of Bacillus subtilis. MOLECULAR BIOSYSTEMS 2009; 5:1840-52. [PMID: 20023724 DOI: 10.1039/b907310h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adaptation of bacteria to the vigorous environmental changes they undergo is crucial to their survival. They achieve this adaptation partly via intricate regulation of the transcription of their genes. In this study, we infer the transcriptional network of the Gram-positive model organism, Bacillus subtilis. We use a data integration workflow, exploiting both motif and expression data, towards the generation of condition-dependent transcriptional modules. In building the motif data, we rely on both known and predicted information. Known motifs were derived from DBTBS, while predicted motifs were generated by a de novo motif detection method that utilizes comparative genomics. The expression data consists of a compendium of microarrays across different platforms. Our results indicate that a considerable part of the B. subtilis network is yet undiscovered; we could predict 417 new regulatory interactions for known regulators and 453 interactions for yet uncharacterized regulators. The regulators in our network showed a preference for regulating modules in certain environmental conditions. Also, substantial condition-dependent intra-operonic regulation seems to take place. Global regulators seem to require functional flexibility to attain their roles by acting as both activators and repressors.
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Affiliation(s)
- Abeer Fadda
- Department of Microbial and Molecular Systems, KULeuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
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Rao JS, Zipse H, Sastry GN. Explicit Solvent Effect on Cation−π Interactions: A First Principle Investigation. J Phys Chem B 2009; 113:7225-36. [DOI: 10.1021/jp900013e] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- J. Srinivasa Rao
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad - 500 607, India, and Department Chemie and Biochemie, LMU München, Butenandtstrasse 5-13, D-81377, München, Germany
| | - Hendrik Zipse
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad - 500 607, India, and Department Chemie and Biochemie, LMU München, Butenandtstrasse 5-13, D-81377, München, Germany
| | - G. Narahari Sastry
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad - 500 607, India, and Department Chemie and Biochemie, LMU München, Butenandtstrasse 5-13, D-81377, München, Germany
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Rao JS, Sastry GN. Structural and Energetic Preferences of π, σ, and Bidentate Cation Binding (Li+, Na+, and Mg2+) to Aromatic Amines (Ph−(CH2)n−NH2, n = 2−5): A Theoretical Study. J Phys Chem A 2009; 113:5446-54. [DOI: 10.1021/jp811124g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- J. Srinivasa Rao
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India
| | - G. Narahari Sastry
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India
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A P-type ATPase importer that discriminates between essential and toxic transition metals. Proc Natl Acad Sci U S A 2009; 106:4677-82. [PMID: 19264958 DOI: 10.1073/pnas.0900666106] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Transition metals, although being essential cofactors in many physiological processes, are toxic at elevated concentrations. Among the membrane-embedded transport proteins that maintain appropriate intracellular levels of transition metals are ATP-driven pumps belonging to the P-type ATPase superfamily. These metal transporters may be differentiated according to their substrate specificities, where the majority of pumps can extrude either silver and copper or zinc, cadmium, and lead. In the present report, we have established the substrate specificities of nine previously uncharacterized prokaryotic transition-metal P-type ATPases. We find that all of the newly identified exporters indeed fall into one of the two above-mentioned categories. In addition to these exporters, one importer, Pseudomonas aeruginosa Q9I147, was also identified. This protein, designated HmtA (heavy metal transporter A), exhibited a different substrate recognition profile from the exporters. In vivo metal susceptibility assays, intracellular metal measurements, and transport experiments all suggest that HmtA mediates the uptake of copper and zinc but not of silver, mercury, or cadmium. The substrate selectivity of this importer ensures the high-affinity uptake of essential metals, while avoiding intracellular contamination by their toxic counterparts.
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Ranjan S, Yellaboina S, Ranjan A. IdeR in Mycobacteria: From Target Recognition to Physiological Function. Crit Rev Microbiol 2008; 32:69-75. [PMID: 16809230 DOI: 10.1080/10408410600709768] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In mycobacteria, iron dependent transcription regulator (IdeR) regulates transcription of genes in response to iron levels. The IdeR regulated genes have been investigated mostly in M. tuberculosis, M. smegmatis, and in few of the other related species. Recent advances in crystal structure solution and computational as well as experimental identification of IdeR targets has provided insight into IdeR structure and function. Here in this review we take stock of current state of knowledge on IdeR and its targets to understand the underlying design of the IdeR regulon and its role in mycobacterial physiology.
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Affiliation(s)
- Sarita Ranjan
- Sun Centre of Excellence in Medical Bioinformatics, Centre for DNA Fingerprinting and Diagnostics, EMBnet India Node, Hyderabad 500076, India
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O'Brien BA, Archer NS, Simpson AM, Torpy FR, Nassif NT. Association of SLC11A1 promoter polymorphisms with the incidence of autoimmune and inflammatory diseases: A meta-analysis. J Autoimmun 2008; 31:42-51. [DOI: 10.1016/j.jaut.2008.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/07/2008] [Accepted: 02/08/2008] [Indexed: 10/22/2022]
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Reddy AS, Zipse H, Sastry GN. Cation−π Interactions of Bare and Coordinatively Saturated Metal Ions: Contrasting Structural and Energetic Characteristics. J Phys Chem B 2007; 111:11546-53. [PMID: 17850069 DOI: 10.1021/jp075768l] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the present work, we address an apparent disparity in the structural parameters of the X-ray structures and theoretical models of cation-pi complexes in biological and chemical recognition. Hydrated metal ion (Li+, Na+, K+, Mg2+, Ca2+) complexes with benzene (cation-pi) are considered as model systems to perform quantum mechanical calculations in evaluating the geometrical parameters and interaction energies of these complexes. The computations disclose that there is a variation in the structural parameters as well as in the interaction energies of these complexes with the multiple additions of water molecules. The distance between the cation and the pi-system increases with the addition of water molecules, delineating the influence of solvent or the neighborhood atoms on the structural parameters of cation-pi systems present in crystal structures.
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Affiliation(s)
- A Srinivas Reddy
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
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Waterman SR, Williamson PR. Pathogen diversity and adaptation to the host: applications to clinical genomics. Future Microbiol 2007; 2:215-8. [PMID: 17661692 DOI: 10.2217/17460913.2.3.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Abstract
Cation-aromatic database (CAD) is a publicly available web-based database that aims to provide further understanding of interaction between a cation and the pi interactions. A tool to identify the interactions in a user-given protein is also added to the database. CAD is freely accessible via the Internet at http://203.199.182.73/gnsmmg/databases/cad/.
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Affiliation(s)
- A Srinivas Reddy
- Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology, Hyderabad 500007, India
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Stern BR, Solioz M, Krewski D, Aggett P, Aw TC, Baker S, Crump K, Dourson M, Haber L, Hertzberg R, Keen C, Meek B, Rudenko L, Schoeny R, Slob W, Starr T. Copper and human health: biochemistry, genetics, and strategies for modeling dose-response relationships. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2007; 10:157-222. [PMID: 17454552 DOI: 10.1080/10937400600755911] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Copper (Cu) and its alloys are used extensively in domestic and industrial applications. Cu is also an essential element in mammalian nutrition. Since both copper deficiency and copper excess produce adverse health effects, the dose-response curve is U-shaped, although the precise form has not yet been well characterized. Many animal and human studies were conducted on copper to provide a rich database from which data suitable for modeling the dose-response relationship for copper may be extracted. Possible dose-response modeling strategies are considered in this review, including those based on the benchmark dose and categorical regression. The usefulness of biologically based dose-response modeling techniques in understanding copper toxicity was difficult to assess at this time since the mechanisms underlying copper-induced toxicity have yet to be fully elucidated. A dose-response modeling strategy for copper toxicity was proposed associated with both deficiency and excess. This modeling strategy was applied to multiple studies of copper-induced toxicity, standardized with respect to severity of adverse health outcomes and selected on the basis of criteria reflecting the quality and relevance of individual studies. The use of a comprehensive database on copper-induced toxicity is essential for dose-response modeling since there is insufficient information in any single study to adequately characterize copper dose-response relationships. The dose-response modeling strategy envisioned here is designed to determine whether the existing toxicity data for copper excess or deficiency may be effectively utilized in defining the limits of the homeostatic range in humans and other species. By considering alternative techniques for determining a point of departure and low-dose extrapolation (including categorical regression, the benchmark dose, and identification of observed no-effect levels) this strategy will identify which techniques are most suitable for this purpose. This analysis also serves to identify areas in which additional data are needed to better define the characteristics of dose-response relationships for copper-induced toxicity in relation to excess or deficiency.
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Affiliation(s)
- Bonnie Ransom Stern
- Consulting in Health Sciences and Risk Assessment, BR Stern Associates, Annandale, Virginia 22003, USA.
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