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Song W, Chen X, Yu J, Qiao J, Yang J, Chen X, Wang Z. Effects of Bacillus altitudinis inoculants on cigar tobacco leaf fermentation. Front Bioeng Biotechnol 2024; 12:1417601. [PMID: 39045536 PMCID: PMC11264575 DOI: 10.3389/fbioe.2024.1417601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/12/2024] [Indexed: 07/25/2024] Open
Abstract
Introduction Microbial succession and metabolic adjustment during cigar tobacco leaf (CTL) fermentation are key factors to improve the quality and flavor of CTLs. However, the interactions in the above processes remain to be further elucidated. Methods Bacillus altitudinis inoculants were added to the CTLs, and metagenomics and metabolomics were used to analyze the effects of the inoculants on regulating microbial succession, metabolic shift, and aroma production during fermentation. Results and discussion The addition of the inoculants reinforced the CTL macromolecule transformation and facilitated the aroma production efficiently, and the total aroma production was increased by 43% compared with natural fermentation. The omics analysis showed that Staphylococcus was a main contributor to fatty acid degradation, inositol phosphate metabolism, energy supply (oxidative phosphorylation), nutrient transport (ABC transporter and phosphotransferase system [PTS]), and aroma production (terpenoid backbone biosynthesis, phenylalanine metabolism, and degradation of aromatic compounds). Furthermore, Staphylococcus was positively correlated with TCA cycle intermediates (citric acid, fumaric acid, and aconitic acid), cell wall components, peptidoglycan intermediates (GlcNAc-1-P and UDP-GlcNAc), and phytic acid degradation products (inositol). The characteristics collectively showed Staphylococcus to be the most dominant in the microbial community at the genus level during microflora succession. The addition of the inoculants supplemented the nutritional components of the CTLs, enhanced the metabolic activity and diversity of bacteria such as Corynebacterium, improved their competitive advantages in the microflora succession, and facilitated the richness of microbial communities. Additionally, a metabolic shift in nicotine degradation and NAD + anabolism from Staphylococcus to Corynebacterium in fermentation with inoculants was first observed. Meanwhile, the significantly correlative differential metabolites with Staphylococcus and Corynebacterium were a metabolic complement, thus forming a completely dynamic fermentation ecosystem. The results provided evidence for CTL fermentation optimization.
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Affiliation(s)
- Wen Song
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Hubei University of Technology, Wuhan, China
| | - Xi Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Hubei University of Technology, Wuhan, China
| | - Jun Yu
- Hubei Institute of Tobacco Science, Wuhan, China
| | - Jingyu Qiao
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Hubei University of Technology, Wuhan, China
| | - Jinpeng Yang
- Hubei Institute of Tobacco Science, Wuhan, China
| | - Xiong Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Hubei University of Technology, Wuhan, China
| | - Zhi Wang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), Hubei University of Technology, Wuhan, China
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2
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Soni V, Rosenn EH, Venkataraman R. Insights into the central role of N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmU) in peptidoglycan metabolism and its potential as a therapeutic target. Biochem J 2023; 480:1147-1164. [PMID: 37498748 DOI: 10.1042/bcj20230173] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
Several decades after the discovery of the first antibiotic (penicillin) microbes have evolved novel mechanisms of resistance; endangering not only our abilities to combat future bacterial pandemics but many other clinical challenges such as acquired infections during surgeries. Antimicrobial resistance (AMR) is attributed to the mismanagement and overuse of these medications and is complicated by a slower rate of the discovery of novel drugs and targets. Bacterial peptidoglycan (PG), a three-dimensional mesh of glycan units, is the foundation of the cell wall that protects bacteria against environmental insults. A significant percentage of drugs target PG, however, these have been rendered ineffective due to growing drug resistance. Identifying novel druggable targets is, therefore, imperative. Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) is one of the key building blocks in PG production, biosynthesized by the bifunctional enzyme N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmU). UDP-GlcNAc metabolism has been studied in many organisms, but it holds some distinctive features in bacteria, especially regarding the bacterial GlmU enzyme. In this review, we provide an overview of different steps in PG biogenesis, discuss the biochemistry of GlmU, and summarize the characteristic structural elements of bacterial GlmU vital to its catalytic function. Finally, we will discuss various studies on the development of GlmU inhibitors and their significance in aiding future drug discoveries.
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Affiliation(s)
- Vijay Soni
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, NY 10065, U.S.A
| | - Eric H Rosenn
- Tel Aviv University School of Medicine, Tel Aviv 6997801, Israel
| | - Ramya Venkataraman
- Laboratory of Innate Immunity, National Institute of Immunology, New Delhi 110067, India
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3
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Wyllie JA, McKay MV, Barrow AS, Soares da Costa TP. Biosynthesis of uridine diphosphate N-Acetylglucosamine: An underexploited pathway in the search for novel antibiotics? IUBMB Life 2022; 74:1232-1252. [PMID: 35880704 PMCID: PMC10087520 DOI: 10.1002/iub.2664] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 07/04/2022] [Indexed: 11/06/2022]
Abstract
Although the prevalence of antibiotic resistance is increasing at an alarming rate, there are a dwindling number of effective antibiotics available. Thus, the development of novel antibacterial agents should be of utmost importance. Peptidoglycan biosynthesis has been and is still an attractive source for antibiotic targets; however, there are several components that remain underexploited. In this review, we examine the enzymes involved in the biosynthesis of one such component, UDP-N-acetylglucosamine, an essential building block and precursor of bacterial peptidoglycan. Furthermore, given the presence of a similar biosynthesis pathway in eukaryotes, we discuss the current knowledge on the differences and similarities between the bacterial and eukaryotic enzymes. Finally, this review also summarises the recent advances made in the development of inhibitors targeting the bacterial enzymes.
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Affiliation(s)
- Jessica A Wyllie
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Mirrin V McKay
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Andrew S Barrow
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Tatiana P Soares da Costa
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia
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4
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Belete TM. Recent Progress in the Development of Novel Mycobacterium Cell Wall Inhibitor to Combat Drug-Resistant Tuberculosis. Microbiol Insights 2022; 15:11786361221099878. [PMID: 35645569 PMCID: PMC9131376 DOI: 10.1177/11786361221099878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
Despite decades of research in drug development against TB, it is still the leading cause of death due to infectious diseases. The long treatment duration, patient noncompliance coupled with the ability of the tuberculosis bacilli to resist the current drugs increases multidrug-resistant tuberculosis that exacerbates the situation. Identification of novel drug targets is important for the advancement of drug development against Mycobacterium tuberculosis. The development of an effective treatment course that could help us eradicates TB. Hence, we require drugs that could eliminate the bacteria and shorten the treatment duration. This review briefly describes the available data on the peptidoglycan component structural characterization, identification of the metabolic pathway, and the key enzymes involved in the peptidoglycan synthesis, like N-Acetylglucosamine-1-phosphate uridyltransferase, mur enzyme, alanine racemase as well as their inhibition. Besides, this paper also provides studies on mycolic acid and arabinogalactan synthesis and the transport mechanisms that show considerable promise as new targets to develop a new product with their inhibiter.
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Affiliation(s)
- Tafere Mulaw Belete
- Department of Pharmacology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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5
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Advances in Key Drug Target Identification and New Drug Development for Tuberculosis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5099312. [PMID: 35252448 PMCID: PMC8896939 DOI: 10.1155/2022/5099312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 02/14/2022] [Indexed: 12/15/2022]
Abstract
Tuberculosis (TB) is a severe infectious disease worldwide. The increasing emergence of drug-resistant Mycobacterium tuberculosis (Mtb) has markedly hampered TB control. Therefore, there is an urgent need to develop new anti-TB drugs to treat drug-resistant TB and shorten the standard therapy. The discovery of targets of drug action will lay a theoretical foundation for new drug development. With the development of molecular biology and the success of Mtb genome sequencing, great progress has been made in the discovery of new targets and their relevant inhibitors. In this review, we summarized 45 important drug targets and 15 new drugs that are currently being tested in clinical stages and several prospective molecules that are still at the level of preclinical studies. A comprehensive understanding of the drug targets of Mtb can provide extensive insights into the development of safer and more efficient drugs and may contribute new ideas for TB control and treatment.
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6
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Dysregulation of Streptococcus pneumoniae zinc homeostasis breaks ampicillin resistance in a pneumonia infection model. Cell Rep 2022; 38:110202. [PMID: 35021083 PMCID: PMC9084593 DOI: 10.1016/j.celrep.2021.110202] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 09/24/2021] [Accepted: 12/13/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the primary cause of community-acquired bacterial pneumonia with rates of penicillin and multidrug-resistance exceeding 80% and 40%, respectively. The innate immune response generates a variety of antimicrobial agents to control infection, including zinc stress. Here, we characterize the impact of zinc intoxication on S. pneumoniae, observing disruptions in central carbon metabolism, lipid biogenesis, and peptidoglycan biosynthesis. Characterization of the pivotal peptidoglycan biosynthetic enzyme GlmU indicates a sensitivity to zinc inhibition. Disruption of the sole zinc efflux pathway, czcD, renders S. pneumoniae highly susceptible to β-lactam antibiotics. To dysregulate zinc homeostasis in the wild-type strain, we investigated the safe-for-human-use ionophore 5,7-dichloro-2-[(dimethylamino)methyl]quinolin-8-ol (PBT2). PBT2 rendered wild-type S. pneumoniae strains sensitive to a range of antibiotics. Using an invasive ampicillin-resistant strain, we demonstrate in a murine pneumonia infection model the efficacy of PBT2 + ampicillin treatment. These findings present a therapeutic modality to break antibiotic resistance in multidrug-resistant S. pneumoniae.
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7
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Le TS, Nguyen PT, Nguyen-Ho SH, Nguyen TP, Nguyen TT, Thai MN, Nguyen-Thi TU, Nguyen MC, Hoang QK, Nguyen HT. Expression of genes involved in exopolysaccharide synthesis in Lactiplantibacillus plantarum VAL6 under environmental stresses. Arch Microbiol 2021; 203:4941-4950. [PMID: 34255124 DOI: 10.1007/s00203-021-02479-0] [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: 04/23/2021] [Revised: 06/30/2021] [Accepted: 07/04/2021] [Indexed: 10/20/2022]
Abstract
Environmental factors can alter exopolysaccharide biosynthesis in lactic acid bacteria (LAB). To further clarify this potential relationship, the mRNA expression of genes involved in exopolysaccharide synthesis such as glmU, pgmB1, cps4E, cps4F, cps4J, and cps4H in Lactiplantibacillus plantarum VAL6 under different conditions including temperature, pH, sodium chloride (NaCl), and carbon dioxide (CO2) intensification culture was studied. The transcriptomic data revealed that the exposure of L. plantarum VAL6 at pH 3 increased the expression level of cps4H but decreased the expression levels of pgmB1 and cps4E. Under pH 8, cps4F and cps4E were significantly upregulated, whereas pgmB1 was downregulated. Similarly, the expression levels of cps4F, cps4E, and cps4J increased sharply under stresses at 42 or 47 °C. In the case of NaCl stress, glmU, pgmB1, cps4J, and cps4H were downregulated in exposure to NaCl at 7 and 10% concentrations while cps4E and cps4F were upregulated at 1 h of 10%-NaCl treatment and at 5 h of 4%-NaCl treatment. Remarkably, CO2 intensification culture stimulated the expression of all tested genes. In addition, simultaneous changes in expression of cps4E and cps4F under environmental challenges may elicit the possibility of an association between the two genes. These findings indicated that the expression level of eps genes is responsible for changes in the yield and monosaccharide composition of exopolysaccharides under environmental stresses.
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Affiliation(s)
- Trung-Son Le
- Biotechnology Research and Development Institute, Can Tho University, Can Tho City, Vietnam
| | - Phu-Tho Nguyen
- Graduate University of Sciences and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam. .,Department of Biotechnology, An Giang University, An Giang, Vietnam. .,Vietnam National University, Ho Chi Minh City, Vietnam.
| | - Song-Hao Nguyen-Ho
- Biotechnology Research and Development Institute, Can Tho University, Can Tho City, Vietnam
| | - Tang-Phu Nguyen
- Biotechnology Research and Development Institute, Can Tho University, Can Tho City, Vietnam
| | - Thi-Tho Nguyen
- Ho Chi Minh City University of Tecnology (Hutech), Ho Chi Minh City, Vietnam
| | - My-Ngan Thai
- Department of Biotechnology, An Giang University, An Giang, Vietnam.,Vietnam National University, Ho Chi Minh City, Vietnam
| | | | - Minh-Chon Nguyen
- Biotechnology Research and Development Institute, Can Tho University, Can Tho City, Vietnam
| | - Quoc-Khanh Hoang
- Institute of Tropical Biology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Huu-Thanh Nguyen
- Department of Biotechnology, An Giang University, An Giang, Vietnam. .,Vietnam National University, Ho Chi Minh City, Vietnam.
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Batt SM, Burke CE, Moorey AR, Besra GS. Antibiotics and resistance: the two-sided coin of the mycobacterial cell wall. Cell Surf 2020; 6:100044. [PMID: 32995684 PMCID: PMC7502851 DOI: 10.1016/j.tcsw.2020.100044] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 01/07/2023] Open
Abstract
Mycobacterium tuberculosis, the bacterium responsible for tuberculosis, is the global leading cause of mortality from an infectious agent. Part of this success relies on the unique cell wall, which consists of a thick waxy coat with tightly packed layers of complexed sugars, lipids and peptides. This coat provides a protective hydrophobic barrier to antibiotics and the host's defences, while enabling the bacterium to spread efficiently through sputum to infect and survive within the macrophages of new hosts. However, part of this success comes at a cost, with many of the current first- and second-line drugs targeting the enzymes involved in cell wall biosynthesis. The flip side of this coin is that resistance to these drugs develops either in the target enzymes or the activation pathways of the drugs, paving the way for new resistant clinical strains. This review provides a synopsis of the structure and synthesis of the cell wall and the major current drugs and targets, along with any mechanisms of resistance.
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Affiliation(s)
- Sarah M. Batt
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Christopher E. Burke
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Alice R. Moorey
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Gurdyal S. Besra
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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9
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Hevey R. The Role of Fluorine in Glycomimetic Drug Design. Chemistry 2020; 27:2240-2253. [DOI: 10.1002/chem.202003135] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Rachel Hevey
- Department of Pharmaceutical Sciences University of Basel, Pharmazentrum Klingelbergstrasse 50 4056 Basel Switzerland
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10
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Shetye GS, Franzblau SG, Cho S. New tuberculosis drug targets, their inhibitors, and potential therapeutic impact. Transl Res 2020; 220:68-97. [PMID: 32275897 DOI: 10.1016/j.trsl.2020.03.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/28/2020] [Accepted: 03/09/2020] [Indexed: 11/18/2022]
Abstract
The current tuberculosis (TB) predicament poses numerous challenges and therefore every incremental scientific work and all positive socio-political engagements, are steps taken in the right direction to eradicate TB. Progression of the late stage TB-drug pipeline into the clinics is an immediate deliverable of this global effort. At the same time, fueling basic research and pursuing early discovery work must be sustained to maintain a healthy TB-drug pipeline. This review encompasses a broad analysis of chemotherapeutic strategies that target the DNA replication, protein synthesis, cell wall biosynthesis, energy metabolism and proteolysis of Mycobacterium tuberculosis (Mtb). It includes a status check of the current TB-drug pipeline with a focus on the associated biology, emerging targets, and their promising chemical inhibitors. Potential synergies and/or gaps within or across different chemotherapeutic strategies are systematically reviewed as well.
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Affiliation(s)
- Gauri S Shetye
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Scott G Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois
| | - Sanghyun Cho
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois.
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11
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Ausmus AP, Hogue M, Snyder JL, Rundell SR, Bednarz KM, Banahene N, Swarts BM. Ferrier Carbocyclization-Mediated Synthesis of Enantiopure Azido Inositol Analogues. J Org Chem 2020; 85:3182-3191. [DOI: 10.1021/acs.joc.9b03064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alex P. Ausmus
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Maxwell Hogue
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Justin L. Snyder
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Sarah R. Rundell
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Krestina M. Bednarz
- 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
| | - Benjamin M. Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
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12
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Design, properties and applications of fluorinated and fluoroalkylated N-containing monosaccharides and their analogues. J Fluor Chem 2019. [DOI: 10.1016/j.jfluchem.2019.109364] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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13
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Sharipova RR, Garifullin BF, Sapunova AS, Voloshina AD, Kravchenko MA, Kataev VE. Synthesis and Biological Activity of 3,4,-Tri-О-Acetyl-N-Acetylglucosamine and Tetraacetylglucopyranose Conjugated with Alkyl Phosphates. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019020110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Catalão MJ, Filipe SR, Pimentel M. Revisiting Anti-tuberculosis Therapeutic Strategies That Target the Peptidoglycan Structure and Synthesis. Front Microbiol 2019; 10:190. [PMID: 30804921 PMCID: PMC6378297 DOI: 10.3389/fmicb.2019.00190] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 01/23/2019] [Indexed: 12/27/2022] Open
Abstract
Tuberculosis (TB), which is caused by Mycobacterium tuberculosis (Mtb), is one of the leading cause of death by an infectious diseases. The biosynthesis of the mycobacterial cell wall (CW) is an area of increasing research significance, as numerous antibiotics used to treat TB target biosynthesis pathways of essential CW components. The main feature of the mycobacterial cell envelope is an intricate structure, the mycolyl-arabinogalactan-peptidoglycan (mAGP) complex responsible for its innate resistance to many commonly used antibiotics and involved in virulence. A hallmark of mAGP is its unusual peptidoglycan (PG) layer, which has subtleties that play a key role in virulence by enabling pathogenic species to survive inside the host and resist antibiotic pressure. This dynamic and essential structure is not a target of currently used therapeutics as Mtb is considered naturally resistant to most β-lactam antibiotics due to a highly active β-lactamase (BlaC) that efficiently hydrolyses many β-lactam drugs to render them ineffective. The emergence of multidrug- and extensive drug-resistant strains to the available antibiotics has become a serious health threat, places an immense burden on health care systems, and poses particular therapeutic challenges. Therefore, it is crucial to explore additional Mtb vulnerabilities that can be used to combat TB. Remodeling PG enzymes that catalyze biosynthesis and recycling of the PG are essential to the viability of Mtb and are therefore attractive targets for novel antibiotics research. This article reviews PG as an alternative antibiotic target for TB treatment, how Mtb has developed resistance to currently available antibiotics directed to PG biosynthesis, and the potential of targeting this essential structure to tackle TB by attacking alternative enzymatic activities involved in Mtb PG modifications and metabolism.
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Affiliation(s)
- Maria João Catalão
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Sérgio R. Filipe
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Caparica, Portugal
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Madalena Pimentel
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
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15
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Raghavendra T, Patil S, Mukherjee R. Peptidoglycan in Mycobacteria: chemistry, biology and intervention. Glycoconj J 2018; 35:421-432. [DOI: 10.1007/s10719-018-9842-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/20/2018] [Accepted: 09/05/2018] [Indexed: 01/07/2023]
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16
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Ahangar MS, Furze CM, Guy CS, Cooper C, Maskew KS, Graham B, Cameron AD, Fullam E. Structural and functional determination of homologs of the Mycobacterium tuberculosis N-acetylglucosamine-6-phosphate deacetylase (NagA). J Biol Chem 2018; 293:9770-9783. [PMID: 29728457 PMCID: PMC6016474 DOI: 10.1074/jbc.ra118.002597] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/30/2018] [Indexed: 12/23/2022] Open
Abstract
The Mycobacterium tuberculosis (Mtb) pathogen encodes a GlcNAc-6-phosphate deacetylase enzyme, NagA (Rv3332), that belongs to the amidohydrolase superfamily. NagA enzymes catalyze the deacetylation of GlcNAc-6-phosphate (GlcNAc6P) to glucosamine-6-phosphate (GlcN6P). NagA is a potential antitubercular drug target because it represents the key enzymatic step in the generation of essential amino-sugar precursors required for Mtb cell wall biosynthesis and also influences recycling of cell wall peptidoglycan fragments. Here, we report the structural and functional characterization of NagA from Mycobacterium smegmatis (MSNagA) and Mycobacterium marinum (MMNagA), close relatives of Mtb. Using a combination of X-ray crystallography, site-directed mutagenesis, and biochemical and biophysical assays, we show that these mycobacterial NagA enzymes are selective for GlcNAc6P. Site-directed mutagenesis studies revealed crucial roles of conserved residues in the active site that underpin stereoselective recognition, binding, and catalysis of substrates. Moreover, we report the crystal structure of MSNagA in both ligand-free form and in complex with the GlcNAc6P substrate at 2.6 and 2.0 Å resolutions, respectively. The GlcNAc6P complex structure disclosed the precise mode of GlcNAc6P binding and the structural framework of the active site, including two divalent metals located in the α/β binuclear site. Furthermore, we observed a cysteine residue located on a flexible loop region that occludes the active site. This cysteine is unique to mycobacteria and may represent a unique subsite for targeting mycobacterial NagA enzymes. Our results provide critical insights into the structural and mechanistic properties of mycobacterial NagA enzymes having an essential role in amino-sugar and nucleotide metabolism in mycobacteria.
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Affiliation(s)
| | | | - Collette S Guy
- From the School of Life Sciences and.,the Department of Chemistry, University of Warwick, Warwick, Coventry CV4 7AL, United Kingdom
| | | | | | - Ben Graham
- the Department of Chemistry, University of Warwick, Warwick, Coventry CV4 7AL, United Kingdom
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17
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Patel K, Song F, Andreana PR. Synthesis of substrate analogues as potential inhibitors for Mycobacterium tuberculosis enzyme MshC. Carbohydr Res 2017; 453-454:10-18. [PMID: 29107814 DOI: 10.1016/j.carres.2017.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/20/2017] [Accepted: 10/21/2017] [Indexed: 01/03/2023]
Abstract
Mycothiol cysteine ligase (MshC) is a key enzyme in the mycothiol (MSH) biosynthesis and a promising target for developing new anti-mycobacterial compounds. Herein, we report on the synthesis of substrate analogues, as potential inhibitors, for the MshC enzyme. The target molecules were synthesized employing a Schmidt glycosylation strategy using an enantiomerically pure inositol acceptor and 2-deoxy trichloroacetimidate glycosyl donors with glycosylation yields greater than 70% and overall yields >5%. The inositol acceptor was obtained via chiral resolution of (±)-myo-inositol.
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Affiliation(s)
- Krishnakant Patel
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States
| | - Fengling Song
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States
| | - Peter R Andreana
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States.
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18
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Skarbek K, Gabriel I, Szweda P, Wojciechowski M, Khan MA, Görke B, Milewski S, Milewska MJ. Synthesis and antimicrobial activity of 6-sulfo-6-deoxy-D-glucosamine and its derivatives. Carbohydr Res 2017. [PMID: 28628891 DOI: 10.1016/j.carres.2017.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
6-Sulfo-6-deoxy-D-glucosamine (GlcN6S), 6-sulfo-6-deoxy-D-glucosaminitol (ADGS) and their N-acetyl and methyl ester derivatives have been synthesized and tested as inhibitors of enzymes catalyzing reactions of the UDP-GlcNAc pathway in bacteria and yeasts. GlcN6S and ADGS at micromolar concentrations inhibited glucosamine-6-phosphate (GlcN6P) synthase of microbial origin. The former was also inhibitory towards fungal GlcN6P N-acetyl transferase, but at millimolar concentrations. Both compounds and their N-acetyl derivatives exhibited antimicrobial in vitro activity, with MICs in the 0.125-2.0 mg mL-1 range. Antibacterial but not antifungal activity of GlcN6S was potentiated by D-glucosamine and a synergistic antibacterial effect was observed for combination of ADGP and a dipeptide Nva-FMDP.
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Affiliation(s)
- Kornelia Skarbek
- Department of Organic Chemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Iwona Gabriel
- Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Piotr Szweda
- Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Marek Wojciechowski
- Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Muna A Khan
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Boris Görke
- Department of Microbiology, Immunobiology and Genetics, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Sławomir Milewski
- Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, Gdańsk, Poland.
| | - Maria J Milewska
- Department of Organic Chemistry, Gdańsk University of Technology, Gdańsk, Poland
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19
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Borsari C, Ferrari S, Venturelli A, Costi MP. Target-based approaches for the discovery of new antimycobacterial drugs. Drug Discov Today 2017; 22:576-584. [DOI: 10.1016/j.drudis.2016.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 11/07/2016] [Accepted: 11/15/2016] [Indexed: 12/24/2022]
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20
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Wang M, Huang M, Gu H, Li S, Ma Y, Wang J. Mutational analysis to identify the residues essential for the acetyltransferase activity of GlmU in Bacillus subtilis. RSC Adv 2017. [DOI: 10.1039/c7ra00086c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Amino acid mutation analysis and molecular modeling to verify the essential residues in acetyltransferase catalytic mechanism of Bs-GlmU.
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Affiliation(s)
- Meng Wang
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
| | - Minhua Huang
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
| | - Huawei Gu
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
| | - Shan Li
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
| | - Yi Ma
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
| | - Jufang Wang
- School of Bioscience and Bioengineering
- South China University of Technology
- 510006 Guangzhou
- China
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21
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Abstract
Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis (TB), is recognized as a global health emergency as promoted by the World Health Organization. Over 1 million deaths per year, along with the emergence of multi- and extensively-drug resistant strains of Mtb, have triggered intensive research into the pathogenicity and biochemistry of this microorganism, guiding the development of anti-TB chemotherapeutic agents. The essential mycobacterial cell wall, sharing some common features with all bacteria, represents an apparent ‘Achilles heel’ that has been targeted by TB chemotherapy since the advent of TB treatment. This complex structure composed of three distinct layers, peptidoglycan, arabinogalactan and mycolic acids, is vital in supporting cell growth, virulence and providing a barrier to antibiotics. The fundamental nature of cell wall synthesis and assembly has rendered the mycobacterial cell wall as the most widely exploited target of anti-TB drugs. This review provides an overview of the biosynthesis of the prominent cell wall components, highlighting the inhibitory mechanisms of existing clinical drugs and illustrating the potential of other unexploited enzymes as future drug targets.
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22
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Horník Š, Červenková Šťastná L, Cuřínová P, Sýkora J, Káňová K, Hrstka R, Císařová I, Dračínský M, Karban J. Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine. Beilstein J Org Chem 2016; 12:750-9. [PMID: 27340467 PMCID: PMC4901990 DOI: 10.3762/bjoc.12.75] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/30/2016] [Indexed: 11/23/2022] Open
Abstract
Background: Derivatives of D-glucosamine and D-galactosamine represent an important family of the cell surface glycan components and their fluorinated analogs found use as metabolic inhibitors of complex glycan biosynthesis, or as probes for the study of protein–carbohydrate interactions. This work is focused on the synthesis of acetylated 3-deoxy-3-fluoro, 4-deoxy-4-fluoro and 3,4-dideoxy-3,4-difluoro analogs of D-glucosamine and D-galactosamine via 1,6-anhydrohexopyranose chemistry. Moreover, the cytotoxicity of the target compounds towards selected cancer cells is determined. Results: Introduction of fluorine at C-3 was achieved by the reaction of 1,6-anhydro-2-azido-2-deoxy-4-O-benzyl-β-D-glucopyranose or its 4-fluoro analog with DAST. The retention of configuration in this reaction is discussed. Fluorine at C-4 was installed by the reaction of 1,6:2,3-dianhydro-β-D-talopyranose with DAST, or by fluoridolysis of 1,6:3,4-dianhydro-2-azido-β-D-galactopyranose with KHF2. The amino group was introduced and masked as an azide in the synthesis. The 1-O-deacetylated 3-fluoro and 4-fluoro analogs of acetylated D-galactosamine inhibited proliferation of the human prostate cancer cell line PC-3 more than cisplatin and 5-fluorouracil (IC50 28 ± 3 μM and 54 ± 5 μM, respectively). Conclusion: A complete series of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine is now accessible by 1,6-anhydrohexopyranose chemistry. Intermediate fluorinated 1,6-anhydro-2-azido-hexopyranoses have potential as synthons in oligosaccharide assembly.
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Affiliation(s)
- Štěpán Horník
- Institute of Chemical Process Fundamentals of the CAS, Rozvojová 135, 165 02 Praha, Czech Republic
| | - Lucie Červenková Šťastná
- Institute of Chemical Process Fundamentals of the CAS, Rozvojová 135, 165 02 Praha, Czech Republic
| | - Petra Cuřínová
- Institute of Chemical Process Fundamentals of the CAS, Rozvojová 135, 165 02 Praha, Czech Republic
| | - Jan Sýkora
- Institute of Chemical Process Fundamentals of the CAS, Rozvojová 135, 165 02 Praha, Czech Republic
| | - Kateřina Káňová
- Regional Centre for Applied and Molecular Oncology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, 656 53 Brno, Czech Republic
| | - Roman Hrstka
- Regional Centre for Applied and Molecular Oncology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, 656 53 Brno, Czech Republic
| | - Ivana Císařová
- Department of Inorganic Chemistry, Charles University, Hlavova 2030, 128 43 Praha 2, Czech Republic
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry, Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| | - Jindřich Karban
- Institute of Chemical Process Fundamentals of the CAS, Rozvojová 135, 165 02 Praha, Czech Republic
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23
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Mehra R, Rani C, Mahajan P, Vishwakarma RA, Khan IA, Nargotra A. Computationally Guided Identification of Novel Mycobacterium tuberculosis GlmU Inhibitory Leads, Their Optimization, and in Vitro Validation. ACS COMBINATORIAL SCIENCE 2016; 18:100-16. [PMID: 26812086 DOI: 10.1021/acscombsci.5b00019] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Mycobacterium tuberculosis (Mtb) infections are causing serious health concerns worldwide. Antituberculosis drug resistance threatens the current therapies and causes further need to develop effective antituberculosis therapy. GlmU represents an interesting target for developing novel Mtb drug candidates. It is a bifunctional acetyltransferase/uridyltransferase enzyme that catalyzes the biosynthesis of UDP-N-acetyl-glucosamine (UDP-GlcNAc) from glucosamine-1-phosphate (GlcN-1-P). UDP-GlcNAc is a substrate for the biosynthesis of lipopolysaccharide and peptidoglycan that are constituents of the bacterial cell wall. In the current study, structure and ligand based computational models were developed and rationally applied to screen a drug-like compound repository of 20,000 compounds procured from ChemBridge DIVERSet database for the identification of probable inhibitors of Mtb GlmU. The in vitro evaluation of the in silico identified inhibitor candidates resulted in the identification of 15 inhibitory leads of this target. Literature search of these leads through SciFinder and their similarity analysis with the PubChem training data set (AID 1376) revealed the structural novelty of these hits with respect to Mtb GlmU. IC50 of the most potent identified inhibitory lead (5810599) was found to be 9.018 ± 0.04 μM. Molecular dynamics (MD) simulation of this inhibitory lead (5810599) in complex with protein affirms the stability of the lead within the binding pocket and also emphasizes on the key interactive residues for further designing. Binding site analysis of the acetyltransferase pocket with respect to the identified structural moieties provides a thorough analysis for carrying out the lead optimization studies.
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Affiliation(s)
- Rukmankesh Mehra
- Discovery
Informatics, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Chitra Rani
- Clinical
Microbiology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
- Academy
of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Priya Mahajan
- Discovery
Informatics, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
- Academy
of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Ram Ashrey Vishwakarma
- Discovery
Informatics, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Inshad Ali Khan
- Clinical
Microbiology, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
- Academy
of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Amit Nargotra
- Discovery
Informatics, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
- Academy
of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
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24
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UDP-GlcNAc pathway: Potential target for inhibitor discovery against M. tuberculosis. Eur J Pharm Sci 2016; 83:62-70. [DOI: 10.1016/j.ejps.2015.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/29/2015] [Accepted: 12/08/2015] [Indexed: 11/23/2022]
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25
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Jia X, Kang J, Yin H. A simple and rapid method for measuring α-D-phosphohexomutases activity by using anion-exchange chromatography coupled with an electrochemical detector. PeerJ 2016; 4:e1517. [PMID: 26788420 PMCID: PMC4715444 DOI: 10.7717/peerj.1517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 11/27/2015] [Indexed: 11/20/2022] Open
Abstract
The interconversion of hexose-6-phosphate and hexose-1-phosphate can be directly analyzed by high-performance anion-exchange chromatography coupled with an electrochemical detector (HPAEC-PAD). Thus, this method can be used to measure the activities of N-acetylglucosamine-phosphate mutase (AGM), glucosamine-phosphate mutase (GlmM) and phosphoglucomutase (PGM), which are the members of α-D-phosphohexomutases superfamily. The detection limits were extremely low as 2.747 pmol, 1.365 pmol, 0.512 pmol, 0.415 pmol, 1.486 pmol and 0.868 pmol for N-acetylglucosamine-1-phosphate (GlcNAc-1-P), N-acetylglucosamine-6-phosphate (GlcNAc-6-P), glucosamine-1-phosphate (GlcN-1-P), glucosamine-6-phosphate (GlcN-6-P), glucose-1-phosphate (Glc-1-P) and glucose-6-phosphate (Glc-6-P), respectively. By employing HPAEC-PAD, activities of AtAGM (AGM from Arabidopsis thaliana) on these six phosphohexoses can be detected. The Km of AtAGM on Glc-1-P determined by HPAEC-PAD was 679.18 ± 156.40 µM, which is comparable with the Km of 707.09 ± 170.36 µM detected by traditional coupled assay. Moreover, the activity of MtGlmM (GlmM from Mycobacterium tuberculosis) on GlcN-6-P tested by HPAEC-PAD was 7493.40 ± 309.12 nmol∕min ⋅ mg, which is much higher than 288.97 ± 35.28 nmol∕min ⋅ mg obtained by the traditional coupled assay. Accordingly, HPAEC-PAD is a more rapid and simple method than the traditional coupled assays given its high specificity and sensitivity, and will certainly bring convenience to further research of α-D-phosphohexomutases.
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Affiliation(s)
- Xiaochen Jia
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jian Kang
- Department of Biochemistry and Molecular Biology, Dalian Medical University , Dalian , China
| | - Heng Yin
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian , China
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26
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Soni V, Upadhayay S, Suryadevara P, Samla G, Singh A, Yogeeswari P, Sriram D, Nandicoori VK. Depletion of M. tuberculosis GlmU from Infected Murine Lungs Effects the Clearance of the Pathogen. PLoS Pathog 2015; 11:e1005235. [PMID: 26489015 PMCID: PMC4619583 DOI: 10.1371/journal.ppat.1005235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/27/2015] [Indexed: 01/06/2023] Open
Abstract
M. tuberculosis N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmUMtb) is a bi-functional enzyme engaged in the synthesis of two metabolic intermediates N-acetylglucosamine-1-phosphate (GlcNAc-1-P) and UDP-GlcNAc, catalyzed by the C- and N-terminal domains respectively. UDP-GlcNAc is a key metabolite essential for the synthesis of peptidoglycan, disaccharide linker, arabinogalactan and mycothiols. While glmUMtb was predicted to be an essential gene, till date the role of GlmUMtb in modulating the in vitro growth of Mtb or its role in survival of pathogen ex vivo / in vivo have not been deciphered. Here we present the results of a comprehensive study dissecting the role of GlmUMtb in arbitrating the survival of the pathogen both in vitro and in vivo. We find that absence of GlmUMtb leads to extensive perturbation of bacterial morphology and substantial reduction in cell wall thickness under normoxic as well as hypoxic conditions. Complementation studies show that the acetyl- and uridyl- transferase activities of GlmUMtb are independently essential for bacterial survival in vitro, and GlmUMtb is also found to be essential for mycobacterial survival in THP-1 cells as well as in guinea pigs. Depletion of GlmUMtb from infected murine lungs, four weeks post infection, led to significant reduction in the bacillary load. The administration of Oxa33, a novel oxazolidine derivative that specifically inhibits GlmUMtb, to infected mice resulted in significant decrease in the bacillary load. Thus our study establishes GlmUMtb as a strong candidate for intervention measures against established tuberculosis infections. The synthesis of the Mtb cell wall involves a cascade of reactions catalyzed by cytosolic and cell membrane-bound enzymes. The reaction catalyzed by GlmUMtb (an enzyme with acetyltransferase and uridyltransferase activities) generates UDP-GlcNAc, a central nucleotide-sugar building block of the cell wall. Apart from cell wall synthesis UDP-GlcNAc is an essential metabolite participating in other cellular processes including disaccharide linker and mycothiol biosynthesis. GlmUMtb shares very little sequence similarity with eukaryotic acetyltransferase and uridyltransferase enzymes. Many pathogens have alternative pathway(s) for foraging GlcNAc from the host. The present study was undertaken to see the effects of depleting GlmUMtb on pathogen survival in the host animal. We have generated a conditional gene replacement mutant of glmUMtb and find that depletion of GlmUMtb at any stage of bacterial growth or in mice infected with Mtb including a well-established infection, results in irreversible bacterial death due to perturbation of cell wall synthesis. We have developed a novel anti-GlmUMtb inhibitor (Oxa33), identified its binding site on GlmUMtb, and shown its specificity for GlmUMtb. The study demonstrates that GlmUMtb is a promising target for therapeutic intervention and Oxa33 can be pursued as a lead molecule.
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Affiliation(s)
- Vijay Soni
- National Institute of Immunology, New Delhi, India
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
| | | | - Priyanka Suryadevara
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - Ganesh Samla
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - Archana Singh
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Perumal Yogeeswari
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, India
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27
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Forget SM, Jee A, Smithen DA, Jagdhane R, Anjum S, Beaton SA, Palmer DRJ, Syvitski RT, Jakeman DL. Kinetic evaluation of glucose 1-phosphate analogues with a thymidylyltransferase using a continuous coupled enzyme assay. Org Biomol Chem 2015; 13:866-75. [PMID: 25408103 DOI: 10.1039/c4ob02057j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cps2L, a thymidylytransferase, is the first enzyme in Streptococcus pneumoniae L-rhamnose biosynthesis and an antibacterial target. We herein report the evaluation of six sugar phosphate analogues selected to further probe Cps2L substrate tolerance. A modified continuous spectrophotometric assay was employed for facile detection of pyrophosphate (PPi) released from nucleotidylyltransfase-catalysed condensation of sugar 1-phosphates and nucleoside triphosphates to produce sugar nucleotides. Additionally, experiments using waterLOGSY NMR spectroscopy were investigated as a complimentary method to evaluate binding affinity to Cps2L.
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Affiliation(s)
- S M Forget
- Department of Chemistry, Dalhousie University, 6274 Coburg Rd, PO Box 15, 000, Halifax, Nova Scotia B3H 4R2, Canada.
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28
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High-throughput screen identifies small molecule inhibitors targeting acetyltransferase activity of Mycobacterium tuberculosis GlmU. Tuberculosis (Edinb) 2015; 95:664-677. [PMID: 26318557 DOI: 10.1016/j.tube.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/18/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
Abstract
N-acetylglucosamine-1-phosphate uridyltransferase (GlmU) is a pivotal bifunctional enzyme, its N and C terminal domains catalyzes uridyltransferase and acetyltransferase activities, respectively. Final product of GlmU catalyzed reaction, uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), acts as sugar donor providing GlcNAc residues in the synthesis of peptidoglycan and a disaccharide linker (D-N-GlcNAc-1-rhamnose), the key structural components of Mycobacterium tuberculosis (M. tuberculosis) cell wall. In the present study, we have searched new inhibitors against acetyltransferase activity of M. tuberculosis GlmU. A subset of 1607 synthetic compounds, selected through dual approach i.e., in-silico and whole cell screen against 20,000 compounds from ChemBridge library, was further screened using an in-vitro high throughput bioassay to identify inhibitors of acetyltransferase domain of M. tuberculosis GlmU. Four compounds were found to inhibit GlmU enzyme specific to acetyltransferase activity, with IC50 values ranging from 9 to 70 μM. Two compounds (6624116, 5655606) also exhibited whole cell activity against drug susceptible as well as drug resistant M. tuberculosis. These two compounds also exhibited increased anti-TB activity when tested in combination with rifampicin, isoniazid and ethambutol, however 5655606 was cytotoxic to eukaryotic cell line. These results demonstrate that identified chemical scaffolds can be used as inhibitors of M. tuberculosis cell wall enzyme after optimizations for future anti-TB drug development program.
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29
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Melnyk JE, Mohanan V, Schaefer AK, Hou CW, Grimes CL. Peptidoglycan Modifications Tune the Stability and Function of the Innate Immune Receptor Nod2. J Am Chem Soc 2015; 137:6987-90. [PMID: 26035228 PMCID: PMC4878121 DOI: 10.1021/jacs.5b01607] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Natural modifications of peptidoglycan modulate the innate immune response. Peptidoglycan derivatives activate this response via the intracellular innate immune receptor, Nod2. To probe how these modifications alter the response, a novel and efficient carbohydrate synthesis was developed to allow for late-stage modification of the amine at the 2-position. Modification of the carbohydrate was found to be important for stabilizing Nod2 and generating the proper response. The native Nod2 ligands demonstrate a significant increase in the cellular stability of Nod2. Moreover, changing the identity of the natural ligands at the carbohydrate 2-position allows for the Nod2-dependent immune response to be either up-regulated or down-regulated. The ligand structure can be adjusted to tune the Nod2 response, suggesting that other innate immune receptors and their ligands could use a similar strategy.
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Affiliation(s)
- James E. Melnyk
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Vishnu Mohanan
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Amy K. Schaefer
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Ching-Wen Hou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Catherine Leimkuhler Grimes
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
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30
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Alderwick LJ, Harrison J, Lloyd GS, Birch HL. The Mycobacterial Cell Wall--Peptidoglycan and Arabinogalactan. Cold Spring Harb Perspect Med 2015; 5:a021113. [PMID: 25818664 DOI: 10.1101/cshperspect.a021113] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mycobacterial bacillus is encompassed by a remarkably elaborate cell wall structure. The mycolyl-arabinogalactan-peptidoglycan (mAGP) complex is essential for the viability of Mycobacterium tuberculosis and maintains a robust basal structure supporting the upper "myco-membrane." M. tuberculosis peptidoglycan, although appearing to be unexceptional at first glance, contains a number of unique molecular subtleties that become particularly important as the TB-bacilli enters into nonreplicative growth during dormancy. Arabinogalactan, a highly branched polysaccharide, serves to connect peptidoglycan with the outer mycolic acid layer, and a variety of unique glycolsyltransferases are used for its assembly. In this review, we shall explore the microbial chemistry of this unique heteropolysacchride, examine the molecular genetics that underpins its fabrication, and discuss how the essential biosynthetic process might be exploited for the development of future anti-TB chemotherapies.
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Affiliation(s)
- Luke J Alderwick
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - James Harrison
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Georgina S Lloyd
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Helen L Birch
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
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31
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Albler C, Schmid W. From Amino Acids to Fluorine-Containing Carbohydrates: De Novo Synthesis of 2-Amino-4-Fluoroxylose and -lyxose. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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32
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Purification and biochemical characterisation of GlmU from Yersinia pestis. Arch Microbiol 2014; 197:371-8. [PMID: 25417006 DOI: 10.1007/s00203-014-1065-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 11/12/2014] [Accepted: 11/16/2014] [Indexed: 12/22/2022]
Abstract
Antibiotic resistance has emerged as a real threat to mankind, rendering many compounds ineffective in the fight against bacterial infection, including for significant diseases such as plague caused by Yersinia pestis. Essential genes have been identified as promising targets for inhibiting with new classes of compounds. Previously, the gene encoding the bifunctional UDP-N-acetylglucosamine pyrophosphorylase/glucosamine-1-phosphate N-acetyltransferase enzyme GlmU was confirmed as an essential gene in Yersinia. As a step towards exploiting this target for antimicrobial screening, we undertook a biochemical characterisation of the Yersinia GlmU. Effects of pH and magnesium concentration on the acetyltransferase and uridyltransferase activities were analysed, and kinetic parameters were determined. The acetyltransferase activity, which is strongly increased in the presence of reducing agent, was shown to be susceptible to oxidation and thiol-specific reagents.
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Albler C, Schmid W. Synthetic Routes towards Fluorine-Containing Amino Sugars: Synthesis of Fluorinated Analogues of Tomosamine and 4-Amino-4-deoxyarabinose. European J Org Chem 2014. [DOI: 10.1002/ejoc.201301614] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Inhibitors of the acetyltransferase domain of N-acetylglucosamine-1-phosphate-uridylyltransferase/glucosamine-1-phosphate-acetyltransferase (GlmU). Part 2: Optimization of physical properties leading to antibacterial aryl sulfonamides. Bioorg Med Chem Lett 2012; 22:7019-23. [DOI: 10.1016/j.bmcl.2012.10.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 09/24/2012] [Accepted: 10/01/2012] [Indexed: 11/22/2022]
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Kinetic modelling of GlmU reactions - prioritization of reaction for therapeutic application. PLoS One 2012; 7:e43969. [PMID: 22952829 PMCID: PMC3428340 DOI: 10.1371/journal.pone.0043969] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 07/30/2012] [Indexed: 11/22/2022] Open
Abstract
Mycobacterium tuberculosis(Mtu), a successful pathogen, has developed resistance against the existing anti-tubercular drugs necessitating discovery of drugs with novel action. Enzymes involved in peptidoglycan biosynthesis are attractive targets for antibacterial drug discovery. The bifunctional enzyme mycobacterial GlmU (Glucosamine 1-phosphate N-acetyltransferase/ N-acetylglucosamine-1-phosphate uridyltransferase) has been a target enzyme for drug discovery. Its C- and N- terminal domains catalyze acetyltransferase (rxn-1) and uridyltransferase (rxn-2) activities respectively and the final product is involved in peptidoglycan synthesis. However, the bifunctional nature of GlmU poses difficulty in deciding which function to be intervened for therapeutic advantage. Genetic analysis showed this as an essential gene but it is still unclear whether any one or both of the activities are critical for cell survival. Often enzymatic activity with suitable high-throughput assay is chosen for random screening, which may not be the appropriate biological function inhibited for maximal effect. Prediction of rate-limiting function by dynamic network analysis of reactions could be an option to identify the appropriate function. With a view to provide insights into biochemical assays with appropriate activity for inhibitor screening, kinetic modelling studies on GlmU were undertaken. Kinetic model of Mtu GlmU-catalyzed reactions was built based on the available kinetic data on Mtu and deduction from Escherichia coli data. Several model variants were constructed including coupled/decoupled, varying metabolite concentrations and presence/absence of product inhibitions. This study demonstrates that in coupled model at low metabolite concentrations, inhibition of either of the GlmU reactions cause significant decrement in the overall GlmU rate. However at higher metabolite concentrations, rxn-2 showed higher decrement. Moreover, with available intracellular concentration of the metabolites and in vivo variant of model, uncompetitive inhibition of rxn-2 caused highest decrement. Thus, at physiologically relevant metabolite concentrations, targeting uridyltranferase activity of Mtu GlmU would be a better choice for therapeutic intervention.
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Zhou Y, Yu W, Zheng Q, Xin Y, Ma Y. Identification of amino acids involved in catalytic process of M. tuberculosis GlmU acetyltransferase. Glycoconj J 2012; 29:297-303. [PMID: 22669463 DOI: 10.1007/s10719-012-9402-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/19/2012] [Accepted: 05/23/2012] [Indexed: 10/28/2022]
Abstract
M. tuberculosis GlmU is a bifunctional enzyme with acetyltransferase activity in C-terminus and uridyltransferase activity in N-terminus, and it is involved in the biosynthesis of glycosyl donor UDP-N-acetylglucosamine (UDP-GlcNAc). The crystal structure of M. tuberculosis GlmU clearly determines the active site and catalytic mechanism of GlmU uridyltransferase domain but not succeed in GlmU acetyltransferase domain. Sequence comparison analysis revealed highly conserved amino acid residues in the C-terminus between M. tuberculosis GlmU and GlmU enzymes from other bacteria. To find the essential amino acids related to M. tuberculosis GlmU acetyltransferase activity, we substituted 10 conserved amino acids in the acetyltransferase domain of M. tuberculosis GlmU by site-directed mutagenesis. All the mutant GlmU proteins were largely expressed in soluble and purified by affinity chromatography. Enzyme assays showed that K362A, H374A, Y398A and W460A mutants abolished more than 90% activity of M. tuberculosis GlmU acetyltransferase and totally lost the affinity with two substrates, suggesting the potential substrate-binding functions. However, K403A, S416A, N456A and E458A mutants exhibited decreased GlmU acetyltransferase activity and lower kinetic parameters, probably responsible for substrate releasing by conformation shifting.
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Affiliation(s)
- Yan Zhou
- Department of Biochemistry and Molecular Biology, Dalian Medical Universtiy, Dalian, China
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Pinheiro M, Lúcio M, Lima JLFC, Reis S. Liposomes as drug delivery systems for the treatment of TB. Nanomedicine (Lond) 2012; 6:1413-28. [PMID: 22026379 DOI: 10.2217/nnm.11.122] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
TB is an infectious disease that is far from being eradicated and controlled. The treatment for TB is associated with noncompliance to therapy because it consists of a long-term treatment with a multidrug combination and is associated with the appearance of several side effects. Liposomal formulations are being developed with first- and second-line antibiotics, and might be an extremely useful alternative to current therapies. This article will thus focus on the role of liposomes as nanodelivery systems for the treatment of TB. Among several advantages, these nanocarriers allow an increase in the bioavailability of antibiotics, which may lead to a reduction in the time of treatment. Results obtained with such nanosystems, although preliminary, are promising and are perspective of the use of inhalation for TB treatment.
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Affiliation(s)
- Marina Pinheiro
- REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto Rua Aníbal Cunha, 164, 4099-030 Porto, Portugal
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