1
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Siekierska I, Burmistrz M, Trylska J. Evaluating delivery of peptide nucleic acids to gram-negative bacteria using differently linked membrane-active peptides and their stapled analogs. Bioorg Med Chem Lett 2024:129993. [PMID: 39426432 DOI: 10.1016/j.bmcl.2024.129993] [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: 07/30/2024] [Revised: 09/27/2024] [Accepted: 10/14/2024] [Indexed: 10/21/2024]
Abstract
Antisense oligonucleotides have been developed as therapeutic compounds, with peptide nucleic acid (PNA) emerging as a promising nucleic acid mimic for antimicrobial applications. To be effective, PNAs must be internalized into bacterial cells, as they are not naturally absorbed. A strategy to improve PNA membrane penetration and cellular uptake involves covalently conjugating them to cell-penetrating peptides. However, these membrane-active peptides can exhibit cytotoxicity, and their efficiency as PNA carriers needs to be enhanced. Therefore, we explored new peptide-PNA conjugates and their linkers to understand how they affect PNA uptake into bacteria. We conjugated PNA to two peptides, anoplin and (KFF)3K, along with their structurally stabilized hydrocarbon-stapled derivatives, and evaluated their transport into various bacterial strains. The PNA sequence targeted bacterial mRNA encoding the essential acyl carrier protein. As linkages, we used either a non-cleavable 8-amino-2,6-dioxaoctanoyl (ethylene glycol, eg1) linker or a reducible disulfide bridge. We found that the hydrocarbon-stapled peptides did not enhance PNA delivery, despite the strong inner- and outer-membrane-penetrating capabilities of the standalone peptides. Additionally, the disulfide bridge linkage, which is cleavable in the bacterial cytoplasm, decreased the antimicrobial activity of the peptide-PNA conjugates. Notably, we identified anoplin as a new potent PNA carrier peptide, with the anoplin-eg1-PNA conjugate demonstrating antibacterial activity against E. coli and S. typhimurium strains in the 2-4 µM range.
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Affiliation(s)
- Izabela Siekierska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Michał Burmistrz
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland.
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2
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Saini S, Goel K, Ghosh S, Das A, Saraogi I. Effects of PNA Sequence and Target Site Selection on Function of a 4.5S Non-Coding RNA. Chembiochem 2024:e202400029. [PMID: 38595046 DOI: 10.1002/cbic.202400029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024]
Abstract
Peptide nucleic acid (PNA) based antisense strategy is a promising therapeutic approach to specifically inhibit target gene expression. However, unlike protein coding genes, identification of an ideal PNA binding site for non-coding RNA is not straightforward. Here, we compare the inhibitory activities of PNA molecules that bind a non-coding 4.5S RNA called SRP RNA, a key component of the bacterial signal recognition particle (SRP). A 9-mer PNA (PNA9) complementary to the tetraloop region of the RNA was more potent in inhibiting its interaction with the SRP protein, compared to an 8-mer PNA (PNA8) targeting a stem-loop. PNA9, which contained a homo-pyrimidine sequence could form a triplex with the complementary stretch of RNA in vitro as confirmed using a fluorescent derivative of PNA9 (F-PNA13). The RNA-PNA complex formation resulted in inhibition of SRP function with PNA9 and F-PNA13, but not PNA8 highlighting the importance of target site selection. Surprisingly, F-PNA13 which was more potent in inhibiting SRP function in vitro, showed weaker antibacterial activity compared to PNA9 likely due to poor cell penetration of the longer PNA. Our results underscore the importance of suitable target site selection and optimum PNA length to develop better antisense molecules against non-coding RNA.
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Affiliation(s)
- Snehlata Saini
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Khushboo Goel
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Sudipta Ghosh
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Anirban Das
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Ishu Saraogi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
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3
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MacLelland V, Kravitz M, Gupta A. Therapeutic and diagnostic applications of antisense peptide nucleic acids. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102086. [PMID: 38204913 PMCID: PMC10777018 DOI: 10.1016/j.omtn.2023.102086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Peptide nucleic acids (PNAs) are synthetic nucleic acid analogs with a neutral N-(2-aminoethyl) glycine backbone. PNAs possess unique physicochemical characteristics such as increased resistance to enzymatic degradation, ionic strength and stability over a wide range of temperatures and pH, and low intrinsic electrostatic repulsion against complementary target oligonucleotides. PNA has been widely used as an antisense oligonucleotide (ASO). Despite the favorable characteristics of PNA, in comparison with other ASO technologies, the use of antisense PNA for novel therapeutics has lagged. This review provides a brief overview of PNA, its antisense mechanisms of action, delivery strategies, and highlights successful applications of PNA, focusing on anti-pathogenic, anti-neurodegenerative disease, anti-cancer, and diagnostic agents. For each application, several studies are discussed focusing on the different target sites of the PNA, design of different PNAs and the therapeutic outcome in different cell lines and animal models. Thereafter, persisting limitations slowing the successful integration of antisense PNA therapeutics are discussed in order to highlight actionable next steps in the development and optimization of PNA as an ASO.
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Affiliation(s)
- Victoria MacLelland
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
| | - Madeline Kravitz
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
| | - Anisha Gupta
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
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4
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El-Fateh M, Chatterjee A, Zhao X. A systematic review of peptide nucleic acids (PNAs) with antibacterial activities: Efficacy, potential and challenges. Int J Antimicrob Agents 2024; 63:107083. [PMID: 38185398 DOI: 10.1016/j.ijantimicag.2024.107083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/11/2023] [Accepted: 12/30/2023] [Indexed: 01/09/2024]
Abstract
Peptide nucleic acids (PNAs) are synthetic molecules that are like DNA/RNA, but with different building blocks. PNAs target and bind to mRNAs and disrupt the function of a targeted gene, hence they have been studied as potential antibacterials. The aim of this systematic review was to provide an in-depth analysis of the current status of PNAs as antibacterial agents, define the characteristics of the effective PNA constructs, and address the gap in advancing PNAs to become clinically competent agents. Following the PRISMA model, four electronic databases were searched: Web of Science, PubMed, SciFinder and Scopus. A total of 627 articles published between 1994 and 2023 were found. After screening and a rigorous selection process using explicit inclusion and exclusion criteria, 65 scientific articles were selected, containing 656 minimum inhibitory concentration (MIC) data. The antibacterial activity of PNAs was assessed against 20 bacterial species. The most studied Gram-negative and Gram-positive bacteria were Escherichia coli (n=266) and Staphylococcus aureus (n=53), respectively. In addition, the effect of PNA design, including construct length, binding location, and carrier agents, on antibacterial activity was shown. Finally, antibacterial test models to assess the inhibitory effects of PNAs were examined, emphasising gaps and prospects. This systematic review provides a comprehensive assessment of the potential of PNAs as antibacterial agents and offers valuable insights for researchers and clinicians seeking novel therapeutic strategies in the context of increasing rates of antibiotic-resistant bacteria.
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Affiliation(s)
- Mohamed El-Fateh
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada, H9X3V9; Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, 35516, El-Dakhelia, Egypt; Antimicrobial Regeneration Consortium Labs, Louisville, CO, 80027, USA
| | - Anushree Chatterjee
- Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, 80303, USA; Antimicrobial Regeneration Consortium Labs, Louisville, CO, 80027, USA
| | - Xin Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada, H9X3V9; Antimicrobial Regeneration Consortium Labs, Louisville, CO, 80027, USA.
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5
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Selvaraj SP, Chen JY. Conjugation of antimicrobial peptides to enhance therapeutic efficacy. Eur J Med Chem 2023; 259:115680. [PMID: 37515922 DOI: 10.1016/j.ejmech.2023.115680] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/05/2023] [Accepted: 07/23/2023] [Indexed: 07/31/2023]
Abstract
The growing prevalence of antimicrobial resistance (AMR) has brought with it a continual increase in the numbers of deaths from multidrug-resistant (MDR) infections. Since the current arsenal of antibiotics has become increasingly ineffective, there exists an urgent need for discovery and development of novel antimicrobials. Antimicrobial peptides (AMPs) are considered to be a promising class of molecules due to their broad-spectrum activities and low resistance rates compared with other types of antibiotics. Since AMPs also often play major roles in elevating the host immune response, the molecules may also be called "host defense peptides." Despite the great promise of AMPs, the majority remain unsuitable for clinical use due to issues of structural instability, degradation by proteases, and/or toxicity to host cells. Moreover, AMP activities in vivo can be influenced by many factors, such as interaction with blood and serum biomolecules, physiological salt concentrations or different pH values. To overcome these limitations, structural modifications can be made to the AMP. Among several modifications, physical and chemical conjugation of AMP to other biomolecules is widely considered an effective strategy. In this review, we discuss structural modification strategies related to conjugation of AMPs and their possible effects on mode of action. The conjugation of fatty acids, glycans, antibiotics, photosensitizers, polymers, nucleic acids, nanoparticles, and immobilization to biomaterials are highlighted.
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Affiliation(s)
- Sanjay Prasad Selvaraj
- Molecular and Biological Agricultural Science Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan; Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 402, Taiwan
| | - Jyh-Yih Chen
- Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, 23-10 Dahuen Rd, Jiaushi, Ilan, 262, Taiwan; The iEGG and Animal Biotechnology Center and the Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, 402, Taiwan.
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6
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Tsylents U, Siekierska I, Trylska J. Peptide nucleic acid conjugates and their antimicrobial applications-a mini-review. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:533-544. [PMID: 37610696 PMCID: PMC10618302 DOI: 10.1007/s00249-023-01673-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 08/24/2023]
Abstract
Peptide nucleic acid (PNA) is a nucleic acid mimic with high specificity and binding affinity to natural DNA or RNA, as well as resistance to enzymatic degradation. PNA sequences can be designed to selectively silence gene expression, which makes PNA a promising tool for antimicrobial applications. However, the poor membrane permeability of PNA remains the main limiting factor for its applications in cells. To overcome this obstacle, PNA conjugates with different molecules have been developed. This mini-review focuses on covalently linked conjugates of PNA with cell-penetrating peptides, aminosugars, aminoglycoside antibiotics, and non-peptidic molecules that were tested, primarily as PNA carriers, in antibacterial and antiviral applications. The chemistries of the conjugation and the applied linkers are also discussed.
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Affiliation(s)
- Uladzislava Tsylents
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
| | - Izabela Siekierska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland.
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7
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Macyszyn J, Chyży P, Burmistrz M, Lobka M, Miszkiewicz J, Wojciechowska M, Trylska J. Structural dynamics influences the antibacterial activity of a cell-penetrating peptide (KFF) 3K. Sci Rep 2023; 13:14826. [PMID: 37684254 PMCID: PMC10491836 DOI: 10.1038/s41598-023-38745-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/13/2023] [Indexed: 09/10/2023] Open
Abstract
Given the widespread demand for novel antibacterial agents, we modified a cell-penetrating peptide (KFF)3K to transform it into an antibacterial peptide. Namely, we inserted a hydrocarbon staple into the (KFF)3K sequence to induce and stabilize its membrane-active secondary structure. The staples were introduced at two positions, (KFF)3K[5-9] and (KFF)3K[2-6], to retain the initial amphipathic character of the unstapled peptide. The stapled analogues are protease resistant contrary to (KFF)3K; 90% of the stapled (KFF)3K[5-9] peptide remained undigested after incubation in chymotrypsin solution. The stapled peptides showed antibacterial activity (with minimal inhibitory concentrations in the range of 2-16 µM) against various Gram-positive and Gram-negative strains, contrary to unmodified (KFF)3K, which had no antibacterial effect against any strain at concentrations up to 32 µM. Also, both stapled peptides adopted an α-helical structure in the buffer and micellar environment, contrary to a mostly undefined structure of the unstapled (KFF)3K in the buffer. We found that the antibacterial activity of (KFF)3K analogues is related to their disruptive effect on cell membranes and we showed that by stapling this cell-penetrating peptide, we can induce its antibacterial character.
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Affiliation(s)
- Julia Macyszyn
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Piotr Chyży
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Michał Burmistrz
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Małgorzata Lobka
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Joanna Miszkiewicz
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, Poland
| | | | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland.
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8
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Cimicata G, Fridkin G, Bose T, Eyal Z, Halfon Y, Breiner-Goldstein E, Fox T, Zimmerman E, Bashan A, de Val N, Wlodawer A, Yonath A. Structural Studies Reveal the Role of Helix 68 in the Elongation Step of Protein Biosynthesis. mBio 2022; 13:e0030622. [PMID: 35348349 PMCID: PMC9040758 DOI: 10.1128/mbio.00306-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 02/04/2023] Open
Abstract
The ribosome, a multicomponent assembly consisting of RNA and proteins, is a pivotal macromolecular machine that translates the genetic code into proteins. The large ribosomal subunit rRNA helix 68 (H68) is a key element in the protein synthesis process, as it coordinates the coupled movements of the actors involved in translocation, including the tRNAs and L1 stalk. Examination of cryo-electron microscopy (cryo-EM) structures of ribosomes incubated for various time durations at physiological temperatures led to the identification of functionally relevant H68 movements. These movements assist the transition of the L1 stalk between its open and closed states. H68 spatial flexibility and its significance to the protein synthesis process were confirmed through its effective targeting with antisense PNA oligomers. Our results suggest that H68 is actively involved in ribosome movements that are central to the elongation process. IMPORTANCE The mechanism that regulates the translocation step in ribosomes during protein synthesis is not fully understood. In this work, cryo-EM techniques used to image ribosomes from Staphylococcus aureus after incubation at physiological temperature allowed the identification of a conformation of the helix 68 that has never been observed so far. We then propose a mechanism in which such helix, switching between two different conformations, actively coordinates the translocation step, shedding light on the dynamics of ribosomal components. In addition, the relevance of helix 68 to ribosome function and its potential as an antibiotic target was proved by inhibiting Staphylococcus aureus ribosomes activity in vitro using oligomers with sequence complementarity.
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Affiliation(s)
- Giuseppe Cimicata
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Gil Fridkin
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
- Department of Organic Chemistry, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Tanaya Bose
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Zohar Eyal
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Yehuda Halfon
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Elinor Breiner-Goldstein
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Tara Fox
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Ella Zimmerman
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Anat Bashan
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Natalia de Val
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Alexander Wlodawer
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Ada Yonath
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
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9
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Liang X, Liu M, Komiyama M. Recognition of Target Site in Various Forms of DNA and RNA by Peptide Nucleic Acid (PNA): From Fundamentals to Practical Applications. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210086] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Xingguo Liang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, P. R. China
| | - Mengqin Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
| | - Makoto Komiyama
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, P. R. China
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10
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Chen W, Dong B, Liu W, Liu Z. Recent Advances in Peptide Nucleic Acids as Antibacterial Agents. Curr Med Chem 2021; 28:1104-1125. [PMID: 32484766 DOI: 10.2174/0929867327666200602132504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/06/2020] [Accepted: 05/13/2020] [Indexed: 11/22/2022]
Abstract
The emergence of antibiotic-resistant bacteria and the slow progress in searching for new antimicrobial agents makes it hard to treat bacterial infections and cause problems for the healthcare system worldwide, including high costs, prolonged hospitalizations, and increased mortality. Therefore, the discovery of effective antibacterial agents is of great importance. One attractive alternative is antisense peptide nucleic acid (PNA), which inhibits or eliminates gene expression by binding to the complementary messenger RNA (mRNA) sequence of essential genes or the accessible and functionally important regions of the ribosomal RNA (rRNA). Following 30 years of development, PNAs have played an extremely important role in the treatment of Gram-positive, Gram-negative, and acidfast bacteria due to their desirable stability of hybrid complex with target RNA, the strong affinity for target mRNA/rRNA, and the stability against nucleases. PNA-based antisense antibiotics can strongly inhibit the growth of pathogenic and antibiotic-resistant bacteria in a sequence-specific and dose-dependent manner at micromolar concentrations. However, several fundamental challenges, such as intracellular delivery, solubility, physiological stability, and clearance still need to be addressed before PNAs become broadly applicable in clinical settings. In this review, we summarize the recent advances in PNAs as antibacterial agents and the challenges that need to be overcome in the future.
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Affiliation(s)
- Wei Chen
- Hunan Key Laboratory for Super Microstructure and Ultrafast Process, School of Physics and Electronics Central South University, Changsha 410083, China
| | - Bo Dong
- Hunan Key Laboratory for Super Microstructure and Ultrafast Process, School of Physics and Electronics Central South University, Changsha 410083, China
| | - Wenen Liu
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China
| | - Zhengchun Liu
- Hunan Key Laboratory for Super Microstructure and Ultrafast Process, School of Physics and Electronics Central South University, Changsha 410083, China
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11
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Wojciechowska M, Miszkiewicz J, Trylska J. Conformational Changes of Anoplin, W-MreB 1-9, and (KFF) 3K Peptides near the Membranes. Int J Mol Sci 2020; 21:E9672. [PMID: 33352981 PMCID: PMC7766051 DOI: 10.3390/ijms21249672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
Many peptides interact with biological membranes, but elucidating these interactions is challenging because cellular membranes are complex and peptides are structurally flexible. To contribute to understanding how the membrane-active peptides behave near the membranes, we investigated peptide structural changes in different lipid surroundings. We focused on two antimicrobial peptides, anoplin and W-MreB1-9, and one cell-penetrating peptide, (KFF)3K. Firstly, by using circular dichroism spectroscopy, we determined the secondary structures of these peptides when interacting with micelles, liposomes, E. coli lipopolysaccharides, and live E. coli bacteria. The peptides were disordered in the buffer, but anoplin and W-MreB1-9 displayed lipid-induced helicity. Yet, structural changes of the peptide depended on the composition and concentration of the membranes. Secondly, we quantified the destructive activity of peptides against liposomes by monitoring the release of a fluorescent dye (calcein) from the liposomes treated with peptides. We observed that only for anoplin and W-MreB1-9 calcein leakage from liposomes depended on the peptide concentration. Thirdly, bacterial growth inhibition assays showed that peptide conformational changes, evoked by the lipid environments, do not directly correlate with the antimicrobial activity of the peptides. However, understanding the relation between peptide structural properties, mechanisms of membrane disruption, and their biological activities can guide the design of membrane-active peptides.
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Affiliation(s)
- Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
| | - Joanna Miszkiewicz
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
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12
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Yang L, Toh DFK, Krishna MS, Zhong Z, Liu Y, Wang S, Gong Y, Chen G. Tertiary Base Triple Formation in the SRV-1 Frameshifting Pseudoknot Stabilizes Secondary Structure Components. Biochemistry 2020; 59:4429-4438. [PMID: 33166472 DOI: 10.1021/acs.biochem.0c00611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Minor-groove base triples formed between stem 1 and loop 2 of the simian retrovirus type 1 (SRV-1) mRNA frameshifting pseudoknot are essential in stimulating -1 ribosomal frameshifting. How tertiary base triple formation affects the local stabilities of secondary structures (stem 1 and stem 2) and thus ribosomal frameshifting efficiency is not well understood. We made a short peptide nucleic acid (PNA) that is expected to invade stem 1 of the SRV-1 pseudoknot by PNA-RNA duplex formation to mimic the stem 1 unwinding process by a translating ribosome. In addition, we used a PNA for invading stem 2 in the SRV-1 pseudoknot. Our nondenaturing polyacrylamide gel electrophoresis data for the binding of PNA to the SRV-1 pseudoknot and mutants reveal that mutations in loop 2 disrupting base triple formation between loop 2 and stem 1 in the SRV-1 pseudoknot result in enhanced invasion by both PNAs. Our data suggest that tertiary stem 1-loop 2 base triple interactions in the SRV-1 pseudoknot can stabilize both of the secondary structural components, stem 1 and stem 2. Stem 2 stability is thus coupled to the structural stability of stem 1-loop 2 base triples, mediated through a long-range effect. The apparent dissociation constants of both PNAs are positively correlated with the pseudoknot mechanical stabilities and frameshifting efficiencies. The relatively simple PNA local invasion experiment may be used to characterize the energetic contribution of tertiary interactions and ligand binding in many other RNA and DNA structures.
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Affiliation(s)
- Lixia Yang
- School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, Sichuan 610054, P. R. China.,School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), No. 2001 Longxiang Boulevard, Longgang District, Shenzhen, Guangdong 518172, P. R. China.,Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Desiree-Faye Kaixin Toh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Manchugondanahalli S Krishna
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhensheng Zhong
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Yiyao Liu
- School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, Sichuan 610054, P. R. China
| | - Shaomeng Wang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, Sichuan 610054, P. R. China
| | - Yubin Gong
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, Sichuan 610054, P. R. China
| | - Gang Chen
- School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), No. 2001 Longxiang Boulevard, Longgang District, Shenzhen, Guangdong 518172, P. R. China.,Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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13
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Pifer R, Greenberg DE. Antisense antibacterial compounds. Transl Res 2020; 223:89-106. [PMID: 32522669 DOI: 10.1016/j.trsl.2020.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/28/2020] [Accepted: 06/01/2020] [Indexed: 02/08/2023]
Abstract
Extensive antibiotic use combined with poor historical drug stewardship practices have created a medical crisis in which once treatable bacterial infections are now increasingly unmanageable. To combat this, new antibiotics will need to be developed and safeguarded. An emerging class of antibiotics based upon nuclease-stable antisense technologies has proven valuable in preclinical testing against a variety of bacterial pathogens. This review describes the current state of development of antisense-based antibiotics, the mechanisms thus far employed by these compounds, and possible future avenues of research.
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Affiliation(s)
- Reed Pifer
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - David E Greenberg
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas.
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14
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Antibacterial Peptide Nucleic Acids-Facts and Perspectives. Molecules 2020; 25:molecules25030559. [PMID: 32012929 PMCID: PMC7038079 DOI: 10.3390/molecules25030559] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Antibiotic resistance is an escalating, worldwide problem. Due to excessive use of antibiotics, multidrug-resistant bacteria have become a serious threat and a major global healthcare problem of the 21st century. This fact creates an urgent need for new and effective antimicrobials. The common strategies for antibiotic discovery are based on either modifying existing antibiotics or screening compound libraries, but these strategies have not been successful in recent decades. An alternative approach could be to use gene-specific oligonucleotides, such as peptide nucleic acid (PNA) oligomers, that can specifically target any single pathogen. This approach broadens the range of potential targets to any gene with a known sequence in any bacterium, and could significantly reduce the time required to discover new antimicrobials or their redesign, if resistance arises. We review the potential of PNA as an antibacterial molecule. First, we describe the physicochemical properties of PNA and modifications of the PNA backbone and nucleobases. Second, we review the carriers used to transport PNA to bacterial cells. Furthermore, we discuss the PNA targets in antibacterial studies focusing on antisense PNA targeting bacterial mRNA and rRNA.
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15
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Computational and NMR studies of RNA duplexes with an internal pseudouridine-adenosine base pair. Sci Rep 2019; 9:16278. [PMID: 31700156 PMCID: PMC6838189 DOI: 10.1038/s41598-019-52637-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 10/03/2019] [Indexed: 01/28/2023] Open
Abstract
Pseudouridine (Ψ) is the most common chemical modification present in RNA. In general, Ψ increases the thermodynamic stability of RNA. However, the degree of stabilization depends on the sequence and structural context. To explain experimentally observed sequence dependence of the effect of Ψ on the thermodynamic stability of RNA duplexes, we investigated the structure, dynamics and hydration of RNA duplexes with an internal Ψ-A base pair in different nearest-neighbor sequence contexts. The structures of two RNA duplexes containing 5′-GΨC/3′-CAG and 5′-CΨG/3′-GAC motifs were determined using NMR spectroscopy. To gain insight into the effect of Ψ on duplex dynamics and hydration, we performed molecular dynamics (MD) simulations of RNA duplexes with 5′-GΨC/3′-CAG, 5′-CΨG/3′-GAC, 5′-AΨU/3′-UAA and 5′-UΨA/3′-AAU motifs and their unmodified counterparts. Our results showed a subtle impact from Ψ modification on the structure and dynamics of the RNA duplexes studied. The MD simulations confirmed the change in hydration pattern when U is replaced with Ψ. Quantum chemical calculations showed that the replacement of U with Ψ affected the intrinsic stacking energies at the base pair steps depending on the sequence context. The calculated intrinsic stacking energies help to explain the experimentally observed sequence dependent changes in the duplex stability from Ψ modification.
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16
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Kawano M, Morohashi S, Oda K, Ishikawa M, Fujita S, Saito M. Artificial small RNA-mediated growth inhibition in Escherichia coli and Salmonella enterica serovar Typhimurium. Biochem Biophys Res Commun 2019; 521:577-583. [PMID: 31679698 DOI: 10.1016/j.bbrc.2019.10.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/05/2019] [Indexed: 11/25/2022]
Abstract
We developed a synthetic RNA approach to identify growth inhibition sequences by cloning random 24-nucleotide (nt) sequences into an arabinose-inducible expression vector. This vector expressed a small RNA (sRNA) of ∼140 nt containing a 24 nt random sequence insert. After transforming Escherichia coli with the vector, 10 out of 954 transformants showed strong growth defect phenotypes and two clones caused cell lysis. We then examined growth inhibition phenotypes in the Salmonella Typhimurium LT2 strain using the twelve sRNAs that exerted an inhibitory effect on E. coli growth. Three of these clones showed strong growth inhibition phenotypes in S. Typhimurium LT2. The most effective sRNA contained the same insert (N1) in both bacteria. The 24 nt random sequence insert of N1 was abundant in guanine residues (ten out of 24 nt), and other random sequences causing growth defects were also highly enriched for guanine (G) nucleotides. We, therefore, generated clones that express sRNAs containing a stretch of 16 to 24 continuous guanine sequences (poly-G16, -G18, -G20, -G22, and -G24). All of these clones induced growth inhibition in both liquid and agar plate media and the poly-G20 clone showed the strongest effect in E. coli. These results demonstrate that our sRNA expression system can be used to identify nucleotide sequences that are potential candidates for oligonucleotide antimicrobial drugs.
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Affiliation(s)
- Mitsuoki Kawano
- Department of Human Nutrition, Faculty of Contemporary Life Science, Chugokugakuen University, Okayama, Japan; Department of Microbiology, Kawasaki Medical School, Kurashiki, Japan.
| | - Shota Morohashi
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Kohei Oda
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Masataka Ishikawa
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Shouta Fujita
- Laboratory of Gene Regulation Study, Department of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan
| | - Mineki Saito
- Department of Microbiology, Kawasaki Medical School, Kurashiki, Japan
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17
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Jasiński M, Miszkiewicz J, Feig M, Trylska J. Thermal Stability of Peptide Nucleic Acid Complexes. J Phys Chem B 2019; 123:8168-8177. [PMID: 31491077 DOI: 10.1021/acs.jpcb.9b05168] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Peptide nucleic acid (PNA) is a neutral nucleic acid analogue that base pairs with itself and natural nucleic acids. PNA-nucleic acid complexes are more thermally stable than the corresponding complexes of natural nucleic acids. In addition, PNA is biostable and thus used in many antisense and antigene applications to block functional RNA or DNA via sequence-specific interactions. We have recently developed force field parameters for molecular dynamics (MD) simulations of PNA and PNA-involving duplexes with natural nucleic acids. In this work, we provide the first application of this force field to biologically relevant PNA sequences and their complexes with RNA. We investigated thermal stabilities of short PNA-PNA, PNA-RNA, and RNA-RNA duplexes using UV-monitored thermal denaturation experiments and MD simulations at ambient and elevated temperatures. The simulations show a two-state melting transition and reproduce the thermal stability from melting experiments, with PNA-PNA being the most and RNA-RNA the least stable. The PNA-PNA duplex also displays the highest activation energy for melting. The atomistic details of unfolding of PNA duplexes suggest that all PNA-PNA bases melt concomitantly, whereas the RNA-RNA and PNA-RNA are destabilized from the termini toward the central part of the duplexes.
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Affiliation(s)
| | | | - Michael Feig
- Department of Biochemistry and Molecular Biology , Michigan State University , 603 Wilson Road , East Lansing , Michigan 48824 , United States
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18
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Równicki M, Pieńko T, Czarnecki J, Kolanowska M, Bartosik D, Trylska J. Artificial Activation of Escherichia coli mazEF and hipBA Toxin-Antitoxin Systems by Antisense Peptide Nucleic Acids as an Antibacterial Strategy. Front Microbiol 2018; 9:2870. [PMID: 30534121 PMCID: PMC6275173 DOI: 10.3389/fmicb.2018.02870] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/08/2018] [Indexed: 12/14/2022] Open
Abstract
The search for new, non-standard targets is currently a high priority in the design of new antibacterial compounds. Bacterial toxin-antitoxin systems (TAs) are genetic modules that encode a toxin protein that causes growth arrest by interfering with essential cellular processes, and a cognate antitoxin, which neutralizes the toxin activity. TAs have no human analogs, are highly abundant in bacterial genomes, and therefore represent attractive alternative targets for antimicrobial drugs. This study demonstrates how artificial activation of Escherichia coli mazEF and hipBA toxin-antitoxin systems using sequence-specific antisense peptide nucleic acid oligomers is an innovative antibacterial strategy. The growth arrest observed in E. coli resulted from the inhibition of translation of the antitoxins by the antisense oligomers. Furthermore, two other targets, related to the activities of mazEF and hipBA, were identified as promising sites of action for antibacterials. These results show that TAs are susceptible to sequence-specific antisense agents and provide a proof-of-concept for their further exploitation in antimicrobial strategies.
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Affiliation(s)
- Marcin Równicki
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, Poland
| | - Tomasz Pieńko
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Department of Drug Chemistry, Faculty of Pharmacy with the Laboratory Medicine Division, Medical University of Warsaw, Warsaw, Poland
| | - Jakub Czarnecki
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
- Unit of Bacterial Genome Plasticity, Department of Genomes and Genetics, Pasteur Institute, Paris, France
| | - Monika Kolanowska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Genomic Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Dariusz Bartosik
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
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19
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Ghosh S, Saini S, Saraogi I. Peptide nucleic acid mediated inhibition of the bacterial signal recognition particle. Chem Commun (Camb) 2018; 54:8257-8260. [PMID: 29989112 DOI: 10.1039/c8cc04715d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have identified the bacterial signal recognition particle (SRP) as a novel antibacterial target. As a proof of principle, we used an antisense peptide nucleic acid to target a key SRP RNA. The PNA molecules showed efficient inhibition of SRP function and bacterial cell growth, thereby validating our hypothesis.
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Affiliation(s)
- Sudipta Ghosh
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, MP, India.
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20
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Antimicrobial synergy between mRNA targeted peptide nucleic acid and antibiotics in E. coli. Bioorg Med Chem Lett 2018; 28:3094-3098. [PMID: 30082123 DOI: 10.1016/j.bmcl.2018.07.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/18/2018] [Accepted: 07/26/2018] [Indexed: 11/22/2022]
Abstract
A combination of antibacterial agents should make the emergence of resistance in bacteria less probable. Thus we have analyzed the synergistic effects between antibacterial antisense peptide nucleic acids (PNA) and conventional antibiotics against Escherichia coli AS19 (lipopolysaccharide defective) strain and a derivative of a pathogenic strain E. coli O157:H7. PNAs were designed to target mRNA transcripts encoding the essential acyl carrier protein (gene acpP) and conjugated to the cell-penetrating peptide (KFF)3K for cellular uptake. Antibiotics included aminoglycosides, aminopenicillins, polymyxins, rifamycins, sulfonamides and trimethoprim. Synergies were evaluated using the checkerboard technique. Fractional Inhibitory Concentration indices (FICi) were calculated for all combinations based on the minimal inhibitory concentration of each individual agent. The results demonstrate two novel synergistic combinations of antimicrobial agents, namely, (KFF)3K-PNA anti-acpP with polymyxin B and (KFF)3K-PNA anti-acpP with trimethoprim (both with FICi = 0.38). Polymyxin B's synergy postulates cell wall targeted antibiotics as attractive agents to improve the uptake of PNA while trimethoprim's interaction with PNA my reveal a new inhibitory mechanism.
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21
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Jasiński M, Feig M, Trylska J. Improved Force Fields for Peptide Nucleic Acids with Optimized Backbone Torsion Parameters. J Chem Theory Comput 2018; 14:3603-3620. [PMID: 29791152 DOI: 10.1021/acs.jctc.8b00291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Peptide nucleic acids are promising nucleic acid analogs for antisense therapies as they can form stable duplex and triplex structures with DNA and RNA. Computational studies of PNA-containing duplexes and triplexes are an important component for guiding their design, yet existing force fields have not been well validated and parametrized with modern computational capabilities. We present updated CHARMM and Amber force fields for PNA that greatly improve the stability of simulated PNA-containing duplexes and triplexes in comparison with experimental structures and allow such systems to be studied on microsecond time scales. The force field modifications focus on reparametrized PNA backbone torsion angles to match high-level quantum mechanics reference energies for a model compound. The microsecond simulations of PNA-PNA, PNA-DNA, PNA-RNA, and PNA-DNA-PNA complexes also allowed a comprehensive analysis of hydration and ion interactions with such systems.
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Affiliation(s)
- Maciej Jasiński
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States.,Centre of New Technologies , University of Warsaw , Warsaw , Poland
| | - Michael Feig
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Joanna Trylska
- Centre of New Technologies , University of Warsaw , Warsaw , Poland
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22
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Puah RY, Jia H, Maraswami M, Toh DFK, Ero R, Yang L, Patil KM, Ong AAL, Krishna MS, Sun R, Tong C, Huang M, Chen X, Loh TP, Gao YG, Liu DX, Chen G. Selective Binding to mRNA Duplex Regions by Chemically Modified Peptide Nucleic Acids Stimulates Ribosomal Frameshifting. Biochemistry 2017; 57:149-159. [PMID: 29116759 DOI: 10.1021/acs.biochem.7b00744] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Minus-one programmed ribosomal frameshifting (-1 PRF) allows the precise maintenance of the ratio between viral proteins and is involved in the regulation of the half-lives of cellular mRNAs. Minus-one ribosomal frameshifting is activated by several stimulatory elements such as a heptameric slippery sequence (X XXY YYZ) and an mRNA secondary structure (hairpin or pseudoknot) that is positioned 2-8 nucleotides downstream from the slippery site. Upon -1 RF, the ribosomal reading frame is shifted from the normal zero frame to the -1 frame with the heptameric slippery sequence decoded as XXX YYY Z instead of X XXY YYZ. Our research group has developed chemically modified peptide nucleic acid (PNA) L and Q monomers to recognize G-C and C-G Watson-Crick base pairs, respectively, through major-groove parallel PNA·RNA-RNA triplex formation. L- and Q-incorporated PNAs show selective binding to double-stranded RNAs (dsRNAs) over single-stranded RNAs (ssRNAs). The sequence specificity and structural selectivity of L- and Q-modified PNAs may allow the precise targeting of desired viral and cellular RNA structures, and thus may serve as valuable biological tools for mechanistic studies and potential therapeutics for fighting diseases. Here, for the first time, we demonstrate by cell-free in vitro translation assays using rabbit reticulocyte lysate that the dsRNA-specific chemically modified PNAs targeting model mRNA hairpins stimulate -1 RF (from 2% to 32%). An unmodified control PNA, however, shows nonspecific inhibition of translation. Our results suggest that the modified dsRNA-binding PNAs may be advantageous for targeting structured RNAs.
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Affiliation(s)
| | | | | | | | - Rya Ero
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | | | | | | | | | | | | | - Mei Huang
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | | | | | - Yong-Gui Gao
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | - Ding Xiang Liu
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551.,Guangdong Province Key Laboratory Microbial Signals & Disease Co, and Integrative Microbiology Research Centre, South China Agricultural University , Guangzhou 510642, Guangdong, People's Republic of China
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23
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Równicki M, Wojciechowska M, Wierzba AJ, Czarnecki J, Bartosik D, Gryko D, Trylska J. Vitamin B 12 as a carrier of peptide nucleic acid (PNA) into bacterial cells. Sci Rep 2017; 7:7644. [PMID: 28794451 PMCID: PMC5550456 DOI: 10.1038/s41598-017-08032-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/06/2017] [Indexed: 01/02/2023] Open
Abstract
Short modified oligonucleotides targeted at bacterial DNA or RNA could serve as antibacterial agents provided that they are efficiently taken up by bacterial cells. However, the uptake of such oligonucleotides is hindered by the bacterial cell wall. To overcome this problem, oligomers have been attached to cell-penetrating peptides, but the efficiency of delivery remains poor. Thus, we have investigated the ability of vitamin B12 to transport peptide nucleic acid (PNA) oligomers into cells of Escherichia coli and Salmonella Typhimurium. Vitamin B12 was covalently linked to a PNA oligomer targeted at the mRNA of a reporter gene expressing Red Fluorescent Protein. Cu-catalyzed 1,3-dipolar cycloaddition was employed for the synthesis of PNA-vitamin B12 conjugates; namely the vitamin B12 azide was reacted with PNA possessing the terminal alkyne group. Different types of linkers and spacers between vitamin B12 and PNA were tested, including a disulfide bond. We found that vitamin B12 transports antisense PNA into E. coli cells more efficiently than the most widely used cell-penetrating peptide (KFF)3K. We also determined that the structure of the linker impacts the antisense effect. The results of this study provide the foundation for developing vitamin B12 as a carrier of PNA oligonucleotides into bacterial cells.
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Affiliation(s)
- Marcin Równicki
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, Banacha 2c, 02-097, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Aleksandra J Wierzba
- Institute of Organic Chemistry, Polish Academy of Sciences, M. Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Jakub Czarnecki
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Dariusz Bartosik
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Dorota Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, M. Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.
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