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Martynowycz MW, Andreev K, Mor A, Gidalevitz D. Cancer-Associated Gangliosides as a Therapeutic Target for Host Defense Peptide Mimics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:12541-12549. [PMID: 37647566 DOI: 10.1021/acs.langmuir.3c01008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Aberrant levels of glycolipids expressed on cellular surfaces are characteristic of different types of cancers. The oligomer of acylated lysine (OAK) mimicking antimicrobial peptides displays in vitro activity against human and murine melanoma cell lines with upregulated GD3 and GM3 gangliosides. Herein, we demonstrate the capability of OAK to intercalate into the sialo-oligosaccharides of DPPC/GD3 and DPPC/GM3 lipid monolayers using X-ray scattering. The lack of insertion into monolayers containing phosphatidylserine suggests that the mechanism of action by OAKs against glycosylated lipid membranes is not merely driven by charge effects. The fluorescence microscopy data demonstrates the membrane-lytic activity of OAK. Understanding the molecular basis for selectivity toward GD3 and GM3 gangliosides by antimicrobial lipopeptides will contribute to the development of novel therapies to cure melanoma and other malignancies.
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Affiliation(s)
- Michael W Martynowycz
- Department of Physics, Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, 10 W 35th Street, Chicago, Illinois 60616, United States
| | - Konstantin Andreev
- Department of Physics, Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, 10 W 35th Street, Chicago, Illinois 60616, United States
| | - Amram Mor
- Department of Biotechnology and Food Engineering, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - David Gidalevitz
- Department of Physics, Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, 10 W 35th Street, Chicago, Illinois 60616, United States
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Zaknoon F, Meir O, Mor A. Mechanistic Studies of Antibiotic Adjuvants Reducing Kidney's Bacterial Loads upon Systemic Monotherapy. Pharmaceutics 2021; 13:pharmaceutics13111947. [PMID: 34834362 PMCID: PMC8621570 DOI: 10.3390/pharmaceutics13111947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/11/2021] [Accepted: 11/14/2021] [Indexed: 12/01/2022] Open
Abstract
We describe the design and attributes of a linear pentapeptide-like derivative (C14(ω5)OOc10O) screened for its ability to elicit bactericidal competences of plasma constituents against Gram-negative bacteria (GNB). In simpler culture media, the lipopeptide revealed high aptitudes to sensitize resilient GNB to hydrophobic and/or efflux-substrate antibiotics, whereas in their absence, C14(ω5)OOc10O only briefly delayed bacterial proliferation. Instead, at low micromolar concentrations, the lipopeptide has rapidly lowered bacterial proton and ATP levels, although significantly less than upon treatment with its bactericidal analog. Mechanistic studies support a two-step scenario providing a plausible explanation for the lipopeptide’s biological outcomes against GNB: initially, C14(ω5)OOc10O permeabilizes the outer membrane similarly to polymyxin B, albeit in a manner not necessitating as much LPS-binding affinity. Subsequently, C14(ω5)OOc10O would interact with the inner membrane gently yet intensively enough to restrain membrane-protein functions such as drug efflux and/or ATP generation, while averting the harsher inner membrane perturbations that mediate the fatal outcome associated with bactericidal peers. Preliminary in vivo studies where skin wound infections were introduced in mice, revealed a significant efficacy in affecting bacterial viability upon topical treatment with creams containing C14(ω5)OOc10O, whereas synergistic combination therapies were able to secure the pathogen’s eradication. Further, capitalizing on the finding that C14(ω5)OOc10O plasma-potentiating concentrations were attainable in mice blood at sub-maximal tolerated doses, we used a urinary tract infection model to acquire evidence for the lipopeptide’s systemic capacity to reduce the kidney’s bacterial loads. Collectively, the data establish the role of C14(ω5)OOc10O as a compelling antibacterial potentiator and suggest its drug-like potential.
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Limwongyut J, Liu Y, Chilambi GS, Seviour T, Hinks J, Mu Y, Bazan GC. Interactions of a paracyclophane-based conjugated oligoelectrolyte with biological membranes. RSC Adv 2018; 8:39849-39853. [PMID: 35558200 PMCID: PMC9091243 DOI: 10.1039/c8ra08069k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/14/2018] [Indexed: 11/21/2022] Open
Abstract
We report a non-planar conjugated oligoelectrolyte as a membrane permeabilizing material and its membrane interactions compared to the linear analog.
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Affiliation(s)
- Jakkarin Limwongyut
- Center for Polymers and Organic Solids
- Department of Chemistry and Biochemistry
- University of California
- Santa Barbara
- USA
| | - Yang Liu
- School of Biological Sciences
- Nanyang Technological University
- Singapore
| | - Gayatri Shankar Chilambi
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE)
- Nanyang Technological University
- Singapore
| | - Thomas Seviour
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE)
- Nanyang Technological University
- Singapore
| | - Jamie Hinks
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE)
- Nanyang Technological University
- Singapore
| | - Yuguang Mu
- School of Biological Sciences
- Nanyang Technological University
- Singapore
| | - Guillermo C. Bazan
- Center for Polymers and Organic Solids
- Department of Chemistry and Biochemistry
- University of California
- Santa Barbara
- USA
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4
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β-Defensins in the Fight against Helicobacter pylori. Molecules 2017; 22:molecules22030424. [PMID: 28272373 PMCID: PMC6155297 DOI: 10.3390/molecules22030424] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/04/2017] [Indexed: 12/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) play a pivotal role in the innate immune responses to Helicobacter pylori (Hp) in humans. β-Defensins, a class of cationic arginine-rich AMPs, are small peptides secreted by immune cells and epithelial cells that exert antimicrobial activity against a broad spectrum of microorganisms, including Gram-positive and Gram-negative bacteria and fungi. During Hp infections, AMP expression is able to eradicate the bacteria, thereby preventing Hp infections in gastrointestinal tract. It is likely that gastric β-defensins expression is increased during Hp infection. The aim of this review is to focus on increased knowledge of the role of β-defensins in response to Hp infection. We also briefly discuss the potential use of AMPs, either alone or in combination with conventional antibiotics, for the treatment of Hp infection.
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Malanovic N, Lohner K. Antimicrobial Peptides Targeting Gram-Positive Bacteria. Pharmaceuticals (Basel) 2016; 9:E59. [PMID: 27657092 PMCID: PMC5039512 DOI: 10.3390/ph9030059] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/07/2016] [Accepted: 09/13/2016] [Indexed: 01/01/2023] Open
Abstract
Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan. While interaction of AMPs with peptidoglycan might rather facilitate penetration, interaction with anionic teichoic acids may act as either a trap for AMPs or a ladder for a route to the cytoplasmic membrane. Interaction with the cytoplasmic membrane frequently leads to lipid segregation affecting membrane domain organization, which affects membrane permeability, inhibits cell division processes or leads to delocalization of essential peripheral membrane proteins. Further, precursors of cell wall components, especially the highly conserved lipid II, are directly targeted by AMPs. Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which in addition can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target.
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Affiliation(s)
- Nermina Malanovic
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
| | - Karl Lohner
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
- BioTechMed Graz, Humboldtstrasse 50/III, 8010 Graz, Austria.
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Midura-Nowaczek K, Markowska A. Antimicrobial peptides and their analogs: searching for new potential therapeutics. PERSPECTIVES IN MEDICINAL CHEMISTRY 2014; 6:73-80. [PMID: 25374459 PMCID: PMC4213192 DOI: 10.4137/pmc.s13215] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/28/2014] [Accepted: 09/05/2014] [Indexed: 12/14/2022]
Abstract
Antimicrobial peptides (AMPs) are an essential part of innate immunity. These compounds have been considered as potential therapeutics because of their broad-spectrum activities and proven ability to avoid antimicrobial resistance, but their clinical and commercial developments have some limitations, such as susceptibility to proteases and a high cost of peptide production. To overcome these problems, many researchers have tried to develop short active peptides, their modifications and mimics with better properties while retaining their basic features of natural AMPs such as cationic charge and the amphipathic structure.
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Affiliation(s)
| | - Agnieszka Markowska
- Department of Organic Chemistry, Medical University of Bialystok, Bialystok, Poland
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Andreev K, Bianchi C, Laursen JS, Citterio L, Hein-Kristensen L, Gram L, Kuzmenko I, Olsen CA, Gidalevitz D. Guanidino groups greatly enhance the action of antimicrobial peptidomimetics against bacterial cytoplasmic membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2492-2502. [PMID: 24878450 DOI: 10.1016/j.bbamem.2014.05.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 05/11/2014] [Accepted: 05/19/2014] [Indexed: 11/18/2022]
Abstract
Antimicrobial peptides or their synthetic mimics are a promising class of potential new antibiotics. Herein we assess the effect of the type of cationic side chain (i.e., guanidino vs. amino groups) on the membrane perturbing mechanism of antimicrobial α-peptide-β-peptoid chimeras. Langmuir monolayers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylglycerol (DPPG) were used to model cytoplasmic membranes of both Gram-positive and Gram-negative bacteria, while lipopolysaccharide Kdo2-lipid A monolayers were mimicking the outer membrane of Gram-negative species. We report the results of the measurements using an array of techniques, including high-resolution synchrotron surface X-ray scattering, epifluorescence microscopy, and in vitro antimicrobial activity to study the molecular mechanisms of peptidomimetic interaction with bacterial membranes. We found guanidino group-containing chimeras to exhibit greater disruptive activity on DPPG monolayers than the amino group-containing analogues. However, this effect was not observed for lipopolysaccharide monolayers where the difference was negligible. Furthermore, the addition of the nitrobenzoxadiazole fluorophore did not reduce the insertion activity of these antimicrobials into both model membrane systems examined, which may be useful for future cellular localization studies.
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Affiliation(s)
- Konstantin Andreev
- Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering and Department of Physics, Illinois Institute of Technology, 3440 S. Dearborn St., Chicago, IL 60616 (USA)
| | - Christopher Bianchi
- Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering and Department of Physics, Illinois Institute of Technology, 3440 S. Dearborn St., Chicago, IL 60616 (USA)
| | - Jonas S Laursen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby (Denmark)
| | - Linda Citterio
- Department of Systems Biology, Technical University of Denmark, Matematiktorvet 301, DK-2800 Kgs. Lyngby (Denmark)
| | - Line Hein-Kristensen
- , National Food Institute, Technical University of Denmark, Søltofts Plads 221, DK-2800, Kgs Lyngby (Denmark)
| | - Lone Gram
- Department of Systems Biology, Technical University of Denmark, Matematiktorvet 301, DK-2800 Kgs. Lyngby (Denmark)
| | - Ivan Kuzmenko
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Lemont, IL 60439 (USA)
| | - Christian A Olsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby (Denmark)
| | - David Gidalevitz
- Center for Molecular Study of Condensed Soft Matter (μCoSM), Pritzker Institute of Biomedical Science and Engineering and Department of Physics, Illinois Institute of Technology, 3440 S. Dearborn St., Chicago, IL 60616 (USA)
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8
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Nontraditional therapies to treat Helicobacter pylori infection. J Microbiol 2014; 52:259-72. [PMID: 24682990 DOI: 10.1007/s12275-014-3603-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 12/16/2013] [Indexed: 12/15/2022]
Abstract
The Gram-negative pathogen Helicobacter pylori is increasingly more resistant to the three major antibiotics (metronidazole, clarithromycin and amoxicillin) that are most commonly used to treat infection. As a result, there is an increased rate of treatment failure; this translates into an overall higher cost of treatment due to the need for increased length of treatment and/or the requirement for combination or sequential therapy. Given the rise in antibiotic resistance, the complicated treatment regime, and issues related to patient compliance that stem from the duration and complexity of treatment, there is clearly a pressing need for the development of novel therapeutic strategies to combat H. pylori infection. As such, researchers are actively investigating the utility of antimicrobial peptides, small molecule inhibitors and naturopathic therapies. Herein we review and discuss each of these novel approaches as a means to target this important gastric pathogen.
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Murugan RN, Jacob B, Ahn M, Hwang E, Sohn H, Park HN, Lee E, Seo JH, Cheong C, Nam KY, Hyun JK, Jeong KW, Kim Y, Shin SY, Bang JK. De novo design and synthesis of ultra-short peptidomimetic antibiotics having dual antimicrobial and anti-inflammatory activities. PLoS One 2013; 8:e80025. [PMID: 24302996 PMCID: PMC3841161 DOI: 10.1371/journal.pone.0080025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/27/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability. METHODOLOGY/PRINCIPAL FINDINGS In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti-methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. CONCLUSION/SIGNIFICANCE The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics.
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Affiliation(s)
- Ravichandran N. Murugan
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
| | - Binu Jacob
- Department of Bio-Materials, Graduate School and Department of Cellular & Molecular Medicine, School of Medicine, Chosun University, Gwangju, Republic of Korea
| | - Mija Ahn
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
| | - Eunha Hwang
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
| | - Hoik Sohn
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, United States of America
| | - Hyo-Nam Park
- Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Eunjung Lee
- Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Ji-Hyung Seo
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
| | - Chaejoon Cheong
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
| | - Ky-Youb Nam
- Bioinformatics and Molecular Design Research Center, Yonsei University Research Complex, Seoul, Republic of Korea
| | - Jae-Kyung Hyun
- Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Ki-Woong Jeong
- Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Yangmee Kim
- Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Song Yub Shin
- Department of Bio-Materials, Graduate School and Department of Cellular & Molecular Medicine, School of Medicine, Chosun University, Gwangju, Republic of Korea
- * E-mail: (JKB); (SYS)
| | - Jeong Kyu Bang
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of Korea
- * E-mail: (JKB); (SYS)
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Fu TH, Li Y, Thaker HD, Scott RW, Tew GN. Expedient Synthesis of SMAMPs via Click Chemistry. ACS Med Chem Lett 2013; 4:841-5. [PMID: 24936243 DOI: 10.1021/ml400155a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/22/2013] [Indexed: 02/07/2023] Open
Abstract
A novel series of synthetic mimics of antimicrobial peptides (SMAMPs) containing triazole linkers were assembled using click chemistry. While only moderately active in buffer alone, an increase in antimicrobial activity against Staphylococcus aureus and Escherichia coli was observed when these SMAMPs were administered in the presence of mouse serum. One compound had minimum inhibitory concentrations (MICs) of 0.39 μg/mL and 6.25 μg/mL, respectively, and an HC50 of 693 μg/mL. These values compared favorably to peptide-based antimicrobials. A correlation between the net positive charge and SMAMP antimicrobial activity was observed. The triazole linker, an amide surrogate, was found to provide better antimicrobial activity against both S. aureus and E. coli when compared to other analogues.
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Affiliation(s)
- Tsung-hao Fu
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Yan Li
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Hitesh D. Thaker
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Richard W. Scott
- PolyMedix, Inc., 170 North Radnor-Chester Road, Suite 300, Radnor, Pennsylvania 19087, United States
| | - Gregory N. Tew
- Polymer Science and Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, United States
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Adaptive evolution of Escherichia coli to an α-peptide/β-peptoid peptidomimetic induces stable resistance. PLoS One 2013; 8:e73620. [PMID: 24040003 PMCID: PMC3764026 DOI: 10.1371/journal.pone.0073620] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/29/2013] [Indexed: 01/20/2023] Open
Abstract
Antimicrobial peptides (AMPs) and synthetic analogues thereof target conserved structures of bacterial cell envelopes and hence, development of resistance has been considered an unlikely event. However, recently bacterial resistance to AMPs has been observed, and the aim of the present study was to determine whether bacterial resistance may also evolve against synthetic AMP analogues, e.g. α-peptide/β-peptoid peptidomimetics. E. coli ATCC 25922 was exposed to increasing concentrations of a peptidomimetic (10 lineages), polymyxin B (10 lineages), or MilliQ water (4 lineages) in a re-inoculation culturing setup covering approx. 500 generations. All 10 lineages exposed to the peptidomimetic adapted to 32×MIC while this occurred for 8 out of 10 of the polymyxin B-exposed lineages. All lineages exposed to 32×MIC of either the peptidomimetic or polymyxin B had a significantly increased MIC (16–32×) to the selection agent. Five transfers (∼35 generations) in unsupplemented media did not abolish resistance indicating that resistance was heritable. Single isolates from peptidomimetic-exposed lineage populations displayed MICs against the peptidomimetic from wild-type MIC to 32×MIC revealing heterogeneous populations. Resistant isolates showed no cross-resistance against a panel of membrane-active AMPs. These isolates were highly susceptible to blood plasma antibacterial activity and were killed when plasma concentrations exceeded ∼30%. Notably, MIC of the peptidomimetic against resistant isolates returned to wild-type level upon addition of 25% plasma. Whole-genome sequencing of twenty isolates from four resistant lineages revealed mutations, in murein transglycosylase D (mltD) and outer-membrane proteins, which were conserved within and between lineages. However, no common resistance-conferring mutation was identified. We hypothesise that alterations in cell envelope structure result in peptidomimetic resistance, and that this may occur via several distinct mechanisms. Interestingly, this type of resistance result in a concomitant high susceptibility towards plasma, and therefore the present study does not infer additional concern for peptidomimetics as future therapeutics.
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Joshi S, Dewangan RP, Yadav S, Rawat DS, Pasha S. Synthesis, antibacterial activity and mode of action of novel linoleic acid–dipeptide–spermidine conjugates. Org Biomol Chem 2012; 10:8326-35. [DOI: 10.1039/c2ob26393a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Brogden NK, Brogden KA. Will new generations of modified antimicrobial peptides improve their potential as pharmaceuticals? Int J Antimicrob Agents 2011; 38:217-25. [PMID: 21733662 DOI: 10.1016/j.ijantimicag.2011.05.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 05/09/2011] [Indexed: 12/20/2022]
Abstract
The concept of antimicrobial peptides (AMPs) as potent pharmaceuticals is firmly established in the literature, and most research articles on this topic conclude by stating that AMPs represent promising therapeutic agents against bacterial and fungal pathogens. Indeed, early research in this field showed that AMPs were diverse in nature, had high activities with low minimal inhibitory concentrations, had broad spectrums of activity against bacterial, fungal and viral pathogens, and could easily be manipulated to alter their specificities, reduce their cytotoxicities and increase their antimicrobial activities. Unfortunately, commercial development of these peptides, for even the simplest of applications, has been very limited. With some peptides there are obstacles with their manufacture, in vivo efficacy and in vivo retention. More recently, the focus has shifted. Contemporary research now uses a more sophisticated approach to develop AMPs that surmount many of these prior obstacles. AMP mimetics, hybrid AMPs, AMP congeners, cyclotides and stabilised AMPs, AMP conjugates and immobilised AMPs have all emerged with selective or 'targeted' antimicrobial activities, improved retention, or unique abilities that allow them to bind to medical or industrial surfaces. These groups of new peptides have creative medical and industrial application potentials to treat antibiotic-resistant bacterial infections and septic shock, to preserve food or to sanitise surfaces both in vitro and in vivo.
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Affiliation(s)
- Nicole K Brogden
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA
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14
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Hein-Kristensen L, Knapp KM, Franzyk H, Gram L. Bacterial membrane activity of α-peptide/β-peptoid chimeras: influence of amino acid composition and chain length on the activity against different bacterial strains. BMC Microbiol 2011; 11:144. [PMID: 21693068 PMCID: PMC3224213 DOI: 10.1186/1471-2180-11-144] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/22/2011] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Characterization and use of antimicrobial peptides (AMPs) requires that their mode of action is determined. The interaction of membrane-active peptides with their target is often established using model membranes, however, the actual permeabilization of live bacterial cells and subsequent killing is usually not tested. In this report, six α-peptide/β-peptoid chimeras were examined for the effect of amino acid/peptoid substitutions and chain length on the membrane perturbation and subsequent killing of food-borne and clinical bacterial isolates. RESULTS All six AMP analogues inhibited growth of twelve food-borne and clinical bacterial strains including Extended Spectrum Beta-Lactamase-producing Escherichia coli. In general, the Minimum Inhibitory Concentrations (MIC) against Gram-positive and -negative bacteria were similar, ranging from 1 to 5 μM. The type of cationic amino acid only had a minor effect on MIC values, whereas chain length had a profound influence on activity. All chimeras were less active against Serratia marcescens (MICs above 46 μM). The chimeras were bactericidal and induced leakage of ATP from Staphylococcus aureus and S. marcescens with similar time of onset and reduction in the number of viable cells. EDTA pre-treatment of S. marcescens and E. coli followed by treatment with chimeras resulted in pronounced killing indicating that disintegration of the Gram-negative outer membrane eliminated innate differences in susceptibility. Chimera chain length did not influence the degree of ATP leakage, but the amount of intracellular ATP remaining in the cell after treatment was influenced by chimera length with the longest analogue causing complete depletion of intracellular ATP. Hence some chimeras caused a complete disruption of the membrane, and this was parallel by the largest reduction in number of viable bacteria. CONCLUSION We found that chain length but not type of cationic amino acid influenced the antibacterial activity of a series of synthetic α-peptide/β-peptoid chimeras. The synthetic chimeras exert their killing effect by permeabilization of the bacterial cell envelope, and the outer membrane may act as a barrier in Gram-negative bacteria. The tolerance of S. marcescens to chimeras may be due to differences in the composition of the lipopolysaccharide layer also responsible for its resistance to polymyxin B.
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Affiliation(s)
- Line Hein-Kristensen
- Division of Industrial Food Research, National Food Institute, Technical University of Denmark, Søltofts Plads, Lyngby, DK-Denmark.
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15
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Antiplasmodial properties of acyl-lysyl oligomers in culture and animal models of malaria. Antimicrob Agents Chemother 2011; 55:3803-11. [PMID: 21646484 DOI: 10.1128/aac.00129-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our previous analysis of antiplasmodial properties exhibited by dodecanoyl-based oligo-acyl-lysyls (OAKs) has outlined basic attributes implicated in potent inhibition of parasite growth and underlined the critical role of excess hydrophobicity in hemotoxicity. To dissociate hemolysis from antiplasmodial effect, we screened >50 OAKs for in vitro growth inhibition of Plasmodium falciparum strains, thus revealing the minimal requirements for antiplasmodial potency in terms of sequence and composition, as confirmed by efficacy studies in vivo. The most active sequence, dodecanoyllysyl-bis(aminooctanoyllysyl)-amide (C(12)K-2α(8)), inhibited parasite growth at submicromolar concentrations (50% inhibitory concentration [IC(50)], 0.3 ± 0.1 μM) and was devoid of hemolytic activity (<0.4% hemolysis at 150 μM). Unlike the case of dodecanoyl-based analogs, which equally affect ring and trophozoite stages of the parasite developmental cycle, the ability of various octanoyl-based OAKs to distinctively affect these stages (rings were 4- to 5-fold more sensitive) suggests a distinct antiplasmodial mechanism, nonmembranolytic to host red blood cells (RBCs). Upon intraperitoneal administration to mice, C(12)K-2α(8) demonstrated sustainable high concentrations in blood (e.g., 0.1 mM at 25 mg/kg of body weight). In Plasmodium vinckei-infected mice, C(12)K-2α(8) significantly affected parasite growth (50% effective dose [ED(50)], 22 mg/kg) but also caused mortality in 2/3 mice at high doses (50 mg/kg/day × 4).
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Zhou H, Dou J, Wang J, Chen L, Wang H, Zhou W, Li Y, Zhou C. The antibacterial activity of BF-30 in vitro and in infected burned rats is through interference with cytoplasmic membrane integrity. Peptides 2011; 32:1131-8. [PMID: 21515321 DOI: 10.1016/j.peptides.2011.04.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/07/2011] [Accepted: 04/08/2011] [Indexed: 10/18/2022]
Abstract
Cathelicidin-BF (BF-30) is found in the venom of the snake Bungarus fasciatus and exhibits broad antimicrobial activity against bacteria and fungi. Nevertheless, its antibacterial activity in vivo and antibacterial mechanism is unknown. In the present study, we examined the antibacterial activity of BF-30 in vitro against drug-resistant Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, first identifying its protection against P. aeruginosa in infected burns and then delineating the antimicrobial mechanism of BF-30. The data showed that BF-30 had stronger antimicrobial activities against a broad spectrum of microorganisms than gentamicin, ampicillin or bacitracin. The killing curves of BF-30 against P. aeruginosa and S. aureus showed that CFU counts rapidly decreased by almost 2 logs within 6min, and it took just less than 2h to kill all the bacteria. In addition, we investigated whether BF-30 had antibacterial activity in a burn/acute infection rat model. Dose-response (0.75, 3, 12mg/kg/day) studies indicated that BF-30 significantly reduced the colonization of P. aeruginosa in the burn eschars, lungs and liver of burn injured rats and that it could prevent subsequent systemic infection and development of inflammation. The peptide induced chaotic membrane morphology and cell debris, as determined by electron microscopy, and caused the cytoplasmic membrane to crack, resulting in β-galactosidase leakage and EtBr accumulation. This suggests that the antimicrobial activity of BF-30 is based on cytoplasmic membrane permeability. Taken together, our data demonstrate that antibacterial activity of BF-30 has potential therapeutic value for the prevention and treatment of burn and wound infections.
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Affiliation(s)
- Huimin Zhou
- School of Life Science & Technology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, PR China
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Thaker HD, Sgolastra F, Clements D, Scott RW, Tew GN. Synthetic mimics of antimicrobial peptides from triaryl scaffolds. J Med Chem 2011; 54:2241-54. [PMID: 21388190 PMCID: PMC3072574 DOI: 10.1021/jm101410t] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this report, we describe the synthesis of a new series of small amphiphilic aromatic compounds that mimic the essential properties of cationic antimicrobial peptides using Suzuki-Miyaura coupling. The new design allowed the easy tuning of the conformational restriction, controlled by introduction of intramolecular hydrogen bonds, and the overall hydrophobicity by modifications to the central ring and the side chains. This approach allowed us to better understand the influence of these features on the antimicrobial activity and selectivity. We found that the overall hydrophobicity had a more significant impact on antimicrobial and hemolytic activity than the conformational stiffness. A novel compound was discovered which has MICs of 0.78 μg/mL against S. Aureus and 6.25 μg/mL against E. Coli, similar to the well-known antimicrobial peptide, MSI-78.
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Affiliation(s)
- Hitesh D. Thaker
- Department of Polymer Science & Engineering, University of Massachusetts, Amherst, MA 01003
| | - Federica Sgolastra
- Department of Polymer Science & Engineering, University of Massachusetts, Amherst, MA 01003
| | - Dylan Clements
- PolyMedix Inc., 170 North Radnor-Chester Road, Suite 300, Radnor, PA 19087
| | - Richard W. Scott
- PolyMedix Inc., 170 North Radnor-Chester Road, Suite 300, Radnor, PA 19087
| | - Gregory N. Tew
- Department of Polymer Science & Engineering, University of Massachusetts, Amherst, MA 01003
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Livne L, Epand RF, Papahadjopoulos-Sternberg B, Epand RM, Mor A. OAK-based cochleates as a novel approach to overcome multidrug resistance in bacteria. FASEB J 2010. [PMID: 20720156 DOI: 10.1096/fj.10.167809] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antibiotic resistance has become a worldwide medical problem. To find new ways of overcoming this phenomenon, we investigated the role of the membrane-active oligo-acyl-lysyl (OAK) sequence C(12)K-7α(8), in combination with essentially ineffective antibiotics. Determination of minimal inhibitory concentration (MIC) against gram-negative multidrug-resistant strains of Escherichia coli revealed combinations with sub-MIC OAK levels that acted synergistically with several antibiotics, thus lowering their MICs by several orders of magnitude. To shed light into the molecular basis for this synergism, we used both mutant strains and biochemical assays. Our results suggest that bacterial sensitization to antibiotics was derived mainly from the OAK's capacity to overcome the efflux-enhanced resistance mechanism, by promoting backdoor entry of otherwise excluded antibiotics. To facilitate simultaneous delivery of the pooled drugs to an infection site, we developed a novel OAK-based cochleate system with demonstrable stability in whole blood. To assess the potential therapeutic use of such cochleates, we performed preliminary experiments that imitate systemic treatment of neutropenic mice infected with lethal inoculums of multidrug resistance E. coli. Single-dose administration of erythromycin coencapsulated in OAK-based cochleates has decreased drug toxicity and increased therapeutic efficacy in a dose-dependent manner. Collectively, our findings suggest a potentially useful approach for fighting efflux-enhanced resistance mechanisms.
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Affiliation(s)
- L Livne
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Livne L, Epand RF, Papahadjopoulos-Sternberg B, Epand RM, Mor A. OAK-based cochleates as a novel approach to overcome multidrug resistance in bacteria. FASEB J 2010; 24:5092-101. [PMID: 20720156 DOI: 10.1096/fj.10-167809] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antibiotic resistance has become a worldwide medical problem. To find new ways of overcoming this phenomenon, we investigated the role of the membrane-active oligo-acyl-lysyl (OAK) sequence C(12)K-7α(8), in combination with essentially ineffective antibiotics. Determination of minimal inhibitory concentration (MIC) against gram-negative multidrug-resistant strains of Escherichia coli revealed combinations with sub-MIC OAK levels that acted synergistically with several antibiotics, thus lowering their MICs by several orders of magnitude. To shed light into the molecular basis for this synergism, we used both mutant strains and biochemical assays. Our results suggest that bacterial sensitization to antibiotics was derived mainly from the OAK's capacity to overcome the efflux-enhanced resistance mechanism, by promoting backdoor entry of otherwise excluded antibiotics. To facilitate simultaneous delivery of the pooled drugs to an infection site, we developed a novel OAK-based cochleate system with demonstrable stability in whole blood. To assess the potential therapeutic use of such cochleates, we performed preliminary experiments that imitate systemic treatment of neutropenic mice infected with lethal inoculums of multidrug resistance E. coli. Single-dose administration of erythromycin coencapsulated in OAK-based cochleates has decreased drug toxicity and increased therapeutic efficacy in a dose-dependent manner. Collectively, our findings suggest a potentially useful approach for fighting efflux-enhanced resistance mechanisms.
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Affiliation(s)
- L Livne
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Livne L, Kovachi T, Sarig H, Epand RF, Zaknoon F, Epand RM, Mor A. Design and characterization of a broad -spectrum bactericidal acyl-lysyl oligomer. ACTA ACUST UNITED AC 2010; 16:1250-8. [PMID: 20064435 DOI: 10.1016/j.chembiol.2009.11.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 10/07/2009] [Accepted: 11/02/2009] [Indexed: 10/20/2022]
Abstract
Previously characterized chemical mimics of host defense peptides belonging to the oligo-acyl-lysyl (OAK) family have so far failed to demonstrate broad-spectrum antibacterial potency combined with selectivity toward host cells. Here, we investigated OAK sequences and characterized a promising representative, designated C(12)K-3beta(10), with broad-spectrum activity (MIC(90) = 6.2 microM) and low hemotoxicity (LC(50) > 100 microM). Whereas C(12)K-3beta(10) exerted an essentially bactericidal effect, E. coli bacteria were killed faster than S. aureus (minutes versus hours). Mechanistic studies addressing this difference revealed that unlike E. coli, S. aureus bacteria undergo a transient rapid bactericidal stage that over time converts to a bacteriostatic effect. This behavior was dictated by interactions with cell wall-specific components. Preliminary efficacy studies in mice using the thigh infection model demonstrated the OAK's ability to significantly affect bacterial viability upon single-dose systemic treatment (2 mg/kg).
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Affiliation(s)
- Liran Livne
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
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