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Kumar A, Mitra JB, Khatoon E, Pramanik A, Sharma RK, Chandak A, Rakshit S, Mukherjee A. Exploring the potential of radiolabeled duramycin as an infection imaging probe. Drug Dev Res 2024; 85:e22138. [PMID: 38078492 DOI: 10.1002/ddr.22138] [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: 09/14/2023] [Revised: 11/13/2023] [Accepted: 11/25/2023] [Indexed: 02/15/2024]
Abstract
The continuous pursuit of designing an ideal infection imaging agent is a crucial and ongoing endeavor in the field of biomedical research. Duramycin, an antimicrobial peptide exerts its antimicrobial action on bacteria by specific recognition of phosphatidylethanolamine (PE) moiety present on most bacterial membranes, particularly Escherichia coli (E. coli). E. coli membranes contain more than 60% PE. Therefore, duramycin is an attractive candidate for the formulation of probes for in situ visualization of E. coli driven focal infections. The aim of the present study is to develop 99m Tc labeled duramycin as a single-photon emission computed tomography (SPECT)-based agent to image such infections. Duramycin was successfully conjugated with a bifunctional chelator, hydrazinonicotinamide (HYNIC). PE specificity of HYNIC-duramycin was confirmed by a dye release assay on PE-containing model membranes. Radiolabeling of HYNIC-duramycin with 99m Tc was performed with consistently high radiochemical yield (>90%) and radiochemical purity (>90%). [99m Tc]Tc-HYNIC-duramycin retained its specificity for E. coli, in vitro. SPECT and biodistribution studies showed that the tracer could specifically identify E. coli driven infection at 3 h post injection. While 99m Tc-labeled duramycin is employed for monitoring early response to cancer therapy and cardiotoxicity, the current studies have confirmed, for the first time, the potential of utilizing 99m Tc labeled duramycin as an imaging agent for detecting bacteria. Its application in imaging PE-positive bacteria represents a novel and promising advancement.
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Affiliation(s)
- Anuj Kumar
- Radiopharmaceutical Division, Bhabha Atomic Research Centre, Mumbai, India
- Life Sciences, Homi Bhabha National Institute, Mumbai, India
| | - Jyotsna Bhatt Mitra
- Radiopharmaceutical Division, Bhabha Atomic Research Centre, Mumbai, India
- Life Sciences, Homi Bhabha National Institute, Mumbai, India
| | - Elina Khatoon
- Radiopharmaceutical Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Aparna Pramanik
- Department of Chemistry, Centre of Advanced Studies, Panjab University, Chandigarh, India
| | - Rohit K Sharma
- Department of Chemistry, Centre of Advanced Studies, Panjab University, Chandigarh, India
| | - Ashok Chandak
- Board of Radiation and Isotope Technology, Navi Mumbai, India
| | | | - Archana Mukherjee
- Radiopharmaceutical Division, Bhabha Atomic Research Centre, Mumbai, India
- Life Sciences, Homi Bhabha National Institute, Mumbai, India
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2
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Zhang D, Gao M, Jin Q, Ni Y, Li H, Jiang C, Zhang J. Development of Duramycin-Based Molecular Probes for Cell Death Imaging. Mol Imaging Biol 2022; 24:612-629. [PMID: 35142992 DOI: 10.1007/s11307-022-01707-3] [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: 10/09/2021] [Revised: 01/10/2022] [Accepted: 01/27/2022] [Indexed: 10/19/2022]
Abstract
Cell death is involved in numerous pathological conditions such as cardiovascular disorders, ischemic stroke and organ transplant rejection, and plays a critical role in the treatment of cancer. Cell death imaging can serve as a noninvasive means to detect the severity of tissue damage, monitor the progression of diseases, and evaluate the effectiveness of treatments, which help to provide prognostic information and guide the formulation of individualized treatment plans. The high abundance of phosphatidylethanolamine (PE), which is predominantly confined to the inner leaflet of the lipid bilayer membrane in healthy mammalian cells, becomes exposed on the cell surface in the early stages of apoptosis or accessible to the extracellular milieu when the cell suffers from necrosis, thus representing an attractive target for cell death imaging. Duramycin is a tetracyclic polypeptide that contains 19 amino acids and can bind to PE with excellent affinity and specificity. Additionally, this peptide has several favorable structural traits including relatively low molecular weight, stability to enzymatic hydrolysis, and ease of conjugation and labeling. All these highlight the potential of duramycin as a candidate ligand for developing PE-specific molecular probes. By far, a couple of duramycin-based molecular probes such as Tc-99 m-, F-18-, or Ga-68-labeled duramycin have been developed to target exposed PE for in vivo noninvasive imaging of cell death in different animal models. In this review article, we describe the state of the art with respect to in vivo imaging of cell death using duramycin-based molecular probes, as validated by immunohistopathology.
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Affiliation(s)
- Dongjian Zhang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China.,Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China
| | - Meng Gao
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China.,Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China
| | - Qiaomei Jin
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China.,Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China
| | - Yicheng Ni
- Theragnostic Laboratory, Campus Gasthuisberg, 3000, Leuven, Leuven, KU, Belgium
| | - Huailiang Li
- Department of General Surgery, Nanjing Lishui District Hospital of Traditional Chinese Medicine, Nanjing, 211200, Jiangsu Province, People's Republic of China
| | - Cuihua Jiang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China. .,Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China.
| | - Jian Zhang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China. .,Laboratories of Translational Medicine, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, Jiangsu Province, People's Republic of China.
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3
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Haskali MB, Denoyer D, Roselt PD, Hicks RJ, Hutton CA. Radiosynthesis and preliminary in vivo evaluation of 18F-labelled glycosylated duramycin peptides for imaging of phosphatidylethanolamine during apoptosis. MEDCHEMCOMM 2019. [DOI: 10.1039/c9md00354a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[18F]-Labelled duramycin derivatives incorporating hydrophilic aminogalacturonic acid moieties were prepared as tracers for in vivo imaging of phosphatidylethanolamine during apoptosis.
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Affiliation(s)
- Mohammad B. Haskali
- School of Chemistry
- The University of Melbourne
- Australia
- Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
| | - Delphine Denoyer
- The Centre for Molecular Imaging and Translational Research Laboratory
- The Peter MacCallum Cancer Centre
- Melbourne
- Australia
| | - Peter D. Roselt
- The Centre for Molecular Imaging and Translational Research Laboratory
- The Peter MacCallum Cancer Centre
- Melbourne
- Australia
| | - Rodney J. Hicks
- The Centre for Molecular Imaging and Translational Research Laboratory
- The Peter MacCallum Cancer Centre
- Melbourne
- Australia
- The Sir Peter MacCallum Department of Oncology
| | - Craig A. Hutton
- School of Chemistry
- The University of Melbourne
- Australia
- Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
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4
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Substrate-assisted enzymatic formation of lysinoalanine in duramycin. Nat Chem Biol 2018; 14:928-933. [PMID: 30177849 PMCID: PMC6372306 DOI: 10.1038/s41589-018-0122-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 07/17/2018] [Indexed: 02/07/2023]
Abstract
Duramycin is a heavily post-translationally modified peptide that binds phosphatidylethanolamine. It has been investigated as an antibiotic, inhibitor of viral entry, therapeutic for cystic fibrosis, and tumor and vasculature imaging agent. Duramycin contains a β-hydroxylated Asp (Hya) and four macrocycles, including an essential lysinoalanine (Lal) crosslink. The mechanism of Lal formation is not known. We here show that Lal is installed stereospecifically by DurN via addition of Lys19 to a dehydroalanine. The structure of DurN reveals an unusual dimer with a new fold. Surprisingly, in the structure of duramycin bound to DurN, no residues of the enzyme are near the Lal crosslink. Instead, Hya15 of the substrate makes interactions with Lal, suggesting it acts as a base to deprotonate Lys19 during catalysis. Biochemical data suggest that DurN preorganizes the reactive conformation of the substrate, such that the Hya15 of the substrate can serve as the catalytic base for Lal formation.
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5
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Rybczynska AA, Boersma HH, de Jong S, Gietema JA, Noordzij W, Dierckx RAJO, Elsinga PH, van Waarde A. Avenues to molecular imaging of dying cells: Focus on cancer. Med Res Rev 2018. [PMID: 29528513 PMCID: PMC6220832 DOI: 10.1002/med.21495] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Successful treatment of cancer patients requires balancing of the dose, timing, and type of therapeutic regimen. Detection of increased cell death may serve as a predictor of the eventual therapeutic success. Imaging of cell death may thus lead to early identification of treatment responders and nonresponders, and to “patient‐tailored therapy.” Cell death in organs and tissues of the human body can be visualized, using positron emission tomography or single‐photon emission computed tomography, although unsolved problems remain concerning target selection, tracer pharmacokinetics, target‐to‐nontarget ratio, and spatial and temporal resolution of the scans. Phosphatidylserine exposure by dying cells has been the most extensively studied imaging target. However, visualization of this process with radiolabeled Annexin A5 has not become routine in the clinical setting. Classification of death modes is no longer based only on cell morphology but also on biochemistry, and apoptosis is no longer found to be the preponderant mechanism of cell death after antitumor therapy, as was earlier believed. These conceptual changes have affected radiochemical efforts. Novel probes targeting changes in membrane permeability, cytoplasmic pH, mitochondrial membrane potential, or caspase activation have recently been explored. In this review, we discuss molecular changes in tumors which can be targeted to visualize cell death and we propose promising biomarkers for future exploration.
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Affiliation(s)
- Anna A Rybczynska
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Genetics, University of Groningen, Groningen, the Netherlands
| | - Hendrikus H Boersma
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Clinical Pharmacy & Pharmacology, University of Groningen, Groningen, the Netherlands
| | - Steven de Jong
- Department of Medical Oncology, University of Groningen, Groningen, the Netherlands
| | - Jourik A Gietema
- Department of Medical Oncology, University of Groningen, Groningen, the Netherlands
| | - Walter Noordzij
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rudi A J O Dierckx
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.,Department of Nuclear Medicine, Ghent University, Ghent, Belgium
| | - Philip H Elsinga
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Aren van Waarde
- Molecular Imaging Center, Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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Hasim S, Allison DP, Mendez B, Farmer AT, Pelletier DA, Retterer ST, Campagna SR, Reynolds TB, Doktycz MJ. Elucidating Duramycin's Bacterial Selectivity and Mode of Action on the Bacterial Cell Envelope. Front Microbiol 2018; 9:219. [PMID: 29491859 PMCID: PMC5817074 DOI: 10.3389/fmicb.2018.00219] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/30/2018] [Indexed: 11/25/2022] Open
Abstract
The use of naturally occurring antimicrobial peptides provides a promising route to selectively target pathogenic agents and to shape microbiome structure. Lantibiotics, such as duramycin, are one class of bacterially produced peptidic natural products that can selectively inhibit the growth of other bacteria. However, despite longstanding characterization efforts, the microbial selectivity and mode of action of duramycin are still obscure. We describe here a suite of biological, chemical, and physical characterizations that shed new light on the selective and mechanistic aspects of duramycin activity. Bacterial screening assays have been performed using duramycin and Populus-derived bacterial isolates to determine species selectivity. Lipidomic profiles of selected resistant and sensitive strains show that the sensitivity of Gram-positive bacteria depends on the presence of phosphatidylethanolamine (PE) in the cell membrane. Further the surface and interface morphology were studied by high resolution atomic force microscopy and showed a progression of cellular changes in the cell envelope after treatment with duramycin for the susceptible bacterial strains. Together, these molecular and cellular level analyses provide insight into duramycin’s mode of action and a better understanding of its selectivity.
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Affiliation(s)
- Sahar Hasim
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - David P Allison
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | - Berlin Mendez
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Abigail T Farmer
- Department of Chemistry, University of Tennessee, Knoxville, TN, United States
| | - Dale A Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Scott T Retterer
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Shawn R Campagna
- Department of Chemistry, University of Tennessee, Knoxville, TN, United States
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States
| | - Mitchel J Doktycz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States
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7
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Palmieri L, Elvas F, Vangestel C, Pak K, Gray B, Stroobants S, Staelens S, wyffels L. [ 99m Tc]duramycin for cell death imaging: Impact of kit formulation, purification and species difference. Nucl Med Biol 2018; 56:1-9. [DOI: 10.1016/j.nucmedbio.2017.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 01/23/2023]
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9
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Sharma R, Huang X, Brekken RA, Schroit AJ. Detection of phosphatidylserine-positive exosomes for the diagnosis of early-stage malignancies. Br J Cancer 2017. [PMID: 28641308 PMCID: PMC5558679 DOI: 10.1038/bjc.2017.183] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background: There has been increasing interest in the detection of tumour exosomes in blood for cancer diagnostics. Most studies have focussed on miRNA and protein signatures that are surrogate markers for specific tumour types. Because tumour cells and tumour-derived exosomes display phosphatidylserine (PS) in their outer membrane leaflet, we developed a highly sensitive ELISA-based system that detects picogram amounts of exosomal phospholipid in plasma as a cancer biomarker. Methods: This report describes the development of a highly specific and sensitive ELISA for the capture of PS-expressing tumour exosomes in the blood of tumour-bearing mice. To monitor the relationship between tumour burden and tumour exosome plasma concentrations, plasma from one transplantable breast cancer model (MDA-MB-231) and three genetic mouse models (MMTV-PyMT; breast and KIC and KPC; pancreatic) were screened for captured exosomal phospholipid. Results: We show that quantitative assessment of PS-expressing tumour exosomes detected very early-stage malignancies before clinical evidence of disease in all four model systems. Tumour exosome levels showed significant increases by day 7 after tumour implantation in the MDA-MB-231 model while palpable tumours appeared only after day 27. For the MMTV-PyMT and KIC models, tumour exosome levels increased significantly by day 49 (P⩽0.0002) and day 21 (P⩽0.001) while tumours developed only after days 60 and 40, respectively. For the KPC model, a significant increase in blood exosome levels was detected by day 70 (P=0.023) when only preinvasive lesions are microscopically detectable. Conclusions: These data indicate that blood PS exosome levels is a specific indicator of cancer and suggest that blood PS is a biomarker for early-stage malignancies.
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Affiliation(s)
- Raghava Sharma
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xianming Huang
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rolf A Brekken
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Surgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Alan J Schroit
- Harold Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Immunology, UT Southwestern Medical Center, Dallas 75390, TX, USA
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10
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Repka LM, Chekan JR, Nair SK, van der Donk WA. Mechanistic Understanding of Lanthipeptide Biosynthetic Enzymes. Chem Rev 2017; 117:5457-5520. [PMID: 28135077 PMCID: PMC5408752 DOI: 10.1021/acs.chemrev.6b00591] [Citation(s) in RCA: 313] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
![]()
Lanthipeptides
are ribosomally synthesized and post-translationally
modified peptides (RiPPs) that display a wide variety of biological
activities, from antimicrobial to antiallodynic. Lanthipeptides that
display antimicrobial activity are called lantibiotics. The post-translational
modification reactions of lanthipeptides include dehydration of Ser
and Thr residues to dehydroalanine and dehydrobutyrine, a transformation
that is carried out in three unique ways in different classes of lanthipeptides.
In a cyclization process, Cys residues then attack the dehydrated
residues to generate the lanthionine and methyllanthionine thioether
cross-linked amino acids from which lanthipeptides derive their name.
The resulting polycyclic peptides have constrained conformations that
confer their biological activities. After installation of the characteristic
thioether cross-links, tailoring enzymes introduce additional post-translational
modifications that are unique to each lanthipeptide and that fine-tune
their activities and/or stability. This review focuses on studies
published over the past decade that have provided much insight into
the mechanisms of the enzymes that carry out the post-translational
modifications.
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Affiliation(s)
- Lindsay M Repka
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Jonathan R Chekan
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Satish K Nair
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Wilfred A van der Donk
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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11
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Insights into the Biosynthesis of Duramycin. Appl Environ Microbiol 2017; 83:AEM.02698-16. [PMID: 27864176 DOI: 10.1128/aem.02698-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 11/10/2016] [Indexed: 12/25/2022] Open
Abstract
Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are characterized by the thioether cross-linked bisamino acids lanthionine (Lan) and methyllanthionine (MeLan). Duramycin contains 19 amino acids, including one Lan and two MeLans, an unusual lysinoalanine (Lal) bridge formed from the ε-amino group of lysine 19 and a serine residue at position 6, and an erythro-3-hydroxy-l-aspartic acid at position 15. These modifications are important for the interactions of duramycin with its biological target, phosphatidylethanolamine (PE). Based on the binding affinity and specificity for PE, duramycin has been investigated as a potential therapeutic, as a molecular probe to investigate the role and localization of PE in biological systems, and to block viral entry into mammalian cells. In this study, we identified the duramycin biosynthetic gene cluster by genome sequencing of Streptomyces cinnamoneus ATCC 12686 and investigated the dur biosynthetic machinery by heterologous expression in Escherichia coli In addition, the analog duramycin C, containing six amino acid changes compared to duramycin, was successfully generated in E. coli The substrate recognition motif of DurX, an α-ketoglutarate/iron(II)-dependent hydroxylase that carries out the hydroxylation of aspartate 15 of the precursor peptide DurA, was also investigated using mutagenesis of the DurA peptide. Both in vivo and in vitro results demonstrated that Gly16 is important for DurX activity. IMPORTANCE Duramycin is a natural product produced by certain bacteria that binds to phosphatidylethanolamine (PE). Because PE is involved in many cellular processes, duramycin is an antibiotic that kills bacteria, but it has also been used as a molecular probe to detect PE and monitor its localization in mammalian cells and even whole organisms, and it was recently shown to display broad-spectrum inhibition of viral entry into host cells. In addition, the molecule has been evaluated as treatment for cystic fibrosis. We report here the genes that are involved in duramycin biosynthesis, and we produced duramycin by expressing those genes in Escherichia coli We show that duramycin analogs can also be produced. The ability to access duramycin and analogs by production in E. coli opens opportunities to improve duramycin as an antibiotic, PE probe, antiviral, or cystic fibrosis therapeutic.
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12
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Probing phosphoethanolamine-containing lipids in membranes with duramycin/cinnamycin and aegerolysin proteins. Biochimie 2016; 130:81-90. [DOI: 10.1016/j.biochi.2016.09.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/27/2016] [Indexed: 02/07/2023]
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13
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Broughton LJ, Giuntini F, Savoie H, Bryden F, Boyle RW, Maraveyas A, Madden LA. Duramycin-porphyrin conjugates for targeting of tumour cells using photodynamic therapy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 163:374-84. [DOI: 10.1016/j.jphotobiol.2016.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 12/27/2022]
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Abstract
Duramycin, through binding with phosphatidylethanolamine (PE), has shown potential to be an effective antitumour agent. However, its mode of action in relation to tumour cells is not fully understood. PE expression on the surface of a panel of cancer cell lines was analysed using duramycin and subsequent antibody labelling, and then analysed by flow cytometry. Cell viability was also assessed by flow cytometry using annexin V and propidium iodide. Calcium ion (Ca) release by tumour cells in response to duramycin was determined by spectrofluorometry following incubation with Fluo-3, AM. Confocal microscopy was performed on the cancer cell line AsPC-1 to assess real-time cell response to duramycin treatment. Duramycin could detect cell surface PE expression on all 15 cancer cell lines screened, which was shown to be duramycin concentration dependent. However, higher concentrations induced necrotic cell death. Duramycin induced calcium ion (Ca) release from the cancer cell lines also in a concentration-dependent and time-dependent manner. Confocal microscopy showed an influx of propidium iodide into the cells over time and induced morphological changes. Duramycin induces Ca release from cancer cell lines in a time-dependent and concentration-dependent manner.
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15
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Isolation and structure determination of a new lantibiotic cinnamycin B from Actinomadura atramentaria based on genome mining. J Ind Microbiol Biotechnol 2016; 43:1159-65. [PMID: 27255974 DOI: 10.1007/s10295-016-1788-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/21/2016] [Indexed: 01/26/2023]
Abstract
New lantibiotic cinnamycin B was isolated from the extract of Actinomadura atramentaria NBRC 14695(T), based on genome mining and chemical investigation. The partial structure of cinnamycin B was established by 2D NMR experiments, which indicated that cinnamycin B had same methyl lanthionine bridging pattern with cinnamycin. The reduction with NaBH4-NiCl2 afforded the reduced cinnamycin B, and MS/MS experiment indicated the presence of hydroxy asparatic acid in the molecule. Cinnamycin B showed an antibacterial activity against Streptomyces antibioticus with dosage of 5 μg (0.5μL, 10 mg/mL solution) at spot-on-lawn testing method. The gene cluster of cinnamycin B on the genome of A. atramentaria was identified and discussed in comparison with that of cinnamycin.
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16
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Medhora M, Haworth S, Liu Y, Narayanan J, Gao F, Zhao M, Audi S, Jacobs ER, Fish BL, Clough AV. Biomarkers for Radiation Pneumonitis Using Noninvasive Molecular Imaging. J Nucl Med 2016; 57:1296-301. [PMID: 27033892 DOI: 10.2967/jnumed.115.160291] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 01/21/2016] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED Our goal is to develop minimally invasive biomarkers for predicting radiation-induced lung injury before symptoms develop. Currently, there are no biomarkers that can predict radiation pneumonitis. Radiation damage to the whole lung is a serious risk in nuclear accidents or in radiologic terrorism. Our previous studies have shown that a single dose of 15 Gy of x-rays to the thorax causes severe pneumonitis in rats by 6-8 wk. We have also developed a mitigator for radiation pneumonitis and fibrosis that can be started as late as 5 wk after radiation. METHODS We used 2 functional SPECT probes in vivo in irradiated rat lungs. Regional pulmonary perfusion was measured by injection of (99m)Tc-macroaggregated albumin. Perfused volume was determined by comparing the volume of distribution of (99m)Tc-macroaggregated albumin to the anatomic lung volume obtained by small-animal CT. A second probe, (99m)Tc-labeled Duramycin, which binds to apoptotic cells, was used to measure pulmonary cell death in the same rat model. RESULTS The perfused volume of lung was decreased by about 25% at 1, 2, and 3 wk after receipt of 15 Gy, and (99m)Tc-Duramycin uptake was more than doubled at 2 and 3 wk. There was no change in body weight, breathing rate, or lung histology between irradiated and nonirradiated rats at these times. Pulmonary vascular resistance and vascular permeability measured in isolated perfused lungs ex vivo increased at 2 wk after 15 Gy of irradiation. CONCLUSION Our results suggest that SPECT biomarkers have the potential to predict radiation injury to the lungs before substantial functional or histologic damage is observed. Early prediction of radiation pneumonitis in time to initiate mitigation will benefit those exposed to radiation in the context of therapy, accidents, or terrorism.
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Affiliation(s)
- Meetha Medhora
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Steven Haworth
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Yu Liu
- Center for Imaging Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jayashree Narayanan
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Feng Gao
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ming Zhao
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Said Audi
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin; and
| | - Elizabeth R Jacobs
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Brian L Fish
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Anne V Clough
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin Department of Mathematics, Statistics and Computer Science, Marquette University, Milwaukee, Wisconsin
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Luo R, Niu L, Qiu F, Fang W, Fu T, Zhao M, Zhang YJ, Hua ZC, Li XF, Wang F. Monitoring Apoptosis of Breast Cancer Xenograft After Paclitaxel Treatment With 99mTc-Labeled Duramycin SPECT/CT. Mol Imaging 2016; 15:1536012115624918. [PMID: 27030401 PMCID: PMC5469599 DOI: 10.1177/1536012115624918] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/23/2015] [Accepted: 10/29/2015] [Indexed: 01/05/2023] Open
Abstract
Our goal was to validate the feasibility of(99m)Tc-duramycin as a potential apoptosis probe for monitoring tumor response to paclitaxel in breast cancer xenografts. The binding of(99m)Tc-duramycin to phosphatidylethanolamine was validated in vitro using paclitaxel-treated human breast carcinoma MDA-MB-231 cells. Female BALB/c mice (n = 5) bearing breast cancer xenografts were randomized into 2 groups and intraperitoneally injected with 40 mg/kg paclitaxel or phosphate-buffered saline.(99m)Tc-duramycin (37-55.5 MBq) was injected at 72 hours posttreatment, and single-photon emission computed tomography/computed tomography was performed at 2 hours postinjection. Apoptotic cells and activated caspase 3 in explanted tumor tissue were measured by flow cytometry. Cellular ultrastructural changes were assessed by light and transmission electron microscopy.(99m)Tc-duramycin with radiochemical purity of >90% exhibited rapid blood clearance and predominantly renal clearance. The tumor-to-muscle ratio in the paclitaxel-treated group (5.29 ± 0.62) was significantly higher than that in the control. Tumor volume was decreased dramatically, whereas tumor uptake of(99m)Tc-duramycin (ex vivo) significantly increased following paclitaxel treatment, which was consistent with apoptotic index, histological findings, and ultrastructural changes. Our data demonstrated the feasibility of(99m)Tc-duramycin for early detection of apoptosis after paclitaxel chemotherapy in breast carcinoma xenografts.
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Affiliation(s)
- Rui Luo
- Department of Nuclear Medicine, Nanjing Hospital, Affiliated to Nanjing Medical University, Nanjing, China
| | - Lei Niu
- Department of Nuclear Medicine, Nanjing Hospital, Affiliated to Nanjing Medical University, Nanjing, China
| | - Fan Qiu
- Department of Nuclear Medicine, Nanjing Hospital, Affiliated to Nanjing Medical University, Nanjing, China
| | - Wei Fang
- Cardiovascular Institute & Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China
| | - Tong Fu
- Department of Nuclear Medicine, Nanjing Hospital, Affiliated to Nanjing Medical University, Nanjing, China
| | - Ming Zhao
- Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ying-Jian Zhang
- Department of Nuclear Medicine, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Zi-Chun Hua
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, Nanjing University, Nanjing, Jiangsu, China
| | - Xiao-Feng Li
- Department of Radiology, University of Louisville, Louisville, KY, USA
| | - Feng Wang
- Department of Nuclear Medicine, Nanjing Hospital, Affiliated to Nanjing Medical University, Nanjing, China
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18
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Iftime D, Jasyk M, Kulik A, Imhoff JF, Stegmann E, Wohlleben W, Süssmuth RD, Weber T. Streptocollin, a Type IV Lanthipeptide Produced by Streptomyces collinus Tü 365. Chembiochem 2015; 16:2615-23. [PMID: 26437689 DOI: 10.1002/cbic.201500377] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Indexed: 11/10/2022]
Abstract
Lanthipeptides are ribosomally synthesized and post-translationally modified microbial secondary metabolites. Here, we report the identification and isolation of streptocollin from Streptomyces collinus Tü 365, a new member of class IV lanthipeptides. Insertion of the constitutive ermE* promoter upstream of the lanthipeptide synthetase gene stcL resulted in peptide production. The streptocollin gene cluster was heterologously expressed in S. coelicolor M1146 and M1152 with 3.5- and 5.5-fold increased yields, respectively. The structure and ring topology of streptocollin were determined by high resolution MS/MS analysis. Streptocollin contains four macrocyclic rings, with one lanthionine and three methyllanthionine residues. To the best of our knowledge, this is the first report on the isolation of a class IV lanthipeptide in preparative amounts, and on the successful heterologous expression of a class IV lanthipeptide gene cluster.
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Affiliation(s)
- Dumitrita Iftime
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
| | - Martin Jasyk
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Andreas Kulik
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
| | - Johannes F Imhoff
- GEOMAR, Helmholtz-Zentrum für Ozeanforschung Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Evi Stegmann
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.,Deutsches Zentrum für Infektionsforschung, Partner Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
| | - Wolfgang Wohlleben
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.,Deutsches Zentrum für Infektionsforschung, Partner Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
| | - Roderich D Süssmuth
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Tilmann Weber
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany. .,Deutsches Zentrum für Infektionsforschung, Partner Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany. .,The Novo Nordisk foundation Center for Biosustainability, Technical University of Denmark, Kogle Alle 6, 2970, Hørsholm, Denmark.
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20
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Phoenix DA, Harris F, Mura M, Dennison SR. The increasing role of phosphatidylethanolamine as a lipid receptor in the action of host defence peptides. Prog Lipid Res 2015; 59:26-37. [PMID: 25936689 DOI: 10.1016/j.plipres.2015.02.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 01/04/2023]
Abstract
Host defence peptides (HDPs) are antimicrobial agents produced by organisms across the prokaryotic and eukaryotic kingdoms. Many prokaryotes produce HDPs, which utilise lipid and protein receptors in the membranes of bacterial competitors to facilitate their antibacterial action and thereby survive in their niche environment. As a major example, it is well established that cinnamycin and duramycins from Streptomyces have a high affinity for phosphatidylethanolamine (PE) and exhibit activity against other Gram-positive organisms, such as Bacillus. In contrast, although eukaryotic HDPs utilise membrane interactive mechanisms to facilitate their antimicrobial activity, the prevailing view has long been that these mechanisms do not involve membrane receptors. However, this view has been recently challenged by reports that a number of eukaryotic HDPs such as plant cyclotides also use PE as a receptor to promote their antimicrobial activities. Here, we review current understanding of the mechanisms that underpin the use of PE as a receptor in the antimicrobial and other biological actions of HDPs and describe medical and biotechnical uses of these peptides, which range from tumour imaging and detection to inclusion in topical microbicidal gels to prevent the sexual transmission of HIV.
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Affiliation(s)
- David A Phoenix
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK.
| | - Frederick Harris
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK; School of Forensic and Investigative Science, University of Central Lancashire, Preston PR1 2HE, UK
| | - Manuela Mura
- School of Mathematics and Physics, College of Science, University of Lincoln, Brayford Pool, Lincoln, Lincolnshire LN6 7TS, UK
| | - Sarah R Dennison
- School of Applied Science, London South Bank University, 103 Borough Road, London SE1 0AA, UK; School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK
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21
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Yao S, Hu K, Tang G, Liang X, Du K, Nie D, Jiang S, Zang L. Positron emission tomography imaging of cell death with [(18)F]FPDuramycin. Apoptosis 2014; 19:841-50. [PMID: 24464510 DOI: 10.1007/s10495-013-0964-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The noninvasive imaging of cell death, including apoptosis and necrosis, is an important tool for the assessment of degenerative diseases and in the monitoring of tumor treatments. Duramycin is a peptide of 19-amino acids. It binds specifically to phosphatidylethanolamine a novel molecular target for cell death. N-(2-(18)F-Fluoropropionyl)duramycin ([(18)F]FPDuramycin) was prepared as a novel positron emission tomography (PET) tracer from the reaction of duramycin with 4-nitrophenyl 2-[(18)F]fluoropropionate ([(18)F]NFP). Compared with control cells (viable tumor cells), the in vitro binding of [(18)F]FPDuramycin with apoptotic cells induced by anti-Fas antibody resulted in a doubling increase, while the binding of [(18)F]FPDuramycin with necrotic cells induced by three freeze and thaw cycles resulted in a threefold increase. Biodistribution study in mice exhibited its rapid blood and renal clearance and predominant accumulation in liver and spleen over 120 min postinjection. Small-animal PET/CT imaging with [(18)F]FPDuramycin proved to be a successful way to visualize in vivo therapeutic-induced tumor cell death. In summary, [(18)F]FPDuramycin seems to be a potential PET probe candidate for noninvasive visualization of in vivo cell death sites induced by chemotherapy in tumors.
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Affiliation(s)
- Shaobo Yao
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China,
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22
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Radiolabeled apoptosis imaging agents for early detection of response to therapy. ScientificWorldJournal 2014; 2014:732603. [PMID: 25383382 PMCID: PMC4212626 DOI: 10.1155/2014/732603] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/11/2014] [Accepted: 08/12/2014] [Indexed: 12/12/2022] Open
Abstract
Since apoptosis plays an important role in maintaining homeostasis and is associated with responses to therapy, molecular imaging of apoptotic cells could be useful for early detection of therapeutic effects, particularly in oncology. Radiolabeled annexin V compounds are the hallmark in apoptosis imaging in vivo. These compounds are reviewed from the genesis of apoptosis (cell death) imaging agents up to recent years. They have some disadvantages, including slow clearance and immunogenicity, because they are protein-based imaging agents. For this reason, several studies have been conducted in recent years to develop low molecule apoptosis imaging agents. In this review, radiolabeled phosphatidylserine targeted peptides, radiolabeled bis(zinc(II)-dipicolylamine) complex, radiolabeled 5-fluoropentyl-2-methyl-malonic acid (ML-10), caspase-3 activity imaging agents, radiolabeled duramycin, and radiolabeled phosphonium cation are reviewed as promising low-molecular-weight apoptosis imaging agents.
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Wang L, Wang F, Fang W, Johnson SE, Audi S, Zimmer M, Holly TA, Lee DC, Zhu B, Zhu H, Zhao M. The feasibility of imaging myocardial ischemic/reperfusion injury using (99m)Tc-labeled duramycin in a porcine model. Nucl Med Biol 2014; 42:198-204. [PMID: 25451214 DOI: 10.1016/j.nucmedbio.2014.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/10/2014] [Accepted: 09/02/2014] [Indexed: 02/08/2023]
Abstract
UNLABELLED When pathologically externalized, phosphatidylethanolamine (PE) is a potential surrogate marker for detecting tissue injuries. (99m)Tc-labeled duramycin is a peptide-based imaging agent that binds PE with high affinity and specificity. The goal of the current study was to investigate the clearance kinetics of (99m)Tc-labeled duramycin in a large animal model (normal pigs) and to assess its uptake in the heart using a pig model of myocardial ischemia-reperfusion injury. METHODS The clearance and distribution of intravenously injected (99m)Tc-duramycin were characterized in sham-operated animals (n=5). In a closed chest model of myocardial ischemia, coronary occlusion was induced by balloon angioplasty (n=9). (99m)Tc-duramycin (10-15mCi) was injected intravenously at 1hour after reperfusion. SPECT/CT was acquired at 1 and 3hours after injection. Cardiac tissues were analyzed for changes associated with acute cellular injuries. Autoradiography and gamma counting were used to determine radioactivity uptake. For the remaining animals, (99m)Tc-tetrafosamin scan was performed on the second day to identify the infarct site. RESULTS Intravenously injected (99m)Tc-duramycin cleared from circulation predominantly via the renal/urinary tract with an α-phase half-life of 3.6±0.3minutes and β-phase half-life of 179.9±64.7minutes. In control animals, the ratios between normal heart and lung were 1.76±0.21, 1.66±0.22, 1.50±0.20 and 1.75±0.31 at 0.5, 1, 2 and 3hours post-injection, respectively. The ratios between normal heart and liver were 0.88±0.13, 0.80±0.13, 0.82±0.19 and 0.88±0.14. In vivo visualization of focal radioactivity uptake in the ischemic heart was attainable as early as 30min post-injection. The in vivo ischemic-to-normal uptake ratios were 3.57±0.74 and 3.69±0.91 at 1 and 3hours post-injection, respectively. Ischemic-to-lung ratios were 4.89±0.85 and 4.93±0.57; and ischemic-to-liver ratios were 2.05±0.30 to 3.23±0.78. The size of (99m)Tc-duramycin positive myocardium was qualitatively larger than the infarct size delineated by the perfusion defect in (99m)Tc-tetrafosmin uptake. This was consistent with findings from tissue analysis and autoradiography. CONCLUSION (99m)Tc-duramycin was demonstrated, in a large animal model, to have suitable clearance and biodistribution profiles for imaging. The agent has an avid target uptake and a fast background clearance. It is appropriate for imaging myocardial injury induced by ischemia/reperfusion.
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Affiliation(s)
- Lei Wang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Peking Union Medical College & Chinese Academy of Medical Science, Beijing, China
| | - Feng Wang
- Department of Nuclear Medicine, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing, China
| | - Wei Fang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Peking Union Medical College & Chinese Academy of Medical Science, Beijing, China
| | - Steven E Johnson
- Department of Medicine, Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Said Audi
- Department of Biomedical Engineering, Marquette University, Milwaukee, WI, USA
| | - Michael Zimmer
- Nuclear Medicine Department, Northwestern Memorial Hospital, Chicago, IL, USA
| | - Thomas A Holly
- Department of Medicine, Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Daniel C Lee
- Department of Medicine, Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Bao Zhu
- Department of Nuclear Medicine, Wuxi People's Hospital Affiliated to Nanjing Medical University, Wuxi, China.
| | - Haibo Zhu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China.
| | - Ming Zhao
- Department of Medicine, Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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24
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Johnson SE, Li Z, Liu Y, Moulder JE, Zhao M. Whole-body imaging of high-dose ionizing irradiation-induced tissue injuries using 99mTc-duramycin. J Nucl Med 2013; 54:1397-403. [PMID: 23804327 DOI: 10.2967/jnumed.112.112490] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED High-dose ionizing irradiation can cause extensive injuries in susceptible tissues. A noninvasive imaging technique that detects a surrogate marker of apoptosis may help characterize the dynamics of radiation-induced tissue damage. The goal of this study was to prove the concept of imaging the temporal and spatial distribution of damage in susceptible tissues after high-dose radiation exposure, using (99m)Tc-duramycin as a phosphatidylethanolamine-binding radiopharmaceutical. METHODS Rats were subjected to 15 Gy of total-body irradiation with x-rays. Planar whole-body (99m)Tc-duramycin scanning (n = 4 per time point) was conducted at 24, 48, and 72 h using a clinical γ-camera. On the basis of findings from planar imaging, preclinical SPECT data were acquired on control rats and on irradiated rats at 6 and 24 h after irradiation (n = 4 per time point). Imaging data were validated by γ-counting and histology, using harvested tissues in parallel groups of animals (n = 4). RESULTS Prominent focal uptake was detected in the thymus as early as 6 h after irradiation, followed by a gradual decline in (99m)Tc-duramycin binding accompanied by extensive thymic atrophy. Early (6-24 h) radioactivity uptake in the gastrointestinal region was detected. Significant signal was seen in major bones in a slightly delayed fashion, at 24 h, which persisted for at least 2 d. This finding was paralleled by an elevation in signal intensity in the kidneys, spleen, and liver. The imaging results were consistent with ex vivo γ-counting results and histology. Relatively high levels of apoptosis were detected from histology in the thymus, guts, and bones, with the thymus undergoing substantial atrophy. CONCLUSION As a proof of principle, this study demonstrated a noninvasive imaging technique that allows characterization of the temporal and spatial dynamics of injuries in susceptible tissues during the acute phase after high-dose ionizing irradiation. Such an imaging capability will potentially be useful for global, whole-body, assessment of tissue damage after radiation exposure. These data, in turn, will contribute to our general knowledge of tissue susceptibility to ionizing irradiation, as well as the onset and progression of tissue injuries.
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Affiliation(s)
- Steven E Johnson
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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25
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Duramycin exhibits antiproliferative properties and induces apoptosis in tumour cells. Blood Coagul Fibrinolysis 2013; 23:396-401. [PMID: 22543977 DOI: 10.1097/mbc.0b013e3283538875] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Duramycin is a polypeptide that binds specifically to phosphatidylethanolamine (PE) on cell surfaces with high affinity, and has been shown to disrupt tumour cell surface-based coagulation and exhibit weak antimicrobial activity. The aim of the present study was to characterize the effect of duramycin on tumour cell proliferation and viability. Duramycin was used to detect phosphatidylethanolamine expression on cell lines by flow cytometry. Cells were cultured in the presence of duramycin and proliferation and cell viability assessed. Electron microscopy and confocal microscopy were utilized to investigate cell membrane structure after duramycin treatment. Pancreatic tumour cells were shown to express phosphatidylethanolamine on their cell surfaces by specific labelling with duramycin. Phosphatidylethanolamine expression was generally increased in apoptotic cells and more so in necrotic cells. Cells cultured in the presence of duramycin showed increasing levels of apoptosis and ultimately necrosis with increasing duramycin concentrations, and cell proliferation was reduced in a duramycin dose-dependent manner between 0.125 and 12.5 μmol/l. Tissue factor expression was also reduced when cells were cultured in the presence of duramycin. Cells imaged by electron microscopy were fragile, suggesting that membrane integrity was compromised by duramycin, although no obvious differences in membrane structure were observed by live cell confocal imaging. Duramycin induced apoptosis and exhibited antiproliferative and anticoagulant effects on pancreatic tumour cells, most probably by disrupting cell membrane structure and/or function.
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26
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Zhao M, Li Z. A single-step kit formulation for the (99m)Tc-labeling of HYNIC-Duramycin. Nucl Med Biol 2012; 39:1006-11. [PMID: 22858374 DOI: 10.1016/j.nucmedbio.2012.03.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 03/20/2012] [Accepted: 03/30/2012] [Indexed: 11/26/2022]
Abstract
INTRODUCTION (99m)Tc-Duramycin is a unique radiopharmaceutical that binds specifically to phosphatidylethanolamine (PE). The current effort is to develop a single-step kit formulation for the (99m)Tc labeling of HYNIC-Duramycin. METHODS A titration series of Tricine/TPPTS coligand systems were tested for an optimal formulation to produce (99m)Tc-Duramycin with high radiochemical purity and specific activity. The radiopharmaceutical prepared using the kit formulation was tested for PE binding specificity using polystyrene microbeads coated with different phospholipid species. Radiochemical performance of the kits was assessed after storage at -20°C, room temperature and 37°C. Biodistribution profile of kit-prepared (99m)Tc-Duramycin was characterized in healthy rats at 3, 10, 20, 60 and 180min after intravenous injection. Binding studies were performed using the rat aortic arch and a rat model of myocardial ischemia/reperfusion, which represent scenarios of physiological and pathological PE externalization. RESULTS A Tricine/TPPTS ratio of 10:1 led to a consistent production of (99m)Tc-Duramycin with high radiochemical purity (> 90%), whereas a higher ratio at 40:1 produced radiopharmaceuticals with incomplete substitution of Tricine coligand. (99m)Tc-Duramycin prepared using the single-step kit formulation retained PE-binding specificity. The kits are stable over long-term storage. The biodistribution profile of kit-prepared (99m)Tc-Duramycin is consistent with HPLC purified radiopharmaceutical from prior studies. Binding studies on a tissue level indicate that the radiopharmaceutical is suitable for studying biological processes that involve PE distribution and redistribution in various physiological and pathological conditions. CONCLUSION A single-step kit formulation is developed for (99m)Tc-labeling of HYNIC-Duramycin. The radiopharmaceutical has high radiochemical purity and specific activity, retained PE binding activities, amiable to long-term storage, and is injection-ready for in vivo applications.
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Affiliation(s)
- Ming Zhao
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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Audi S, Li Z, Capacete J, Liu Y, Fang W, Shu LG, Zhao M. Understanding the in vivo uptake kinetics of a phosphatidylethanolamine-binding agent (99m)Tc-Duramycin. Nucl Med Biol 2012; 39:821-5. [PMID: 22534031 DOI: 10.1016/j.nucmedbio.2012.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 01/06/2012] [Accepted: 02/04/2012] [Indexed: 11/29/2022]
Abstract
INTRODUCTION (99m)Tc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between (99m)Tc-Duramycin and the target tissue. METHODS High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague-Dawley rats. Target binding and biodistribution of (99m)Tc-duramycin were captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of (99m)Tc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of (99m)Tc-Duramycin in normal and ischemic myocardial tissue. RESULTS (99m)Tc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to (99m)Tc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for (99m)Tc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9-fold reduction in binding affinity. CONCLUSION (99m)Tc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of (99m)Tc-Duramycin as a novel PE-binding agent.
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Affiliation(s)
- Said Audi
- Department of Biomedical Engineering, Marquette University, Milwaukee, WI 53233, USA
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Abstract
Phosphatidylethanolamine (PE) is a major component in the mammalian plasma membrane. It is present mainly in the inner leaflet of the membrane bilayer in a viable, typical mammalian cell. However, accumulating evidence indicates that a number of biological events involve PE externalization. For instance, PE is concentrated at the surface of cleavage furrow between mitotic daughter cells and is correlated with the dynamics of contractile ring. In apoptotic cells, PE is exposed to the cell surface, thus providing a molecular marker for detection. In addition, PE is a cofactor in the anticoagulant mechanism, and a distinct distribution profile of PE has been documented at the blood-endothelium interface. These recent discoveries were made possible using PE-specific probes derived from duramycin and cinnamycin, which are members of type B lantibiotics. This review provides an account on the features of these PE-specific lantibiotics in the context of molecular probes for the characterization of PE on a cellular and tissue level. According to the existing data, PE is likely a versatile chemical species that plays a role in the regulation of defined biological and physiological activities. The utilities of lantibiotic-based molecular probes will help accelerate the characterization of PE as an abundant, yet elusive membrane component.
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Affiliation(s)
- Ming Zhao
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, 53226, USA.
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29
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Increased exposure of phosphatidylethanolamine on the surface of tumor vascular endothelium. Neoplasia 2011; 13:299-308. [PMID: 21472134 DOI: 10.1593/neo.101366] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 01/12/2011] [Accepted: 01/17/2011] [Indexed: 01/01/2023] Open
Abstract
We have previously shown that oxidative stress within the tumor microenvironment causes phosphatidylserine (PS) to redistribute from the inner to the outer membrane leaflet of the endothelial cells (EC) creating a highly specific marker for the tumor vasculature. Because the distribution of phosphatidylethanolamine (PE) and PS within the membrane is coregulated, we reasoned that PE would also be localized in the outer membrane leaflet of tumor EC. To demonstrate this, the PE-binding peptide duramycin was biotinylated and used to determine the distribution of PE on EC in vitro and in vivo. Exposure of cultured EC to hypoxia, acidity, reactive oxygen species, or irradiation resulted in the formation of membrane blebs that were intensely PE-positive. When biotinylated duramycin was intravenously injected into tumor-bearing mice, it preferentially localized to the luminal surface of the vascular endothelium. Depending on tumor type, 13% to 56% of the tumor vessels stained positive for PE. PE-positive vessels were observed in and around hypoxic regions of the tumor. With the exception of intertubular vessels of the kidney, normal vessels remained unstained. To test the potential of PE as a biomarker for imaging, duramycin was conjugated to the near-infrared fluorophore 800CW and used for optical imaging of RM-9 prostate carcinomas. The near-infrared probe was easily detected within tumors in live animals. These results show that PE, like PS, becomes exposed on tumor vascular endothelium of multiple types of tumors and holds promise as a biomarker for noninvasive imaging and drug targeting.
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Matsunaga S, Matsunaga T, Iwamoto K, Yamada T, Shibayama M, Kawai M, Kobayashi T. Visualization of phospholipid particle fusion induced by duramycin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8200-8207. [PMID: 19432393 DOI: 10.1021/la900616c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We visualized nanometer-scale phospholipid particle fusion by scanning tunneling microscopy (STM) on an alkanethiol-modified gold substrate, induced by duramycin, a tetracyclic antibiotic peptide with 19 amino residues. Ultrasonic homogenization generated a suspension mainly consisting of minimal lipid particles (MLP) from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) in a phosphate buffer solution, confirmed by dynamic light scattering (DLS). In situ STM discerned individual MLP as particles (diameter approximately 8 nm) spread on Au(111), modified with alkanethiol, within the suspension. The MLP became fragile by the presence of duramycin, and the MLP were easily scratched by the scanning tip into multilayers along the surface. This process of particle fusion on the gold surface coincides with the aggregation of MLP in the suspension, observed by DLS. It was demonstrated that STM is capable of discerning and monitoring the nanometer-scale features of phospholipid particles altered by antibiotics with biochemical impact. STM might allow in situ, real-space, nanometer-scale observations of minute particles composed of phospholipids within the real cells with the highest magnification ratio.
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Affiliation(s)
- Soichiro Matsunaga
- Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, 277-8561, Japan
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McIntosh JA, Donia MS, Schmidt EW. Ribosomal peptide natural products: bridging the ribosomal and nonribosomal worlds. Nat Prod Rep 2009; 26:537-59. [PMID: 19642421 PMCID: PMC2975598 DOI: 10.1039/b714132g] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Ribosomally synthesized bacterial natural products rival the nonribosomal peptides in their structural and functional diversity. The last decade has seen substantial progress in the identification and characterization of biosynthetic pathways leading to ribosomal peptide natural products with new and unusual structural motifs. In some of these cases, the motifs are similar to those found in nonribosomal peptides, and many are constructed by convergent or even paralogous enzymes. Here, we summarize the major structural and biosynthetic categories of ribosomally synthesized bacterial natural products and, where applicable, compare them to their homologs from nonribosomal biosynthesis.
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Affiliation(s)
- John A. McIntosh
- Department of Medicinal Chemistry, University of Utah, 30 South 2000 East Rm 201, Salt Lake City, UT 84112 USA
| | - Mohamed S. Donia
- Department of Medicinal Chemistry, University of Utah, 30 South 2000 East Rm 201, Salt Lake City, UT 84112 USA
| | - Eric W. Schmidt
- Department of Medicinal Chemistry, University of Utah, 30 South 2000 East Rm 201, Salt Lake City, UT 84112 USA
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Li Z, Wells CW, Esmon CT, Zhao M. Phosphatidylethanolamine at the endothelial surface of aortic flow dividers. J Thromb Haemost 2009; 7:227-9. [PMID: 18983507 DOI: 10.1111/j.1538-7836.2008.03193.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zhao M, Li Z, Bugenhagen S. 99mTc-labeled duramycin as a novel phosphatidylethanolamine-binding molecular probe. J Nucl Med 2008; 49:1345-52. [PMID: 18632826 DOI: 10.2967/jnumed.107.048603] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED With only 19 amino acids, duramycin is the smallest known polypeptide that has a defined 3-dimensional binding structure. Duramycin binds phosphatidylethanolamine (PtdE) at a 1:1 ratio with high affinity and exclusive specificity. As an abundant binding target, PtdE is a major phospholipid and accounts for about 20% of the phospholipid content in mammalian cellular membranes. PtdE is externalized to the surface of apoptotic cells and also becomes accessible in necrotic cells because of compromised plasma membrane integrity. Given the unique physicochemical properties of duramycin and the availability of PtdE in acute cell death, the goal of this study was to develop and evaluate 99mTc-duramycin as a novel molecular probe for imaging PtdE. METHODS Duramycin is covalently modified with succinimidyl 6-hydrazinonicotinate acetone hydrazone (HYNIC) and labeled with 99mTc using a coordination chemistry involving tricine-phosphine coligands. The retention of PtdE-binding activities was confirmed using competition assays with PtdE-containing liposomes. The blood clearance, pharmacokinetics, and biodistribution of 99mTc-duramycin were measured in rats. Finally, 99mTc-duramycin binding to acute cell death in vivo was demonstrated using a rat model of acute myocardial infarction induced by ischemia and reperfusion and confirmed using autoradiography and histology. RESULTS HYNIC-derivatized duramycin with 1:1 stoicheometry was synthesized and confirmed by mass spectrometry. The radiolabeling efficiency was 80%-85%, radiochemical purity was 78%-89%, and specific activity was 54 GBq. The radiotracer was purified with high-performance liquid chromatography radiodetection before use. The specific uptake of 99mTc-duramycin in apoptotic cells, compared with that in viable control cells, was enhanced by more than 30-fold. This binding was competitively diminished in the presence of PtdE-containing liposomes but not by liposomes consisting of other phospholipid species. Intravenously injected 99mTc-duramycin has favorable pharmacokinetic and biodistribution profiles: it quickly clears from the circulation via the renal system, with a blood half-life of less than 4 min in rats. The hepatic and gastrointestinal uptake were very low. 99mTc-duramycin is completely unmetabolized in vivo, and the intact agent is recovered from the urine. Combined with a fast clearance and low hepatic background, the avid binding of 99mTc-duramycin to the infarcted myocardium quickly becomes conspicuous shortly after injection. The uptake of radioactivity in infarcted tissues was confirmed by autoradiography and histology. CONCLUSION 99mTc-duramycin is a stable, low-molecular-weight PtdE-binding radiopharmaceutical, with favorable in vivo imaging profiles. It is a strong candidate as a molecular probe for PtdE imaging and warrants further development and characterization.
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Affiliation(s)
- Ming Zhao
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Butler MS. Natural products to drugs: natural product-derived compounds in clinical trials. Nat Prod Rep 2008; 25:475-516. [PMID: 18497896 DOI: 10.1039/b514294f] [Citation(s) in RCA: 502] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Natural product and natural product-derived compounds that are being evaluated in clinical trials or are in registration (as at 31st December 2007) have been reviewed, as well as natural product-derived compounds for which clinical trials have been halted or discontinued since 2005. Also discussed are natural product-derived drugs launched since 2005, new natural product templates and late-stage development candidates.
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Affiliation(s)
- Mark S Butler
- MerLion Pharmaceuticals, 1 Science Park Road, The Capricorn 05-01, Singapore Science Park II, Singapore 117528.
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Izzo I, Licen S, Maulucci N, Autore G, Marzocco S, Tecilla P, De Riccardis F. Cationic calix[4]arenes as anion-selective ionophores. Chem Commun (Camb) 2008:2986-8. [DOI: 10.1039/b719482j] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Iwamoto K, Hayakawa T, Murate M, Makino A, Ito K, Fujisawa T, Kobayashi T. Curvature-dependent recognition of ethanolamine phospholipids by duramycin and cinnamycin. Biophys J 2007; 93:1608-19. [PMID: 17483159 PMCID: PMC1948045 DOI: 10.1529/biophysj.106.101584] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Duramycin is a 19-amino-acid tetracyclic lantibiotic closely related to cinnamycin (Ro09-0198), which is known to bind phosphatidylethanolamine (PE). The lipid specificity of duramycin was not established. The present study indicates that both duramycin and cinnamycin exclusively bind to ethanolamine phospholipids (PE and ethanolamine plasmalogen). Model membrane study indicates that the binding of duramycin and cinnamycin to PE-containing liposomes is dependent on membrane curvature, i.e., the lantibiotics bind small vesicles more efficiently than large liposomes. The binding of the lantibiotics to multilamellar liposomes induces tubulation of membranes, as revealed by electron microscopy and small-angle x-ray scattering. These results suggest that both duramycin and cinnamycin promote their binding to the PE-containing membrane by deforming membrane curvature.
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Affiliation(s)
- Kunihiko Iwamoto
- Supra-Biomolecular System Research Group, RIKEN (Institute of Physical and Chemical Research) Frontier Research System, Saitama, Japan
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Ondeykal JG, Herath KB, Jayasuriya H, Polishook JD, Bills GF, Dombrowski AW, Mojena M, Koch G, DiSalvo J, DeMartino J, Guan Z, Nanakorn W, Morenberg CM, Balick MJ, Stevenson DW, Slattery M, Borris RP, Singh SB. Discovery of structurally diverse natural product antagonists of chemokine receptor CXCR3. Mol Divers 2005; 9:123-9. [PMID: 15789559 DOI: 10.1007/s11030-005-1296-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The chemokines (CXCL9, CXCL10 and CXCL11) and associated CXCR3 receptor are expressed during the inflammatory process from multiple sclerosis, atherosclerosis or organ transplantation resulting in the recruitment of lymphocytes leading to tissue damage. It is hypothesized that blocking of the ligand/CXCR3 receptor interaction has potential to provide opportunity for development of agents that would block tissue rejection. In this paper, four classes of natural product inhibitors (IC50 ranging 0.1-41 microM) have been described that block the CXCR3 receptor interaction of IP-10 ligand. These include a cyclic thiopeptide (duramycin), polyketide glycosides (roselipins), steroidal glycosides (hypoglausin A and dioscin) and a novel alkyl pyridinium alkaloid that were isolated by bioassay-guided fractionation of the organic extracts derived from actinomycete, fungal, plant and marine sources and discovered using 125I IP-10/CXCR3 binding assay. Duramycin was the most potent with an IC50 of 0.1 microM. Roselipins 2A, 2B and 1A showed IC50 values of 14.6, 23.5, and 41 microM, respectively. Diosgenin glycosides dioscin, hypoglaucin A and kallstroemin D exhibited IC50 values of 2.1, 0.47 and 3 microM, respectively. A novel cyclic 3-alkyl pyridinium salt isolated from a sponge displayed a binding IC50 of 0.67 microM.
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Rickert DE, Dingley K, Ubick E, Dix KJ, Molina L. Determination of the tissue distribution and excretion by accelerator mass spectrometry of the nonadecapeptide 14C-Moli1901 in beagle dogs after intratracheal instillation. Chem Biol Interact 2005; 155:55-61. [PMID: 15893299 DOI: 10.1016/j.cbi.2005.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 04/12/2005] [Indexed: 11/16/2022]
Abstract
Moli1901 is a 19 residue polycyclic peptide antibiotic which increases chloride transport and water mobilization in airway epithelium. These properties suggest that it may be a useful treatment for cystic fibrosis (CF). In this study, we used accelerator mass spectrometry (AMS) to quantify Moli1901 following administration of only 0.045 microCi of 14C-Moli1901 per dog. Limits of quantitation of AMS were 0.03 (urine) to 0.3 (feces) ng equiv. Moli1901/g. Administration of 14C-Moli1901 by intratracheal instillation (approximately 100 microg) into the left cranial lobe of the lung of beagle dogs resulted in retention of 64% of the dose in the left cranial lobe for up to 28 days. Whole blood and plasma concentrations of 14C were <5 ng/ml at all times after the dose. Concentrations of 14C in whole blood and plasma declined over the first day after the dose and rose thereafter, with the rise in plasma concentrations lagging behind those in whole blood. During the first 3 days after the dose, plasma accounted for the majority of 14C in whole blood, but after that time, plasma accounted for only 25-30% of the 14C in whole blood. Tissue (left and right caudal lung lobe, liver, kidney, spleen, brain) and bile concentrations were low, always less than 0.25% the concentrations found in the left cranial lung lobe. Approximately 13% of the dose was eliminated in urine and feces in 28 days, with fecal elimination accounting for about 10% of the dose. The data presented here are consistent with that obtained in other species. Moli1901 is slowly absorbed and excreted from the lung, and it does not accumulate in other tissues. Moli1901 is currently in the clinic and has proven to be safe in single dose studies in human volunteers and cystic fibrosis patients by the inhalation route. No information on the disposition of the compound in humans is available. This study in dogs demonstrates the feasibility of obtaining that information using 14C-Moli1901 and AMS.
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Affiliation(s)
- D E Rickert
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
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Chatterjee C, Paul M, Xie L, van der Donk WA. Biosynthesis and mode of action of lantibiotics. Chem Rev 2005; 105:633-84. [PMID: 15700960 DOI: 10.1021/cr030105v] [Citation(s) in RCA: 556] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Champak Chatterjee
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois, USA
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McNulty MJ, Hutabarat RH, Findlay JWA, Devereux K, Knick VC, Harvey RJ, Molina L. Pharmacokinetics and tissue distribution of the nonadecapeptide Moli1901 in rats and mice. Xenobiotica 2003; 33:197-210. [PMID: 12623761 DOI: 10.1080/0049825021000022320] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. Administration of aerosolized, radiolabelled Moli1901 (duramycin, 2622U90), a 19 amino acid polycyclic peptide, to rats resulted in the deposition of high amounts of radiolabel in the respiratory tract, with deposited radiolabel persisting almost unchanged through 7 days after dosing. Little to no radiolabel was present in the bloodstream of these rats. 2. Rats absorbed little radiolabel after p.o. administration, with nearly all of the dose excreted in the faeces by 2 days after dosing. 3. At 7 days following an intravenous dose, rats excreted 54% of the radiolabel in faeces and 5.4% in the urine, with 44% remaining in the carcass, primarily in the liver (33%). 4. Following an intratracheal instillation dose to rats, radiolabel was eliminated from the pulmonary system with a half-life of 64 days. Excretion was almost exclusively via faeces, with an elimination half-life of 52 days. Plasma and blood concentrations in these animals were uniformly <1 ng eq. ml(-1) at all sampling times. 5. Results in mice given intravenous and oral doses were consistent with those observed in rats. 6. Prolonged retention of Moli1901 in pulmonary tissue supports its use in the treatment of respiratory diseases.
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Affiliation(s)
- M J McNulty
- GlaxoSmithKline, Inc., Research Triangle Park, NC 27709, USA
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Abstract
OBJECTIVE To review the antimicrobial activity, pharmacokinetics, clinical efficacy, and tolerability of ceftibuten, a new expanded-spectrum oral cephalosporin. DATA SOURCES Literature was identified by a MEDLINE search (January 1983-June 1996) of the medical literature, review of English-language literature and bibliographies of these articles, and data on file. STUDY SELECTION Clinical efficacy data were selected from all published and unpublished trials and abstracts that mentioned ceftibuten. Additional information concerning in vitro susceptibility, safety, chemistry, and pharmacokinetic profile of ceftibuten also was reviewed. DATA SYNTHESIS Ceftibuten, an oral expanded-spectrum cephalosporin, has a broad spectrum of activity against many gram-negative and selected gram-positive organisms, including Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis, and Haemophilus influenzae. Ceftibuten is stable to hydrolysis by many common beta-lactamases. Ceftibuten is rapidly and almost completely absorbed from the gastrointestinal tract and is primarily eliminated renally as unchanged drug. The elimination half-life of ceftibuten is slightly longer than 2 hours. Efficacy has been demonstrated in a number of clinical trials in adults and children with upper and lower respiratory tract infections (e.g., acute otitis media, pharyngitis, sinusitis, bronchitis) and urinary tract infections. The adverse effect profile is equal to that of comparator agents. CONCLUSIONS Ceftibuten is an alternative to other antimicrobial agents with convenient once-daily dosing in the treatment of upper and lower respiratory tract infections. Similar to other oral expanded-spectrum cephalosporins, ceftibuten has antimicrobial activity against common pathogens of the respiratory tract and is stable in the presence of many beta-lactamases. The clinical choice of an oral expanded-spectrum cephalosporin will be based on patient acceptance, frequency of administration, and cost.
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Affiliation(s)
- D R Guay
- University of Minnesota, Minneapolis, USA
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Davankov VA. Chiral selectors with chelating properties in liquid chromatography: Fundamental reflections and selective review of recent developments. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)80370-6] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hensens OD. Modern spectroscopic approaches to structure elucidation. BIOTECHNOLOGY (READING, MASS.) 1994; 26:389-444. [PMID: 7749313 DOI: 10.1016/b978-0-7506-9003-4.50020-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- O D Hensens
- Merck Research Laboratories, Rahway, New Jersey, USA
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Chapter 17. Progress in Antimicrobial Peptides. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1992. [DOI: 10.1016/s0065-7743(08)60415-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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