1
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Sundar S, Piramanayagam S, Natarajan J. A comprehensive review on human disease-causing bacterial proteases and their impeding agents. Arch Microbiol 2023; 205:276. [PMID: 37414902 DOI: 10.1007/s00203-023-03618-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/20/2023] [Accepted: 06/24/2023] [Indexed: 07/08/2023]
Abstract
Proteases are enzymes that catalyze the amide bond dissociation in polypeptide and protein peptide units. They are categorized into seven families and are responsible for a wide spectrum of human ailments, such as various types of cancers, skin infections, urinary tract infections etc. Specifically, the bacterial proteases cause a huge impact in the disease progression. Extracellular bacterial proteases break down the host defense proteins, while intracellular proteases are essential for pathogens virulence. Due to its involvement in disease pathogenesis and virulence, bacterial proteases are considered to be potential drug targets. Several studies have reported potential bacterial protease inhibitors in both Gram-positive and Gram-negative disease causing pathogens. In this study, we have comprehensively reviewed about the various human disease-causing cysteine, metallo, and serine bacterial proteases as well as their potential inhibitors.
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Affiliation(s)
- Shobana Sundar
- Department of Biotechnology, PSG College of Technology, Coimbatore, India
| | | | - Jeyakumar Natarajan
- Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, Tamil Nadu, India.
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2
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Lee SC, Yoon MY. Development of a receptor-based inhibitory penta-unit-conjugated peptide to enhance anthrax toxin neutralization. Int J Biol Macromol 2020; 163:327-335. [PMID: 32619663 DOI: 10.1016/j.ijbiomac.2020.06.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/21/2022]
Abstract
Anthrax toxin is a key virulence factor for Bacillus anthracis. The cell-binding component of anthrax toxin, protective antigen (PA), mediates the entry of the toxin into cells by first binding to the extracellular von Willebrand factor A (VWA) domain of the cellular anthrax toxin receptor (ATR). Herein, we targeted the VWA domain of the cellular receptor to develop a more effective antitoxin agent for neutralization of anthrax toxin. We selected ATR-binding peptides by using a phage display: among these, we identified two novel peptides binding to the ATR with high affinity and specificity, and that neutralized anthrax toxicity in cells. Furthermore, to enhance the functional efficiency of the probes, the peptides were modified and conjugated to three polyvalent probe backbones: a 17 amino-acid-based cyclic form penta-unit, poly-d-lysine (PDL), or the M13 bacteriophage. One of the functionally modified polyvalent peptide probes, the penta-unit-conjugated probe (PUCP) produced the most potent neutralization of anthrax toxin, with half-maximal inhibitory concentration (IC50) of 20 nM. The PUCP disrupted anthrax toxin binding to its receptor and reduced endocytosis of anthrax toxin. This peptide-based approach may, therefore, represent a promising strategy to combat anthrax toxicosis and other bacterial diseases and may be efficient for disease treatment.
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Affiliation(s)
- Sang-Choon Lee
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.
| | - Moon-Young Yoon
- Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea.
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3
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Sadeghpour SD, Karimi F, Alizadeh H. Predictive and fluorescent nanosensing experimental methods for evaluating anthrax protective antigen and lethal factor interactions for therapeutic applications. Int J Biol Macromol 2020; 160:1158-1167. [DOI: 10.1016/j.ijbiomac.2020.05.190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 10/24/2022]
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4
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Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
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Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
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5
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Yamini G, Nestorovich EM. Multivalent Inhibitors of Channel-Forming Bacterial Toxins. Curr Top Microbiol Immunol 2019; 406:199-227. [PMID: 27469304 PMCID: PMC6814628 DOI: 10.1007/82_2016_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Rational design of multivalent molecules represents a remarkable modern tool to transform weak non-covalent interactions into strong binding by creating multiple finely-tuned points of contact between multivalent ligands and their supposed multivalent targets. Here, we describe several prominent examples where the multivalent blockers were investigated for their ability to directly obstruct oligomeric channel-forming bacterial exotoxins, such as the pore-forming bacterial toxins and B component of the binary bacterial toxins. We address problems related to the blocker/target symmetry match and nature of the functional groups, as well as chemistry and length of the linkers connecting the functional groups to their multivalent scaffolds. Using the anthrax toxin and AB5 toxin case studies, we briefly review how the oligomeric toxin components can be successfully disabled by the multivalent non-channel-blocking inhibitors, which are based on a variety of multivalent scaffolds.
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Affiliation(s)
- Goli Yamini
- Department of Biology, The Catholic University of America, Washington, D.C., 20064, USA
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6
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Haque S, Yadav DK, Bisht SC, Yadav N, Singh V, Dubey KK, Jawed A, Wahid M, Dar SA. Quorum sensing pathways in Gram-positive and -negative bacteria: potential of their interruption in abating drug resistance. J Chemother 2019; 31:161-187. [DOI: 10.1080/1120009x.2019.1599175] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Gene Expression Laboratory, Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India
| | - Dinesh K. Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Shekhar C. Bisht
- Department of Biotechnology, H.N.B Garhwal University, Srinagar, Uttarakhand, India
| | - Neelam Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Vineeta Singh
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Kashyap Kumar Dubey
- Industrial Biotechnology Laboratory, University Institute of Engineering and Technology, M.D. University, Rohtak, Haryana, India
| | - Arshad Jawed
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Sajad Ahmad Dar
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Departments of Microbiology, University College of Medical Sciences (University of Delhi), Delhi, India
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7
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Liu D, Dang X, Song W, Xi L, Wang Q, Zhang S, Miao Y, Li G, Jiang J. Molecular characterization and expression patterns of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) heat shock protein genes and their response to host stress. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 100:e21536. [PMID: 30659637 DOI: 10.1002/arch.21536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/01/2019] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
As a polyphagous insect, little is known at the molecular level about the effects of different host plants on physiological changes in Phenacoccus solenopsis. In this study, four heat shock protein (Hsp) genes (PsHsp60, PsHsp70, PsHsp90, and PsHsp20.7) were identified from the transcriptome of P. solenopsis. Analysis of Hsp expression levels revealed significant differences in Hsp gene expression levels in P. solenopsis fed on different host plants. In host conversion tests, the expression levels of PsHsp90 and PsHsp60 were upregulated after transfer of second instar nymphs from tomato to cotton. The expression levels of PsHsp70 and PsHsp20.7 were, respectively, significantly upregulated at 9 and 48 hr after transfer from tomato to Hibiscus. The results of this study aid molecular characterization and understanding of the expression patterns of Hsp genes during different developmental stages and host transfer of P. solenopsis.
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Affiliation(s)
- Dan Liu
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiangli Dang
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Wei Song
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Lingyu Xi
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Qi Wang
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Shaobing Zhang
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Yong Miao
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Guiting Li
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
| | - Junqi Jiang
- Department of Entomology, College of Plant Protection, Anhui Agricultural University, Hefei, Anhui, China
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8
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Workman AM, Chitko-McKown CG, Smith TPL, Bennett GL, Kalbfleisch TS, Basnayake V, Heaton MP. A bovine CD18 signal peptide variant with increased binding activity to Mannheimia hemolytica leukotoxin. F1000Res 2018; 7:1985. [PMID: 30881690 PMCID: PMC6406179 DOI: 10.12688/f1000research.17187.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/13/2018] [Indexed: 11/20/2022] Open
Abstract
Background: Mannheimia haemolytica is the major bacterial infectious agent of bovine respiratory disease complex and causes severe morbidity and mortality during lung infections.
M. haemolytica secretes a protein leukotoxin (Lkt) that binds to the CD18 receptor on leukocytes, initiates lysis, induces inflammation, and causes acute fibrinous bronchopneumonia. Lkt binds the 22-amino acid CD18 signal peptide domain, which remains uncleaved in ruminant species. Our aim was to identify missense variation in the bovine CD18 signal peptide and measure the effects on Lkt binding. Methods: Missense variants in the integrin beta 2 gene (
ITGB2) encoding CD18 were identified by whole genome sequencing of 96 cattle from 19 breeds, and targeted Sanger sequencing of 1238 cattle from 46 breeds. The ability of different CD18 signal peptide variants to bind Lkt was evaluated by preincubating the toxin with synthetic peptides and applying the mixture to susceptible bovine cell cultures in cytotoxicity-blocking assays. Results: We identified 14 missense variants encoded on 15 predicted haplotypes, including a rare signal peptide variant with a cysteine at position 5 (C
5) instead of arginine (R
5). Preincubating Lkt with synthetic signal peptides with C
5 blocked cytotoxicity significantly better than those with R
5. The most potent synthetic peptide (C
5PQLLLLAGLLA) had 30-fold more binding activity compared to that with R
5. Conclusions: The results suggest that missense variants in the CD18 signal peptide affect Lkt binding, and animals carrying the C
5 allele may be more susceptible to the effects of Lkt. The results also identify a potent class of non-antibiotic Lkt inhibitors that could potentially protect cattle from cytotoxic effects during acute lung infections.
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Affiliation(s)
- Aspen M Workman
- USDA, US Meat Animal Research Center (USMARC), Clay Center, Nebraska, 68933, USA
| | | | - Timothy P L Smith
- USDA, US Meat Animal Research Center (USMARC), Clay Center, Nebraska, 68933, USA
| | - Gary L Bennett
- USDA, US Meat Animal Research Center (USMARC), Clay Center, Nebraska, 68933, USA
| | - Theodore S Kalbfleisch
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Louisville, Louisville, Kentucky, 40292, USA
| | | | - Michael P Heaton
- USDA, US Meat Animal Research Center (USMARC), Clay Center, Nebraska, 68933, USA
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9
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Lahousse M, Park HC, Lee SC, Ha NR, Jung IP, Schlesinger SR, Shackelford K, Yoon MY, Kim SK. Inhibition of anthrax lethal factor by ssDNA aptamers. Arch Biochem Biophys 2018; 646:16-23. [PMID: 29580944 DOI: 10.1016/j.abb.2018.03.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/04/2018] [Accepted: 03/22/2018] [Indexed: 01/12/2023]
Abstract
Anthrax is caused by Bacillus anthracis, a bacterium that is able to secrete the toxins protective antigen, edema factor and lethal factor. Due to the high level of secretion from the bacteria and its severe virulence, lethal factor (LF) has been sought as a biomarker for detecting bacterial infection and as an effective target to neutralize toxicity. In this study, we found three aptamers, and binding affinity was determined by fluorescently labeled aptamers. One of the aptamers exhibited high affinity, with a Kd value of 11.0 ± 2.7 nM, along with low cross reactivity relative to bovine serum albumin and protective antigen. The therapeutic functionality of the aptamer was examined by assessing the inhibition of LF protease activity against a mitogen-activated protein kinase kinase. The aptamer appears to be an effective inhibitor of LF with an IC50 value of 15 ± 1.5 μM and approximately 85% cell viability, suggesting that this aptamer provides a potential clue for not only development of a sensitive diagnostic device of B. anthracis infection but also the design of novel inhibitors of LF.
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Affiliation(s)
- Mieke Lahousse
- The Institute of Biomedical Studies, and the Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798-7348, USA
| | - Hae-Chul Park
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sang-Choon Lee
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Na-Reum Ha
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - In-Pil Jung
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sara R Schlesinger
- The Institute of Biomedical Studies, and the Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798-7348, USA
| | - Kaylin Shackelford
- Department of Natural Sciences, Northeastern State University, Tahlequah, OK 74464, USA
| | - Moon-Young Yoon
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sung-Kun Kim
- Department of Natural Sciences, Northeastern State University, Tahlequah, OK 74464, USA.
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10
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Sadaf A, Du Y, Santillan C, Mortensen JS, Molist I, Seven AB, Hariharan P, Skiniotis G, Loland CJ, Kobilka BK, Guan L, Byrne B, Chae PS. Dendronic trimaltoside amphiphiles (DTMs) for membrane protein study. Chem Sci 2017; 8:8315-8324. [PMID: 29619178 PMCID: PMC5858085 DOI: 10.1039/c7sc03700g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/14/2017] [Indexed: 01/07/2023] Open
Abstract
A novel amphiphile with a dendronic hydrophobic group (DTM-A6) was markedly effective at stabilizing and visualizing a GPCR-Gs complex.
The critical contribution of membrane proteins in normal cellular function makes their detailed structure and functional analysis essential. Detergents, amphipathic agents with the ability to maintain membrane proteins in a soluble state in aqueous solution, have key roles in membrane protein manipulation. Structural and functional stability is a prerequisite for biophysical characterization. However, many conventional detergents are limited in their ability to stabilize membrane proteins, making development of novel detergents for membrane protein manipulation an important research area. The architecture of a detergent hydrophobic group, that directly interacts with the hydrophobic segment of membrane proteins, is a key factor in dictating their efficacy for both membrane protein solubilization and stabilization. In the current study, we developed two sets of maltoside-based detergents with four alkyl chains by introducing dendronic hydrophobic groups connected to a trimaltoside head group, designated dendronic trimaltosides (DTMs). Representative DTMs conferred enhanced stabilization to multiple membrane proteins compared to the benchmark conventional detergent, DDM. One DTM (i.e., DTM-A6) clearly outperformed DDM in stabilizing human β2 adrenergic receptor (β2AR) and its complex with Gs protein. A further evaluation of this DTM led to a clear visualization of β2AR-Gs complex via electron microscopic analysis. Thus, the current study not only provides novel detergent tools useful for membrane protein study, but also suggests that the dendronic architecture has a role in governing detergent efficacy for membrane protein stabilization.
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Affiliation(s)
- Aiman Sadaf
- Department of Bionanotechnology , Hanyang University , Ansan , 155-88 , Korea .
| | - Yang Du
- Molecular and Cellular Physiology , Stanford , CA 94305 , USA .
| | - Claudia Santillan
- Department of Cell Physiology and Molecular Biophysics , Center for Membrane Protein Research , School of Medicine , Texas Tech University Health Sciences Center , Lubbock , TX 79430 , USA .
| | - Jonas S Mortensen
- Center of Neuroscience , University of Copenhagen , DK 2200 Copenhagen , Denmark .
| | - Iago Molist
- Department of Life Sciences , Imperial College London , London , SW7 2AZ , UK .
| | - Alpay B Seven
- Structural Biology & Molecular and Cellular Physiology , Stanford , CA 94305 , USA .
| | - Parameswaran Hariharan
- Department of Cell Physiology and Molecular Biophysics , Center for Membrane Protein Research , School of Medicine , Texas Tech University Health Sciences Center , Lubbock , TX 79430 , USA .
| | - Georgios Skiniotis
- Structural Biology & Molecular and Cellular Physiology , Stanford , CA 94305 , USA .
| | - Claus J Loland
- Center of Neuroscience , University of Copenhagen , DK 2200 Copenhagen , Denmark .
| | - Brian K Kobilka
- Molecular and Cellular Physiology , Stanford , CA 94305 , USA .
| | - Lan Guan
- Department of Cell Physiology and Molecular Biophysics , Center for Membrane Protein Research , School of Medicine , Texas Tech University Health Sciences Center , Lubbock , TX 79430 , USA .
| | - Bernadette Byrne
- Department of Life Sciences , Imperial College London , London , SW7 2AZ , UK .
| | - Pil Seok Chae
- Department of Bionanotechnology , Hanyang University , Ansan , 155-88 , Korea .
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11
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Targeting Bacillus anthracis toxicity with a genetically selected inhibitor of the PA/CMG2 protein-protein interaction. Sci Rep 2017; 7:3104. [PMID: 28596569 PMCID: PMC5465072 DOI: 10.1038/s41598-017-03253-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/25/2017] [Indexed: 11/23/2022] Open
Abstract
The protein-protein interaction between the human CMG2 receptor and the Bacillus anthracis protective antigen (PA) is essential for the transport of anthrax lethal and edema toxins into human cells. We used a genetically encoded high throughput screening platform to screen a SICLOPPS library of 3.2 million cyclic hexapeptides for inhibitors of this protein-protein interaction. Unusually, the top 3 hits all contained stop codons in the randomized region of the library, resulting in linear rather than cyclic peptides. These peptides disrupted the targeted interaction in vitro; two act by binding to CMG2 while one binds PA. The efficacy of the most potent CMG2-binding inhibitor was improved through the incorporation of non-natural phenylalanine analogues. Cell based assays demonstrated that the optimized inhibitor protects macrophages from the toxicity of lethal factor.
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12
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Munguia J, Nizet V. Pharmacological Targeting of the Host-Pathogen Interaction: Alternatives to Classical Antibiotics to Combat Drug-Resistant Superbugs. Trends Pharmacol Sci 2017; 38:473-488. [PMID: 28283200 DOI: 10.1016/j.tips.2017.02.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 01/17/2023]
Abstract
The rise of multidrug-resistant pathogens and the dearth of new antibiotic development place an existential strain on successful infectious disease therapy. Breakthrough strategies that go beyond classical antibiotic mechanisms are needed to combat this looming public health catastrophe. Reconceptualizing antibiotic therapy in the richer context of the host-pathogen interaction is required for innovative solutions. By defining specific virulence factors, the essence of a pathogen, and pharmacologically neutralizing their activities, one can block disease progression and sensitize microbes to immune clearance. Likewise, host-directed strategies to boost phagocyte bactericidal activity, enhance leukocyte recruitment, or reverse pathogen-induced immunosuppression seek to replicate the success of cancer immunotherapy in the field of infectious diseases. The answer to the threat of multidrug-resistant pathogens lies 'outside the box' of current antibiotic paradigms.
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Affiliation(s)
- Jason Munguia
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; Rady Children's Hospital, San Diego, CA 92123, USA.
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13
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Wang B, Swaminathan S, Bhattacharyya MK. Identification of Fusarium virguliforme FvTox1-Interacting Synthetic Peptides for Enhancing Foliar Sudden Death Syndrome Resistance in Soybean. PLoS One 2015; 10:e0145156. [PMID: 26709700 PMCID: PMC4692527 DOI: 10.1371/journal.pone.0145156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/01/2015] [Indexed: 12/01/2022] Open
Abstract
Soybean is one of the most important crops grown across the globe. In the United States, approximately 15% of the soybean yield is suppressed due to various pathogen and pests attack. Sudden death syndrome (SDS) is an emerging fungal disease caused by Fusarium virguliforme. Although growing SDS resistant soybean cultivars has been the main method of controlling this disease, SDS resistance is partial and controlled by a large number of quantitative trait loci (QTL). A proteinacious toxin, FvTox1, produced by the pathogen, causes foliar SDS. Earlier, we demonstrated that expression of an anti-FvTox1 single chain variable fragment antibody resulted in reduced foliar SDS development in transgenic soybean plants. Here, we investigated if synthetic FvTox1-interacting peptides, displayed on M13 phage particles, can be identified for enhancing foliar SDS resistance in soybean. We screened three phage-display peptide libraries and discovered four classes of M13 phage clones displaying FvTox1-interacting peptides. In vitro pull-down assays and in vivo interaction assays in yeast were conducted to confirm the interaction of FvTox1 with these four synthetic peptides and their fusion-combinations. One of these peptides was able to partially neutralize the toxic effect of FvTox1 in vitro. Possible application of the synthetic peptides in engineering SDS resistance soybean cultivars is discussed.
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Affiliation(s)
- Bing Wang
- Department of Agronomy, Iowa State University, Ames, 50011–1010, United States of America
| | - Sivakumar Swaminathan
- Department of Agronomy, Iowa State University, Ames, 50011–1010, United States of America
| | - Madan K. Bhattacharyya
- Department of Agronomy, Iowa State University, Ames, 50011–1010, United States of America
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14
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Fang RH, Luk BT, Hu CMJ, Zhang L. Engineered nanoparticles mimicking cell membranes for toxin neutralization. Adv Drug Deliv Rev 2015; 90:69-80. [PMID: 25868452 DOI: 10.1016/j.addr.2015.04.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/08/2015] [Accepted: 04/01/2015] [Indexed: 11/27/2022]
Abstract
Protein toxins secreted from pathogenic bacteria and venomous animals rely on multiple mechanisms to overcome the cell membrane barrier to inflict their virulence effect. A promising therapeutic concept toward developing a broadly applicable anti-toxin platform is to administer cell membrane mimics as decoys to sequester these virulence factors. As such, lipid membrane-based nanoparticulates are an ideal candidate given their structural similarity to cellular membranes. This article reviews the virulence mechanisms employed by toxins at the cell membrane interface and highlights the application of cell-membrane mimicking nanoparticles as toxin decoys for systemic detoxification. In addition, the implication of particle/toxin nanocomplexes in the development of toxoid vaccines is discussed.
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15
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Abstract
Anthrax is caused by the spore-forming, gram-positive bacterium Bacillus anthracis. The bacterium's major virulence factors are (a) the anthrax toxins and (b) an antiphagocytic polyglutamic capsule. These are encoded by two large plasmids, the former by pXO1 and the latter by pXO2. The expression of both is controlled by the bicarbonate-responsive transcriptional regulator, AtxA. The anthrax toxins are three polypeptides-protective antigen (PA), lethal factor (LF), and edema factor (EF)-that come together in binary combinations to form lethal toxin and edema toxin. PA binds to cellular receptors to translocate LF (a protease) and EF (an adenylate cyclase) into cells. The toxins alter cell signaling pathways in the host to interfere with innate immune responses in early stages of infection and to induce vascular collapse at late stages. This review focuses on the role of anthrax toxins in pathogenesis. Other virulence determinants, as well as vaccines and therapeutics, are briefly discussed.
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Affiliation(s)
- Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Catherine Vrentas
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Andrei P Pomerantsev
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
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Ohanjanian L, Remy KE, Li Y, Cui X, Eichacker PQ. An overview of investigational toxin-directed therapies for the adjunctive management of Bacillus anthracis infection and sepsis. Expert Opin Investig Drugs 2015; 24:851-65. [PMID: 25920540 DOI: 10.1517/13543784.2015.1041587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Sepsis with Bacillus anthracis infection has a very high mortality rate despite appropriate antibiotic and supportive therapies. Over the past 15 years, recent outbreaks in the US and in Europe, coupled with anthrax's bioterrorism weapon potential, have stimulated efforts to develop adjunctive therapies to improve clinical outcomes. Since lethal toxin and edema toxin (LT and ET) make central contributions to the pathogenesis of B. anthracis, these have been major targets in this effort. AREAS COVERED Here, the authors review different investigative biopharmaceuticals that have been recently identified for their therapeutic potential as inhibitors of LT or ET. Among these inhibitors are two antibody preparations that have been included in the Strategic National Stockpile (SNS) and several more that have reached Phase I testing. Presently, however, many of these candidate agents have only been studied in vitro and very few tested in bacteria-challenged models. EXPERT OPINION Although a large number of drugs have been identified as potential therapeutic inhibitors of LT and ET, in most cases their testing has been limited. The use of the two SNS antibody therapies during a large-scale exposure to B. anthracis will be difficult. Further testing and development of agents with oral bioavailability and relatively long shelf lives should be a focus for future research.
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Affiliation(s)
- Lernik Ohanjanian
- National Institutes of Health, Clinical Center, Critical Care Medicine Department , Building 10, Room 2C145, Bethesda, MD 20892 , USA +1 301 402 2914 ; +1 301 402 1213 ;
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Lee SC, Gedi V, Ha NR, Cho JH, Park HC, Yoon MY. Development of receptor-based inhibitory RNA aptamers for anthrax toxin neutralization. Int J Biol Macromol 2015; 77:293-302. [PMID: 25841381 DOI: 10.1016/j.ijbiomac.2015.03.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/27/2015] [Accepted: 03/15/2015] [Indexed: 10/23/2022]
Abstract
Anthrax toxin excreted by Bacillus anthracis is the key causative agent of infectious anthrax disease. In the present study, we targeted the binding of PA to the ATR/TEM8 Von Willebrand factor type A (VWA) domain, which we cloned into Escherichia coli and purified to homogeneity under denaturing conditions. To develop an anthrax toxin inhibitor, we selected and identified short single strand RNA aptamers (approximately 30mer) consisting of different sequences of nucleic acids with a high binding affinity in the 100 nanomolar range against the recombinant ATR/TEM8 VWA domain using systematic evolution of ligands by exponential enrichment (SELEX). Five candidate aptamers were further characterized by several techniques including secondary structural analysis. The inhibitor efficiency (IC50) of one of the aptamers toward anthrax toxin was approximately 5μM in macrophage RAW 264.7 cells, as determined from cytotoxicity analysis by MTT assay. We believe that the candidate aptamers should be useful for blocking the binding of PA to its receptor in order to neutralize anthrax toxin.
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Affiliation(s)
- Sang-Choon Lee
- Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea
| | - Vinayakumar Gedi
- Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea
| | - Na-Reum Ha
- Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea
| | - Jun-Haeng Cho
- Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea
| | - Hae-Chul Park
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency (QIA), Anyang 430-757, Republic of Korea
| | - Moon-Young Yoon
- Department of Chemistry and Research Institute of Natural Sciences, Hanyang University, Seoul 133-791, Republic of Korea.
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Abstract
Resistance of important bacterial pathogens to common antimicrobial therapies and the emergence of multidrug-resistant bacteria are increasing at an alarming rate and constitute one of our greatest challenges in the combat of bacterial infection and accompanied diseases. The current shortage of effective drugs, lack of successful prevention measures and only a few new antibiotics in the clinical pipeline demand the development of novel treatment options and alternative antimicrobial therapies. Our increasing understanding of bacterial virulence strategies and the induced molecular pathways of the infectious disease provides novel opportunities to target and interfere with crucial pathogenicity factors or virulence-associated traits of the bacteria while bypassing the evolutionary pressure on the bacterium to develop resistance. In the past decade, numerous new bacterial targets for anti-virulence therapies have been identified, and structure-based tailoring of intervention strategies and screening assays for small-molecule inhibitors of such pathways were successfully established. In this chapter, we will take a closer look at the bacterial virulence-related factors and processes that present promising targets for anti-virulence therapies, recently discovered inhibitory substances and their promises and discuss the challenges, and problems that have to be faced.
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Förstner P, Bayer F, Kalu N, Felsen S, Förtsch C, Aloufi A, Ng DYW, Weil T, Nestorovich EM, Barth H. Cationic PAMAM dendrimers as pore-blocking binary toxin inhibitors. Biomacromolecules 2014; 15:2461-74. [PMID: 24954629 PMCID: PMC4215879 DOI: 10.1021/bm500328v] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dendrimers are unique highly branched macromolecules with numerous groundbreaking biomedical applications under development. Here we identified poly(amido amine) (PAMAM) dendrimers as novel blockers for the pore-forming B components of the binary anthrax toxin (PA63) and Clostridium botulinum C2 toxin (C2IIa). These pores are essential for delivery of the enzymatic A components of the internalized toxins from endosomes into the cytosol of target cells. We demonstrate that at low μM concentrations cationic PAMAM dendrimers block PA63 and C2IIa to inhibit channel-mediated transport of the A components, thereby protecting HeLa and Vero cells from intoxication. By channel reconstitution and high-resolution current recording, we show that the PAMAM dendrimers obstruct transmembrane PA63 and C2IIa pores in planar lipid bilayers at nM concentrations. These findings suggest a new potential role for the PAMAM dendrimers as effective polyvalent channel-blocking inhibitors, which can protect human target cells from intoxication with binary toxins from pathogenic bacteria.
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Affiliation(s)
- Philip Förstner
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center , D-89081 Ulm, Germany
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Citorik RJ, Mimee M, Lu TK. Bacteriophage-based synthetic biology for the study of infectious diseases. Curr Opin Microbiol 2014; 19:59-69. [PMID: 24997401 PMCID: PMC4125527 DOI: 10.1016/j.mib.2014.05.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/14/2014] [Accepted: 05/28/2014] [Indexed: 01/01/2023]
Abstract
Since their discovery, bacteriophages have contributed enormously to our understanding of molecular biology as model systems. Furthermore, bacteriophages have provided many tools that have advanced the fields of genetic engineering and synthetic biology. Here, we discuss bacteriophage-based technologies and their application to the study of infectious diseases. New strategies for engineering genomes have the potential to accelerate the design of novel phages as therapies, diagnostics, and tools. Though almost a century has elapsed since their discovery, bacteriophages continue to have a major impact on modern biological sciences, especially with the growth of multidrug-resistant bacteria and interest in the microbiome.
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Affiliation(s)
- Robert J. Citorik
- MIT Microbiology Program, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- MIT Synthetic Biology Center, 500 Technology Square, Cambridge, MA 02139, USA
| | - Mark Mimee
- MIT Microbiology Program, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- MIT Synthetic Biology Center, 500 Technology Square, Cambridge, MA 02139, USA
| | - Timothy K. Lu
- MIT Microbiology Program, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- MIT Synthetic Biology Center, 500 Technology Square, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Kaur M, Singh S, Bhatnagar R. Anthrax vaccines: present status and future prospects. Expert Rev Vaccines 2014; 12:955-70. [PMID: 23984963 DOI: 10.1586/14760584.2013.814860] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The management of anthrax remains a top priority among the biowarfare/bioterror agents. It was the Bacillus anthracis spore attack through the US mail system after the September 11, 2001, terrorist attacks in the USA that highlighted the potential of B. anthracis as a bioterrorism agent and the threat posed by its deliberate dissemination. These attacks invigorated the efforts toward understanding the anthrax pathogenesis and development of more comprehensive medical intervention strategies for its containment in case of both natural disease and manmade, accidental or deliberate infection of a non-suspecting population. Currently, efforts are directed toward the development of safe and efficacious vaccines as well as intervention tools for controlling the disease in the advanced fulminant stage when toxemia has already developed. This work presents an overview of the current understanding of anthrax pathogenesis and recent advances made, particularly after 2001, for the successful management of anthrax and outlines future perspectives.
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Affiliation(s)
- Manpreet Kaur
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, Delhi, India
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Abstract
INTRODUCTION Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded 'for the development of multiscale models for complex chemical systems' once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial-and-error approach to a minimum. The intentional dissemination of Bacillus anthracis spores in 2001 via the so-called anthrax letters has led to increased efforts, politically and scientifically, to develop medical countermeasures that will protect people from the threat of anthrax bioterrorism. AREAS COVERED This article provides an overview of the recent rational drug design approaches for discovering inhibitors of anthrax toxin. The review also directs the readers to the vast literature on the recognized advances and future possibilities in the field. EXPERT OPINION Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (protective antigen-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, the situation, in our view, is still insecure. Further, the FDA's animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Better identification and validation of anthrax toxin therapeutic targets at the molecular level as well as elucidation of the parameters determining the corresponding therapeutic windows are still necessary for more effective therapeutic options.
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Affiliation(s)
- Ekaterina M Nestorovich
- The Catholic University of America, Department of Biology , Washington, DC , USA +1 202 319 6723 ;
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Bouzianas DG. Potential biological targets ofBacillus anthracisin anti-infective approaches against the threat of bioterrorism. Expert Rev Anti Infect Ther 2014; 5:665-84. [PMID: 17678429 DOI: 10.1586/14787210.5.4.665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The terrorist attacks of 2001 involving anthrax underscore the imperative that safe and effective medical countermeasures should be readily available. Vaccination appears to be the most effective form of mass protection against a biological attack, but the current vaccines have drawbacks that justify the enormous amount of effort currently being put into developing more effective vaccines and other treatment modalities. After providing a comprehensive overview of the organism Bacillus anthracis as a biological weapon and its pathogenicity, this review briefly summarizes the current knowledge vital to the management of anthrax disease. This knowledge has been acquired since 2001 as a result of the progress on anthrax research and focuses on the possible development of improved human anti-infective strategies targeting B. anthracis spore components, as well as strategies based on host-pathogen interactions.
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Affiliation(s)
- Dimitrios G Bouzianas
- Department of Medical Laboratories, Faculty of Health and Care Professions, University-level Technological Educational Institute of Thessaloniki, Greece.
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Brojatsch J, Casadevall A, Goldman DL. Molecular determinants for a cardiovascular collapse in anthrax. Front Biosci (Elite Ed) 2014; 6:139-47. [PMID: 24389148 DOI: 10.2741/e697] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Bacillus anthracis releases two bipartite proteins, lethal toxin and edema factor, that contribute significantly to the progression of anthrax-associated shock. As blocking the anthrax toxins prevents disease, the toxins are considered the main virulence factors of the bacterium. The anthrax bacterium and the anthrax toxins trigger multi-organ failure associated with enhanced vascular permeability, hemorrhage and cardiac dysfunction in animal challenge models. A recent study using mice that either lacked the anthrax toxin receptor in specific cells and corresponding mice expressing the receptor in specific cell types demonstrated that cardiovascular cells are critical for disease mediated by anthrax lethal toxin. These studies are consistent with involvement of the cardiovascular system, and with an increase of cardiac failure markers observed in human anthrax and in animal models using B. anthracis and anthrax toxins. This review discusses the current state of knowledge regarding the pathophysiology of anthrax and tries to provide a mechanistic model and molecular determinants for the circulatory shock in anthrax.
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Affiliation(s)
- Jurgen Brojatsch
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
| | - David L Goldman
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
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Ayyaswamy PS, Muzykantov V, Eckmann DM, Radhakrishnan R. Nanocarrier Hydrodynamics and Binding in Targeted Drug Delivery: Challenges in Numerical Modeling and Experimental Validation. J Nanotechnol Eng Med 2013; 4:101011-1010115. [PMID: 23917383 PMCID: PMC3708709 DOI: 10.1115/1.4024004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 03/06/2013] [Indexed: 11/08/2022]
Abstract
This review discusses current progress and future challenges in the numerical modeling of targeted drug delivery using functionalized nanocarriers (NC). Antibody coated nanocarriers of various size and shapes, also called functionalized nanocarriers, are designed to be injected in the vasculature, whereby they undergo translational and rotational motion governed by hydrodynamic interaction with blood particulates as well as adhesive interactions mediated by the surface antibody binding to target antigens/receptors on cell surfaces. We review current multiscale modeling approaches rooted in computational fluid dynamics and nonequilibrium statistical mechanics to accurately resolve fluid, thermal, as well as adhesive interactions governing nanocarrier motion and their binding to endothelial cells lining the vasculature. We also outline current challenges and unresolved issues surrounding the modeling methods. Experimental approaches in pharmacology and bioengineering are discussed briefly from the perspective of model validation.
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Affiliation(s)
- Portonovo S. Ayyaswamy
- Department of Mechanical Engineering and Applied Mechanics,University of Pennsylvania,Philadelphia, PA 19104
| | - Vladimir Muzykantov
- Department of Pharmacology,and Center for Targeted Therapeutics and Translational Nanomedicine,University of Pennsylvania,Philadelphia, PA 19104
| | - David M. Eckmann
- Institute of Translational Medicine and Therapeutics,Department of Anesthesiology and Critical Care,and Department of Bioengineering,University of Pennsylvania,Philadelphia, PA 19104
| | - Ravi Radhakrishnan
- Institute of Translational Medicine and Therapeutics,Department of Bioengineering,Department of Chemical and Biomolecular Engineering,University of Pennsylvania,Philadelphia, PA 19104e-mail:
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Affiliation(s)
| | - Sergey M. Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, U.S.A
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Panning of a phage display library against a synthetic capsule for peptide ligands that bind to the native capsule of Bacillus anthracis. PLoS One 2012; 7:e45472. [PMID: 23029033 PMCID: PMC3446873 DOI: 10.1371/journal.pone.0045472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/17/2012] [Indexed: 11/19/2022] Open
Abstract
Bacillus anthracis is the causative agent of anthrax with the ability to not only produce a tripartite toxin, but also an enveloping capsule comprised primarily of γ-D-glutamic acid residues. The purpose of this study was to isolate peptide ligands capable of binding to the native capsule of B. anthracis from a commercial phage display peptide library using a synthetic form of the capsule consisting of 12 γ-D-glutamic acid residues. Following four rounds of selection, 80 clones were selected randomly and analysed by DNA sequencing. Four clones, each containing a unique consensus sequence, were identified by sequence alignment analysis. Phage particles were prepared and their derived 12-mer peptides were also chemically synthesized and conjugated to BSA. Both the phage particles and free peptide-BSA conjugates were evaluated by ELISA for binding to encapsulated cells of B. anthracis as well as a B. anthracis capsule extract. All the phage particles tested except one were able to bind to both the encapsulated cells and the capsule extract. However, the peptide-BSA conjugates could only bind to the encapsulated cells. One of the peptide-BSA conjugates, with the sequence DSSRIPMQWHPQ (termed G1), was fluorescently labelled and its binding to the encapsulated cells was further confirmed by confocal microscopy. The results demonstrated that the synthetic capsule was effective in isolating phage-displayed peptides with binding affinity for the native capsule of B. anthracis.
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Wein AN, Williams BN, Liu S, Ermolinsky B, Provenzano D, Abagyan R, Orry A, Leppla SH, Peredelchuk M. Small molecule inhibitors of Bacillus anthracis protective antigen proteolytic activation and oligomerization. J Med Chem 2012; 55:7998-8006. [PMID: 22954387 DOI: 10.1021/jm300804e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protective antigen (PA), lethal factor, and edema factor, the protein toxins of Bacillus anthracis , are among its most important virulence factors and play a key role in infection. We performed a virtual ligand screen of a library of 10000 members to identify compounds predicted to bind to PA and prevent its oligomerization. Four of these compounds slowed PA association in a FRET-based oligomerization assay, and two of those protected cells from intoxication at concentrations of 1-10 μM. Exploration of the protective mechanism by Western blot showed decreased SDS-resistant PA oligomer on cells and, surprisingly, decreased amounts of activated PA. In vitro assays showed that one of the inhibitors blocked furin-mediated cleavage of PA, apparently through its binding to the PA substrate. Thus, we have identified inhibitors that can independently block both PA's cleavage by furin and its subsequent oligomerization. Lead optimization on these two backbones may yield compounds with high activity and specificity for the anthrax toxins.
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Affiliation(s)
- Alexander N Wein
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 33 North Drive, Bethesda, Maryland 20892, USA
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Muzykantov VR, Radhakrishnan R, Eckmann DM. Dynamic factors controlling targeting nanocarriers to vascular endothelium. Curr Drug Metab 2012; 13:70-81. [PMID: 22292809 DOI: 10.2174/138920012798356916] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 03/05/2011] [Accepted: 04/15/2011] [Indexed: 12/22/2022]
Abstract
Endothelium lining the luminal surface of blood vessels is the key target and barrier for vascular drug delivery. Nanocarriers coated with antibodies or affinity peptides that bind specifically to endothelial surface determinants provide targeted delivery of therapeutic cargoes to these cells. Endothelial targeting consists of several phases including circulation in the bloodstream, anchoring on the endothelial surface and, in some cases, intracellular uptake and trafficking of the internalized materials. Dynamic parameters of the vasculature including the blood hydrodynamics as well as surface density, accessibility, membrane mobility and clustering of target determinants modulate these phases of the targeting, especially anchoring to endothelium. Further, such controlled parameters of design of drug nanocarriers such as affinity, surface density and epitope specificity of targeting antibodies, carrier size and shape also modulate endothelial targeting and resultant sub-cellular addressing. This article reviews experimental and computational approaches for analysis of factors modulating targeting nanocarriers to the endothelial cells.
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Rogers MS, Cryan LM, Habeshian KA, Bazinet L, Caldwell TP, Ackroyd PC, Christensen KA. A FRET-based high throughput screening assay to identify inhibitors of anthrax protective antigen binding to capillary morphogenesis gene 2 protein. PLoS One 2012; 7:e39911. [PMID: 22768167 PMCID: PMC3386954 DOI: 10.1371/journal.pone.0039911] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 06/03/2012] [Indexed: 11/18/2022] Open
Abstract
Anti-angiogenic therapies are effective for the treatment of cancer, a variety of ocular diseases, and have potential benefits in cardiovascular disease, arthritis, and psoriasis. We have previously shown that anthrax protective antigen (PA), a non-pathogenic component of anthrax toxin, is an inhibitor of angiogenesis, apparently as a result of interaction with the cell surface receptors capillary morphogenesis gene 2 (CMG2) protein and tumor endothelial marker 8 (TEM8). Hence, molecules that bind the anthrax toxin receptors may be effective to slow or halt pathological vascular growth. Here we describe development and testing of an effective homogeneous steady-state fluorescence resonance energy transfer (FRET) high throughput screening assay designed to identify molecules that inhibit binding of PA to CMG2. Molecules identified in the screen can serve as potential lead compounds for the development of anti-angiogenic and anti-anthrax therapies. The assay to screen for inhibitors of this protein–protein interaction is sensitive and robust, with observed Z' values as high as 0.92. Preliminary screens conducted with a library of known bioactive compounds identified tannic acid and cisplatin as inhibitors of the PA-CMG2 interaction. We have confirmed that tannic acid both binds CMG2 and has anti-endothelial properties. In contrast, cisplatin appears to inhibit PA-CMG2 interaction by binding both PA and CMG2, and observed cisplatin anti-angiogenic effects are not mediated by interaction with CMG2. This work represents the first reported high throughput screening assay targeting CMG2 to identify possible inhibitors of both angiogenesis and anthrax intoxication.
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Affiliation(s)
- Michael S. Rogers
- Department of Surgery, Vascular Biology Program, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lorna M. Cryan
- Department of Surgery, Vascular Biology Program, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kaiane A. Habeshian
- Department of Surgery, Vascular Biology Program, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lauren Bazinet
- Department of Surgery, Vascular Biology Program, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Thomas P. Caldwell
- Department of Chemistry, Clemson University, Clemson, South Carolina, United States of America
| | - P. Christine Ackroyd
- Department of Chemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Kenneth A. Christensen
- Department of Chemistry, Clemson University, Clemson, South Carolina, United States of America
- * E-mail:
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Danial M, Root MJ, Klok HA. Polyvalent side chain peptide-synthetic polymer conjugates as HIV-1 entry inhibitors. Biomacromolecules 2012; 13:1438-47. [PMID: 22455441 DOI: 10.1021/bm300150q] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This report describes the synthesis and properties of a series of polyvalent side chain peptide-synthetic polymer conjugates designed to block the CD4 binding site on gp120 and inhibit HIV-1 entry into a host cell. The peptide sequences in the conjugates are based on the CDR H3 region of the neutralizing anti-HIV-1 antibody IgG1 b12. Using a consecutive ester-amide/thiol-ene postpolymerization modification strategy, a library of polymer conjugates was prepared. Evaluation of the HIV-1 inhibitory properties revealed that midsized polymer conjugates displayed the highest antiviral activity, while shorter and longer conjugates proved to be less efficacious inhibitors. The lower molecular weight conjugates may not have sufficient length to span the distance between two neighboring gp120 containing spikes, while the higher molecular weight conjugates may be compromised due to a higher entropic penalty that would accompany their binding to the viral envelope. Although the IC(50) values for these polymer conjugates are higher than that of the parent IgG1 b12 antibody, the strategy presented here may represent an interesting antiviral approach due to the attractive properties of such polymer therapeutics (relatively inexpensive production and purification costs, high thermal and chemical stability in storage conditions, long half-life in biological tissues, low immunogenicity, and protection from proteolytic degradation).
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Affiliation(s)
- Maarten Danial
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
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Ahn HC, Kim NY, Hur GH, Yang JM, Shin S. Role of chondroitin sulfate C in the action of anthrax toxin. Toxicology 2012; 297:10-6. [PMID: 22503668 DOI: 10.1016/j.tox.2012.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 03/26/2012] [Accepted: 03/28/2012] [Indexed: 11/30/2022]
Abstract
Anthrax toxin is produced by Bacillus anthracis, the causative agent of anthrax, and is responsible for the majority of disease symptoms. The toxin consists of 3 proteins, protective antigen (PA), lethal factor (LF), and edema factor (EF), which combine to form lethal and edema toxin. Glycosaminoglycans, which are present on the surface of cells, were investigated with regard to their role in toxicity resulting from anthrax toxin exposure. Lethal toxin-induced cytotoxicity of the RAW 264.7 cells was significantly inhibited by the addition of chondroitin sulfate C as determined by the MTT assay. By contrast, several other glycosaminoglycans, including heparin, heparan sulfate, and dermatan sulfate did not show significant levels of inhibition. Studies utilizing fluorescence-labeled PA demonstrated decreased PA binding to RAW 264.7 cells with the addition of chondroitin sulfate C. Formation of PA oligomers at the surface of cells after binding was also inhibited by chondroitin sulfate C. Interestingly, enzymatic degradation of endogenous chondroitin sulfate C from the cell surface with chondroitinase ABC was accompanied by increased sensitivity to the toxin. These findings were further confirmed by pretreating cells with sodium chlorate to reduce the degree of cell surface glycosaminoglycans sulfation. In addition, chondroitin sulfate C effectively inhibits edema toxin-induced cAMP accumulation in cells. Our results indicate that chondroitin sulfate C may play an important role in the toxicity of anthrax toxin.
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Affiliation(s)
- Hyun Chan Ahn
- Department of Life Science, Sogang University, Shinsu-Dong, Mapo, Seoul 121-742, Republic of Korea
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Bricarello DA, Patel MA, Parikh AN. Inhibiting host-pathogen interactions using membrane-based nanostructures. Trends Biotechnol 2012; 30:323-30. [PMID: 22464596 DOI: 10.1016/j.tibtech.2012.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/28/2012] [Accepted: 03/02/2012] [Indexed: 12/24/2022]
Abstract
Virulent strains of bacteria and viruses recognize host cells by their plasma membrane receptors and often exploit the native translocation machinery to invade the cell. A promising therapeutic concept for early interruption of pathogen infection is to subvert this pathogenic trickery using exogenously introduced decoys that present high-affinity mimics of cellular receptors. This review highlights emerging applications of molecularly engineered lipid-bilayer-based nanostructures, namely (i) functionalized liposomes, (ii) supported colloidal bilayers or protocells and (iii) reconstituted lipoproteins, which display functional cellular receptors in optimized conformational and aggregative states. These decoys outcompete host cell receptors by preferentially binding to and neutralizing virulence factors of both bacteria and viruses, thereby promising a new approach to antipathogenic therapy.
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Affiliation(s)
- Daniel A Bricarello
- Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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Ivarsson ME, Leroux JC, Castagner B. Targeting bacterial toxins. Angew Chem Int Ed Engl 2012; 51:4024-45. [PMID: 22441768 DOI: 10.1002/anie.201104384] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/21/2011] [Indexed: 12/18/2022]
Abstract
Protein toxins constitute the main virulence factors of several species of bacteria and have proven to be attractive targets for drug development. Lead candidates that target bacterial toxins range from small molecules to polymeric binders, and act at each of the multiple steps in the process of toxin-mediated pathogenicity. Despite recent and significant advances in the field, a rationally designed drug that targets toxins has yet to reach the market. This Review presents the state of the art in bacterial toxin targeted drug development with a critical consideration of achieved breakthroughs and withstanding challenges. The discussion focuses on A-B-type protein toxins secreted by four species of bacteria, namely Clostridium difficile (toxins A and B), Vibrio cholerae (cholera toxin), enterohemorrhagic Escherichia coli (Shiga toxin), and Bacillus anthracis (anthrax toxin), which are the causative agents of diseases for which treatments need to be improved.
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Affiliation(s)
- Mattias E Ivarsson
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich, Wolfgang-Pauli-Strasse 10, Zurich, Switzerland
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Phage display against corneal epithelial cells produced bioactive peptides that inhibit Aspergillus adhesion to the corneas. PLoS One 2012; 7:e33578. [PMID: 22428072 PMCID: PMC3299800 DOI: 10.1371/journal.pone.0033578] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 02/15/2012] [Indexed: 02/08/2023] Open
Abstract
Dissection of host-pathogen interactions is important for both understanding the pathogenesis of infectious diseases and developing therapeutics for the infectious diseases like various infectious keratitis. To enhance the knowledge about pathogenesis infectious keratitis, a random 12-mer peptide phage display library was screened against cultured human corneal epithelial cells (HCEC). Fourteen sequences were obtained and BLASTp analysis showed that most of their homologue counterparts in GenBank were for defined or putative proteins in various pathogens. Based on known or predicted functions of the homologue proteins, ten synthetic peptides (Pc-A to Pc-J) were measured for their affinity to bind cells and their potential efficacy to interfere with pathogen adhesion to the cells. Besides binding to HCEC, most of them also bound to human corneal stromal cells and umbilical endothelial cells to different extents. When added to HCEC culture, the peptides induced expression of MyD88 and IL-17 in HCEC, and the stimulated cell culture medium showed fungicidal potency to various extents. While peptides Pc-C and Pc-E inhibited Aspergillus fumigatus (A.f) adhesion to HCEC in a dose-dependent manner, the similar inhibition ability of peptides Pc-A and Pc-B required presence of their homologue ligand Alb1p on A.f. When utilized in an eyeball organ culture model and an in vivo A.f keratitis model established in mouse, Pc-C and Pc-E inhibited fungal adhesion to corneas, hence decreased corneal disruption caused by inflammatory infiltration. Affinity pull-down of HCEC membrane proteins with peptide Pc-C revealed several molecules as potential receptors for this peptide. In conclusion, besides proving that phage display-selected peptides could be utilized to interfere with adhesion of pathogens to host cells, hence could be exploited for managing infectious diseases including infectious keratitis, we also proposed that the phage display technique and the resultant peptides could be used to explore host-pathogen interactions at molecular levels.
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Prussia A, Thepchatri P, Snyder JP, Plemper RK. Systematic approaches towards the development of host-directed antiviral therapeutics. Int J Mol Sci 2011; 12:4027-52. [PMID: 21747723 PMCID: PMC3131607 DOI: 10.3390/ijms12064027] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 06/03/2011] [Accepted: 06/03/2011] [Indexed: 12/11/2022] Open
Abstract
Since the onset of antiviral therapy, viral resistance has compromised the clinical value of small-molecule drugs targeting pathogen components. As intracellular parasites, viruses complete their life cycle by hijacking a multitude of host-factors. Aiming at the latter rather than the pathogen directly, host-directed antiviral therapy has emerged as a concept to counteract evolution of viral resistance and develop broad-spectrum drug classes. This approach is propelled by bioinformatics analysis of genome-wide screens that greatly enhance insights into the complex network of host-pathogen interactions and generate a shortlist of potential gene targets from a multitude of candidates, thus setting the stage for a new era of rational identification of drug targets for host-directed antiviral therapies. With particular emphasis on human immunodeficiency virus and influenza virus, two major human pathogens, we review screens employed to elucidate host-pathogen interactions and discuss the state of database ontology approaches applicable to defining a therapeutic endpoint. The value of this strategy for drug discovery is evaluated, and perspectives for bioinformatics-driven hit identification are outlined.
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Affiliation(s)
- Andrew Prussia
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA; E-Mails: (A.P.); (J.P.S.)
- Emory Institute for Drug Discovery (EIDD), Emory University, Atlanta, GA 30322, USA
| | - Pahk Thepchatri
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA; E-Mails: (A.P.); (J.P.S.)
- Emory Institute for Drug Discovery (EIDD), Emory University, Atlanta, GA 30322, USA
- Authors to whom correspondence should be addressed; E-Mails: (P.T.); (R.K.P.); Tel.: +1-404-593-0547 (P.T.); +1-404-727-1605 (R.K.P.); Fax: +1-404-727-9223 (P.T.); +1-404-727-9223 (R.K.P.)
| | - James P. Snyder
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA; E-Mails: (A.P.); (J.P.S.)
- Emory Institute for Drug Discovery (EIDD), Emory University, Atlanta, GA 30322, USA
| | - Richard K. Plemper
- Department of Pediatrics, Emory University, Atlanta, GA 30322, USA
- Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
- Authors to whom correspondence should be addressed; E-Mails: (P.T.); (R.K.P.); Tel.: +1-404-593-0547 (P.T.); +1-404-727-1605 (R.K.P.); Fax: +1-404-727-9223 (P.T.); +1-404-727-9223 (R.K.P.)
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Cai C, Che J, Xu L, Guo Q, Kong Y, Fu L, Xu J, Cheng Y, Chen W. Tumor endothelium marker-8 based decoys exhibit superiority over capillary morphogenesis protein-2 based decoys as anthrax toxin inhibitors. PLoS One 2011; 6:e20646. [PMID: 21674060 PMCID: PMC3107238 DOI: 10.1371/journal.pone.0020646] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/06/2011] [Indexed: 01/06/2023] Open
Abstract
Anthrax toxin is the major virulence factor produced by Bacillus anthracis. The toxin consists of three protein subunits: protective antigen (PA), lethal factor, and edema factor. Inhibition of PA binding to its receptors, tumor endothelium marker-8 (TEM8) and capillary morphogenesis protein-2 (CMG2) can effectively block anthrax intoxication, which is particularly valuable when the toxin has already been overproduced at the late stage of anthrax infection, thus rendering antibiotics ineffectual. Receptor-like agonists, such as the mammalian cell-expressed von Willebrand factor type A (vWA) domain of CMG2 (sCMG2), have demonstrated potency against the anthrax toxin. However, the soluble vWA domain of TEM8 (sTEM8) was ruled out as an anthrax toxin inhibitor candidate due to its inferior affinity to PA. In the present study, we report that L56A, a PA-binding-affinity-elevated mutant of sTEM8, could inhibit anthrax intoxication as effectively as sCMG2 in Fisher 344 rats. Additionally, pharmacokinetics showed that L56A and sTEM8 exhibit advantages over sCMG2 with better lung-targeting and longer plasma retention time, which may contribute to their enhanced protective ability in vivo. Our results suggest that receptor decoys based on TEM8 are promising anthrax toxin inhibitors and, together with the pharmacokinetic studies in this report, may contribute to the development of novel anthrax drugs.
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Affiliation(s)
- Chenguang Cai
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jinjing Che
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Long Xu
- Laboratory of protein engineering, Beijing Institute of Biotechnology, Beijing, China
| | - Qiang Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yirong Kong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Ling Fu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Junjie Xu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (JX) (JX); (YC) (YC); (WC) (WC)
| | - Yuanguo Cheng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (JX) (JX); (YC) (YC); (WC) (WC)
| | - Wei Chen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (JX) (JX); (YC) (YC); (WC) (WC)
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Abstract
By wrapping a ligand-functionalized lipid membrane around a silica core, nanoparticles with a fluid surface are created. These combine unprecedented specificity in binding to cancer cells with the combinatorial delivery of drug cocktails.
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Affiliation(s)
- Darrell J. Irvine
- the Department of Biological Engineering, the Department of Materials Science and Engineering and the Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA, and the Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, Massachusetts, USA. He is also an investigator of the Howard Hughes Medical Institute, Maryland, USA
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Joshi A, Kate S, Poon V, Mondal D, Boggara MB, Saraph A, Martin JT, McAlpine R, Day R, Garcia AE, Mogridge J, Kane RS. Structure-based design of a heptavalent anthrax toxin inhibitor. Biomacromolecules 2011; 12:791-6. [PMID: 21302959 DOI: 10.1021/bm101396u] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The design of polyvalent molecules, consisting of multiple copies of a biospecific ligand attached to a suitable scaffold, represents a promising approach to inhibit pathogens and oligomeric microbial toxins. Despite the increasing interest in structure-based drug design, few polyvalent inhibitors based on this approach have shown efficacy in vivo. Here we demonstrate the structure-based design of potent biospecific heptavalent inhibitors of anthrax lethal toxin. Specifically, we illustrate the ability to design potent polyvalent ligands by matching the pattern of binding sites on the biological target. We used a combination of experimental studies based on mutagenesis and computational docking studies to identify the binding site for an inhibitory peptide on the heptameric subunit of anthrax toxin. We developed an approach based on copper-catalyzed azide-alkyne cycloaddition (click-chemistry) to facilitate the attachment of seven copies of the inhibitory peptide to a β-cyclodextrin core via a polyethylene glycol linker of an appropriate length. The resulting heptavalent inhibitors neutralized anthrax lethal toxin both in vitro and in vivo and showed appreciable stability in serum. Given the inherent biocompatibility of cyclodextrin and polyethylene glycol, these potent well-defined heptavalent inhibitors show considerable promise as anthrax antitoxins.
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Affiliation(s)
- Amit Joshi
- The Howard P. Isermann Department of Chemical and Biological Engineering, Troy, New York 12180, USA
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Lempens EHM, Merkx M, Tirrell M, Meijer EW. Dendrimer Display of Tumor-Homing Peptides. Bioconjug Chem 2011; 22:397-405. [DOI: 10.1021/bc100403e] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Edith H. M. Lempens
- Laboratory of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Maarten Merkx
- Laboratory of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Matthew Tirrell
- Department of Chemical Engineering and Materials Research Laboratory, University of California Santa Barbara, California 93106-5080, United States
| | - E. W. Meijer
- Laboratory of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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Abdeen SJ, Swett RJ, Feig AL. Peptide inhibitors targeting Clostridium difficile toxins A and B. ACS Chem Biol 2010; 5:1097-103. [PMID: 20863124 DOI: 10.1021/cb100209b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Clostridium difficile causes severe hospital-acquired antibiotic-associated diarrhea due to the activity of two large protein toxins. Current treatments suffer from a high relapse rate and are generating resistant strains; thus new methods of dealing with these infections that target the virulence factors directly are of interest. Phage display was used to identify peptides that bind to the catalytic domain of C. difficile Toxin A. Library screening and subsequent quantitative binding and inhibition studies showed that several of these peptides are potent inhibitors. Fragment-based computational docking of these peptides elucidated the binding modes within the active site. These antitoxin peptides may serve as potential lead compounds to further engineer peptidomimetic inhibitors of the clostridial toxins.
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Affiliation(s)
- Sanofar J. Abdeen
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
| | - Rebecca J. Swett
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
| | - Andrew L. Feig
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
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Liu J, Weller GER, Zern B, Ayyaswamy PS, Eckmann DM, Muzykantov VR, Radhakrishnan R. Computational model for nanocarrier binding to endothelium validated using in vivo, in vitro, and atomic force microscopy experiments. Proc Natl Acad Sci U S A 2010. [PMID: 20823256 DOI: 10.1073/pnas.1006611107/-/dcsupplemental] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
A computational methodology based on Metropolis Monte Carlo (MC) and the weighted histogram analysis method (WHAM) has been developed to calculate the absolute binding free energy between functionalized nanocarriers (NC) and endothelial cell (EC) surfaces. The calculated NC binding free energy landscapes yield binding affinities that agree quantitatively when directly compared against analogous measurements of specific antibody-coated NCs (100 nm in diameter) to intracellular adhesion molecule-1 (ICAM-1) expressing EC surface in in vitro cell-culture experiments. The effect of antibody surface coverage (σ(s)) of NC on binding simulations reveals a threshold σ(s) value below which the NC binding affinities reduce drastically and drop lower than that of single anti-ICAM-1 molecule to ICAM-1. The model suggests that the dominant effect of changing σ(s) around the threshold is through a change in multivalent interactions; however, the loss in translational and rotational entropies are also important. Consideration of shear flow and glycocalyx does not alter the computed threshold of antibody surface coverage. The computed trend describing the effect of σ(s) on NC binding agrees remarkably well with experimental results of in vivo targeting of the anti-ICAM-1 coated NCs to pulmonary endothelium in mice. Model results are further validated through close agreement between computed NC rupture-force distribution and measured values in atomic force microscopy (AFM) experiments. The three-way quantitative agreement with AFM, in vitro (cell-culture), and in vivo experiments establishes the mechanical, thermodynamic, and physiological consistency of our model. Hence, our computational protocol represents a quantitative and predictive approach for model-driven design and optimization of functionalized nanocarriers in targeted vascular drug delivery.
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Affiliation(s)
- Jin Liu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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44
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Computational model for nanocarrier binding to endothelium validated using in vivo, in vitro, and atomic force microscopy experiments. Proc Natl Acad Sci U S A 2010; 107:16530-5. [PMID: 20823256 DOI: 10.1073/pnas.1006611107] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A computational methodology based on Metropolis Monte Carlo (MC) and the weighted histogram analysis method (WHAM) has been developed to calculate the absolute binding free energy between functionalized nanocarriers (NC) and endothelial cell (EC) surfaces. The calculated NC binding free energy landscapes yield binding affinities that agree quantitatively when directly compared against analogous measurements of specific antibody-coated NCs (100 nm in diameter) to intracellular adhesion molecule-1 (ICAM-1) expressing EC surface in in vitro cell-culture experiments. The effect of antibody surface coverage (σ(s)) of NC on binding simulations reveals a threshold σ(s) value below which the NC binding affinities reduce drastically and drop lower than that of single anti-ICAM-1 molecule to ICAM-1. The model suggests that the dominant effect of changing σ(s) around the threshold is through a change in multivalent interactions; however, the loss in translational and rotational entropies are also important. Consideration of shear flow and glycocalyx does not alter the computed threshold of antibody surface coverage. The computed trend describing the effect of σ(s) on NC binding agrees remarkably well with experimental results of in vivo targeting of the anti-ICAM-1 coated NCs to pulmonary endothelium in mice. Model results are further validated through close agreement between computed NC rupture-force distribution and measured values in atomic force microscopy (AFM) experiments. The three-way quantitative agreement with AFM, in vitro (cell-culture), and in vivo experiments establishes the mechanical, thermodynamic, and physiological consistency of our model. Hence, our computational protocol represents a quantitative and predictive approach for model-driven design and optimization of functionalized nanocarriers in targeted vascular drug delivery.
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Pande J, Szewczyk MM, Grover AK. Phage display: concept, innovations, applications and future. Biotechnol Adv 2010; 28:849-58. [PMID: 20659548 DOI: 10.1016/j.biotechadv.2010.07.004] [Citation(s) in RCA: 329] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 06/27/2010] [Accepted: 07/08/2010] [Indexed: 12/17/2022]
Abstract
Phage display is the technology that allows expression of exogenous (poly)peptides on the surface of phage particles. The concept is simple in principle: a library of phage particles expressing a wide diversity of peptides is used to select those that bind the desired target. The filamentous phage M13 is the most commonly used vector to create random peptide display libraries. Several methods including recombinant techniques have been developed to increase the diversity of the library. On the other extreme, libraries with various biases can be created for specific purposes. For instance, when the sequence of the peptide that binds the target is known, its affinity and selectivity can be increased by screening libraries created with limited mutagenesis of the peptide. Phage libraries are screened for binding to synthetic or native targets. The initial screening of library by basic biopanning has been extended to column chromatography including negative screening and competition between selected phage clones to identify high affinity ligands with greater target specificity. The rapid isolation of specific ligands by phage display is advantageous in many applications including selection of inhibitors for the active and allosteric sites of the enzymes, receptor agonists and antagonists, and G-protein binding modulatory peptides. Phage display has been used in epitope mapping and analysis of protein-protein interactions. The specific ligands isolated from phage libraries can be used in therapeutic target validation, drug design and vaccine development. Phage display can also be used in conjunction with other methods. The past innovations and those to come promise a bright future for this field.
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Affiliation(s)
- Jyoti Pande
- Department of Medicine, HSC 4N41 McMaster Univ, Hamilton, ON, Canada
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Paradigm shift in discovering next-generation anti-infective agents: targeting quorum sensing, c-di-GMP signaling and biofilm formation in bacteria with small molecules. Future Med Chem 2010; 2:1005-35. [DOI: 10.4155/fmc.10.185] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Small molecules that can attenuate bacterial toxin production or biofilm formation have the potential to solve the bacteria resistance problem. Although several molecules, which inhibit bacterial cell-to-cell communication (quorum sensing), biofilm formation and toxin production, have been discovered, there is a paucity of US FDA-approved drugs that target these processes. Here, we review the current understanding of quorum sensing in important pathogens such as Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus and provide examples of experimental molecules that can inhibit both known and unknown targets in bacterial virulence factor production and biofilm formation. Structural data for protein targets that are involved in both quorum sensing and cyclic diguanylic acid signaling are needed to aid the development of molecules with drug-like properties in order to target bacterial virulence factors production and biofilm formation.
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Kane RS. Thermodynamics of multivalent interactions: influence of the linker. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8636-40. [PMID: 20131760 PMCID: PMC2877167 DOI: 10.1021/la9047193] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This paper describes a thermodynamic analysis of multivalent interactions, with the goal of clarifying the influence of the linker on the enhancement in avidity due to multivalency. The use of multivalency represents a promising approach to inhibit undesired biological interactions, promote desired cellular responses, and control recognition events at surfaces. Several groups have synthesized multivalent ligands that are orders of magnitude more potent than the corresponding monovalent ligands. A better understanding of the theoretical basis for the large enhancements in avidity would help guide the design of more potent synthetic multivalent ligands. In particular, there has been significant controversy regarding the extent to which the loss of conformational entropy of the linker influences the enhancement in avidity due to multivalency. To help clarify this issue, we present the thermodynamic analysis of a heterodivalent ligand-receptor interaction. Our analysis helps reconcile seemingly competing theoretical analyses of multivalent binding. Our results indicate that the dependence of the free energy of multivalent binding on linker length can be weak even if there is a significant decrease in the conformational entropy of the linker on binding. Our results are also consistent with studies demonstrating that the use of flexible linkers represents an effective strategy to design potent multivalent ligands.
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Affiliation(s)
- Ravi S Kane
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
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48
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Mao X, Hong Y, Shao Z, Zhao Y, Liu Z. A Novel Cold-Active and Alkali-Stable β-Glucosidase Gene Isolated from the Marine Bacterium Martelella mediterranea. Appl Biochem Biotechnol 2010; 162:2136-48. [DOI: 10.1007/s12010-010-8988-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 05/06/2010] [Indexed: 10/19/2022]
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49
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Van Der Goot G, Young JA. Receptors of anthrax toxin and cell entry. Mol Aspects Med 2009; 30:406-12. [PMID: 19732789 PMCID: PMC2783407 DOI: 10.1016/j.mam.2009.08.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 08/24/2009] [Indexed: 11/29/2022]
Abstract
Anthrax toxin-receptor interactions are critical for toxin delivery to the host cell cytoplasm. This review summarizes what is known about the molecular details of the protective antigen (PA) toxin subunit interaction with either the ANTXR1 and ANTXR2 cellular receptors, and how receptor-type can dictate the low pH threshold of PA pore formation. The roles played by cellular factors in regulating the endocytosis of toxin-receptor complexes is also discussed.
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Affiliation(s)
- Gisou Van Der Goot
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, SV-AI extension, Station 15, 1015 Lausanne, Switzerland,
| | - John A.T. Young
- Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037,
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50
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Multivalency-assisted control of intracellular signaling pathways: application for ubiquitin- dependent N-end rule pathway. ACTA ACUST UNITED AC 2009; 16:121-31. [PMID: 19246002 DOI: 10.1016/j.chembiol.2009.01.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/04/2009] [Accepted: 01/21/2009] [Indexed: 11/23/2022]
Abstract
Intracellular signaling is often mediated by a family of functionally overlapping signal mediators that contain multiple sites interacting with other proteins or ligands with weak affinity (K(d) > microM). Conjugation of multiple low-affinity ligands into a high-affinity multivalent molecule provides a means to control the entire protein family within a single intracellular pathway. The N-end rule pathway is a ubiquitin (Ub)-dependent proteolytic system where at least four Ub ligases, called N-recognins, have a common domain critical for binding to type 1 (basic) and type 2 (bulky hydrophobic) destabilizing N-terminal residues of substrates as degrons. The recent development of a heterodivalent inhibitor targeting type 1 and type 2 substrate binding sites of the N-recognin family provides new opportunities to manipulate this proteolytic pathway in biochemical and pathophysiological conditions. We overview the N-end rule pathway as an intracellular target for heterodivalent molecules and discuss the basis of thermodynamics and kinetics related to heterodivalent interactions.
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