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Tran HNT, McMahon KL, Deuis JR, Vetter I, Schroeder CI. Structural and functional insights into the inhibition of human voltage-gated sodium channels by μ-conotoxin KIIIA disulfide isomers. J Biol Chem 2022; 298:101728. [PMID: 35167877 PMCID: PMC8927997 DOI: 10.1016/j.jbc.2022.101728] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
μ-Conotoxins are components of cone snail venom, well-known for their analgesic activity through potent inhibition of voltage-gated sodium channel (NaV) subtypes, including NaV1.7. These small, disulfide-rich peptides are typically stabilized by three disulfide bonds arranged in a ‘native’ CysI-CysIV, CysII-CysV, CysIII-CysVI pattern of disulfide connectivity. However, μ-conotoxin KIIIA, the smallest and most studied μ-conotoxin with inhibitory activity at NaV1.7, forms two distinct disulfide bond isomers during thermodynamic oxidative folding, including Isomer 1 (CysI-CysV, CysII-CysIV, CysIII-CysVI) and Isomer 2 (CysI-CysVI, CysII-CysIV, CysIII-CysV), but not the native μ-conotoxin arrangement. To date, there has been no study on the structure and activity of KIIIA comprising the native μ-conotoxin disulfide bond arrangement. Here, we evaluated the synthesis, potency, sodium channel subtype selectivity, and 3D structure of the three isomers of KIIIA. Using a regioselective disulfide bond-forming strategy, we synthetically produced the three μ-conotoxin KIIIA isomers displaying distinct bioactivity and NaV subtype selectivity across human NaV channel subtypes 1.2, 1.4, and 1.7. We show that Isomer 1 inhibits NaV subtypes with a rank order of potency of NaV1.4 > 1.2 > 1.7 and Isomer 2 in the order of NaV1.4≈1.2 > 1.7, while the native isomer inhibited NaV1.4 > 1.7≈1.2. The three KIIIA isomers were further evaluated by NMR solution structure analysis and molecular docking with hNaV1.2. Our study highlights the importance of investigating alternate disulfide isomers, as disulfide connectivity affects not only the overall structure of the peptides but also the potency and subtype selectivity of μ-conotoxins targeting therapeutically relevant NaV subtypes.
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Affiliation(s)
- Hue N T Tran
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland, Australia.
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia; Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA.
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2
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Rodriguez A, Pedersen MØ, Villegas E, Rivas‐Santiago B, Villegas‐Moreno J, Amero C, Norton RS, Corzo G. Antimicrobial activity and structure of a consensus human β‐defensin and its comparison to a novel putative hBD10. Proteins 2019; 88:175-186. [DOI: 10.1002/prot.25785] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Alexis Rodriguez
- Centro de Investigación en BiotecnologíaUniversidad Autónoma del Estado de Morelos Cuernavaca Mexico
| | | | - Elba Villegas
- Centro de Investigación en BiotecnologíaUniversidad Autónoma del Estado de Morelos Cuernavaca Mexico
| | - Bruno Rivas‐Santiago
- Medical Research Unit‐ZacatecasMexican Institute of Social Security IMSS Zacatecas Mexico
| | - Jessica Villegas‐Moreno
- Centro de Investigaciones QuímicasUniversidad Autónoma del Estado de Morelos Cuernavaca Mexico
| | - Carlos Amero
- Centro de Investigaciones QuímicasUniversidad Autónoma del Estado de Morelos Cuernavaca Mexico
| | - Raymond S. Norton
- Monash Institute of Pharmaceutical SciencesMonash University Parkville Victoria Australia
| | - Gerardo Corzo
- Instituto de BiotecnologíaUniversidad Nacional Autónoma de México Cuernavaca Mexico
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3
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Yeh SJ, Yeh CC, Lan CY, Chen BS. Investigating Common Pathogenic Mechanisms between Homo sapiens and Different Strains of Candida albicans for Drug Design: Systems Biology Approach via Two-Sided NGS Data Identification. Toxins (Basel) 2019; 11:toxins11020119. [PMID: 30769958 PMCID: PMC6409619 DOI: 10.3390/toxins11020119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 01/15/2023] Open
Abstract
Candida albicans (C. albicans) is the most prevalent fungal species. Although it is a healthy microbiota, genetic and epigenetic alterations in host and pathogen, and microenvironment changes would lead to thrush, vaginal yeast infection, and even hematogenously disseminated infection. Despite the fact that cytotoxicity is well-characterized, few studies discuss the genome-wide genetic and epigenetic molecular mechanisms between host and C. albicans. The aim of this study is to identify drug targets and design a multiple-molecule drug to prevent the infection from C. albicans. To investigate the common and specific pathogenic mechanisms in human oral epithelial OKF6/TERT-2 cells during the C. albicans infection in different strains, systems modeling and big databases mining were used to construct candidate host–pathogen genetic and epigenetic interspecies network (GEIN). System identification and system order detection are applied on two-sided next generation sequencing (NGS) data to build real host–pathogen cross-talk GEINs. Core host–pathogen cross-talk networks (HPCNs) are extracted by principal network projection (PNP) method. By comparing with core HPCNs in different strains of C. albicans, common pathogenic mechanisms were investigated and several drug targets were suggested as follows: orf19.5034 (YBP1) with the ability of anti-ROS; orf19.939 (NAM7), orf19.2087 (SAS2), orf19.1093 (FLO8) and orf19.1854 (HHF22) with high correlation to the hyphae growth and pathogen protein interaction; orf19.5585 (SAP5), orf19.5542 (SAP6) and orf19.4519 (SUV3) with the cause of biofilm formation. Eventually, five corresponding compounds—Tunicamycin, Terbinafine, Cerulenin, Tetracycline and Tetrandrine—with three known drugs could be considered as a potential multiple-molecule drug for therapeutic treatment of C. albicans.
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Affiliation(s)
- Shan-Ju Yeh
- Laboratory of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Chun-Chieh Yeh
- Laboratory of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan.
- Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Bor-Sen Chen
- Laboratory of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
- Department of Electrical Engineering, Yuan Ze University, Chungli 32003, Taiwan.
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4
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Zheng Y, Li Z, Ren J, Liu W, Wu Y, Zhao Y, Wu C. Artificial disulfide-rich peptide scaffolds with precisely defined disulfide patterns and a minimized number of isomers. Chem Sci 2017; 8:2547-2552. [PMID: 28553486 PMCID: PMC5431680 DOI: 10.1039/c6sc05710a] [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: 12/30/2016] [Accepted: 02/15/2017] [Indexed: 12/21/2022] Open
Abstract
Disulfide-rich peptides are emerging as potential templates for drug design applications. However, the synthesis and reengineering of disulfide-rich peptides are challenging, owing to the complexity of the oxidative folding process involving a number of diverse isomeric structures. Novel disulfide-rich peptide scaffolds that are not besieged by their disulfide isomers are still greatly desired. In this work, we report the design and synthesis of a novel class of artificial disulfide-rich peptide scaffolds with precisely defined disulfide patterns and a minimized number of isomers. In theory, natural peptides with three disulfide bonds have 15 possible isomers. By rationally engineering the thiol-framework of a peptide containing six cysteines with penicillamines and a dithiol amino acid, we demonstrated, for the first time, that the total number of isomers formed after oxidative folding can be decreased to a minimum of two (i.e., from 15 to 2). As fewer isomeric folds are involved in the oxidative folding, the pathway of the folding becomes more concise and the yield of the artificial scaffolds is substantially increased compared to that of its six-cysteine-containing analogue, which makes the artificial disulfide-rich scaffolds (with only 2 predefined isomeric folds) extremely promising for being exploited as structurally complex templates for the design of peptide therapeutics and ligands.
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Affiliation(s)
- Yiwu Zheng
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Zhuoru Li
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Jing Ren
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Weidong Liu
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Yaqi Wu
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Yibing Zhao
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
| | - Chuanliu Wu
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation , State Key Laboratory of Physical Chemistry of Solid Surfaces , Collaborative Innovation Center of Chemistry for Energy Materials , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , P.R. China .
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Nix MA, Kaelin CB, Palomino R, Miller JL, Barsh GS, Millhauser GL. Electrostatic Similarity Analysis of Human β-Defensin Binding in the Melanocortin System. Biophys J 2016; 109:1946-58. [PMID: 26536271 DOI: 10.1016/j.bpj.2015.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/27/2015] [Accepted: 09/03/2015] [Indexed: 12/13/2022] Open
Abstract
The β-defensins are a class of small cationic proteins that serve as components of numerous systems in vertebrate biology, including the immune and melanocortin systems. Human β-defensin 3 (HBD3), which is produced in the skin, has been found to bind to melanocortin receptors 1 and 4 through complementary electrostatics, a unique mechanism of ligand-receptor interaction. This finding indicates that electrostatics alone, and not specific amino acid contact points, could be sufficient for function in this ligand-receptor system, and further suggests that other small peptide ligands could interact with these receptors in a similar fashion. Here, we conducted molecular-similarity analyses and functional studies of additional members of the human β-defensin family, examining their potential as ligands of melanocortin-1 receptor, through selection based on their electrostatic similarity to HBD3. Using Poisson-Boltzmann electrostatic calculations and molecular-similarity analysis, we identified members of the human β-defensin family that are both similar and dissimilar to HBD3 in terms of electrostatic potential. Synthesis and functional testing of a subset of these β-defensins showed that peptides with an HBD3-like electrostatic character bound to melanocortin receptors with high affinity, whereas those that were anticorrelated to HBD3 showed no binding affinity. These findings expand on the central role of electrostatics in the control of this ligand-receptor system and further demonstrate the utility of employing molecular-similarity analysis. Additionally, we identified several new potential ligands of melanocortin-1 receptor, which may have implications for our understanding of the role defensins play in melanocortin physiology.
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Affiliation(s)
- Matthew A Nix
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Christopher B Kaelin
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama; Department of Genetics, Stanford University, Stanford, California
| | - Rafael Palomino
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Jillian L Miller
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California
| | - Gregory S Barsh
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama; Department of Genetics, Stanford University, Stanford, California.
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California.
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6
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The role of antimicrobial peptides in chronic inflammatory skin diseases. Postepy Dermatol Alergol 2016; 33:6-12. [PMID: 26985172 PMCID: PMC4793058 DOI: 10.5114/pdia.2015.48066] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 11/12/2014] [Indexed: 11/17/2022] Open
Abstract
Antimicrobial peptides (AMPs) are effector molecules of the innate immune system of the skin. They present an activity against a broad spectrum of Gram-positive and Gram-negative bacteria as well as some fungi, parasites and enveloped viruses. Several inflammatory skin diseases including psoriasis, atopic dermatitis, acne vulgaris and rosacea are characterized by a dysregulated expression of AMPs. Antimicrobial peptides are excessively produced in lesional psoriatic scales or rosacea in contrast to the atopic skin that shows lower AMP levels when compared with psoriasis. The importance of the AMPs contribution to host immunity is indisputable as alterations in the antimicrobial peptide expression have been associated with various pathologic processes. This review discusses the biology and clinical relevance of antimicrobial peptides expressed in the skin and their role in the pathogenesis of inflammatory skin diseases.
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7
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Zheng Y, Zhai L, Zhao Y, Wu C. Orthogonal Cysteine–Penicillamine Disulfide Pairing for Directing the Oxidative Folding of Peptides. J Am Chem Soc 2015; 137:15094-7. [DOI: 10.1021/jacs.5b10779] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Yiwu Zheng
- The MOE Key Laboratory of
Spectrochemical Analysis and Instrumentation, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Linxiang Zhai
- The MOE Key Laboratory of
Spectrochemical Analysis and Instrumentation, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Yibing Zhao
- The MOE Key Laboratory of
Spectrochemical Analysis and Instrumentation, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Chuanliu Wu
- The MOE Key Laboratory of
Spectrochemical Analysis and Instrumentation, State Key Laboratory
of Physical Chemistry of Solid Surfaces, Department of Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
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8
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Guo Y, Sun DM, Wang FL, He Y, Liu L, Tian CL. Diaminodiacid Bridges to Improve Folding and Tune the Bioactivity of Disulfide-Rich Peptides. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201500699] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Guo Y, Sun D, Wang F, He Y, Liu L, Tian C. Diaminodiacid Bridges to Improve Folding and Tune the Bioactivity of Disulfide‐Rich Peptides. Angew Chem Int Ed Engl 2015; 54:14276-81. [DOI: 10.1002/anie.201500699] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 04/07/2015] [Indexed: 12/11/2022]
Affiliation(s)
- Ye Guo
- Tsinghua‐Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084 (China)
| | - De‐Meng Sun
- Tsinghua‐Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084 (China)
| | - Feng‐Liang Wang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026 (China)
| | - Yao He
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230027 (China)
| | - Lei Liu
- Tsinghua‐Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084 (China)
| | - Chang‐Lin Tian
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230027 (China)
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10
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Sharma H, Nagaraj R. Human β-defensin 4 with non-native disulfide bridges exhibit antimicrobial activity. PLoS One 2015; 10:e0119525. [PMID: 25785690 PMCID: PMC4364940 DOI: 10.1371/journal.pone.0119525] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/14/2015] [Indexed: 01/05/2023] Open
Abstract
Human defensins play multiple roles in innate immunity including direct antimicrobial killing and immunomodulatory activity. They have three disulfide bridges which contribute to the stability of three anti-parallel β-strands. The exact role of disulfide bridges and canonical β-structure in the antimicrobial action is not yet fully understood. In this study, we have explored the antimicrobial activity of human β-defensin 4 (HBD4) analogs that differ in the number and connectivity of disulfide bridges. The cysteine framework was similar to the disulfide bridges present in μ-conotoxins, an unrelated class of peptide toxins. All the analogs possessed enhanced antimicrobial potency as compared to native HBD4. Among the analogs, the single disulfide bridged peptide showed maximum potency. However, there were no marked differences in the secondary structure of the analogs. Subtle variations were observed in the localization and membrane interaction of the analogs with bacteria and Candida albicans, suggesting a role for disulfide bridges in modulating their antimicrobial action. All analogs accumulated in the cytosol where they can bind to anionic molecules such as nucleic acids which would affect several cellular processes leading to cell death. Our study strongly suggests that native disulfide bridges or the canonical β-strands in defensins have not evolved for maximal activity but they play important roles in determining their antimicrobial potency.
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Affiliation(s)
- Himanshu Sharma
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Ramakrishnan Nagaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
- * E-mail:
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11
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Wang G. Human antimicrobial peptides and proteins. Pharmaceuticals (Basel) 2014; 7:545-94. [PMID: 24828484 PMCID: PMC4035769 DOI: 10.3390/ph7050545] [Citation(s) in RCA: 337] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/15/2014] [Accepted: 04/29/2014] [Indexed: 12/11/2022] Open
Abstract
As the key components of innate immunity, human host defense antimicrobial peptides and proteins (AMPs) play a critical role in warding off invading microbial pathogens. In addition, AMPs can possess other biological functions such as apoptosis, wound healing, and immune modulation. This article provides an overview on the identification, activity, 3D structure, and mechanism of action of human AMPs selected from the antimicrobial peptide database. Over 100 such peptides have been identified from a variety of tissues and epithelial surfaces, including skin, eyes, ears, mouths, gut, immune, nervous and urinary systems. These peptides vary from 10 to 150 amino acids with a net charge between -3 and +20 and a hydrophobic content below 60%. The sequence diversity enables human AMPs to adopt various 3D structures and to attack pathogens by different mechanisms. While α-defensin HD-6 can self-assemble on the bacterial surface into nanonets to entangle bacteria, both HNP-1 and β-defensin hBD-3 are able to block cell wall biosynthesis by binding to lipid II. Lysozyme is well-characterized to cleave bacterial cell wall polysaccharides but can also kill bacteria by a non-catalytic mechanism. The two hydrophobic domains in the long amphipathic α-helix of human cathelicidin LL-37 lays the basis for binding and disrupting the curved anionic bacterial membrane surfaces by forming pores or via the carpet model. Furthermore, dermcidin may serve as ion channel by forming a long helix-bundle structure. In addition, the C-type lectin RegIIIα can initially recognize bacterial peptidoglycans followed by pore formation in the membrane. Finally, histatin 5 and GAPDH(2-32) can enter microbial cells to exert their effects. It appears that granulysin enters cells and kills intracellular pathogens with the aid of pore-forming perforin. This arsenal of human defense proteins not only keeps us healthy but also inspires the development of a new generation of personalized medicine to combat drug-resistant superbugs, fungi, viruses, parasites, or cancer. Alternatively, multiple factors (e.g., albumin, arginine, butyrate, calcium, cyclic AMP, isoleucine, short-chain fatty acids, UV B light, vitamin D, and zinc) are able to induce the expression of antimicrobial peptides, opening new avenues to the development of anti-infectious drugs.
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Affiliation(s)
- Guangshun Wang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA.
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12
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Dekan Z, Mobli M, Pennington MW, Fung E, Nemeth E, Alewood PF. Total Synthesis of Human Hepcidin through Regioselective Disulfide-Bond Formation by using the Safety-Catch Cysteine Protecting Group 4,4′-Dimethylsulfinylbenzhydryl. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201310103] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Dekan Z, Mobli M, Pennington MW, Fung E, Nemeth E, Alewood PF. Total Synthesis of Human Hepcidin through Regioselective Disulfide-Bond Formation by using the Safety-Catch Cysteine Protecting Group 4,4′-Dimethylsulfinylbenzhydryl. Angew Chem Int Ed Engl 2014; 53:2931-4. [DOI: 10.1002/anie.201310103] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 12/30/2013] [Indexed: 11/08/2022]
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14
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Molecular and functional analysis of human β-defensin 3 action at melanocortin receptors. ACTA ACUST UNITED AC 2014; 20:784-95. [PMID: 23790489 DOI: 10.1016/j.chembiol.2013.04.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 04/24/2013] [Accepted: 04/26/2013] [Indexed: 11/23/2022]
Abstract
The β-defensins are a class of small, cationic proteins first recognized as antimicrobial components of the innate and adaptive immune system. More recently, one of the major β-defensins produced in skin, β-defensin 3, has been discovered to function as a melanocortin receptor ligand in vivo and in vitro, but its biophysical and pharmacological basis of action has been enigmatic. Here, we report functional and biochemical studies focused on human β-defensin 3 (HBD3) and melanocortin receptors 1 and 4. Genetic and pharmacologic studies indicate that HBD3 acts as a neutral melanocortin receptor antagonist capable of blocking the action of either stimulatory agonists such as α-melanocyte stimulating hormone or inhibitory inverse agonists such as Agouti signaling protein (ASIP) and Agouti-related protein (AGRP). A comprehensive structure-function analysis demonstrates that two patches of positively charged residues, located on opposite poles of HBD3 and spatially organized by the compact β-defensin fold, are primarily responsible for high-affinity binding to melanocortin receptors. These findings identify a distinct mode of melanocortin receptor-ligand interactions based primarily on electrostatic complementarity, with implications for designing ligands that target melanocortin and potentially other seven transmembrane receptors.
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16
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Chen WW, Sing Tay DK, Leong SSJ, Kwak SK. Three-dimensional structure of human β-defensin 28 via homology modelling and molecular dynamics. MOLECULAR SIMULATION 2012. [DOI: 10.1080/08927022.2011.604854] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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17
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Mackenzie-Dyck S, Attah-Poku S, Juillard V, Babiuk LA, van Drunen Littel-van den Hurk S. The synthetic peptides bovine enteric β-defensin (EBD), bovine neutrophil β-defensin (BNBD) 9 and BNBD 3 are chemotactic for immature bovine dendritic cells. Vet Immunol Immunopathol 2011; 143:87-107. [PMID: 21764462 DOI: 10.1016/j.vetimm.2011.06.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 05/11/2011] [Accepted: 06/17/2011] [Indexed: 11/17/2022]
Abstract
Human and murine immature DCs (iDCs) are highly efficient in antigen capture and processing, while as mature cells they present antigen and are potent initiators of cell-mediated immune responses. Consequently, iDCs are logical targets for vaccine antigens. Originally discovered for their antimicrobial activity, and thought of as strictly part of the innate immune system, studies with defensins such as human β (beta)-defensin 2 (hBD2) and murine β-defensin 2 (mBD2) have shown that they can function as chemo-attractant for iDCs and, in vaccination strategies, can enhance antigen-specific adaptive immune responses. Most studies to date have been conducted in mice. In contrast, little is known about defensins in cattle. To expand our understanding of the role of defensins in modulating immune responses in cattle, DCs were generated from bovine monocytes and the immature state of these bovine DCs was characterized phenotypically and through functional assays. By day 3 (DC3), bovine monocyte-derived DCs stained positively for DC-specific receptors CD1, CD80/86, CD205, DC-Lamp and MMR. When compared to conventional 6-day DC cultures or DCs cultured for 10 days with and without maturation factors, these DC3 were functionally at their most immature stage. Fourteen of the 16 known bovine β-defensins were synthesized and the synthetic peptides were screened for their ability to attract bovine iDCs. Bovine DC3 were consistently attracted to BNBD3, an analog of BNBD3 (aBNBD3), BNBD9 and bovine EBD in vitro and to aBNBD3 in vivo. These results are the first to describe chemotactic ability of synthetic bovine β-defensins for immature bovine monocyte-derived DCs.
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Affiliation(s)
- Sarah Mackenzie-Dyck
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
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Shen F, Zhang ZP, Li JB, Lin Y, Liu L. Hydrazine-Sensitive Thiol Protecting Group for Peptide and Protein Chemistry. Org Lett 2011; 13:568-71. [DOI: 10.1021/ol1028755] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fei Shen
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China, and Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Zhi-Ping Zhang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China, and Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jia-Bin Li
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China, and Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yun Lin
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China, and Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Lei Liu
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China, and Department of Chemistry, Tsinghua University, Beijing 100084, China
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Tay DKS, Rajagopalan G, Li X, Chen Y, Lua LH, Leong SSJ. A new bioproduction route for a novel antimicrobial peptide. Biotechnol Bioeng 2010; 108:572-81. [DOI: 10.1002/bit.22970] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 08/31/2010] [Accepted: 09/30/2010] [Indexed: 11/07/2022]
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20
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Liu H, Boudreau MA, Zheng J, Whittal RM, Austin P, Roskelley CD, Roberge M, Andersen RJ, Vederas JC. Chemical Synthesis and Biological Activity of the Neopetrosiamides and Their Analogues: Revision of Disulfide Bond Connectivity. J Am Chem Soc 2010; 132:1486-7. [DOI: 10.1021/ja9102925] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hongqiang Liu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Marc A. Boudreau
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Jing Zheng
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Randy M. Whittal
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Pamela Austin
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Calvin D. Roskelley
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Michel Roberge
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Raymond J. Andersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - John C. Vederas
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Departments of Biochemistry and Molecular Biology, Cellular and Physiological Sciences, and Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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21
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Erez O, Romero R, Tarca AL, Chaiworapongsa T, Kim YM, Than NG, Vaisbuch E, Draghici S, Tromp G. Differential expression pattern of genes encoding for anti-microbial peptides in the fetal membranes of patients with spontaneous preterm labor and intact membranes and those with preterm prelabor rupture of the membranes. J Matern Fetal Neonatal Med 2009; 22:1103-15. [PMID: 19916708 PMCID: PMC3560925 DOI: 10.3109/14767050902994796] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Increased amniotic fluid concentrations of anti-microbial peptides, components of the innate immune system, have been reported in patients with preterm labor (PTL) with intact membranes and intra-amniotic infection and/or inflammation (IAI), as well as in patients with preterm prelabor rupture of the membranes (PPROM). This study was designed to confirm these results using a targeted approach, detecting DEFA1, DEFB1, GNLY, and S100A9 gene expression in the choriamniotic membranes in pregnancies complicated with PTL and intact membranes or PPROM, with and without histologic chorioamnionitis. STUDY DESIGN Human fetal membranes were obtained from patients in the following groups: (1) PTL with intact membranes (n = 15); (2) PTL with intact membranes with histologic chorioamnionitis (n = 12); (3) PPROM (n = 17); and (4) PPROM with histologic chorioamnionitis (n = 21). The mRNA expression of alpha-defensin-1, beta-defensin-1, calgranulin B and granulysin in the fetal membranes was determined by qRT-PCR. RESULTS (1) The expression of alpha-defensin-1 mRNA in the fetal membranes was higher in patients with PTL and intact membranes with histologic chorioamnionitis, than those without chorioamnionitis (19.4-fold, p < 0.001); (2) Among patients with histologic chorioamnionitis, patients with PTL and intact membranes had a higher alpha-defensin-1 mRNA expression than those with PPROM (5.5-fold, p = 0.003); (3) Histologic chorioamnionitis was associated with a higher calgranulin B mRNA expression in the chorioamniotic membranes of patients with both PTL and intact membranes (7.9-fold, p = 0.03) and PPROM (7.6-fold, p < 0.0001); (4) The expression of calgranulin B mRNA in the fetal membranes was higher in patients with PTL and intact membranes without histologic chorioamnionitis than in those with PPROM without histologic chorioamnionitis (2.7-fold, p = 0.03); (5) There were no differences in the expression of beta-defensin-1 and granulysin in the chorioamniotic membranes between the study groups even in the presence of histologic chorioamnioniotis. CONCLUSIONS (1) Among patients with histologic chorioamnionitis, the mRNA expression of alpha-defensin-1 and calgranulin B in the fetal membranes of patients with PTL and intact membranes as well as that of calgranulin B in the fetal membranes of patients with PPROM is higher than in the membranes of those without histologic chorioamnionitis; (2) histologic chorioamnionitis is associated with differences in the pattern of alpha-defensin-1 mRNA expression in the fetal membranes in patients with PTL and intact membranes and those with PPROM.
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MESH Headings
- Adolescent
- Adult
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Antimicrobial Cationic Peptides/genetics
- Antimicrobial Cationic Peptides/metabolism
- Calgranulin B/genetics
- Calgranulin B/metabolism
- Defensins/genetics
- Defensins/metabolism
- Extraembryonic Membranes/metabolism
- Extraembryonic Membranes/pathology
- Female
- Fetal Membranes, Premature Rupture/genetics
- Fetal Membranes, Premature Rupture/metabolism
- Fetal Membranes, Premature Rupture/pathology
- Gene Expression Regulation
- Gestational Age
- Humans
- Obstetric Labor, Premature/genetics
- Obstetric Labor, Premature/metabolism
- Obstetric Labor, Premature/pathology
- Pregnancy
- RNA, Messenger/analysis
- Young Adult
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Affiliation(s)
- Offer Erez
- Perinatology Research Branch, NICHD, NIH, DHHS, Detroit, Michigan, USA
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22
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Directional and balancing selection in human beta-defensins. BMC Evol Biol 2008; 8:113. [PMID: 18416833 PMCID: PMC2373304 DOI: 10.1186/1471-2148-8-113] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 04/16/2008] [Indexed: 01/04/2023] Open
Abstract
Background In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. Results We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93), is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Conclusion Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.
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Krishnakumari V, Singh S, Nagaraj R. Antibacterial activities of synthetic peptides corresponding to the carboxy-terminal region of human beta-defensins 1-3. Peptides 2006; 27:2607-13. [PMID: 16860904 DOI: 10.1016/j.peptides.2006.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Revised: 06/03/2006] [Accepted: 06/12/2006] [Indexed: 12/20/2022]
Abstract
The antibacterial activities of synthetic human beta-defensin analogs, constrained by a single disulfide bridge and in the reduced form, have been investigated. The peptides span the carboxy-terminal region of human beta-defensins (HBD-1-3), which have a majority of cationic residues present in the native defensins. The disulfide constrained peptides exhibited activity against Escherichia coli and Staphylococcus aureus whereas the reduced forms were active only against E. coli. The antibacterial activities were attenuated in the presence of increasing concentrations of NaCl and divalent cations such as Ca(2+) and Mg(2+). The site of action was the bacterial membrane. Peptides spanning the carboxy-terminal region of human beta-defensins could be of help in understanding facets of antimicrobial activity of beta-defensins such as salt sensitivity and mechanisms of bacterial membrane damage.
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24
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Pazgier M, Prahl A, Hoover DM, Lubkowski J. Studies of the biological properties of human beta-defensin 1. J Biol Chem 2006; 282:1819-29. [PMID: 17071614 DOI: 10.1074/jbc.m607210200] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Defensins are small (30-45 amino acid residues) cationic proteins with broad antimicrobial activity against many bacteria and fungi, some enveloped viruses, and other activities such as chemoattraction of a range of different cell types to the sites of inflammation. These proteins represent attractive targets for developing novel antimicrobial agents and modulators of immune responses with therapeutic applicability. In this report, we present the results of functional and structural studies of 26 single-site mutants of human beta-defensin 1 (hBD1). All mutants were assayed for antimicrobial activity against Escherichia coli (ATCC strain 25922) and for chemotactic activity with CCR6-transfected HEK293 cells. To analyze the structural implications of mutagenesis and to verify the correctness of the disulfide connectivity, we used x-ray crystallography to conduct complete structural studies for 10 mutants in which the topology of disulfides was the same as in the native hBD1. Mutations did not induce significant changes of the tertiary structure, suggesting that the observed alterations of biological properties of the mutants were solely associated with changes in the respective side chains. We found that cationic residues located near the C terminus (Arg(29), Lys(31), Lys(33), and Lys(36)) of hBD1 define most of the anti-E. coli in vitro activity of this protein. In turn, nearly all mutations altering the CCR6-mediated chemotaxis are located at one area of the protein, defined by the N-terminal alpha-helical region (Asp(1)... Ser(8)) and a few topologically adjacent residues (Lys(22), Arg(29), and Lys(33)). These experimental results allow for the first time drafting of the CCR6-epitope for a defensin molecule.
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Affiliation(s)
- Marzena Pazgier
- Macromolecular Crystallography Laboratory, NCI, National Institutes of Health, Frederick, Maryland 21702, USA
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25
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Dhople V, Krukemeyer A, Ramamoorthy A. The human beta-defensin-3, an antibacterial peptide with multiple biological functions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1499-512. [PMID: 16978580 DOI: 10.1016/j.bbamem.2006.07.007] [Citation(s) in RCA: 208] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 06/13/2006] [Accepted: 07/13/2006] [Indexed: 12/21/2022]
Abstract
A group of interesting molecules called defensins exhibit multiple functions but have been primarily recognized to possess a broad spectrum of antimicrobial activities. Studies have reported two different types of defensins (alpha and beta) from human and animals, a cyclic theta defensin from rhesus, and several defensin-like peptides from plants. There is no amino acid sequence homology between these peptides, but they all contain three Cys-Cys disulfide linkages while the connectivities are different. Human beta-defensin-3 (HbetaD-3) is the most recently discovered member of the host-defense peptide family that has attracted much attention. This molecule is expressed either constitutively or induced upon a challenge, and a growing evidence indicates the involvement of such molecules in adaptive immunity as well. It has been shown to exhibit antibacterial activities towards Gram-negative and Gram-positive bacteria as well as an ability to act as a chemo-attractant. Analysis of NMR structural data suggested a symmetrical dimeric form of this peptide in solution, which consists of three beta strands and a short helix in the N-terminal region. While the disulfide linkages are known to provide the structural stability and stability against proteases, the biological relevance of this dimeric form was contradicted by another biological study. Since there is considerable current interest in developing HbetaD-3 for possible pharmaceutical applications, studies to further our understanding on the determinants of antibacterial activities and immunomodulatory function of HbetaD-3 are considered to be highly significant. The knowledge of its biosynthetic regulation will also help in understanding the role of HbetaD-3 in immunity. This article presents an overview of the expression and regulation of HbetaD-3 in humans, and the structure-function correlations among HbetaD-3 and its modified peptides are discussed emphasizing the functional importance. The future scope for studies on HbetaD-3 and design of short potent antimicrobial peptides, based on the native HbetaD-3 molecule, that do not interfere in the immunomodulatory function is also outlined.
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Affiliation(s)
- Vishnu Dhople
- Biophysics Research Division and Department of Chemistry, The University of Michigan, Ann Arbor, MI 48109-1055, USA
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26
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Motzkus D, Schulz-Maronde S, Heitland A, Schulz A, Forssmann WG, Jübner M, Maronde E. The novel beta-defensin DEFB123 prevents lipopolysaccharide-mediated effects in vitro and in vivo. FASEB J 2006; 20:1701-2. [PMID: 16790530 DOI: 10.1096/fj.05-4970fje] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Defensins are a family of secreted antimicrobial peptides proposed to directly interfere with bacterial membranes. Here we show a functional analysis of the novel beta-defensin DEFB123. A peptide comprising the beta-defensin core region was synthesized and used for our analysis. Like other beta-defensins, DEFB123 exerted antimicrobial activity against a broad spectrum of Gram-positive and Gram-negative bacteria, which was assessed by microbroth dilution assay and radial diffusion zone assay. In addition, the peptide showed lipopolysaccharide (LPS)-binding activity in a Limulus amoebocyte lysate (LAL) assay. Moreover, DEFB123 prevented LPS-induced tumor necrosis factor (TNF)-alpha secretion in a murine monocyte cell line (RAW264.7). Accordingly, DEFB123 abolished LPS-mediated MAPK induction in these cells. Protection against LPS-mediated effects was then investigated in a murine model of acute sepsis. Our experiments show that synthetic beta-defensin DEFB123 prevents LPS-induced mortality in C57BL/6 mice in a therapeutic approach. We propose that the physiological role of beta-defensins may include interference with LPS-action on macrophages, a function formerly thought to be restricted to the family of cathelicidins, a structurally unrelated group of antimicrobial peptides.
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27
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Klüver E, Adermann K, Schulz A. Synthesis and structure-activity relationship of beta-defensins, multi-functional peptides of the immune system. J Pept Sci 2006; 12:243-57. [PMID: 16491514 DOI: 10.1002/psc.749] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
beta-defensins are a large family of multiple disulfide-bonded peptides occurring in mammals and birds. They play an important role in the innate immune system, directly killing microbial organisms. Recent research has demonstrated that beta-defensins are important for other biological functions beyond antimicrobial effects, including inhibition of viral infection, interaction with Toll-like receptors, chemotactic effects, and sperm function. The corresponding broad spectrum of activities makes this peptide class an important subject and tool in immunologic research. In this review, we summarize the current status of the routes to obtain synthetic beta-defensins, their major structural properties and structure-activity relationship.
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28
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Klüver E, Schulz-Maronde S, Scheid S, Meyer B, Forssmann WG, Adermann K. Structure-activity relation of human beta-defensin 3: influence of disulfide bonds and cysteine substitution on antimicrobial activity and cytotoxicity. Biochemistry 2005; 44:9804-16. [PMID: 16008365 DOI: 10.1021/bi050272k] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human beta-defensins form a group of cysteine-rich antimicrobial peptides which have been found in epithelial tissue and, more recently, in the male genital tract. They play a role in the defense against microbial pathogens in innate immunity and display additional chemotactic functions in the adaptive immune system. An important characteristic of antimicrobial peptides is that they also exhibit toxic potential on eukaryotic cells. Very little is known about the structure dependence of antimicrobial and cytotoxic effects. We investigated human beta-defensin 3 (hBD-3), a potent broad-spectrum antimicrobial effector peptide, regarding the influence of structural parameters on the antimicrobial and cytotoxic activity. We have established a structure-activity relation of the hBD-3 using synthetic derivatives differing in length, charge, disulfide connectivity, and overall hydrophobicity. The antimicrobial activity of the peptides was compared to the cyctotoxic effects on monocytic THP-1 cells and the hemolytic activity on human erythrocytes. We found that it is not important for antimicrobial and cytotoxic activity whether and how cysteine residues are arranged to form disulfide bonds. Substitution of half-cystinyl residues by tryptophan resulted in increased activities, while other substitutions did not change activity. Correlation of activities with the structural changes demonstrates that the activity on eukaryotic cells appears to depend strongly on the overall hydrophobicity. In contrast, the antimicrobial potency of hBD-3 peptides is determined by the distribution of positively charged amino acid residues and hydrophobic side chains. The results facilitate the understanding of beta-defensin interaction with different cell types and guide the design of antimicrobially active peptides.
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Affiliation(s)
- Enno Klüver
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Strasse 31, D-30625 Hannover, Germany.
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