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Góngora-Benítez M, Tulla-Puche J, Albericio F. Multifaceted Roles of Disulfide Bonds. Peptides as Therapeutics. Chem Rev 2013; 114:901-26. [DOI: 10.1021/cr400031z] [Citation(s) in RCA: 388] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Miriam Góngora-Benítez
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Judit Tulla-Puche
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Fernando Albericio
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
- Department
of Organic Chemistry, University of Barcelona, Barcelona, 08028 Spain
- School of Chemistry & Physics, University of KwaZulu-Natal, 4001 Durban, South Africa
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102
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Bock JE, Gavenonis J, Kritzer JA. Getting in shape: controlling peptide bioactivity and bioavailability using conformational constraints. ACS Chem Biol 2013; 8:488-499. [PMID: 23170954 PMCID: PMC4847942 DOI: 10.1021/cb300515u] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chemical biologists commonly seek out correlations between the physicochemical properties of molecules and their behavior in biological systems. However, a new paradigm is emerging for peptides in which conformation is recognized as the primary determinant of bioactivity and bioavailability. This review highlights an emerging body of work that directly addresses how a peptide's conformation controls its biological effects, cell penetration, and intestinal absorption. Based on this work, the dream of mimicking the potency and bioavailability of natural product peptides is getting closer to reality.
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Affiliation(s)
- Jonathan E. Bock
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Jason Gavenonis
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Joshua A. Kritzer
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
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103
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Conibear AC, Rosengren KJ, Daly NL, Henriques ST, Craik DJ. The cyclic cystine ladder in θ-defensins is important for structure and stability, but not antibacterial activity. J Biol Chem 2013; 288:10830-40. [PMID: 23430740 DOI: 10.1074/jbc.m113.451047] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
θ-Defensins are ribosomally synthesized cyclic peptides found in the leukocytes of some primate species and have promising applications as antimicrobial agents and scaffolds for peptide drugs. The cyclic cystine ladder motif, comprising a cyclic peptide backbone and three parallel disulfide bonds, is characteristic of θ-defensins. In this study, we explore the role of the cyclic peptide backbone and cystine ladder in the structure, stability, and activity of θ-defensins. θ-Defensin analogues with different numbers and combinations of disulfide bonds were synthesized and characterized in terms of their NMR solution structures, serum and thermal stabilities, and their antibacterial and membrane-binding activities. Whereas the structures and stabilities of the peptides were primarily dependent on the number and position of the disulfide bonds, their antibacterial and membrane-binding properties were dependent on the cyclic backbone. The results provide insights into the mechanism of action of θ-defensins and illustrate the potential of θ-defensin analogues as scaffolds for peptide drug design.
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Affiliation(s)
- Anne C Conibear
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane, Queensland 4072, Australia
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104
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Mishra B, Epand RF, Epand RM, Wang G. Structural location determines functional roles of the basic amino acids of KR-12, the smallest antimicrobial peptide from human cathelicidin LL-37. RSC Adv 2013. [PMID: 24307932 DOI: 10.1039/c3ra42599a] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cationic antimicrobial peptides are recognized templates for developing a new generation of antimicrobials to combat superbugs. Human cathelicidin LL-37 is an essential host defense molecule in human innate immunity. Previously, we identified KR-12 as the smallest antibacterial peptide of LL-37. KR-12 has a narrow activity spectrum since it is active against Gram-negative Escherichia coli but not Gram-positive Staphylococcus aureus. The functional roles of the basic amino acids of KR-12, however, have not yet been elucidated. An alanine scan of cationic amino acids of KR-12 provided evidence for their distinct roles in the activities of the peptides. Bacterial killing and membrane permeation experiments indicate that the R23A and K25A mutants, as well as the lysine-to-arginine mutant, were more potent than KR-12. Another three cationic residues (K18, R19, and R29) of KR-12, which are located in the hydrophilic face of the amphiphathic helix, appeared to be more important in clustering anionic lipids or hemolysis than R23 and K25 in the interfacial region. While the loss of interfacial R23 or K25 reduced peptide helicity, underscoring its important role in membrane binding, the overall increase in peptide activity of KR-12 could be ascribed to the increased peptide hydrophobicity that outweighed the role of basic charge in this case. In contrast, the mutations of interfacial R23 or K25 reduced peptide bactericidal activity of GF-17, an overlapping, more hydrophobic and potent peptide also derived from LL-37. Thus, the hydrophobic context of the peptide determines whether an alanine substitution of an interfacial basic residue increases or decreases membrane permeation and peptide activity.
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Affiliation(s)
- Biswajit Mishra
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA
| | - Raquel F Epand
- Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre, Hamilton, Ontario, L8S 4K1, Canada
| | - Richard M Epand
- Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre, Hamilton, Ontario, L8S 4K1, Canada
| | - 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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105
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Schaal JB, Tran D, Tran P, Ösapay G, Trinh K, Roberts KD, Brasky KM, Tongaonkar P, Ouellette AJ, Selsted ME. Rhesus macaque theta defensins suppress inflammatory cytokines and enhance survival in mouse models of bacteremic sepsis. PLoS One 2012; 7:e51337. [PMID: 23236475 PMCID: PMC3516535 DOI: 10.1371/journal.pone.0051337] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 11/07/2012] [Indexed: 02/08/2023] Open
Abstract
Theta-defensins (θ-defensins) are macrocyclic antimicrobial peptides expressed in leukocytes of Old World monkeys. The peptides are broad spectrum microbicides in vitro and numerous θ-defensin isoforms have been identified in granulocytes of rhesus macaques and Olive baboons. Several mammalian α- and β-defensins, genetically related to θ-defensins, have proinflammatory and immune-activating properties that bridge innate and acquired immunity. In the current study we analyzed the immunoregulatory properties of rhesus θ-defensins 1–5 (RTDs 1–5). RTD-1, the most abundant θ-defensin in macaques, reduced the levels of TNF, IL-1α, IL-1β, IL-6, and IL-8 secreted by blood leukocytes stimulated by several TLR agonists. RTDs 1–5 suppressed levels of soluble TNF released by bacteria- or LPS-stimulated blood leukocytes and THP-1 monocytes. Despite their highly conserved conformation and amino acid sequences, the anti-TNF activities of RTDs 1–5 varied by as much as 10-fold. Systemically administered RTD-1 was non-toxic for BALB/c mice, and escalating intravenous doses were well tolerated and non-immunogenic in adult chimpanzees. The peptide was highly stable in serum and plasma. Single dose administration of RTD-1 at 5 mg/kg significantly improved survival of BALB/c mice with E. coli peritonitis and cecal ligation-and-puncture induced polymicrobial sepsis. Peptide treatment reduced serum levels of several inflammatory cytokines/chemokines in bacteremic animals. Collectively, these results indicate that the anti-inflammatory properties of θ-defensins in vitro and in vivo are mediated by the suppression of numerous proinflammatory cytokines and blockade of TNF release may be a primary effect.
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Affiliation(s)
- Justin B. Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - George Ösapay
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, United States of America
| | - Katie Trinh
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kevin D. Roberts
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kathleen M. Brasky
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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106
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Conibear AC, Rosengren KJ, Harvey PJ, Craik DJ. Structural characterization of the cyclic cystine ladder motif of θ-defensins. Biochemistry 2012; 51:9718-26. [PMID: 23148585 DOI: 10.1021/bi301363a] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The θ-defensins are, to date, the only known ribosomally synthesized cyclic peptides in mammals, and they have promising antimicrobial bioactivities. The characteristic structural motif of the θ-defensins is the cyclic cystine ladder, comprising a cyclic peptide backbone and three parallel disulfide bonds. In contrast to the cyclic cystine knot, which characterizes the plant cyclotides, the cyclic cystine ladder has not been as well described as a structural motif. Here we report the solution structures and nuclear magnetic resonance relaxation properties in aqueous solution of three representative θ-defensins from different species. Our data suggest that the θ-defensins are more rigid and structurally defined than previously thought. In addition, all three θ-defensins were found to self-associate in aqueous solution in a concentration-dependent and reversible manner, a property that might have a role in their mechanism of action. The structural definition of the θ-defensins and the cyclic cystine ladder will help to guide exploitation of these molecules as structural frameworks for the design of peptide drugs.
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Affiliation(s)
- Anne C Conibear
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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