251
|
Wen J, Liao H, Stachowski K, Hempfling JP, Qian Z, Yuan C, Foster MP, Pei D. Rational design of cell-permeable cyclic peptides containing a d-Pro-l-Pro motif. Bioorg Med Chem 2020; 28:115711. [PMID: 33069067 DOI: 10.1016/j.bmc.2020.115711] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 12/01/2022]
Abstract
Cyclic peptides are capable of binding to challenging targets (e.g., proteins involved in protein-protein interactions) with high affinity and specificity, but generally cannot gain access to intracellular targets because of poor membrane permeability. In this work, we discovered a conformationally constrained cyclic cell-penetrating peptide (CPP) containing a d-Pro-l-Pro motif, cyclo(AFΦrpPRRFQ) (where Φ is l-naphthylalanine, r is d-arginine, and p is d-proline). The structural constraints provided by cyclization and the d-Pro-l-Pro motif permitted the rational design of cell-permeable cyclic peptides of large ring sizes (up to 16 amino acids). This strategy was applied to design a potent, cell-permeable, and biologically active cyclic peptidyl inhibitor, cyclo(YpVNFΦrpPRR) (where Yp is l-phosphotyrosine), against the Grb2 SH2 domain. Multidimensional NMR spectroscopic and circular dichroism analyses revealed that the cyclic CPP as well as the Grb2 SH2 inhibitor assume a predominantly random coil structure but have significant β-hairpin character surrounding the d-Pro-l-Pro motif. These results demonstrate cyclo(AFΦrpPRRFQ) as an effective CPP for endocyclic (insertion of cargo into the CPP ring) or exocyclic delivery of biological cargos (attachment of cargo to the Gln side chain).
Collapse
Affiliation(s)
- Jin Wen
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Hui Liao
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Kye Stachowski
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Jordan P Hempfling
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Ziqing Qian
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Chunhua Yuan
- Campus Chemical Instrument Center, The Ohio State University, 460 West 12(th) Avenue, Columbus, OH 43210, USA
| | - Mark P Foster
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA.
| | - Dehua Pei
- Department of Chemistry and Biochemistry and Ohio State Biochemistry Program, The Ohio State University, 484 West 12(th) Avenue, Columbus, OH 43210, USA.
| |
Collapse
|
252
|
Nam HY, Choi J, Kumar SD, Nielsen JE, Kyeong M, Wang S, Kang D, Lee Y, Lee J, Yoon MH, Hong S, Lund R, Jenssen H, Shin SY, Seo J. Helicity Modulation Improves the Selectivity of Antimicrobial Peptoids. ACS Infect Dis 2020; 6:2732-2744. [PMID: 32865961 DOI: 10.1021/acsinfecdis.0c00356] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The modulation of conformational flexibility in antimicrobial peptides (AMPs) has been investigated as a strategy to improve their efficacy against bacterial pathogens while reducing their toxicity. Here, we synthesized a library of helicity-modulated antimicrobial peptoids by the position-specific incorporation of helix-inducing monomers. The peptoids displayed minimal variations in hydrophobicity, which permitted the specific assessment of the effect of conformational differences on antimicrobial activity and selectivity. Among the moderately helical peptoids, the most dramatic increase in selectivity was observed in peptoid 17, providing more than a 20-fold increase compared to fully helical peptoid 1. Peptoid 17 had potent broad-spectrum antimicrobial activity that included clinically isolated multi-drug-resistant pathogens. Compared to pexiganan AMP, 17 showed superior metabolic stability, which could potentially reduce the dosage needed, alleviating toxicity. Dye-uptake assays and high-resolution imaging revealed that the antimicrobial activity of 17 was, as with many AMPs, mainly due to membrane disruption. However, the high selectivity of 17 reflected its unique conformational characteristics, with differential interactions between bacterial and erythrocyte membranes. Our results suggest a way to distinguish different membrane compositions solely by helicity modulation, thereby improving the selectivity toward bacterial cells with the maintenance of potent and broad-spectrum activity.
Collapse
Affiliation(s)
| | | | - S. Dinesh Kumar
- Department of Biomedical Science, Graduate School, and Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| | | | | | | | | | | | - Jiyoun Lee
- Department of Global Medical Science, Sungshin University, Seoul 01133, Republic of Korea
| | | | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, Roskilde DK-4000, Denmark
| | - Song Yub Shin
- Department of Biomedical Science, Graduate School, and Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| | | |
Collapse
|
253
|
Sindhikara D, Wagner M, Gkeka P, Güssregen S, Tiwari G, Hessler G, Yapici E, Li Z, Evers A. Automated Design of Macrocycles for Therapeutic Applications: From Small Molecules to Peptides and Proteins. J Med Chem 2020; 63:12100-12115. [PMID: 33017535 DOI: 10.1021/acs.jmedchem.0c01500] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Macrocycles and cyclic peptides are increasingly attractive therapeutic modalities as they often have improved affinity, are able to bind to extended protein surfaces, and otherwise have favorable properties. Macrocyclization of a known binder may stabilize its bioactive conformation and improve its metabolic stability, cell permeability, and in certain cases oral bioavailability. Herein, we present implementation and application of an approach that automatically generates, evaluates, and proposes cyclizations utilizing a library of well-established chemical reactions and reagents. Using the three-dimensional (3D) conformation of the linear molecule in complex with a target protein as the starting point, this approach identifies attachment points, generates linkers, evaluates their geometric compatibility, and ranks the resulting molecules with respect to their predicted conformational stability and interactions with the target protein. As we show here with prospective and retrospective case studies, this procedure can be applied for the macrocyclization of small molecules and peptides and even PROteolysis TArgeting Chimeras (PROTACs) and proteins.
Collapse
Affiliation(s)
- Dan Sindhikara
- Schrodinger, Inc., 120 West 45th Street, New York, New York 10036, United States
| | - Michael Wagner
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| | - Paraskevi Gkeka
- Integrated Drug Discovery, Sanofi R&D, 1 Avenue Pierre Brossolette, 91385 Chilly-Mazarin, France
| | - Stefan Güssregen
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| | - Garima Tiwari
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| | - Gerhard Hessler
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| | - Engin Yapici
- Schrodinger, Inc., 120 West 45th Street, New York, New York 10036, United States
| | - Ziyu Li
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| | - Andreas Evers
- Integrated Drug Discovery, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt am Main, Germany
| |
Collapse
|
254
|
Tissue-Specific Delivery of CRISPR Therapeutics: Strategies and Mechanisms of Non-Viral Vectors. Int J Mol Sci 2020; 21:ijms21197353. [PMID: 33027946 PMCID: PMC7583726 DOI: 10.3390/ijms21197353] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 09/24/2020] [Accepted: 09/27/2020] [Indexed: 02/07/2023] Open
Abstract
The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) genome editing system has been the focus of intense research in the last decade due to its superior ability to desirably target and edit DNA sequences. The applicability of the CRISPR-Cas system to in vivo genome editing has acquired substantial credit for a future in vivo gene-based therapeutic. Challenges such as targeting the wrong tissue, undesirable genetic mutations, or immunogenic responses, need to be tackled before CRISPR-Cas systems can be translated for clinical use. Hence, there is an evident gap in the field for a strategy to enhance the specificity of delivery of CRISPR-Cas gene editing systems for in vivo applications. Current approaches using viral vectors do not address these main challenges and, therefore, strategies to develop non-viral delivery systems are being explored. Peptide-based systems represent an attractive approach to developing gene-based therapeutics due to their specificity of targeting, scale-up potential, lack of an immunogenic response and resistance to proteolysis. In this review, we discuss the most recent efforts towards novel non-viral delivery systems, focusing on strategies and mechanisms of peptide-based delivery systems, that can specifically deliver CRISPR components to different cell types for therapeutic and research purposes.
Collapse
|
255
|
Sahni A, Qian Z, Pei D. Cell-Penetrating Peptides Escape the Endosome by Inducing Vesicle Budding and Collapse. ACS Chem Biol 2020; 15:2485-2492. [PMID: 32786250 DOI: 10.1021/acschembio.0c00478] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-penetrating peptides (CPPs) are capable of delivering membrane-impermeable cargoes (including small molecules, peptides, proteins, nucleic acids, and nanoparticles) into the cytosol of mammalian cells and have the potential to revolutionize biomedical research and drug discovery. However, the mechanism of action of CPPs has remained poorly understood, especially how they escape from the endosome into the cytosol following endocytic uptake. We show herein that CPPs exit the endosome by inducing budding and collapse of CPP-enriched vesicles from the endosomal membrane. This mechanism provides a theoretical basis for designing CPPs and other delivery vehicles of improved efficiencies.
Collapse
Affiliation(s)
- Ashweta Sahni
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| | - Ziqing Qian
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| | - Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
256
|
Chen K, Pei D. Engineering Cell-Permeable Proteins through Insertion of Cell-Penetrating Motifs into Surface Loops. ACS Chem Biol 2020; 15:2568-2576. [PMID: 32786266 DOI: 10.1021/acschembio.0c00593] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Effective delivery of proteins into the cytosol of mammalian cells would open the door to a wide range of applications. However, despite great efforts from numerous investigators, effective protein delivery in a clinical setting is yet to be accomplished. Herein we report a potentially general approach to engineering cell-permeable proteins by genetically grafting a short cell-penetrating peptide (CPP) to an exposed loop of a protein of interest. The grafted peptide is conformationally constrained, exhibiting enhanced proteolytic stability and cellular entry efficiency. Applying this technique to enhanced green fluorescent protein (EGFP), protein-tyrosine phosphatase 1B (PTP1B), and purine nucleoside phosphorylase (PNP) rendered all three proteins cell-permeable and biologically active in cellular assays. When added into growth medium at 0.5-5 μM concentrations, the engineered PTP1B dose-dependently reduced the phosphotyrosine levels of intracellular proteins, while the modified PNP corrected the metabolic deficiency of PNP-deficient mouse T lymphocytes, providing a potential enzyme replacement therapy for a rare genetic disease.
Collapse
Affiliation(s)
- Kuangyu Chen
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| |
Collapse
|
257
|
Kondow-McConaghy HM, Muthukrishnan N, Erazo-Oliveras A, Najjar K, Juliano RL, Pellois JP. Impact of the Endosomal Escape Activity of Cell-Penetrating Peptides on the Endocytic Pathway. ACS Chem Biol 2020; 15:2355-2363. [PMID: 32786263 PMCID: PMC7502533 DOI: 10.1021/acschembio.0c00319] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cell-penetrating peptides (CPPs) are routinely used for the delivery of macromolecules into live human cells. To enter the cytosolic space of cells, CPPs typically permeabilize the membrane of endosomes. In turn, several approaches have been developed to increase the endosomal membrane permeation activity of CPPs so as to improve delivery efficiencies. The endocytic pathway is, however, important in maintaining cellular homeostasis, and understanding how endosomal permeation impacts cells is now critical to define the general utility of CPPs. Herein, we investigate how CPP-based delivery protocols affect the endocytic network. We detect that, in some cases, cell penetration induces the activation of Chmp1b, Galectin-3, and TFEB, which are components of endosomal repair, organelle clearance, and biogenesis pathways, respectively. We also detect that cellular delivery modulates endocytosis and endocytic proteolysis. Remarkably, a multimeric analogue of the prototypical CPP TAT permeabilizes endosomes efficiently without inducing membrane damage responses. These results challenge the notion that reagents that make endosomes leaky are generally toxic. Instead, our data indicates that it is possible to enter cells with minimal deleterious effects.
Collapse
Affiliation(s)
- Helena M. Kondow-McConaghy
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Nandhini Muthukrishnan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Alfredo Erazo-Oliveras
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Kristina Najjar
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Rudolph L. Juliano
- UNC Eshelman School of Pharmacy and UNC School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jean-Philippe Pellois
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| |
Collapse
|
258
|
Furukawa A, Schwochert J, Pye CR, Asano D, Edmondson QD, Turmon AC, Klein VG, Ono S, Okada O, Lokey RS. Drug‐Like Properties in Macrocycles above MW 1000: Backbone Rigidity versus Side‐Chain Lipophilicity. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Akihiro Furukawa
- Daiichi Sankyo Co., Ltd. 1-2-58, Hiromachi, Shinagawa-ku Tokyo 140-8710 Japan
| | - Joshua Schwochert
- Unnatural Products, Inc. 250 Natural Bridges Drive Santa Cruz CA 95060 USA
| | - Cameron R. Pye
- Unnatural Products, Inc. 250 Natural Bridges Drive Santa Cruz CA 95060 USA
| | - Daigo Asano
- Daiichi Sankyo Co., Ltd. 1-2-58, Hiromachi, Shinagawa-ku Tokyo 140-8710 Japan
| | - Quinn D. Edmondson
- Department of Pharmaceutical Chemistry University of California, San Francisco San Francisco California 94158 USA
| | | | - Victoria G. Klein
- Department of Chemistry & Biochemistry University of California Santa Cruz Santa Cruz CA 96064 USA
| | - Satoshi Ono
- Discovery Technology Laboratories Mitsubishi Tanabe Pharma Corporation Yokohama 227-0033 Japan
| | - Okimasa Okada
- Discovery Technology Laboratories Mitsubishi Tanabe Pharma Corporation Yokohama 227-0033 Japan
| | - R. Scott Lokey
- Department of Chemistry & Biochemistry University of California Santa Cruz Santa Cruz CA 96064 USA
| |
Collapse
|
259
|
Tian Y, Zhou S. Advances in cell penetrating peptides and their functionalization of polymeric nanoplatforms for drug delivery. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 13:e1668. [PMID: 32929866 DOI: 10.1002/wnan.1668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/03/2020] [Accepted: 08/03/2020] [Indexed: 12/19/2022]
Abstract
Cell penetrating peptides (CPPs), known as protein translocation domains, have emerged as efficient molecular transporters to overcome biological barriers and deliver cell-impermeable cargoes into cells. The conjugation of CPPs to polymeric nanoplatforms enhances the drug delivery efficiency thus increasing their therapeutic efficacy. However, conventional CPPs are generally lack of cell specificity and could be easily degraded in vivo. These limitations lead to the development of new CPPs with superior properties. To address the issue of cell specificity, activatable CPPs have been designed to be activated at desired site through different stimuli. On the other hand, macrocyclization has been used to constrain linear CPPs into their cyclic forms. This chemical optimization of peptides endows CPPs with enhanced stability and cell permeability. This brief review will cover recent advances in terms of different types of CPPs for enhanced cell penetration. In addition, the modification chemistry used to functionalize polymeric nanoplatforms with CPPs and their recent applications for drug delivery will also be discussed. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.
Collapse
Affiliation(s)
- Yuan Tian
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Shaobing Zhou
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| |
Collapse
|
260
|
Kumar S, Mandal D, El-Mowafi SA, Mozaffari S, Tiwari RK, Parang K. Click-Free Synthesis of a Multivalent Tricyclic Peptide as a Molecular Transporter. Pharmaceutics 2020; 12:pharmaceutics12090842. [PMID: 32899170 PMCID: PMC7558522 DOI: 10.3390/pharmaceutics12090842] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 01/19/2023] Open
Abstract
The cellular delivery of cell-impermeable and water-insoluble molecules remains an ongoing challenge to overcome. Previously, we reported amphipathic cyclic peptides c[WR]4 and c[WR]5 consisting of alternate arginine and tryptophan residues as nuclear-targeting molecular transporters. These peptides contain an optimal balance of positive charge and hydrophobicity, which is required for interactions with the phospholipid bilayer to facilitate their application as a drug delivery system. To further optimize them, we synthesized and evaluated a multivalent tricyclic peptide as an efficient molecular transporter. The monomeric cyclic peptide building blocks were synthesized using Fmoc/tBu solid-phase chemistry and cyclization in the solution and conjugated with each other through an amide bond to afford the tricyclic peptide, which demonstrated modest antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli (E. coli) with a minimum inhibitory concentration (MIC) of 64–128 µg/mL. The tricyclic peptide was found to be nontoxic up to 30 µM in the breast cancer cell lines (MDA-MB-231). The presence of tricyclic peptide enhanced cellular uptakes of fluorescently-labeled phosphopeptide (F’-GpYEEI, 18-fold), anti-HIV drugs (lamivudine (F’-3TC), emtricitabine (F’-FTC), and stavudine (F’-d4T), 1.7–12-fold), and siRNA (3.3-fold) in the MDA-MB-231 cell lines.
Collapse
Affiliation(s)
- Sumit Kumar
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
- Department of Chemistry, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana 131039, India
| | - Dindyal Mandal
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
- School of Biotechnology, KIIT Deemed to be University, Bhubaneswar 751024, India
| | - Shaima Ahmed El-Mowafi
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
- Peptide Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Saghar Mozaffari
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
| | - Rakesh Kumar Tiwari
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
- Correspondence: (R.K.T.); (K.P.); Tel.: +1-714-516-5483 (R.K.T.); +1-714-516-5489 (K.P.)
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Harry and Diane Rinker Health Science Campus, Chapman University School of Pharmacy, Irvine, CA 92618, USA; (S.K.); (D.M.); (S.A.E.-M.); (S.M.)
- Correspondence: (R.K.T.); (K.P.); Tel.: +1-714-516-5483 (R.K.T.); +1-714-516-5489 (K.P.)
| |
Collapse
|
261
|
Scheuplein NJ, Bzdyl NM, Kibble EA, Lohr T, Holzgrabe U, Sarkar-Tyson M. Targeting Protein Folding: A Novel Approach for the Treatment of Pathogenic Bacteria. J Med Chem 2020; 63:13355-13388. [PMID: 32786507 DOI: 10.1021/acs.jmedchem.0c00911] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Infectious diseases are a major cause of morbidity and mortality worldwide, exacerbated by increasing antibiotic resistance in many bacterial species. The development of drugs with new modes of action is essential. A leading strategy is antivirulence, with the aim to target bacterial proteins that are important in disease causation and progression but do not affect growth, resulting in reduced selective pressure for resistance. Immunophilins, a superfamily of peptidyl-prolyl cis-trans isomerase (PPIase) enzymes have been shown to be important for virulence in a broad-spectrum of pathogenic bacteria. This Perspective will provide an overview of the recent advances made in understanding the role of each immunophilin family, cyclophilins, FK506 binding proteins (FKBPs), and parvulins in bacteria. Inhibitor design and medicinal chemistry strategies for development of novel drugs against bacterial FKBPs will be discussed. Furthermore, drugs against human cyclophilins and parvulins will be reviewed in their current indication as antiviral and anticancer therapies.
Collapse
Affiliation(s)
- Nicolas J Scheuplein
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Nicole M Bzdyl
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia
| | - Emily A Kibble
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia.,School of Veterinary and Life Sciences, Murdoch University, 6150 Murdoch, Australia
| | - Theresa Lohr
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Mitali Sarkar-Tyson
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia
| |
Collapse
|
262
|
Zhang S, Krumberger M, Morris MA, Parrocha CMT, Griffin JH, Kreutzer AG, Nowick JS. Structure-Based Drug Design of an Inhibitor of the SARS-CoV-2 (COVID-19) Main Protease Using Free Software: A Tutorial for Students and Scientists. CHEMRXIV : THE PREPRINT SERVER FOR CHEMISTRY 2020:12791954. [PMID: 32817929 PMCID: PMC7430054 DOI: 10.26434/chemrxiv.12791954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 08/12/2020] [Indexed: 11/25/2022]
Abstract
This paper describes the structure-based design of a preliminary drug candidate against COVID-19 using free software and publicly available X-ray crystallographic structures. The goal of this tutorial is to disseminate skills in structure-based drug design and to allow others to unleash their own creativity to design new drugs to fight the current pandemic. The tutorial begins with the X-ray crystallographic structure of the main protease (Mpro) of the SARS coronavirus (SARS-CoV) bound to a peptide substrate and then uses the UCSF Chimera software to modify the substrate to create a cyclic peptide inhibitor within the Mpro active site. Finally, the tutorial uses the molecular docking software AutoDock Vina to show the interaction of the cyclic peptide inhibitor with both SARS-CoV Mpro and the highly homologous SARS-CoV-2 Mpro. The supporting information (supplementary material) provides an illustrated step-by-step guide for the inhibitor design, to help readers design their own drug candidates for COVID-19 and the coronaviruses that will cause future pandemics. An accompanying preprint in bioRxiv [https://doi.org/10.1101/2020.08.03.234872] describes the synthesis of the cyclic peptide and the experimental validation as an inhibitor of SARS-CoV-2 Mpro.
Collapse
Affiliation(s)
- Sheng Zhang
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Maj Krumberger
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Michael A. Morris
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Chelsea Marie T. Parrocha
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, California 92697-2025, United States
| | - James H. Griffin
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Adam G. Kreutzer
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - James S. Nowick
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, California 92697-2025, United States
| |
Collapse
|
263
|
Ji S, Yang X, Chen X, Li A, Yan D, Xu H, Fei H. Structure-tuned membrane active Ir-complexed oligoarginine overcomes cancer cell drug resistance and triggers immune responses in mice. Chem Sci 2020; 11:9126-9133. [PMID: 34094193 PMCID: PMC8161536 DOI: 10.1039/d0sc03975f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 11/21/2022] Open
Abstract
The development of chemotherapy, an important cancer treatment modality, is hindered by the frequently found drug-resistance phenomenon. Meanwhile, researchers have been enthused lately by the synergistic use of chemotherapy with emerging immunotherapeutic treatments. In an effort to address both of the two unmet needs, reported herein is a study on a series of membrane active iridium(iii) complexed oligoarginine peptides with a new cell death mechanism capable of overcoming drug resistance as well as stimulating immunological responses. A systematic structure-activity relationship study elucidated the interdependent effects of three structural factors, i.e., hydrophobicity, topology and cationicity, on the regulation of the cytotoxicity of the Ir(iii)-oligoarginine peptides. With the most prominent toxicities, Ir-complexed octaarginines (R8) were found to display a progressive oncotic cell death featuring cell membrane-penetration and eruptive cytoplasmic content release. Consequently, this membrane-centric death mechanism showed promising potential in overcoming multiple chemical drug-resistance of cancer cells. More interestingly, the eruptive mode of cell death proved to be immunogenic by stimulating the dendritic cell maturation and inflammatory factor accumulation in mice tumours. Taking these mechanisms together, this work demonstrates that membrane active compounds may become the next generation chemotherapeutics because of their combined advantages.
Collapse
Affiliation(s)
- Shuangshuang Ji
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China Hefei 230026 PR China
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 PR China
| | - Xiuzhu Yang
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 PR China
| | - Xiaolong Chen
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China Hefei 230026 PR China
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 PR China
| | - Ang Li
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China Hefei 230026 PR China
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 PR China
| | - Doudou Yan
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100005 PR China
| | - Haiyan Xu
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100005 PR China
| | - Hao Fei
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China Hefei 230026 PR China
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 PR China
| |
Collapse
|
264
|
Jwad R, Weissberger D, Hunter L. Strategies for Fine-Tuning the Conformations of Cyclic Peptides. Chem Rev 2020; 120:9743-9789. [PMID: 32786420 DOI: 10.1021/acs.chemrev.0c00013] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cyclic peptides are promising scaffolds for drug development, attributable in part to their increased conformational order compared to linear peptides. However, when optimizing the target-binding or pharmacokinetic properties of cyclic peptides, it is frequently necessary to "fine-tune" their conformations, e.g., by imposing greater rigidity, by subtly altering certain side chain vectors, or by adjusting the global shape of the macrocycle. This review systematically examines the various types of structural modifications that can be made to cyclic peptides in order to achieve such conformational control.
Collapse
Affiliation(s)
- Rasha Jwad
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
| | - Daniel Weissberger
- School of Chemistry, University of New South Wales (UNSW) Sydney, New South Wales 2052, Australia
| | - Luke Hunter
- School of Chemistry, University of New South Wales (UNSW) Sydney, New South Wales 2052, Australia
| |
Collapse
|
265
|
Ernenwein D, St. John SE, Stewart AJ, Morimoto BH, Chmielewski J, Lipton MA. Structural studies and cyclization of the neuroprotective octapeptide
NAPVSIPQ
to improve cell permeability. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dawn Ernenwein
- Department of ChemistryPurdue University West Lafayette Indiana USA
| | | | | | | | - Jean Chmielewski
- Department of ChemistryPurdue University West Lafayette Indiana USA
| | - Mark A. Lipton
- Department of ChemistryPurdue University West Lafayette Indiana USA
| |
Collapse
|
266
|
Kotynia A, Marciniak A, Brasuń J. The formation of di-copper (II) complexes with a hetero-site cyclopeptide–spectroscopic and potentiometric studies. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
267
|
Baudet S, Bécret J, Nicol X. Approaches to Manipulate Ephrin-A:EphA Forward Signaling Pathway. Pharmaceuticals (Basel) 2020; 13:ph13070140. [PMID: 32629797 PMCID: PMC7407804 DOI: 10.3390/ph13070140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/19/2020] [Accepted: 06/28/2020] [Indexed: 02/07/2023] Open
Abstract
Erythropoietin-producing hepatocellular carcinoma A (EphA) receptors and their ephrin-A ligands are key players of developmental events shaping the mature organism. Their expression is mostly restricted to stem cell niches in adults but is reactivated in pathological conditions including lesions in the heart, lung, or nervous system. They are also often misregulated in tumors. A wide range of molecular tools enabling the manipulation of the ephrin-A:EphA system are available, ranging from small molecules to peptides and genetically-encoded strategies. Their mechanism is either direct, targeting EphA receptors, or indirect through the modification of intracellular downstream pathways. Approaches enabling manipulation of ephrin-A:EphA forward signaling for the dissection of its signaling cascade, the investigation of its physiological roles or the development of therapeutic strategies are summarized here.
Collapse
|
268
|
Brožek R, Kabelka I, Vácha R. Effect of Helical Kink on Peptide Translocation across Phospholipid Membranes. J Phys Chem B 2020; 124:5940-5947. [PMID: 32603116 DOI: 10.1021/acs.jpcb.0c03291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Biological membranes present a major obstacle for the delivery of therapeutic agents into cells. Some peptides have been shown to translocate across the membrane spontaneously, and they could be thus used as drug-carriers. However, the advantageous peptide properties for the translocation remain unclear. Of particular interest is the effect of a proline-induced kink in α-helical peptides, because the kink was previously reported to both increase and decrease the antimicrobial activity. The antimicrobial activity of peptides could be related to their translocation across the membrane as is the case of the buforin 2 peptide investigated here. Using computer simulations with two independent models, we consistently showed that the presence of the kink has (1) no effect on the translocation barrier, (2) reduces the peptide affinity to the membrane, and (3) disfavors the transmembrane state. Moreover, we were able to determine that these effects are mainly caused by the peptide increased polarity, not the increased flexibility of the kink. The provided molecular understanding can be utilized for the design of cell-penetrating and drug-carrying peptides.
Collapse
Affiliation(s)
- Radim Brožek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.,CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Ivo Kabelka
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.,CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Robert Vácha
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.,CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic.,Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| |
Collapse
|
269
|
Kamenik AS, Kraml J, Hofer F, Waibl F, Quoika PK, Kahler U, Schauperl M, Liedl KR. Macrocycle Cell Permeability Measured by Solvation Free Energies in Polar and Apolar Environments. J Chem Inf Model 2020; 60:3508-3517. [PMID: 32551643 PMCID: PMC7388155 DOI: 10.1021/acs.jcim.0c00280] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The relation of surface polarity and conformational preferences is decisive for cell permeability and thus bioavailability of macrocyclic drugs. Here, we employ grid inhomogeneous solvation theory (GIST) to calculate solvation free energies for a series of six macrocycles in water and chloroform as a measure of passive membrane permeability. We perform accelerated molecular dynamics simulations to capture a diverse structural ensemble in water and chloroform, allowing for a direct profiling of solvent-dependent conformational preferences. Subsequent GIST calculations facilitate a quantitative measure of solvent preference in the form of a transfer free energy, calculated from the ensemble-averaged solvation free energies in water and chloroform. Hence, the proposed method considers how the conformational diversity of macrocycles in polar and apolar solvents translates into transfer free energies. Following this strategy, we find a striking correlation of 0.92 between experimentally determined cell permeabilities and calculated transfer free energies. For the studied model systems, we find that the transfer free energy exceeds the purely water-based solvation free energies as a reliable estimate of cell permeability and that conformational sampling is imperative for a physically meaningful model. We thus recommend this purely physics-based approach as a computational tool to assess cell permeabilities of macrocyclic drug candidates.
Collapse
Affiliation(s)
- Anna S Kamenik
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Johannes Kraml
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Florian Hofer
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Franz Waibl
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Patrick K Quoika
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Ursula Kahler
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Michael Schauperl
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| | - Klaus R Liedl
- Institute of General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80-82, Innsbruck A-6020 Austria
| |
Collapse
|
270
|
Yin H, Huang YH, Deprey K, Condon ND, Kritzer JA, Craik DJ, Wang CK. Cellular Uptake and Cytosolic Delivery of a Cyclic Cystine Knot Scaffold. ACS Chem Biol 2020; 15:1650-1661. [PMID: 32315152 DOI: 10.1021/acschembio.0c00297] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclotides are macrocyclic peptides with exceptionally stable structures and have been reported to penetrate cells, making them promising scaffolds for the delivery of inhibitory peptides to target intracellular proteins. However, their cellular uptake and cytosolic localization have been poorly understood until now, which has limited their therapeutic potential. In this study, the recently developed chloroalkane penetration assay was combined with established assays to characterize the cellular uptake and cytosolic delivery of the prototypic cyclotide, kalata B1. We show that kalata B1 enters the cytosol at low efficiency. A structure-activity study of residues in loop 6 showed that some modifications, such as increasing cationic residue content, did not affect delivery efficiency, whereas others, including introducing a single hydrophobic amino acid, did significantly improve cytosolic delivery. Our results provide a foundation for the further development of a structurally unique class of scaffolds for the delivery of therapeutic cargoes into cells.
Collapse
Affiliation(s)
- Huawu Yin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten Deprey
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Nicholas D. Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Joshua A. Kritzer
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - David J. Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Conan K. Wang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
271
|
Sengupta S, Mehta G. Macrocyclization via C-H functionalization: a new paradigm in macrocycle synthesis. Org Biomol Chem 2020; 18:1851-1876. [PMID: 32101232 DOI: 10.1039/c9ob02765c] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The growing emphasis on macrocycles in engaging difficult therapeutic targets such as protein-protein interactions and GPCRs via preferential adaptation of bioactive and cell penetrating conformations has provided impetus to the search for de novo macrocyclization strategies that are efficient, chemically robust and amenable to diversity creation. An emerging macrocyclization paradigm based on the C-H activation logic, of particular promise in the macrocyclization of complex peptides, has added a new dimension to this pursuit, enabling efficacious access to macrocycles of various sizes and topologies with high atom and step economy. Significant achievements in macrocyclization methodologies and their applications in the synthesis of bioactive natural products and drug-like molecules, employing strategic variations of C-H activation are captured in this review. It is expected that this timely account will foster interest in newer ways of macrocycle construction among practitioners of organic synthesis and chemical biology to advance the field.
Collapse
Affiliation(s)
- Saumitra Sengupta
- School of Chemistry, University of Hyderabad, Gachibowli, Hyderabad-5000 046, Telengana, India.
| | - Goverdhan Mehta
- School of Chemistry, University of Hyderabad, Gachibowli, Hyderabad-5000 046, Telengana, India.
| |
Collapse
|
272
|
Hu QL, Hou KQ, Li J, Ge Y, Song ZD, Chan ASC, Xiong XF. Silanol: a bifunctional group for peptide synthesis and late-stage functionalization. Chem Sci 2020; 11:6070-6074. [PMID: 34094099 PMCID: PMC8159358 DOI: 10.1039/d0sc02439b] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/24/2020] [Indexed: 12/27/2022] Open
Abstract
Chemical modification of a specific amino acid residue on peptides represents an efficient strategy to improve their pharmacokinetics and facilitates the potential to achieve post-synthetic diversification of peptides. Herein, we reported the first Pd-catalyzed late-stage ortho-olefination of Tyr residues on peptides with high chemo- and site-selectivity, by employing the easily attached and removable silanol as a bifunctional protecting group and directing group. Up to hexapeptides with variation on amino acid sequences or locations of the Tyr residue and different olefins were compatible with this protocol, which enriched the chemical toolbox for late-stage modification via C(sp2)-H functionalization. Furthermore, the orthogonal protection strategies of Tyr were also developed and could be applied to SPPS.
Collapse
Affiliation(s)
- Qi-Long Hu
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Ke-Qiang Hou
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Jian Li
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Yang Ge
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Zhen-Dong Song
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Albert S C Chan
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| | - Xiao-Feng Xiong
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University 510006 Guangzhou Guangdong P. R. China
| |
Collapse
|
273
|
Comparative Molecular Transporter Properties of Cyclic Peptides Containing Tryptophan and Arginine Residues Formed through Disulfide Cyclization. Molecules 2020; 25:molecules25112581. [PMID: 32498339 PMCID: PMC7321319 DOI: 10.3390/molecules25112581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 11/17/2022] Open
Abstract
We have previously reported cyclic cell-penetrating peptides [WR]5 and [WR]4 as molecular transporters. To optimize further the utility of our developed peptides for targeted therapy in cancer cells using the redox condition, we designed a new generation of peptides and evaluated their cytotoxicity as well as uptake behavior against different cancer cell lines. Thus, cyclic [C(WR)xC] and linear counterparts (C(WR)xC), where x = 4–5, were synthesized using Fmoc/tBu solid-phase peptide synthesis, purified, and characterized. The compounds did not show any significant cytotoxicity (at 25 µM) against ovarian (SK-OV-3), leukemia (CCRF-CEM), gastric adenocarcinoma (CRL-1739), breast carcinoma (MDA-MB-231), and normal kidney (LLCPK) cells after 24 and 72 h incubation. Both cyclic [C(WR)5C] and linear (C(WR)5C) demonstrated comparable molecular transporter properties versus [WR]5 in the delivery of a phosphopeptide (F′-GpYEEI) in CCRF-CEM cells. The uptake of F′-GpYEEI in the presence of 1,4-dithiothreitol (DTT) as the reducing agent was significantly improved in case of l(C(WR)5C), while it was not changed by [C(WR)5C]. Fluorescence microscopy also demonstrated a significant uptake of F′-GpYEEI in the presence of l(C(WR)5C). Cyclic [C(WR)5C] improved the uptake of the fluorescent-labeled anti-HIV drugs F′-d4T, F′-3TC, and F′-FTC by 3.0–4.9-fold. These data indicate that both [C(WR)5C] and linear (C(WR)5C) peptides can act as molecular transporters.
Collapse
|
274
|
Brayden D, Hill T, Fairlie D, Maher S, Mrsny R. Systemic delivery of peptides by the oral route: Formulation and medicinal chemistry approaches. Adv Drug Deliv Rev 2020; 157:2-36. [PMID: 32479930 DOI: 10.1016/j.addr.2020.05.007] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 02/07/2023]
Abstract
In its 33 years, ADDR has published regularly on the po5tential of oral delivery of biologics especially peptides and proteins. In the intervening period, analysis of the preclinical and clinical trial failures of many purported platform technologies has led to reflection on the true status of the field and reigning in of expectations. Oral formulations of semaglutide, octreotide, and salmon calcitonin have completed Phase III trials, with oral semaglutide being approved by the FDA in 2019. The progress made with oral peptide formulations based on traditional permeation enhancers is against a background of low and variable oral bioavailability values of ~1%, leading to a current perception that only potent peptides with a viable cost of synthesis can be realistically considered. Desirable features of candidates should include a large therapeutic index, some stability in the GI tract, a long elimination half-life, and a relatively low clearance rate. Administration in nanoparticle formats have largely disappointed, with few prototypes reaching clinical trials: insufficient particle loading, lack of controlled release, low epithelial particle uptake, and lack of scalable synthesis being the main reasons for discontinuation. Disruptive technologies based on engineered devices promise improvements, but scale-up and toxicology aspects are issues to address. In parallel, medicinal chemists are synthesizing stable hydrophobic macrocyclic candidate peptides of lower molecular weight and with potential for greater oral bioavailability than linear peptides, but perhaps without the same requirement for elaborate drug delivery systems. In summary, while there have been advances in understanding the limitations of peptides for oral delivery, low membrane permeability, metabolism, and high clearance rates continue to hamper progress.
Collapse
|
275
|
Xie J, Bi Y, Zhang H, Dong S, Teng L, Lee RJ, Yang Z. Cell-Penetrating Peptides in Diagnosis and Treatment of Human Diseases: From Preclinical Research to Clinical Application. Front Pharmacol 2020; 11:697. [PMID: 32508641 PMCID: PMC7251059 DOI: 10.3389/fphar.2020.00697] [Citation(s) in RCA: 239] [Impact Index Per Article: 59.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 04/28/2020] [Indexed: 12/21/2022] Open
Abstract
Cell-penetrating peptides (CPPs) are short peptides (fewer than 30 amino acids) that have been predominantly used in basic and preclinical research during the last 30 years. Since they are not only capable of translocating themselves into cells but also facilitate drug or CPP/cargo complexes to translocate across the plasma membrane, they have potential applications in the disease diagnosis and therapy, including cancer, inflammation, central nervous system disorders, otologic and ocular disorders, and diabetes. However, no CPPs or CPP/cargo complexes have been approved by the US Food and Drug Administration (FDA). Many issues should be addressed before translating CPPs into clinics. In this review, we summarize recent developments and innovations in preclinical studies and clinical trials based on using CPP for improved delivery, which have revealed that CPPs or CPP-based delivery systems present outstanding diagnostic therapeutic delivery potential.
Collapse
Affiliation(s)
- Jing Xie
- School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Ye Bi
- Practice Training Center, Changchun University of Chinese Medicine, Changchun, China
| | - Huan Zhang
- School of Life Sciences, Jilin University, Changchun, China
| | - Shiyan Dong
- School of Life Sciences, Jilin University, Changchun, China
| | - Lesheng Teng
- School of Life Sciences, Jilin University, Changchun, China
| | - Robert J. Lee
- Division of Pharmaceutics and Pharmacology, The Ohio State University, Columbus, OH, United States
| | - Zhaogang Yang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| |
Collapse
|
276
|
Samarasimhareddy M, Shamir M, Shalev DE, Hurevich M, Friedler A. A Rapid and Efficient Building Block Approach for Click Cyclization of Peptoids. Front Chem 2020; 8:405. [PMID: 32509731 PMCID: PMC7248394 DOI: 10.3389/fchem.2020.00405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/17/2020] [Indexed: 12/18/2022] Open
Abstract
Cyclic peptide-peptoid hybrids possess improved stability and selectivity over linear peptides and are thus better drug candidates. However, their synthesis is far from trivial and is usually difficult to automate. Here we describe a new rapid and efficient approach for the synthesis of click-based cyclic peptide-peptoid hybrids. Our methodology is based on a combination between easily synthesized building blocks, automated microwave assisted solid phase synthesis and bioorthogonal click cyclization. We proved the concept of this method using the INS peptide, which we have previously shown to activate the HIV-1 integrase enzyme. This strategy enabled the rapid synthesis and biophysical evaluation of a library of cyclic peptide-peptoid hybrids derived from HIV-1 integrase in high yield and purity. The new cyclic hybrids showed improved biological activity and were significantly more stable than the original linear INS peptide.
Collapse
Affiliation(s)
| | - Mai Shamir
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Deborah E Shalev
- Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Pharmaceutical Engineering, Azrieli College of Engineering Jerusalem, Jerusalem, Israel
| | - Mattan Hurevich
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
277
|
Inaba H, Nagata M, Miyake KJ, Kabir AMR, Kakugo A, Sada K, Matsuura K. Cyclic Tau-derived peptides for stabilization of microtubules. Polym J 2020. [DOI: 10.1038/s41428-020-0356-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
278
|
Nadal‐Bufí F, Henriques ST. How to overcome endosomal entrapment of cell‐penetrating peptides to release the therapeutic potential of peptides? Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24168] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Ferran Nadal‐Bufí
- School of Biomedical Sciences, Faculty of Health, Institute of Health & Biomedical Innovation, Queensland University of Technology Translational Research Institute Brisbane Queensland Australia
| | - Sónia Troeira Henriques
- School of Biomedical Sciences, Faculty of Health, Institute of Health & Biomedical Innovation, Queensland University of Technology Translational Research Institute Brisbane Queensland Australia
| |
Collapse
|
279
|
Li H, Chao J, Zhang Z, Tian G, Li J, Chang N, Qin C. Liquid-Phase Total Synthesis of Plecanatide Aided by Diphenylphosphinyloxyl Diphenyl Ketone (DDK) Derivatives. Org Lett 2020; 22:3323-3328. [PMID: 32275447 DOI: 10.1021/acs.orglett.0c00616] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Plecanatide is an oral guanylate cyclase-C agonist for the treatment of gastrointestinal disorders. The large-scale supply of plecanatide is restrained primarily by its industrial manufacture. Herein we developed diphenylphosphinyloxyl diphenyl ketone (DDK) derivatives as greener supports with unique precipitation-inducing properties to aid the liquid-phase total synthesis of plecanatide without the use of chromatography. Plecanatide could be obtained in high yield, and the ultimately sheared DDK derivative residue could be directly recycled or regenerated for reuse.
Collapse
Affiliation(s)
- Haidi Li
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Jie Chao
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Zixin Zhang
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Guang Tian
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Jun Li
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Ninghui Chang
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| | - Chuanguang Qin
- Shaanxi Key Laboratory of Polymer Science & Technology, OME Key Laboratory of Supernormal Material Physics & Chemistry, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China
| |
Collapse
|
280
|
Deprey K, Kritzer JA. Quantitative measurement of cytosolic penetration using the chloroalkane penetration assay. Methods Enzymol 2020; 641:277-309. [PMID: 32713526 PMCID: PMC7872221 DOI: 10.1016/bs.mie.2020.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A major barrier for drug development is ensuring molecules can access intracellular targets. This is especially true for biomolecules, which are notoriously difficult to deliver to the cytosol. Many current methods for measuring the internalization of therapeutic biomolecules are largely indirect and qualitative, and they do not offer information about subcellular localization. We recently reported a new assay, called the ChloroAlkane Penetration Assay (CAPA), that addresses some of the drawbacks of existing methods. CAPA is high-throughput, quantitative, and compartment-specific, and can be used to monitor cytosolic penetration over time and under a variety of culture conditions. We have used CAPA to investigate the cytosolic localization of peptides, proteins, and oligonucleotides. In this chapter, we discuss the materials, protocols, and troubleshooting necessary to perform CAPA and appropriately analyze the data. We end with a discussion about the applications and limitations of CAPA, and we speculate on the potential of the assay and its variations.
Collapse
Affiliation(s)
- Kirsten Deprey
- Department of Chemistry, Tufts University, Medford, MA, United States
| | - Joshua A Kritzer
- Department of Chemistry, Tufts University, Medford, MA, United States.
| |
Collapse
|
281
|
Gomes Dos Reis L, Traini D. Advances in the use of cell penetrating peptides for respiratory drug delivery. Expert Opin Drug Deliv 2020; 17:647-664. [PMID: 32138567 DOI: 10.1080/17425247.2020.1739646] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Introduction: Respiratory diseases are leading causes of death in the world, still inhalation therapies are the largest fail in drug development. There is an evident need to develop new therapies. Biomolecules represent apotential therapeutic agent in this regard, however their translation to the clinic is hindered by the lack of tools to efficiently deliver molecules. Cell penetrating peptides (CPPs) have arisen as apotential strategy for intracellular delivery that could theoretically enable the translation of new therapies.Areas covered: In this review, the use of CPPs as astrategy to deliver different molecules (cargoes) to treat lung-relateddiseases will be the focus. Abrief description of these molecules and the innovative methods in designing new CPPs is presented. The delivery of different cargoes (proteins, peptides, poorly soluble drugs and nucleic acids) using CPPs is discussed, focusing on benefits to treat different respiratory diseases like inflammatory disorders, cystic fibrosis and lung cancer.Expert opinion: The advantages of using CPPs to deliver biomolecules and poorly soluble drugs to the lungs is evident. This field has advanced in the past few years toward targeted intracellular delivery, although further studies are needed to fully understand its potential and limitations in vitro and in vivo.
Collapse
Affiliation(s)
- Larissa Gomes Dos Reis
- Respiratory Technology, Woolcock Institute of Medical Research and Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - Daniela Traini
- Respiratory Technology, Woolcock Institute of Medical Research and Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| |
Collapse
|
282
|
Tuerkova A, Kabelka I, Králová T, Sukeník L, Pokorná Š, Hof M, Vácha R. Effect of helical kink in antimicrobial peptides on membrane pore formation. eLife 2020; 9:47946. [PMID: 32167466 PMCID: PMC7069690 DOI: 10.7554/elife.47946] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 02/18/2020] [Indexed: 12/19/2022] Open
Abstract
Every cell is protected by a semipermeable membrane. Peptides with the right properties, for example Antimicrobial peptides (AMPs), can disrupt this protective barrier by formation of leaky pores. Unfortunately, matching peptide properties with their ability to selectively form pores in bacterial membranes remains elusive. In particular, the proline/glycine kink in helical peptides was reported to both increase and decrease antimicrobial activity. We used computer simulations and fluorescence experiments to show that a kink in helices affects the formation of membrane pores by stabilizing toroidal pores but disrupting barrel-stave pores. The position of the proline/glycine kink in the sequence further controls the specific structure of toroidal pore. Moreover, we demonstrate that two helical peptides can form a kink-like connection with similar behavior as one long helical peptide with a kink. The provided molecular-level insight can be utilized for design and modification of pore-forming antibacterial peptides or toxins.
Collapse
Affiliation(s)
- Alzbeta Tuerkova
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice, Czech Republic
| | - Ivo Kabelka
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice, Czech Republic
| | - Tereza Králová
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, Czech Republic
| | - Lukáš Sukeník
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, Czech Republic.,Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská, Czech Republic
| | - Šárka Pokorná
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Hof
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice, Czech Republic.,Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská, Czech Republic
| |
Collapse
|
283
|
Sang P, Shi Y, Lu J, Chen L, Yang L, Borcherds W, Abdulkadir S, Li Q, Daughdrill G, Chen J, Cai J. α-Helix-Mimicking Sulfono-γ-AApeptide Inhibitors for p53-MDM2/MDMX Protein-Protein Interactions. J Med Chem 2020; 63:975-986. [PMID: 31971801 PMCID: PMC7025332 DOI: 10.1021/acs.jmedchem.9b00993] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The use of peptidomimetic scaffolds is a promising strategy for the inhibition of protein-protein interactions (PPIs). Herein, we demonstrate that sulfono-γ-AApeptides can be rationally designed to mimic the p53 α-helix and inhibit p53-MDM2 PPIs. The best inhibitor, with Kd and IC50 values of 26 nM and 0.891 μM toward MDM2, respectively, is among the most potent unnatural peptidomimetic inhibitors disrupting the p53-MDM2/MDMX interaction. Using fluorescence polarization assays, circular dichroism, nuclear magnetic resonance spectroscopy, and computational simulations, we demonstrate that sulfono-γ-AApeptides adopt helical structures resembling p53 and competitively inhibit the p53-MDM2 interaction by binding to the hydrophobic cleft of MDM2. Intriguingly, the stapled sulfono-γ-AApeptides showed promising cellular activity by enhancing p53 transcriptional activity and inducing expression of MDM2 and p21. Moreover, sulfono-γ-AApeptides exhibited remarkable resistance to proteolysis, augmenting their biological potential. Our results suggest that sulfono-γ-AApeptides are a new class of unnatural helical foldamers that disrupt PPIs.
Collapse
Affiliation(s)
- Peng Sang
- Department of Chemistry , University of South Florida , 4202 E. Fowler Avenue , Tampa , Florida 33620 , United States
| | - Yan Shi
- Department of Chemistry , University of South Florida , 4202 E. Fowler Avenue , Tampa , Florida 33620 , United States
| | - Junhao Lu
- Department of Molecular Oncology , H. Lee Moffitt Cancer Center and Research Institute , 12902 Magnolia Drive , Tampa , Florida 33612 , United States
| | - Lihong Chen
- Department of Molecular Oncology , H. Lee Moffitt Cancer Center and Research Institute , 12902 Magnolia Drive , Tampa , Florida 33612 , United States
| | - Leixiang Yang
- Department of Molecular Oncology , H. Lee Moffitt Cancer Center and Research Institute , 12902 Magnolia Drive , Tampa , Florida 33612 , United States
| | - Wade Borcherds
- Department of Cell Biology, Microbiology and Molecular Biology , University of South Florida , Tampa , Florida 33620 , United States
| | - Sami Abdulkadir
- Department of Chemistry , University of South Florida , 4202 E. Fowler Avenue , Tampa , Florida 33620 , United States
| | - Qi Li
- Department of Medical Oncology , Shuguang Hospital, Shanghai University of Traditional Chinese Medicine , Shanghai 201203 , China
| | - Gary Daughdrill
- Department of Cell Biology, Microbiology and Molecular Biology , University of South Florida , Tampa , Florida 33620 , United States
| | - Jiandong Chen
- Department of Molecular Oncology , H. Lee Moffitt Cancer Center and Research Institute , 12902 Magnolia Drive , Tampa , Florida 33612 , United States
| | - Jianfeng Cai
- Department of Chemistry , University of South Florida , 4202 E. Fowler Avenue , Tampa , Florida 33620 , United States
| |
Collapse
|
284
|
Methods for generating and screening libraries of genetically encoded cyclic peptides in drug discovery. Nat Rev Chem 2020; 4:90-101. [PMID: 37128052 DOI: 10.1038/s41570-019-0159-2] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2019] [Indexed: 12/14/2022]
Abstract
Drug discovery has traditionally focused on using libraries of small molecules to identify therapeutic drugs, but new modalities, especially libraries of genetically encoded cyclic peptides, are increasingly used for this purpose. Several technologies now exist for the production of libraries of cyclic peptides, including phage display, mRNA display and split-intein circular ligation of peptides and proteins. These different approaches are each compatible with particular methods of screening libraries, such as functional or affinity-based screening, and screening in vitro or in cells. These techniques allow the rapid preparation of libraries of hundreds of millions of molecules without the need for chemical synthesis, and have therefore lowered the entry barrier to generating and screening for inhibitors of a given target. This ease of use combined with the inherent advantages of the cyclic-peptide scaffold has yielded inhibitors of targets that have proved difficult to drug with small molecules. Multiple reports demonstrate that cyclic peptides act as privileged scaffolds in drug discovery, particularly against 'undruggable' targets such as protein-protein interactions. Although substantial challenges remain in the clinical translation of hits from screens of cyclic-peptide libraries, progress continues to be made in this area, with an increasing number of cyclic peptides entering clinical trials. Here, we detail the various platforms for producing and screening libraries of genetically encoded cyclic peptides and discuss and evaluate the advantages and disadvantages of each approach when deployed for drug discovery.
Collapse
|
285
|
Maguire OR, Taylor B, Higgins EM, Rees M, Cobb SL, Simpkins NS, Hayes CJ, O'Donoghue AC. Unusually high α-proton acidity of prolyl residues in cyclic peptides. Chem Sci 2020; 11:7722-7729. [PMID: 34094148 PMCID: PMC8159430 DOI: 10.1039/d0sc02508a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The acidity of the α-proton in peptides has an essential role in numerous biochemical reactions and underpins their stereochemical integrity, which is critical to their biological function. We report a detailed kinetic and computational study of the acidity of the α-proton in two cyclic peptide systems: diketopiperazine (DKP) and triketopiperazine (TKP). The kinetic acidity (protofugality) of the α-protons were determined though hydrogen deuterium exchange studies in aqueous solutions. The acidities of the α-proton in prolyl residues were increased by 3–89 fold relative to other amino acid residues (prolyl > glycyl ≫ alanyl > tyrosyl). Experimental and computational evidence for the stereoelectronic origins of this enhanced prolyl reactivity is presented. TKPs were 106-fold more reactive than their DKP analogues towards deprotonation, which we attribute to the advanced development of aromaticity in the earlier transition state for proton transfer in these cases. A Brønsted linear free energy analysis of the reaction data was conducted to provide estimates of α-proton pKas. Kinetic and computational studies reveal that prolyl residues in cyclic peptides are substantially more acidic than other residues due to a stereoelectronic effect.![]()
Collapse
Affiliation(s)
| | - Bethany Taylor
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
| | | | - Matthew Rees
- School of Chemistry
- University of Birmingham
- Birmingham
- UK
| | - Steven L. Cobb
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
| | | | | | | |
Collapse
|
286
|
Serra G, Posada L, Hojo H. On-resin synthesis of cyclic peptides via tandem N-to-S acyl migration and intramolecular thiol additive-free native chemical ligation. Chem Commun (Camb) 2020; 56:956-959. [DOI: 10.1039/c9cc07783a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A novel methodology for the synthesis of cyclic peptides by on-resin intramolecular native chemical ligation (NCL) assisted by N-ethylcysteine using Fmoc/SPPS is described.
Collapse
Affiliation(s)
- Gloria Serra
- Química Farmacéutica
- Departamento de Química Orgánica
- Facultad de Química
- Universidad de la República
- Montevideo
| | - Laura Posada
- Química Farmacéutica
- Departamento de Química Orgánica
- Facultad de Química
- Universidad de la República
- Montevideo
| | - Hironobu Hojo
- Institute for Protein Research
- Osaka University
- Yamadaoka
- Suita-shi
- Japan
| |
Collapse
|
287
|
Frosi Y, Inoue K, Ramlan SR, Lane DP, Watanabe T, Brown CJ. Simultaneous measurement of p53:Mdm2 and p53:Mdm4 protein-protein interactions in whole cells using fluorescence labelled foci. Sci Rep 2019; 9:17933. [PMID: 31784573 PMCID: PMC6884555 DOI: 10.1038/s41598-019-54123-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/08/2019] [Indexed: 12/26/2022] Open
Abstract
In this report we describe the development of a Fluorescent Protein-Protein Interaction-visualization (FLUOPPI) to enable the simultaneous measurement of both Mdm2:p53 and Mdm4:p53 interactions in order to assess the relative efficiencies of mimetic molecules of the p53 peptide helix against both PPIs. Mdm2 and Mdm4 overexpression frequently leads to the inactivation of non-mutated p53 in human cancers, via inhibition of its transcriptional activity, enhancing its degradation by the proteasome or by preventing its nuclear import. Development of inhibitors to disrupt the binding of one or both of these protein interactions have been the subject of intensive pharmaceutical development for anti-cancer therapies. Using the bimodal FLUOPPI system we have characterised compounds that were either monospecific for Mdm2 or bispecific for both Mdm2 and Mdm4. We have also demonstrated that the FLUOPPI assay can reliably differentiate between specific and non-specific disruption of these protein complexes via accurate assessment and normalization to the cell population under measurement. We envision that this methodology will increase the efficiency of identifying compounds that are either specific against a single PPI from a closely related family of interactions or compounds that interact across multiple related PPI pairs, depending on which is more desirable.
Collapse
Affiliation(s)
- Y Frosi
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - K Inoue
- R&D Division, Medical & Biological Laboratories, Co., Ltd., 1063-103 Terasawaoka, Ina, Nagano, 396-0002, Japan
| | - Siti Radhiah Ramlan
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - D P Lane
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - T Watanabe
- R&D Division, Medical & Biological Laboratories, Co., Ltd., 1063-103 Terasawaoka, Ina, Nagano, 396-0002, Japan.
| | - C J Brown
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore.
| |
Collapse
|
288
|
Kim S, Nam HY, Lee J, Seo J. Mitochondrion-Targeting Peptides and Peptidomimetics: Recent Progress and Design Principles. Biochemistry 2019; 59:270-284. [PMID: 31696703 DOI: 10.1021/acs.biochem.9b00857] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondria are multifunctional subcellular organelles whose operations encompass energy production, signal transduction, and metabolic regulation. Given their wide range of roles, they have been studied extensively as a potential therapeutic target for the treatment of various diseases, including cancer, diabetes, and neurodegenerative diseases. Mitochondrion-mediated pathways have been identified as promising targets in the context of these diseases. However, the delivery of specific probes and drugs to the mitochondria is one of the major problems that remains to be solved. Over the past decade, much effort has been devoted to developing mitochondrion-targeted delivery methods based on the membrane characteristics and the protein import machinery of mitochondria. While various methods utilizing small molecules to polymeric particles have been introduced, it is notable that many of these compounds share common structural elements and physicochemical properties for optimal selectivity and efficiency. In this Perspective, we will review the most recently developed mitochondrion-targeting peptides and peptidomimetics to outline the key aspects of structural requirements and design principles. We will also discuss successful and potential applications of mitochondrial delivery to assess opportunities and challenges in the targeting of mitochondria.
Collapse
Affiliation(s)
- Soyoung Kim
- Department of Chemistry, School of Physics and Chemistry , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea
| | - Ho Yeon Nam
- Department of Chemistry, School of Physics and Chemistry , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea
| | - Jiyoun Lee
- Department of Global Medical Science , Sungshin University , Seoul 01133 , Republic of Korea
| | - Jiwon Seo
- Department of Chemistry, School of Physics and Chemistry , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea
| |
Collapse
|
289
|
Hyun S, Li L, Yoon KC, Yu J. An amphipathic cell penetrating peptide aids cell penetration of cyclosporin A and increases its therapeutic effect in an in vivo mouse model for dry eye disease. Chem Commun (Camb) 2019; 55:13657-13660. [PMID: 31595891 DOI: 10.1039/c9cc05960a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cell penetrating peptide (CPP), LK-3, causes a ca. 10-fold increase in the cell penetration of cyclosporin A (CsA) at nanomolar concentrations. The results of an in vivo dry eye mouse model demonstrated that a 100-fold lower dose of the CsA/LK-3 complex than that of Restasis® is sufficient to cause the same therapeutic effect.
Collapse
Affiliation(s)
- Soonsil Hyun
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Lan Li
- Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju 61469, Korea.
| | - Kyung Chul Yoon
- Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju 61469, Korea.
| | - Jaehoon Yu
- Department of Chemistry and Education, Seoul National University, Seoul 08826, Korea.
| |
Collapse
|
290
|
Salim H, Song J, Sahni A, Pei D. Development of a Cell-Permeable Cyclic Peptidyl Inhibitor against the Keap1-Nrf2 Interaction. J Org Chem 2019; 85:1416-1424. [PMID: 31609620 DOI: 10.1021/acs.joc.9b02367] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Macrocyclic peptides have proven to be highly effective inhibitors of protein-protein interactions but generally lack cell permeability to access intracellular targets. We show herein that macrocyclic peptides may be rendered highly cell-permeable and biologically active by conjugating them with a cyclic cell-penetrating peptide (CPP). A previously reported cyclic peptidyl inhibitor against the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid-2 (Nrf2) interaction (KD = 18 nM) was covalently attached to a cyclic CPP through a flexible linker. The resulting bicyclic peptide retained the Keap1-binding activity, resisted proteolytic degradation, readily entered mammalian cells, and activated the transcriptional activity of Nrf2 at nanomolar to low micromolar concentrations in cell culture. The inhibitor provides a useful tool for investigating the biological function of Keap1-Nrf2 and a potential lead for further development into a novel class of anti-inflammatory and anticancer agents. Our data suggest that other membrane-impermeable cyclic peptides may be similarly rendered cell-permeable by conjugation with a cyclic CPP.
Collapse
Affiliation(s)
- Heba Salim
- Department of Chemistry and Biochemistry , The Ohio State University , 484 West 12th Avenue , Columbus , Ohio 43210 , United States
| | - Jian Song
- Department of Chemistry and Biochemistry , The Ohio State University , 484 West 12th Avenue , Columbus , Ohio 43210 , United States.,School of Pharmacy , Guangdong Pharmaceutical University , Guangzhou , Guangdong Province 510006 , P.R. China
| | - Ashweta Sahni
- Department of Chemistry and Biochemistry , The Ohio State University , 484 West 12th Avenue , Columbus , Ohio 43210 , United States
| | - Dehua Pei
- Department of Chemistry and Biochemistry , The Ohio State University , 484 West 12th Avenue , Columbus , Ohio 43210 , United States
| |
Collapse
|
291
|
Abstract
Macrocyclic peptides make up an emerging class of candidate therapeutics and chemical probes, with properties that make them potentially applicable to a wide range of targets that are intractable using current pharmacological agents. Additionally, a number of biochemical screening strategies have been developed, particularly over the past decade, that allow for the massively parallel screening of cyclic peptide libraries of up to 1 trillion compounds or more, leading to the isolation of molecules with exceptional target affinity, selectivity, and bioactivity. Clinical development of compounds derived from such screens is already underway, but the nature of these molecules means that such development is likely to follow pathways different from those of traditional small molecule drugs or well-established biologics such as monoclonal antibodies. In addition, recent work has shown that the biochemical techniques used to identify macrocyclic peptides can also be used to rapidly characterize and optimize them. These findings are likely to facilitate the development of these compounds as chemical probes and as therapeutics for areas of unmet medical need.
Collapse
Affiliation(s)
- Toby Passioura
- Sydney Analytical, School of Life and Environmental Sciences and School of Chemistry , The University of Sydney , Sydney , NSW 2006 , Australia
| |
Collapse
|
292
|
Jing X, Jin K. A gold mine for drug discovery: Strategies to develop cyclic peptides into therapies. Med Res Rev 2019; 40:753-810. [PMID: 31599007 DOI: 10.1002/med.21639] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/05/2019] [Accepted: 09/26/2019] [Indexed: 12/19/2022]
Abstract
As a versatile therapeutic modality, peptides attract much attention because of their great binding affinity, low toxicity, and the capability of targeting traditionally "undruggable" protein surfaces. However, the deficiency of cell permeability and metabolic stability always limits the success of in vitro bioactive peptides as drug candidates. Peptide macrocyclization is one of the most established strategies to overcome these limitations. Over the past decades, more than 40 cyclic peptide drugs have been clinically approved, the vast majority of which are derived from natural products. The de novo discovered cyclic peptides on the basis of rational design and in vitro evolution, have also enabled the binding with targets for which nature provides no solutions. The current review summarizes different classes of cyclic peptides with diverse biological activities, and presents an overview of various approaches to develop cyclic peptide-based drug candidates, drawing upon series of examples to illustrate each strategy.
Collapse
Affiliation(s)
- Xiaoshu Jing
- Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Kang Jin
- Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, Shandong, China
| |
Collapse
|
293
|
Park SE, Sajid MI, Parang K, Tiwari RK. Cyclic Cell-Penetrating Peptides as Efficient Intracellular Drug Delivery Tools. Mol Pharm 2019; 16:3727-3743. [PMID: 31329448 DOI: 10.1021/acs.molpharmaceut.9b00633] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cyclic cell-penetrating peptides are relatively a newer class of peptides that have a huge potential for the intracellular delivery of therapeutic agents aimed at treating challenging ailments like multidrug-resistant bacterial diseases, cancer, and HIV infection. Cell-penetrating peptides (CPPs) have been extensively explored as intracellular delivery vehicles; however, they have some inherent limitations like poor stability, endosomal entrapment, toxicity, and suboptimal cell penetration. Owing to their favorable properties that avoid these limitations, cyclic CPPs can provide a good alternative to linear CPPs. Several Reviews have been published in the past decade that cover CPPs and cyclic peptides independently. To the best of our knowledge, this is one of the first Reviews that covers cyclic CPPs comprehensively in the light of studies published so far. In this Review, we have detailed examples of cyclic CPPs, their structures, and cyclization strategies followed by a detailed account of their advantages over their linear counterparts. A hot area in cyclic CPPs is the exploration of cell-penetration mechanisms; this Review highlights this topic in detail. Finally, we will review the applications of cyclic CPPs, followed by conclusions and future prospects.
Collapse
Affiliation(s)
- Shang Eun Park
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences , Chapman University School of Pharmacy , Harry and Diane Rinker Health Science Campus, Irvine , California 92618 , United States
| | - Muhammad Imran Sajid
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences , Chapman University School of Pharmacy , Harry and Diane Rinker Health Science Campus, Irvine , California 92618 , United States.,Faculty of Pharmacy , University of Central Punjab , Lahore 54000 , Pakistan
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences , Chapman University School of Pharmacy , Harry and Diane Rinker Health Science Campus, Irvine , California 92618 , United States
| | - Rakesh Kumar Tiwari
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences , Chapman University School of Pharmacy , Harry and Diane Rinker Health Science Campus, Irvine , California 92618 , United States
| |
Collapse
|
294
|
Song J, Qian Z, Sahni A, Chen K, Pei D. Cyclic Cell-Penetrating Peptides with Single Hydrophobic Groups. Chembiochem 2019; 20:2085-2088. [PMID: 31298779 DOI: 10.1002/cbic.201900370] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Indexed: 12/18/2022]
Abstract
A new family of cyclic cell-penetrating peptides (CPPs) has been discovered; they differ from previously reported cyclic CPPs by containing only a single hydrophobic residue. The optimal CPP structure consists of four arginine residues and a hydrophobic residue with a long alkyl chain (e.g., a decyl group) in a cyclohexapeptide ring. The most active member of this family, CPP 17, has an intrinsic cellular entry efficiency similar to that of cyclic CPP12, the most active CPP reported to date. However, CPP 17 is 2.8 times more active than CPP12 under high serum protein concentrations, presumably because of the lower protein binding. CPP 17 enters the cell primarily by direct translocation at a relatively low concentration (≥5 μm).
Collapse
Affiliation(s)
- Jian Song
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA.,School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, Guangdong Province, 510006, China
| | - Ziqing Qian
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Ashweta Sahni
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Kuangyu Chen
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA
| |
Collapse
|
295
|
Pei D, Appiah Kubi G. Developments with bead-based screening for novel drug discovery. Expert Opin Drug Discov 2019; 14:1097-1102. [PMID: 31335229 DOI: 10.1080/17460441.2019.1647164] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Introduction: Combinatorial chemistry provides a cost-effective method for rapid discovery of drug hits/leads. The one-bead-one-compound (OBOC) library method is in principle ideally suited for this application, because it permits a large number of structurally diverse compounds to be rapidly synthesized and simultaneously screened for binding to a target of interest. However, application of OBOC libraries in drug discovery has encountered significant technical challenges. Areas covered: This Special Report covers the challenges associated with first-generation OBOC libraries (difficulty in structural identification of non-peptidic hits, screening biases and high false positive rates, and poor scalability). It also covers the many strategies developed over the past two decades to overcome these challenges. Expert opinion: With most of the technical challenges now overcome and the advent of powerful intracellular delivery technologies, OBOC libraries of metabolically stable and conformationally rigidified molecules (macrocyclic peptides and peptidomimetics, rigidified acyclic oligomers, and D-peptides) can be routinely synthesized and screened to discover initial hits against previously undruggable targets such as intracellular protein-protein interactions. On the other hand, further developments are still needed to expand the utility of the OBOC method to non-peptidic chemical scaffolds.
Collapse
Affiliation(s)
- Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University , Columbus , OH , USA
| | - George Appiah Kubi
- Department of Chemistry and Biochemistry, The Ohio State University , Columbus , OH , USA
| |
Collapse
|
296
|
Lohman RJ, Nielsen DS, Kok WM, Hoang HN, Hill TA, Fairlie DP. Mirror image pairs of cyclic hexapeptides have different oral bioavailabilities and metabolic stabilities. Chem Commun (Camb) 2019; 55:13362-13365. [DOI: 10.1039/c9cc06234c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rule-of-five parameters and membrane permeabilities are not the only determinants of oral bioavailability.
Collapse
Affiliation(s)
- Rink-Jan Lohman
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| | - Daniel S. Nielsen
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| | - W. Mei Kok
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| | - Huy N. Hoang
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| | - Timothy A. Hill
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| | - David P. Fairlie
- Division of Chemistry and Structural Biology
- Institute for Molecular Bioscience
- The University of Queensland
- Brisbane
- Australia
| |
Collapse
|