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Maag PH, Feist F, Truong VX, Frisch H, Roesky PW, Barner-Kowollik C. Visible-Light-Induced Control over Reversible Single-Chain Nanoparticle Folding. Angew Chem Int Ed Engl 2023; 62:e202309259. [PMID: 37485591 DOI: 10.1002/anie.202309259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/25/2023]
Abstract
We introduce a class of single-chain nanoparticles (SCNPs) that respond to visible light (λmax =415 nm) with complete unfolding from their compact structure into linear chain analogues. The initial folding is achieved by a simple esterification reaction of the polymer backbone constituted of acrylic acid and polyethylene glycol carrying monomer units, introducing bimane moieties, which allow for the photochemical unfolding, reversing the ester-bond formation. The compaction and the light driven unfolding proceed cleanly and are readily followed by size exclusion chromatography (SEC) and diffusion ordered NMR spectroscopy (DOSY), monitoring the change in the hydrodynamic radius (RH ). Importantly, the folding reaction and the light-induced unfolding are reversible, supported by the high conversion of the photo cleavage. As the unfolding reaction occurs in aqueous systems, the system holds promise for controlling the unfolding of SCNPs in biological environments.
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Affiliation(s)
- Patrick H Maag
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Florian Feist
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Vinh X Truong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Re-search (A*STAR), 1 Pesek Road, Jurong Island, Singapore, 627833, Republic of Singapore
| | - Hendrik Frisch
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe, Germany
| | - Christopher Barner-Kowollik
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, 4000, Brisbane, QLD, Australia
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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Horsfall AJ, Vandborg BA, Kikhtyak Z, Scanlon DB, Tilley WD, Hickey TE, Bruning JB, Abell AD. A cell permeable bimane-constrained PCNA-interacting peptide. RSC Chem Biol 2021; 2:1499-1508. [PMID: 34704055 PMCID: PMC8496261 DOI: 10.1039/d1cb00113b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022] Open
Abstract
The human sliding clamp protein known as proliferating cell nuclear antigen (PCNA) orchestrates DNA-replication and -repair and as such is an ideal therapeutic target for proliferative diseases, including cancer. Peptides derived from the human p21 protein bind PCNA with high affinity via a 310-helical binding conformation and are known to shut down DNA-replication. Here, we present studies on short analogues of p21 peptides (143-151) conformationally constrained with a covalent linker between i, i + 4 separated cysteine residues at positions 145 and 149 to access peptidomimetics that target PCNA. The resulting macrocycles bind PCNA with K D values ranging from 570 nM to 3.86 μM, with the bimane-constrained peptide 7 proving the most potent. Subsequent X-ray crystallography and computational modelling studies of the macrocyclic peptides bound to PCNA indicated only the high-affinity peptide 7 adopted the classical 310-helical binding conformation. This suggests the 310-helical conformation is critical to high affinity PCNA binding, however NMR secondary shift analysis of peptide 7 revealed this secondary structure was not well-defined in solution. Peptide 7 is cell permeable and localised to the cell cytosol of breast cancer cells (MDA-MB-468), revealed by confocal microscopy showing blue fluorescence of the bimane linker. The inherent fluorescence of the bimane moiety present in peptide 7 allowed it to be directly imaged in the cell uptake assay, without attachment of an auxiliary fluorescent tag. This highlights a significant benefit of using a bimane constraint to access conformationally constrained macrocyclic peptides. This study identifies a small peptidomimetic that binds PCNA with higher affinity than previous reported p21 macrocycles, and is cell permeable, providing a significant advance toward development of a PCNA inhibitor for therapeutic applications.
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Affiliation(s)
- Aimee J Horsfall
- Institute of Photonics and Advanced Sensing (IPAS), The University of Adelaide Adelaide South Australia 5005 Australia .,School of Physical Sciences, The University of Adelaide Adelaide South Australia 5005 Australia.,Australian Research Council Centre of Excellence for Nanoscale BioPhotonics (CNBP) Australia
| | - Beth A Vandborg
- Institute of Photonics and Advanced Sensing (IPAS), The University of Adelaide Adelaide South Australia 5005 Australia .,School of Biological Sciences, The University of Adelaide Adelaide South Australia 5005 Australia
| | - Zoya Kikhtyak
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide Adelaide South Australia 5005 Australia
| | - Denis B Scanlon
- Institute of Photonics and Advanced Sensing (IPAS), The University of Adelaide Adelaide South Australia 5005 Australia .,School of Physical Sciences, The University of Adelaide Adelaide South Australia 5005 Australia
| | - Wayne D Tilley
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide Adelaide South Australia 5005 Australia
| | - Theresa E Hickey
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide Adelaide South Australia 5005 Australia
| | - John B Bruning
- Institute of Photonics and Advanced Sensing (IPAS), The University of Adelaide Adelaide South Australia 5005 Australia .,School of Biological Sciences, The University of Adelaide Adelaide South Australia 5005 Australia
| | - Andrew D Abell
- Institute of Photonics and Advanced Sensing (IPAS), The University of Adelaide Adelaide South Australia 5005 Australia .,School of Physical Sciences, The University of Adelaide Adelaide South Australia 5005 Australia.,Australian Research Council Centre of Excellence for Nanoscale BioPhotonics (CNBP) Australia
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Horsfall AJ, Abell AD. An Inherently Fluorescent Peptide Constraint to Define Secondary Structure: Moving Away from Auxiliary Tags. Aust J Chem 2021. [DOI: 10.1071/ch21169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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