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Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity

Antimicrobial peptides (AMPs) hold promise as novel therapeutics in the fight against multi-drug-resistant pathogens. Cathelicidin-PY (NH(2)-RKCNFLCKLKEKLRTVITSHIDKVLRPQG-COOH) is a 29-residue disulfide-cyclised antimicrobial peptide secreted as an innate host defence mechanism by the frog Paa yunna...

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Autores principales: Dissanayake, Shama, He, Junming, Yang, Sung H., Brimble, Margaret A., Harris, Paul W. R., Cameron, Alan J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9959817/
https://www.ncbi.nlm.nih.gov/pubmed/36838983
http://dx.doi.org/10.3390/molecules28041993
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author Dissanayake, Shama
He, Junming
Yang, Sung H.
Brimble, Margaret A.
Harris, Paul W. R.
Cameron, Alan J.
author_facet Dissanayake, Shama
He, Junming
Yang, Sung H.
Brimble, Margaret A.
Harris, Paul W. R.
Cameron, Alan J.
author_sort Dissanayake, Shama
collection PubMed
description Antimicrobial peptides (AMPs) hold promise as novel therapeutics in the fight against multi-drug-resistant pathogens. Cathelicidin-PY (NH(2)-RKCNFLCKLKEKLRTVITSHIDKVLRPQG-COOH) is a 29-residue disulfide-cyclised antimicrobial peptide secreted as an innate host defence mechanism by the frog Paa yunnanensis (PY) and reported to possess broad-spectrum antibacterial and antifungal properties, exhibiting low cytotoxic and low hemolytic activity. Herein, we detail the total synthesis of cathelicidin-PY using an entirely on-resin synthesis, including assembly of the linear sequence by rapid flow Fmoc-SPPS and iodine-mediated disulfide bridge formation. By optimising a synthetic strategy to prepare cathelicidin-PY, this strategy was subsequently adapted to prepare a bicyclic head-to-tail cyclised derivative of cathelicidin-PY. The structure-activity relationship (SAR) of cathelicidin-PY with respect to the N-terminally positioned disulfide was further probed by preparing an alanine-substituted linear analogue and a series of lactam-bridged peptidomimetics implementing side chain to side chain cyclisation. The analogues were investigated for antimicrobial activity, secondary structure by circular dichroism (CD), and stability in human serum. Surprisingly, the disulfide bridge emerged as non-essential to antimicrobial activity and secondary structure but was amenable to synthetic modification. Furthermore, the synthetic AMP and multiple analogues demonstrated selective activity towards Gram-negative pathogen E. coli in physiologically relevant concentrations of divalent cations.
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spelling pubmed-99598172023-02-26 Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity Dissanayake, Shama He, Junming Yang, Sung H. Brimble, Margaret A. Harris, Paul W. R. Cameron, Alan J. Molecules Article Antimicrobial peptides (AMPs) hold promise as novel therapeutics in the fight against multi-drug-resistant pathogens. Cathelicidin-PY (NH(2)-RKCNFLCKLKEKLRTVITSHIDKVLRPQG-COOH) is a 29-residue disulfide-cyclised antimicrobial peptide secreted as an innate host defence mechanism by the frog Paa yunnanensis (PY) and reported to possess broad-spectrum antibacterial and antifungal properties, exhibiting low cytotoxic and low hemolytic activity. Herein, we detail the total synthesis of cathelicidin-PY using an entirely on-resin synthesis, including assembly of the linear sequence by rapid flow Fmoc-SPPS and iodine-mediated disulfide bridge formation. By optimising a synthetic strategy to prepare cathelicidin-PY, this strategy was subsequently adapted to prepare a bicyclic head-to-tail cyclised derivative of cathelicidin-PY. The structure-activity relationship (SAR) of cathelicidin-PY with respect to the N-terminally positioned disulfide was further probed by preparing an alanine-substituted linear analogue and a series of lactam-bridged peptidomimetics implementing side chain to side chain cyclisation. The analogues were investigated for antimicrobial activity, secondary structure by circular dichroism (CD), and stability in human serum. Surprisingly, the disulfide bridge emerged as non-essential to antimicrobial activity and secondary structure but was amenable to synthetic modification. Furthermore, the synthetic AMP and multiple analogues demonstrated selective activity towards Gram-negative pathogen E. coli in physiologically relevant concentrations of divalent cations. MDPI 2023-02-20 /pmc/articles/PMC9959817/ /pubmed/36838983 http://dx.doi.org/10.3390/molecules28041993 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Dissanayake, Shama
He, Junming
Yang, Sung H.
Brimble, Margaret A.
Harris, Paul W. R.
Cameron, Alan J.
Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title_full Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title_fullStr Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title_full_unstemmed Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title_short Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity
title_sort flow-based fmoc-spps preparation and sar study of cathelicidin-py reveals selective antimicrobial activity
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9959817/
https://www.ncbi.nlm.nih.gov/pubmed/36838983
http://dx.doi.org/10.3390/molecules28041993
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