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Conjugation of CRAMP18–35 Peptide to Chitosan and Hydroxypropyl Chitosan via Copper-Catalyzed Azide–Alkyne Cycloaddition and Investigation of Antibacterial Activity

Authors :
Sankar Rathinam
Kasper K. Sørensen
Martha Á. Hjálmarsdóttir
Mikkel B. Thygesen
Már Másson
Source :
International Journal of Molecular Sciences, Vol 25, Iss 17, p 9440 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

We developed a synthesis strategy involving a diazo transfer reaction and subsequent click reaction to conjugate a murine cathelicidin-related antimicrobial peptide (CRAMP18–35) to chitosan and hydroxypropyl chitosan (HPC), confirmed the structure, and investigated the antimicrobial activity. Chitosan azide and HPC-azide were prepared with a low degree of azidation by reacting the parent chitosan and HPC with imidazole sulfonyl azide hydrochloride. CRAMP18–35 carrying an N-terminal pentynoyl group was successfully grafted onto chitosan and HPC via copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. The chitosan–peptide conjugates were characterized by IR spectroscopy and proton NMR to confirm the conversion of the azide to 1,2,3-triazole and to determine the degree of substitution (DS). The DS of the chitosan and HPC CRAMP18–35 conjugates was 0.20 and 0.13, respectively. The antibacterial activity of chitosan–peptide conjugates was evaluated for activity against two species of Gram-positive bacteria, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and two species of Gram-negative bacteria, Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). The antimicrobial peptide conjugates were selectively active against the Gram-negative bacteria and lacking activity against Gram-positive bacteria.

Details

Language :
English
ISSN :
14220067 and 16616596
Volume :
25
Issue :
17
Database :
Directory of Open Access Journals
Journal :
International Journal of Molecular Sciences
Publication Type :
Academic Journal
Accession number :
edsdoj.7014f89a473242c498bd8f58d42728f2
Document Type :
article
Full Text :
https://doi.org/10.3390/ijms25179440