Simen Bye Borge, Julie Strømberg, and Terje Vasskog
UiT The Arctic University of Norway, Department of Pharmacy, Tromsø, Norway
Email: sbo102@uit.no / simenbyeborge@gmail.com
Background and Objectives
Antimicrobial resistance is a global health concern. Disulfide rich peptides represent a promising class of compounds that can be utilized as new antimicrobial agents. The aim of the study was to synthesize different variants of the derived peptide Turgencin A to study structural activity relationships of these variants by exploring its difference in biological functions.
Methods
In the study, two analogues (SB1 and SB2) were produced using a microwave-assisted Fmoc solid-phase peptide synthesis. The peptides were purified using a preparative reverse-phase HPLC system. Different chromatographic techniques were explored and fine-tuned by adjusting solvent gradients and flow rates to optimize separation efficiency and peptide purity. SB1, which contained multiple cysteine residues, was oxidized to create distinct disulfide bridges. This created different isomers which were studied to look at differences in structural activity relationships and biological functions. UPLC-MS/MS was used for identifying cysteine bridging in the different isomers. SB2, which did not contain any cysteine residues, represented the central region of the Turgencin A sequence. It was studied to evaluate the bioactivity of the linear middle part of the peptide compared to the cysteine containing variants of a larger part of the Turgencin A peptide.
Conclusion
This study highlights the use of various chromatographic methods for peptide characterization, purity, and structural elucidation. Preparative HPLC was used extensively to purify the peptides while UPLC-MS/MS was used for structure elucidation and peptide characterization.