Optimisation and identification of anchovy antimicrobial peptides by enzymolysis and untargeted proteomic profiling

Summary Natural antimicrobial peptides are promising antibiotics without inducing high bacteria resistance and have wide applications in the medical health and food industry. Herein, we prepared and optimised anchovy antimicrobial peptides (AAMPs) by degreasing and enzymolysis of anchovy extracts under different conditions. The enzymolysis mixtures at optimised preparation conditions exhibited concentration-dependent inhibitory activity against Staphylococcus aureus . Then, we applied the mass spectrometry-based proteomics analysis to globally profile the peptide constitutes within the active peptide mixture and finally, 4 unique peptides coming from 68 proteins were confidently identified. We compared the peptide sequences with the antimicrobial peptides (AMPs) database and synthesised 4 potential AAMPs. As a result, peptide GTEDELDKY exhibited inhibitory activity against Escherichia coli , and peptides DREGESGPS, YIGRPIPQ and YEDEINKR exhibited inhibitory activity against SA . Our work established a useful workflow for discovering novel AMPs from fish proteins, which may play important role in the development of effective antibiotics.