Abstract

The misuse of antibacterial agents has contributed to the growing prevalence of antibiotic resistance, highlighting an urgent need to explore alternative anti-infection therapeutic strategies. Antimicrobial peptides (AMPs) are naturally occurring molecules. They exhibit broad-spectrum antimicrobial activity and represent promising candidates for the development of novel therapeutics. A cysteine-rich antimicrobial peptide was identified and characterized from the genome ofTigriopus japonicusand designated “TjRcys1”. The precursor form ofTjRcys1 comprises 96 amino acids. Structural analyses ofTjRcys1 revealed random coils, two α-helices, and two β-strands. RecombinantTjRcys1 had inhibitory effects uponStaphylococcus aureusandBacillussp. T2, with a minimum inhibitory concentration of 64 μM for both.TjRcys1 did not show complete inhibition againstVibrio alginolyticus,Klebsiella pneumoniae, orAeromonas hydrophilaat 64 μM, but it did slow their growth rate.TjRcys1 could disrupt the permeability of the cell membrane ofS. aureus. Transcriptomic analyses indicated thatTjRcys1 could interfere with the ribosome biosynthesis and nucleotide metabolism ofK. pneumoniae. Our results provide a valuable reference for the development of new AMPs and optimization of their design.