Heterologous Expression and Antimicrobial Targets of a Novel Glycine-Rich Antimicrobial Peptide from Artemia franciscana

The growing problem of antimicrobial resistance in aquaculture, caused by the excessive and unregulated use of antibiotics, highlights the critical necessity for developing new anti-infective solutions. Based on the characteristics of glycine-rich antimicrobial peptides (AMPs) and transcriptomic data, an antimicrobial peptide, namely <i>Af</i>Rgly1, was discovered in this study. Subsequently, the peptide was obtained through heterologous expression in <i>E. coli</i>, and its antibacterial spectrum was determined. Molecular dynamics simulation and molecular biology experiments were conducted to explore the antibacterial target of <i>Af</i>Rgly1. Results showed that the mRNA expression level of <i>Af</i>Rgly1 was significantly upregulated after <i>Vibrio alginolyticus</i> infection. <i>Af</i>Rgly1 has broad-spectrum antibacterial activity targeting on bacterial cell membrane, and it may also interact with bacterial DNA. <i>Af</i>Rgly1 displayed low selectivity for fish red blood cells. These results indicate that <i>Af</i>Rgly1 is an antimicrobial peptide with considerable potential for application in the development of therapeutic agents.