Date Published: January 25, 2017
Publisher: Public Library of Science
Author(s): Seung Chul Shin, In Hye Ahn, Do Hwan Ahn, Yung Mi Lee, Jungeun Lee, Jun Hyuck Lee, Han-Woo Kim, Hyun Park, Massimiliano Galdiero.
We identified two antimicrobial peptides (AMPs) with similarity to moronecidin in Antarctic fishes. The characteristics of both AMPs were determined using moronecidin as a control. Moronecidin, which was first isolated from hybrid striped bass, is highly salt-resistant, and possesses broad-spectrum activity against various microbes. The moronecidin-like peptide from Notothenia coriiceps exhibited a narrower spectrum of activity and a higher salt sensitivity than moronecidin. The AMP from Parachaenichthys charcoti exhibited similar antimicrobial activity to moronecidin, and similar salt sensitivity. In an experiment to identify toxic effects, both of the moronecidin-like peptides from the Antarctic fishes exhibited lower hemolytic activity than moronecidin. In spite of its low toxicity, the AMP from N. coriiceps is unlikely to be considered as a candidate for antibiotic development, owing to its narrow spectrum of activity and high salt sensitivity. In contrast, the high salt resistance and broad-spectrum activity of the AMP from P. charcoti could be more advantageous for clinical use than moronecidin, since it could kill bacteria under physiological conditions with low toxicity. A further comparison of these two AMPs from Antarctic fishes with other AMPs could help to reduce the toxicity of AMPs for clinical use.
Antimicrobial agents have defeated many infectious diseases and have improved public health significantly. However, many pathogenic microorganisms are becoming resistant to several antimicrobial agents/drugs, and demand for novel antibiotics continues to grow .
The moronecidin-like peptide from N. coriiceps shows distinctive features for an AMP. The amino acid sequence has very low similarity with other AMPs. The most similar amino acid sequence is that of the piscidin-like antimicrobial peptide from the icefish, C. hamatus, with which it shares 55% identity. It shares 43% identity with moronecidin from hybrid striped bass. However, we could not find any advantages conferred by this distinctive amino acid sequence. In spite of its low toxicity, moroNC-NH2 has a narrow spectrum of antibacterial activity, and high salt sensitivity. These characteristics make it difficult to consider moroNC-NH2 for clinical use.