International Journal of Molecular Sciences (Jul 2022)

Antibacterial Peptide NP-6 Affects <i>Staphylococcus aureus</i> by Multiple Modes of Action

  • Xiaoyan Hou,
  • Jianlong Li,
  • Huaqiao Tang,
  • Qingye Li,
  • Guanghui Shen,
  • Shanshan Li,
  • Anjun Chen,
  • Zixin Peng,
  • Yu Zhang,
  • Chaowei Li,
  • Zhiqing Zhang

DOI
https://doi.org/10.3390/ijms23147812
Journal volume & issue
Vol. 23, no. 14
p. 7812

Abstract

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Our previous study extracted and identified an antibacterial peptide that was named NP-6. Herein, we investigated the physicochemical properties of NP-6, and elucidated the mechanisms underlying its antimicrobial activity against Staphylococcus aureus. The results showed that the hemolysis activity of NP-6 was 2.39 ± 0.13%, lower than Nisin A (3.91 ± 0.43%) at the same concentration (512 µg/mL). Negligible cytotoxicity towards RAW264.7 cells was found when the concentration of NP-6 was lower than 512 µg/mL. In addition, it could keep most of its activity in fetal bovine serum. Moreover, transmission electron microscopy, confocal laser scanning microscopy, and flow cytometry results showed that NP-6 can destroy the integrity of the bacterial cell membrane and increase the membrane permeability. Meanwhile, NP-6 had binding activity with bacterial DNA and RNA in vitro and strongly inhibited the intracellular β-galactosidase activity of S. aureus. Our findings suggest that NP-6 could be a promising candidate against S. aureus.

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