Mechanism of action of recombinant acc-royalisin from royal jelly of Asian honeybee against gram-positive bacteria

PLoS One. 2012;7(10):e47194. doi: 10.1371/journal.pone.0047194. Epub 2012 Oct 9.

Abstract

The antibacterial activity of royalisin, an antimicrobial peptide from the royal jelly produced by honeybees, has been addressed extensively. However, its mechanism of action remains unclear. In this study, a recombinant royalisin, RAcc-royalisin from the royal jelly of Asian honeybee Apis cerana cerana, was expressed by fusing with glutathione S-transferase (GST) in Escherichia coli BL21, isolated and purified. The agar dilution assays with inhibition zone showed that RAcc-royalisin, similar to nisin, inhibits the growth of Gram-positive bacteria. The antibacterial activity of RAcc-royalisin was associated with its concentration, and was weakened by heat treatment ranging from 55°C to 85°C for 15 min. Both RAcc-royalisin and nisin exhibited the minimum inhibitory concentrations (MIC) of 62.5 µg/ml, 125 µg/ml, and 250 µg/ml against Gram-positive bacterial strains, Bacillus subtilis and Micrococcus flavus and Staphyloccocus aureus in the microplate assay, respectively. However, RAcc-royalisin did not show antimicrobial activity against tested Gram-negative bacterial and fungal strains. The antibacterial activity of RAcc-royalisin agrees well with the decrease in bacterial cell hydrophobicity, the leakage of 260-nm absorbing materials, and the observation by transmission electron microscopy, all indicating that RAcc-royalisin induced the disruption and dysfunction of cell walls and membranes. This is the first report detailing the antibacterial mechanism of royalisin against Gram-positive bacteria, and provides insight into the application of recombinant royalisin in food and pharmaceutical industries as an antimicrobial agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Bees / chemistry*
  • Escherichia coli / drug effects
  • Fatty Acids / chemistry*
  • Gram-Positive Bacteria / drug effects*
  • Intercellular Signaling Peptides and Proteins
  • Microbial Sensitivity Tests
  • Microscopy, Electron, Transmission
  • Proteins / pharmacology*
  • Temperature

Substances

  • Anti-Bacterial Agents
  • Fatty Acids
  • Intercellular Signaling Peptides and Proteins
  • Proteins
  • royalisin
  • royal jelly

Grant support

This work was supported by Scientific and Technical Programs of Zhejiang (No.2011C22029) (http://www.zjkjt.gov.cn/); Scientific and Technical Programs of Hangzhou (No.20110232B52) (http://www.hznet.com.cn/); and National program (863) of High-Technology Research and Development from The Ministry of Science and Technology of China (No. 2007AA10Z324) (http://www.most.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.