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Updated: Feb 3, 2026

Expression, Purification, and Antimicrobial Activity of S100A12
Published on: May 13, 2017
Identification of duck liver-expressed antimicrobial peptide 2 and characterization of its bactericidal activity
Yeojin Hong1, Anh Duc Truong1,2, Janggeun Lee1
1Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Korea.
Objective:
This study was conducted to identify duck liver-expressed antimicrobial peptide 2 (LEAP-2) and demonstrate its antimicrobial activity against various pathogens.
Methods:
Tissue samples were collected from 6 to 8-week-old Pekin ducks (Anas platyrhynchos domesticus), total RNA was extracted, and cDNA was synthesized. To confirm the duck LEAP-2 transcript expression levels, quantitative real-time polymerase chain reaction was conducted. Two kinds of peptides (a linear peptide and a disulfide-type peptide) were synthesized to compare the antimicrobial activity. Then, antimicrobial activity assay and fluorescence microscopic analysis were conducted to demonstrate duck LEAP-2 bactericidal activity.
Results:
The duck LEAP-2 peptide sequence showed high identity with those of other avian species (>85%), as well as more than 55% of identity with mammalian sequences. LEAP-2 mRNA was highly expressed in the liver with duodenum next, and then followed by lung, spleen, bursa and jejunum and was the lowest in the muscle. Both of LEAP-2 peptides efficiently killed bacteria, although the disulfide-type LEAP-2 showed more powerful bactericidal activity. Also, gram-positive bacteria was more susceptible to duck LEAP-2 than gram-negative bacteria. Using microscopy, we confirmed that LEAP-2 peptides could kill bacteria by disrupting the bacterial cell envelope.
Conclusion:
Duck LEAP-2 showed its antimicrobial activity against both gram-positive and gram-negative bacteria. Disulfide bonds were important for the powerful killing effect by disrupting the bacterial cell envelope. Therefore, duck LEAP-2 can be used for effective antibiotics alternatives.
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