Advertisement

Identification and polymorphism discovery of the cathelicidins, Lf-CATHs in ranid amphibian (Limnonectes fragilis)

Authors

  • Haining Yu,

    Corresponding author
    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    2. College of Life Sciences, Hebei Normal University, Shijiazhuang, China
    • Correspondence

      H. Yu, Institute of Marine Biological Technology, School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116024, China

      Fax: +86 411 8470 8850

      Tel: +86 411 8470 8850

      E-mail: joannyu@live. cn

      Y. Wang, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, 215123 China

      Fax: +0512 65882438

      Tel: +0512 65882438

      E-mail: wyp010163.Com

    Search for more papers by this author
  • Shasha Cai,

    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    Search for more papers by this author
  • Jiuxiang Gao,

    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    Search for more papers by this author
  • Songyan Zhang,

    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    Search for more papers by this author
  • Yiling Lu,

    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    Search for more papers by this author
  • Xue Qiao,

    1. Institute of Marine Biological Technology, Dalian University of Technology, Dalian, China
    Search for more papers by this author
  • Hailong Yang,

    1. Department of Physiology, Kunming Medical University, Yunnan, China
    Search for more papers by this author
  • Yipeng Wang

    Corresponding author
    1. College of Pharmaceutical Sciences, Soochow University, Suzhou, China
    • Correspondence

      H. Yu, Institute of Marine Biological Technology, School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116024, China

      Fax: +86 411 8470 8850

      Tel: +86 411 8470 8850

      E-mail: joannyu@live. cn

      Y. Wang, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, 215123 China

      Fax: +0512 65882438

      Tel: +0512 65882438

      E-mail: wyp010163.Com

    Search for more papers by this author

  • Shasha Cai and Jiuxiang Gao contributed equally to this work

Abstract

To protect themselves against the invasion of microorganisms, amphibians, especially the Rana frogs, are possibly equipped with complex combinations of antimicrobial peptides (AMPs). The two major AMP families, ranid skin secretion AMPs and cathelicidins might together constitute the host innate immune system of amphibians. Cathelicidins are a group of cationic peptides found in leukocytes and epithelial cells, and they play a central role in the early innate immune defense found in virtually all species of mammals. However, they have rarely been reported from amphibians. Here, we report the identification and discovery of polymorphism cathelicidins in Limnonectes fragilis. The expression profile indicated high cathelicidin transcript levels in frog spleen, liver and kidney, but lower levels in lung, skin and stomach. According to the amphibian's unique proteolytic pattern, R125 and L121 of the prepropeptides are predicted to be the processing positions for protease to generate the mature peptides, Lf-CATH1 and -2, respectively. Both consist of 30 amino acid residues, of which two were cysteines positionally conserved among a few known amphibian cathelicidins. Homology modeling analysis revealed that Lf-CATH1 and -2 adopt a tertiary structure with a mostly α helix that is representative of small cationic cathelicidin family peptides. Recombinant Lf-CATH1 (rLf-CATH1) was produced in Escherichia coli. Synthetic Lf-CATH1 and -2 displayed potent antimicrobial activities in vitro against a broad spectrum of microorganisms, including standard and clinically isolated drug-resistant strains, while showing neglectable hemolysis and cytotoxicities.

Ancillary