Functional diversity of anti-lipopolysaccharide factor isoforms in shrimp and their characters related to antiviral activity.
Anti-lipopolysaccharide factor (ALF) is a small protein with broad-spectrum antimicrobial activity, which has potential application in the disease control. Previously, we isolated seven ALF isoforms from the Chinese shrimp Fenneropenaeus chinensis. In the present study, their distributions in tissues of shrimp were analyzed and the data showed that different isoforms had different expression profiles, which suggested that they might have different functions. Then, the functions of different isoforms were studied by analyzing the antibacterial and antiviral activities of the functional domain of ALFs, the LPS-binding domain (LBD), which were synthesized by chemical methods. Different ALFs showed distinct antibacterial and antiviral activities, which were consistent with their diverse tissue distribution patterns. Sequence analysis on the LBD domain of different isoforms revealed that an identical lysine residue site was specifically conserved in peptides with anti-WSSV activity. In order to confirm whether this lysine residue is critical to the antiviral activity of the peptide, new peptides were synthesized by changing residues at this site. Changing the lysine residue at the specific site to other amino acid residue, the antiviral activity of the peptide apparently decreased. While replacing other residue with a lysine residue at this site in LBD peptide without anti-WSSV activity, the peptide will obtain the antiviral activity to WSSV. These results not only showed us a comprehensive understanding on the function of ALFs from F. chinensis, but also provided clues for the development of ALFs as potential therapeutic drugs to WSSV.
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. lishihao@qdio.ac.cn.|National & Local Joint Engineering Laboratory of Ecological Mariculture, 7 Nanhai Road, Qingdao 266071, China. lishihao@qdio.ac.cn.
Shihao
S
Li
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. guoshuyue@126.com.|Graduate University of Chinese Academy of Sciences, Beijing 100049, China. guoshuyue@126.com.
Shuyue
S
Guo
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. fhli@qdio.ac.cn.|National & Local Joint Engineering Laboratory of Ecological Mariculture, 7 Nanhai Road, Qingdao 266071, China. fhli@qdio.ac.cn.
Fuhua
F
Li
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. jhxiang@qdio.ac.cn.
Jianhai
J
Xiang
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism* / Q000494:pharmacology; D000998:Antiviral Agents / Q000378:metabolism* / Q000494:pharmacology; D060829:Arthropod Proteins / Q000378:metabolism* / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000378:metabolism*; D033561:Penaeidae / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism* / Q000494:pharmacology; D016415:Sequence Alignment; D014018:Tissue Distribution; D059467:Transcriptome / Q000502:physiology
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000998:Antiviral Agents; D060829:Arthropod Proteins; D008070:Lipopolysaccharides; D020033:Protein Isoforms; C034705:antilipopolysaccharide factor (Limulus)