PMID- 36870429 OWN - NLM STAT- MEDLINE DCOM- 20230404 LR - 20230404 IS - 1095-9947 (Electronic) IS - 1050-4648 (Linking) VI - 135 DP - 2023 Apr TI - Antibacterial activity study of a novel piscidin 5-like type 4 from Larimichthys crocea. PG - 108645 LID - S1050-4648(23)00131-6 [pii] LID - 10.1016/j.fsi.2023.108645 [doi] AB - As one of the key components of innate immune system, piscidins are likely to play pivotal role in the first defense line in fish. Piscidins own multiple resistance activity. A novel piscidin 5-like type 4 was excavated from Larimichthys crocea (termed Lc-P5L4) liver transcriptome immuned by Cryptocaryon irritans, and upregulated at 7 days post infection when secondary bacterial infection occurred. In the study, we characterized the antibacterial activity of Lc-P5L4. The liquid growth inhibition assay detected the recombinant Lc-P5L4 (rLc-P5L) had potent antibacterial activity to Photobacterium damselae. Scanning electron microscope (SEM) observed the cell surface of P. damselae collapsed to form pit, and membrane of some bacteria ruptured after co-incubation with rLc-P5L. Further, transmission electron microscope (TEM) was also employed to observe the intracellular microstructural damage, rLc-P5L4 caused cytoplasm contraction, pores formation and contents leakage. After knowing about its antibacterial effects, the preliminary antibacterial mechanism was also explored, western blot analysis showed rLc-P5L4 could bind to P. damselae through targeting to LPS. Agarose gel eletrophoresis analysis further showed rLc-P5L4 could also penetrate into cells and brought about genome DNA degradation. Therefore, rLc-P5L4 was of potential being a candidate to explore new antimicrobial drug or additive agent, especially to P. damselae. CI - Copyright (c) 2023. Published by Elsevier Ltd. FAU - Zheng, Li-Bing AU - Zheng LB AD - School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China. Electronic address: 183627046@qq.com. FAU - Li, Yue-Xin AU - Li YX AD - Shanghai Richen Nutrition Technology Co., Ltd, 200331, Shanghai, China. FAU - Su, Yong-Quan AU - Su YQ AD - State Key Laboratory of Large Yellow Croaker Breeding, Ningde Fufa Fisheries Co., Ltd, 352103, Fujian, China. LA - eng PT - Journal Article DEP - 20230303 PL - England TA - Fish Shellfish Immunol JT - Fish & shellfish immunology JID - 9505220 RN - 0 (Antimicrobial Cationic Peptides) RN - 0 (Anti-Bacterial Agents) RN - 0 (Fish Proteins) SB - IM MH - Animals MH - *Ciliophora Infections MH - Antimicrobial Cationic Peptides/genetics/pharmacology/chemistry MH - *Perciformes MH - *Hymenostomatida MH - Anti-Bacterial Agents/pharmacology/metabolism MH - *Fish Diseases MH - Fish Proteins/chemistry OTO - NOTNLM OT - Antibacterial activity OT - Larimichthys crocea OT - Photobacterium damselae OT - Piscidin 5-like type 4 COIS- Declaration of competing interest The paper is co-authored by Li-bing Zheng, Yue-xin Li, Yongquan Su. All the authors agreed to submit the research paper titled "Antibacterial activity study of a novel piscidin 5-like type 4 from Larimichthys crocea" for publication in *Fish and Shellfish Immunology*. This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal. We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled. EDAT- 2023/03/05 06:00 MHDA- 2023/04/04 06:42 CRDT- 2023/03/04 19:29 PHST- 2023/01/27 00:00 [received] PHST- 2023/02/20 00:00 [revised] PHST- 2023/02/23 00:00 [accepted] PHST- 2023/04/04 06:42 [medline] PHST- 2023/03/05 06:00 [pubmed] PHST- 2023/03/04 19:29 [entrez] AID - S1050-4648(23)00131-6 [pii] AID - 10.1016/j.fsi.2023.108645 [doi] PST - ppublish SO - Fish Shellfish Immunol. 2023 Apr;135:108645. doi: 10.1016/j.fsi.2023.108645. Epub 2023 Mar 3.