Molecular characterization and antimicrobial activity of NK-lysin in black scraper (Thamnaconus modestus).

Autor: Liu MY; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China., Zhang YR; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China., Zhang JH; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China., Miao L; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China., Dang YF; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China., Fei CJ; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China. Electronic address: feichenjie@nbu.edu.cn., Li CH; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China. Electronic address: lichanghong0716@163.com., Chen J; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Meishan Campus, Ningbo, 315832, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Meishan Campus, Ningbo, 315832, China.
Jazyk: angličtina
Zdroj: Fish & shellfish immunology [Fish Shellfish Immunol] 2023 May; Vol. 136, pp. 108703. Date of Electronic Publication: 2023 Mar 21.
DOI: 10.1016/j.fsi.2023.108703
Abstrakt: NK-lysin (NKL) is a positively charged antimicrobial peptide with broad-spectrum bactericidal activities. In this study, the cDNA sequence of NKL (TmNKL) from black scraper (Thamnaconus modestus) was cloned, which encodes a predicted polypeptide of 150 amino acids that contains a surfactant protein B domain with three disulfide bonds. Phylogenetically, TmNKL was most closely related to its teleost counterpart from tiger puffer (Takifugu rubripes). Expression analysis demonstrated that TmNKL transcripts were constitutively expressed in all tested tissues, with the highest expression levels in the gills. Its expression was significantly upregulated in the gills, head kidney, and spleen after infection with Vibrio parahaemolyticus. A linear peptide (TmNKLP40L) and a disulfide-type peptide (TmNKLP40O) were further synthesized and results showed that disulfide bonds are not essential for bactericidal activities of TmNKL, and that both forms of TmNKL exhibited potent bactericidal activities against 4 gram- negative bacteria, including V. parahaemolyticus, V. alginolyticus, Edwardsiella tarda, and V. harveyi. Observed antimicrobial activities are likely due to the effects of TmNKLP40L and TmNKLP40O treatment on disrupting the integrity of both inner and outer membrane of V. parahaemolyticus, resulting in hydrolysis of bacterial genomic DNA. Damaged cell membranes and leakage of intracellular contents were further confirmed using scanning and transmission microscopy. Moreover, administration of 1.0 μg/g TmNKLP40L or TmNKLP40O significantly decreased bacterial load in tissues and thus, pronouncedly enhanced the survival of V. parahaemolyticus-infected fish. Overall, our results demonstrated that TmNKL is a potent innate effector and provides protective effects against bacterial infection.
Competing Interests: Declaration of competing interest The authors confirm they have no known conflicts of interest.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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