水产学报2026，Vol.50Issue(9)：72-86,15.DOI:10.11964/jfc.20251215264
基于嗜冷假单胞菌群体感应系统LuxR蛋白筛选靶向肽及抑制生物被膜形成
Screening of LuxR-targeted peptides in the quorum sensing system of Pseudomonas psychrophila and their inhibition of biofilm formation
摘要
Abstract
Bacterial biofilm formation is closely regulated by quorum sensing(QS).This study screened peptides targeting the LuxR protein of the QS system in Pseudomonas psychrophila isolated from refrigerated squid,and investigated their inhibitory effects on biofilm formation.Candidate peptides were selected from half-fin anchovy(Setipinna taty)protein hydrolysate and Pacific white shrimp(Penaeus vannamei)Pelle protein-derived peptides.Molecular docking was employed to comparatively evaluate the binding interactions of N-acyl homoserine lactone(AHL)signal molecules and candidate peptides with the LuxR protein of P.psychrophila.Peptides exhibiting superior binding affinity relative to AHLs were selected as target peptides,and a series of derivative peptides were rationally designed through site-directed amino acid substitution.The docking capacities of derivative peptides against LuxR proteins were evaluated.Derivatives with optimal LuxR-binding capacity were identified as targeted peptides,and the biofilm inhibition efficacy of both target and targeted peptides was subsequently assessed.Results showed that five candidate peptides(AAVVFMLR,PGK,FWAKSQL,MANRVGF,and HLRVGW)were screened.Only PGK successfully docked with six LuxR proteins,exhibiting a binding energy of-447.26 kcal/mol with the LuxR protein SSOs_2029,markedly lower than that of AHL-type signal molecules.However,PGK failed to dock with SSOs_1080.Through site-directed amino acid substitution,targeted peptides KGG and RGG were yielded,which successfully docked with SSOs_1080 with binding energies lower than most endogenous signal molecules.The minimum inhibitory concentration(MIC)and minimum bactericidal concentration of target peptide PGK and targeted peptides KGG and RGG against P.psychrophila were 4 and 8 mg/mL,respectively.At 1/2 MIC(non-inhibitory to bacterial growth),RGG significantly outperformed PGK and KGG in biofilm inhibition(P<0.05).Collectively,targeted peptide RGG competitively displaces AHL signal molecules from the LuxR protein of P.psychrophila,thereby attenuating biofilm formation.These findings provide a theoretical foundation for the rapid screening of peptide-based QS inhibitors against this psychrophilic spoilage bacterium.关键词
冷藏鱿鱼/嗜冷假单胞菌/群体感应/信号分子/分子对接/LuxR 蛋白靶向肽/生物被膜Key words
refrigerated squid/Pseudomonas psychrophila/quorum sensing/signal molecules/molecular docking/LuxR pro-tein-targeted peptides/biofilm分类
农业科技引用本文复制引用
张文熹,李鹏程,宋茹..基于嗜冷假单胞菌群体感应系统LuxR蛋白筛选靶向肽及抑制生物被膜形成[J].水产学报,2026,50(9):72-86,15.基金项目
国家自然科学基金(32272374) National Natural Science Foundation of China(32272374) （32272374）
