金抗肽 SIF4 基于糖代谢途径和细胞质膜氧化损伤的大肠埃希菌抑菌机理

作者:Li Yuzhen; Xiao Huaiqiu*; Wang Lin; Liu Miao; Zeng Mengqi; Cao Dan; Zhao Mouming
来源:Food and Fermentation Industries, 2022, 48(20): 122-129.
DOI:10.13995/j.cnki.11-1802/ts.032698

摘要

To reveal the antimicrobial mechanism of metal antimicrobial peptide (MAP) SIF4 against Escherichia coli based on glucose metabolism pathway and cytoplasmic membrane oxidative damage, the effects of SIF4 on critical enzymatic activity of Embden-Meyerhof-Parnas (EMP) pathway and tricarboxylic acid (TCA) cycle, cytoplasmic membrane oxidative damage, intracellular ROS production and cell membrane depolarization were investigated. Results showed that, SIF4 inhibited the key enzymes in glycolysis, including hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK), by 66. 61%, 27. 37, and 39. 61%, respectively, and the key enzymes in TCA cycle, including pyruvate dehydrogenase complex (PDHC), citrate synthetase (CS), isocitrate dehydrogenase (IDH) and α-ketoglutaric dehydrogenase (α-KGDH), by 25. 20%, 22. 91%, 26. 99 and 23. 44%, respectively. SIF4 exerted good antimicrobial capacity mainly through regulating glucose oxidation efficiency by restraining the HK activity in glycolysis. It was also confirmed that SIF4 could cause cytoplasmic membrane oxidative damage and induce oxidative stress to produce excessive ROS, resulting in destroying cytoplasmic membrane structural integrity, and exerting synergistic enhancement of antimicrobial capacity by inducing cell apoptosis or programmed cell death. All results can provide direct evidence for systematically elucidating antimicrobial mechanism of SIF4 against E. coli, and also offer theoretical support for its application in the biological control of foodborne E. coli. ? 2022 Food and Fermentation Industries.

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