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Bio-layer Interferometry for Measuring Kinetics of Protein-protein Interactions and Allosteric Ligand Effects
Published on: February 18, 2014
Insights from label free-based proteomic analysis into inhibitory effects ε-Poly-lysine against Vibrio
Wenfu Hou1, Tingting Liu1, Yi Zhang1
1College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, Hubei, 430023, PR China.
Abstract:
Vibrio parahaemolyticus is one of the most common pathogenic bacteria that pose a threat to human health. The purpose of this study was to investigate antibacterial mechanisms of ε-poly-lysine (ε-PL) against V. parahaemolyticus using a lable free-based proteomic analysis. The differentially expressed proteins (DEPs) were subjected to bioinformatics analysis. The results indicated that a total of 196 DEPs, including 118 up-regulated and 78 down-regulated, were identified in the ε-PL-treated cells compared with control group. Upon Go functional enrichment, 13, 9, and 8 specific Go terms in biological processes, molecular functions and cellular components were identified, respectively. KEGG pathways analysis indicated that the DEPs were mainly involved in bacterial chemotaxis, RNA transport and two-component system, which were significantly enriched (P < 0.05). In PPI analysis, Che R and Che V, both involved in bacterial chemotaxis and RNA transport pathways, are closely related to other DEPs. Therefore, the down-regulation of Che R and Che V in ε-PL-treated cells resulted in the reduction or even loss of bacterial adaptability, and they were the critical action sites of ε-PL to inactivate V. parahaemolyticus.
Insights
ε-poly-lysine (ε-PL) inactivates Vibrio parahaemolyticus by down-regulating key proteins involved in bacterial adaptability, such as Che R and Che V. This proteomic study reveals novel antibacterial mechanisms against this common pathogen.
Area of Science:
- Microbiology
- Proteomics
- Biochemistry
Background:
- Vibrio parahaemolyticus is a significant human pathogen.
- Understanding its susceptibility to antimicrobial agents is crucial for public health.
Purpose of the Study:
- To elucidate the antibacterial mechanisms of ε-poly-lysine (ε-PL) against Vibrio parahaemolyticus.
- To identify key proteins and pathways affected by ε-PL treatment using proteomic analysis.
Main Methods:
- Label-free quantitative proteomic analysis was employed to compare ε-PL-treated V. parahaemolyticus with control cells.
- Bioinformatics tools, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, were used to analyze differentially expressed proteins (DEPs).
- Protein-protein interaction (PPI) network analysis was performed to identify critical regulatory proteins.
Main Results:
- A total of 196 differentially expressed proteins (DEPs) were identified, with 118 up-regulated and 78 down-regulated in ε-PL-treated cells.
- GO enrichment analysis revealed significant changes in biological processes, molecular functions, and cellular components.
- KEGG pathway analysis highlighted the involvement of bacterial chemotaxis, RNA transport, and two-component systems, with Che R and Che V identified as critical proteins.
Conclusions:
- ε-poly-lysine (ε-PL) exerts its antibacterial effect by down-regulating Che R and Che V proteins in Vibrio parahaemolyticus.
- This down-regulation leads to reduced bacterial adaptability and potential loss of function, indicating these proteins are critical targets for ε-PL.
- The findings provide insights into the molecular mechanisms of ε-PL as a potential antimicrobial agent against V. parahaemolyticus.

