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Updated: May 1, 2026
Biomimetic Materials to Characterize Bacteria-host Interactions
Published on: November 16, 2015
Effect of the anti-lipopolysaccharide factor isoform 3 (ALFPm3) from Penaeus monodon on Vibrio harveyi cells
Phattarunda Jaree1, Anchalee Tassanakajon, Kunlaya Somboonwiwat
1The Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
Abstract:
The anti-lipopolysaccharide factor isoform 3 from Penaeus monodon (ALFPm3) has previously been shown to have very active in vitro antimicrobial activity against a broad range of Gram-positive and Gram-negative bacteria, certain fungi and viruses, including known pathogens of P. monodon shrimp. With respect to the strong bactericidal effect on Gram-negative and Gram-positive bacteria, the ALFPm3 binds to their principal cell wall components, lipopolysaccharide (LPS) and lipoteichoic acid (LTA), with a high affinity. The aim of this study was, therefore, to reveal the effects of treating ALFPm3 on membrane of Vibrio harveyi, a P. monodon pathogenic Gram-negative bacterium. The recombinant (r)ALFPm3 protein was found to localize on the V. harveyi cells in vivo, followed by inducing membrane permeabilization and leakage of cytoplasmic components. Moreover, the effect of rALFPm3 treatment on the bacterial cell morphology was confirmed by scanning and transmission electron microscopy. Membrane disruption and damage, bleb and pore formation, and the leakage of cytoplasmic contents were all clearly observed. Taken together, these results suggested that ALFPm3 effectively kills bacteria through bacterial membrane permeabilization.
Insights
The anti-lipopolysaccharide factor isoform 3 (ALFPm3) from shrimp effectively targets bacterial membranes, causing them to become permeable and leak vital components. This mechanism demonstrates ALFPm3
Area of Science:
- Marine Biology
- Immunology
- Microbiology
Background:
- The anti-lipopolysaccharide factor isoform 3 (ALFPm3) from Penaeus monodon exhibits broad-spectrum antimicrobial activity.
- ALFPm3 demonstrates high affinity binding to bacterial cell wall components, lipopolysaccharide (LPS) and lipoteichoic acid (LTA).
- Vibrio harveyi is a significant pathogen affecting Penaeus monodon shrimp.
Purpose of the Study:
- To investigate the effects of ALFPm3 treatment on the membrane of the Gram-negative bacterium Vibrio harveyi.
- To elucidate the mechanism of bacterial killing by ALFPm3.
Main Methods:
- Treatment of Vibrio harveyi with recombinant ALFPm3 (rALFPm3) protein.
- In vivo localization studies of rALFPm3 on bacterial cells.
- Assessment of membrane permeabilization and cytoplasmic leakage.
- Scanning and transmission electron microscopy to observe morphological changes.
Main Results:
- Recombinant ALFPm3 localized on the surface of Vibrio harveyi cells.
- ALFPm3 treatment induced significant membrane permeabilization and leakage of cytoplasmic components.
- Electron microscopy revealed membrane damage, pore formation, and bleb development.
Conclusions:
- ALFPm3 effectively disrupts the bacterial membrane integrity.
- Bacterial membrane permeabilization is the primary mechanism by which ALFPm3 exerts its bactericidal effect.
- ALFPm3 shows potential as a therapeutic agent against bacterial infections in shrimp.
