Related Experiment Video
Updated: Apr 1, 2026

Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
Published on: January 1, 2016
Rationale design of quorum-quenching peptides that target the VirSR system of Clostridium perfringens
Ravindra Pal Singh1, Ken-Ichi Okubo1, Kaori Ohtani2
1Laboratory of Microbial Technology, Department of Biochemistry and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan.
Abstract:
In Clostridium perfringens, a 5-membered thiolactone peptide acts as an autoinducing peptide (AIPCp) to activate the VirSR two-component signal transduction system, which in turn controls the expression of genes encoding multiple toxins, including α, θ and κ. To develop anti-pathogenic agents against virulent C. perfringens, quorum-quenching peptides were rationally designed based on the structure-activity relationship (SAR) data on AIPCp. Alanine scanning study of AIPCp suggested that Trp(3) and Phe(4) are involved in receptor binding and activation, respectively. On the basis of the SAR, we designed two quorum-quenching peptides with different modes of action: Z-AIPCp-L2A/T5A (partial agonist) and Z-AIPCp-F4A/T5S (partial antagonist). Both peptides significantly attenuated transcription of θ toxin gene (pfoA) in a virulent strain of C. perfringens with IC50 = 0.32 and 0.72 μM, respectively.
More Related Videos
Related Concept Videos
Gene Regulation in Microbial Communities: Quorum Sensing
Regulation of Bacterial Virulence
Bacterial Signaling
CRISPR and crRNAs
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
Inhibitors of Gram-positive Cell Wall Synthesis

