Related Experiment Video
Updated: Aug 9, 2026

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
Published on: September 16, 2013
Inhibition of lipopolysaccharide activity by a bacterial cyclic lipopeptide surfactin
Taichi Takahashi1, Osamu Ohno, Yoko Ikeda
1Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-0061, Japan.
Abstract:
Compounds that inactivate lipopolysaccharide (LPS) activity have the potential of being new anti-inflammatory agents. Therefore, we searched among microbial secondary metabolites for compounds that inhibited LPS-stimulated adhesion between human umbilical vein endothelial cells (HUVEC) and HL-60 cells. By this screening, we found a cyclic lipopeptide surfactin from the culture broth of Bacillus sp. BML752-121F2 to be inhibitory. The addition of the surfactin prior to the LPS stimulation decreased HL-60 cell-HUVEC adhesion without showing any cytotoxicity. We confirmed that surfactin inhibited LPS-induced expression of ICAM-1 and VCAM-1 in HUVEC. It also inhibited the cellular adhesion induced by lipid A, the active component of LPS; but it did not inhibit TNF-alpha or IL-1 beta-induced cell adhesion. Then, surfactin was shown to suppress the interaction of lipid A with LPS-binding protein (LBP) that mediates the transport of LPS to its receptors. Finally, surface plasmon resonance (SPR) analysis revealed the surfactin to interact reversibly with lipid A. Thus, this Bacillus surfactin was shown to be an inhibitor of LPS-induced signal transduction, directly interacting with LPS.
Related Concept Videos
Inhibitors of Gram-positive Cell Wall Synthesis
Formation of Lipopolysaccharides
Gene Regulation in Microbial Communities: Quorum Sensing
Inhibitors of Bacterial Protein Synthesis
Peptidoglycan Synthesis
Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...

