LPS-EB Biotin - Cell culture tested - TLR4 Agonist

Lipopolysaccharide from Escherichia coli 0111:B4 – Biotinylated 

LPS-EB Biotin is a biotinylated smooth (s)-form lipopolysaccharide purified from the pathogenic E. coli O111:B4. It retains the Toll-like receptor 4 (TLR4) agonist activity of native LPS-EB and is provided in Ultrapure grade for TLR4-selective stimulation.

The purification process combines successive enzymatic hydrolysis steps with phenol–TEA–DOC extraction to remove contaminating lipoproteins.
Biotinylation of LPS-EB is achieved by conjugating biotin-LC-hydrazide to the oxidized carbohydrate moieties of LPS, preserving LPS-EB biological activity.
 

A dual-purpose tool for LPS research

• LPS-EB Biotin can be used to investigate LPS binding sites, internalization, and intracellular trafficking.
• LPS-EB Biotin retains its biological activity to support studies of TLR4-mediated inflammatory signaling.
   

Mechanism of action

LPS recognition by TLR4 involves several accessory proteins, including LPS-binding protein (LBP), CD14, and MD-2. LBP binds LPS and facilitates its transfer to CD14, which promotes LPS delivery to the TLR4/MD-2 complex. As a smooth LPS, LPS-EB relies on CD14 for efficient TLR4 signaling, particularly at low LPS concentrations.

LPS binding to the TLR4/MD-2 complex initiates different signaling pathways through two adaptor proteins:
- MyD88-dependent signaling at the plasma membrane
Cell-surface TLR4 signals through TIRAP and MyD88, leading to NF-κB activation and the production of pro-inflammatory cytokines.
- TRIF-dependent signaling from the endosomes
CD14 facilitates LPS/TLR4/MD-2 endocytosis. Endosomal TLR4 signals through the TRAM-TRIF pathway, leading to IRF3 activation and the production of type I interferons.
 

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