Flagellin, S. typhimurium (FlaF, Hag)

Blue Ice

3060

Supplied as a liquid in PBS, pH 7.4. No preservative added.

Flagellin is a protein (495aa, 30-60kD, refs 1) that arranges itself in a hollow cylinder to form the filament in bacterial flagellum. Individual Salmonella serotypes usually alternate between the production of 2 antigenic forms of flagella, termed phase 1 and phase 2, each specified by separate structural genes, fliC and fljB. Flagellin is the principal protein of bacterial flagellum, and is present in large amounts on nearly all flagellated bacteria. It confers motility on a wide range of bacterial species. Flagellin is a potent stimulator of innate immune responses in a number of eukaryotic cells and organisms, including both mammals and plants. In mammals, flagellin is recognized by TLR51 and triggers defense responses both systemically and at epithelial surfaces. Flagellin induces the activation of NF-kappaB and the production of cytokines and nitric oxide depending on the nature of the TLR5 signaling complex.

The structure of flagellin is responsible for the helical shape of the flagellar filament, which is important for its proper function. The N- and C-termini of flagellin form the inner core of the flagellin protein, and is responsible for flagellin's ability to polymerize into a filament. The central portion of the protein makes up the outer surface of the flagellar filament. While the termini of the protein is quite similar between all bacterial flagellins, the central portion is wildly variable.
In plants, a 22aa sequence (flg22) of the conserved N-terminal part of flagellin is known to activate plant defense mechanisms. Flagellin perception in Arabidopsis thaliana functions via the receptor-like-kinase, FLS2 (flagellin-sensitive-2). Mitogen-activated-protein-kinases (MAPK) acts as signalling compounds and more than 900 genes are affected upon flg22 treatment. Pre-stimulation with a synthetic flg22-peptide led to enhanced resistance against bacterial invaders.

Source:
Flagellin, from S. typhimurium (Strain 14028)

Biological Activity:
Flagellin activity is tested using Caco-2 cells transfected with plasmid encoding CCL20-LUC plasmid (0.0001-1ug/ml).

Endotoxin:
<0.1EU/ug purified protein (LAL test)

Specific Activity:
Flagellin have many known activities such as activation fo TLR5 in human epithelial cells assays based on NF-kB luciferase fuision, on expression of IL-8 (CXCl8), iNOS, beta-defensin 2 and and MMP7, maturation of dendritic cells. TLR5 can be stimulated in vitro at 5-50ng/ml and in invivo at 0.1-1ug/mouse.

Applications:
Suitable for use in ELISA and Western Blot. Other applications not tested.

Recommended Dilution:
ELISA: 1:10-50K, using 50-100ng control antigen/well
Western Blot: 1:1K-5K using Chemiluminescence technique
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.