Technical Data
Bacillus anthracis LF (Lethal Factor) (Anthrax)
After inhalation by mammals, Bacillus anthracis spores germinate in alveolar macrophages then migrate to lymph nodes where they multiply. The vegetative bacteria excrete the tripartite exotoxin which consists of three polypeptides: protective antigen (PA, 83kD), lethal factor (LF, 90kD) and oedma factor (OF, 89kD). The two components (OF and LF) of the toxin enzymatically modify substrates within the cytosol of the mammalian cells: The OF is an adenylate cyclase that impairs the host defenses through a variety of mechanisms inhibiting phagocytosis. The LF is a zinc dependent protease that cleaves several mitogen activated protein kinase kinases (MAPKK) and causes lysis of macrophages. To intoxicate mammalian cells, the third component of the toxin PA, binds to a ubiquitously expressed cellular receptor, Tumor Endothelium Marker-8 (TEM8). Upon binding to TEM8, PA is cleaved into 20 and 63kD fragments (PA20 and PA63) by furin or furin-like proteases. PA20 dissociates into medium and allows the PA63 fragment to heptamerize and bind LF and OF of the toxin. The resulting complex of PA63 fragment with EF and/or OF binds to PA-receptor TEM8/ATR and internalized into endosomes followed by translocation of LF and OF into cytosol of the cells.

Anthrax lethal toxin produced by the bacterium Bacillus anthracis is the major cause of death in animals infected with anthrax. One component of this toxin, lethal factor (LF), inactivates membersof the mitogen-activated protein kinase kinase or MEK family throughproteolysis of their NH2 termini. Although LF has been shown to cleave the NH2 termini of select members of the mitogen-activated protein kinase kinase or MEK family, the substrate requirements that determine LF specificity are unknown. Indirect evidence suggests that epitopes distal tothe cleavage site are required for LF-MEK interaction.

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

Recommended Dilution:
Western Blotting (1-10ug/ml for affinity pure antibody using ECL technique). The antibodies will recognize Bacillus anthracis Lethal Factor (LF) ~90kD in spore extract of Bacillus anthracis.
ELISA: Control antigen can be used to coat ELISA plates at 1ug/ml and detected with antibodies (0.1-2ug/ml).

Storage and Stability:
Lyophilized powder may be stored at -20C. Stable for 12 months at -20C. Reconstitute with sterile ddH2O or PBS. Aliquot to avoid repeated freezing and thawing. Store at -20C. Reconstituted product is stable for 12 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
MabIgG17C14Affinity Purified
100ul-20CBlue IceMouse
As reported
Bacillus anthracis Lethal Factor (LF)
Purified by immunoaffinity chromatography.
Supplied as a lyophilized powder from PBS, 0.05% sodium azide.
Mouse monoclonal antibody does not cross-react with Protective Antigen (PA) of Bacillus anthracis, Y. Pestis, F. Tularensis and Toxoplasma gondi. The cross-reactivity in various species is not known. Recombinant purified LF can be used a positive control.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
(1) Arun P. Chopra et al (2003) JBC Vol. 278, Issue 11, 9402-9406; Sung O et al (2003) JBC Vol. 278, 7413-7421; Bradley KA et al (2001) Nature 414, 225-229; liu S and Leppla SH (2002) JBC (in press); Leppla, SH (1982) PNAS 79, 3182; OBrien J et al (1985) Infect Immun 47, 306; Duesbery, NS et al (1998) Science 280, 734.