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NR-28544?? Anthrax Lethal Factor (LF-A), Native Sequence, Recombinant from Bacillus anthracis(Toxins)|Bacillus anthracis|Anthrax Lethal Factor (LF-A), Native Sequence, Recombinant from Bacillus anthracis|2°C to 8°C|BEI ResourcesAcknowledgment for publications should read “The following reagent was obtained through BEI Resources, NIAID, NIH: Anthrax Lethal Factor (LF-A), Native Sequence, Recombinant from Bacillus anthracis, NR-28544.”| Quantity limit per order for this item is 1.  This item can be ordered twice a year.  Orders over this limit will be sent to NIAID for approval before shipment.Recombinant anthrax lethal factor (LF, 90 kDa) containing the native alanine (A) at the N-terminus was produced using a plasmid licensed from the NIH.  The lethal factor produced from this plasmid has been designated LF-A by the manufacturer. The plasmid was introduced into a non-sporulating, avirulent strain of Bacillus anthracis lacking both of the wild type plasmids, pX01 and pX02. Recombinant LF-A was purified using conventional chromatographic techniques. The resulting purified protein lacks all other anthrax virulence factors.

A recombinant form of the LF protein containing two additional amino acids at the N-terminus, a histidine (H) and a methionine (M), beyond the native N-terminal alanine (A), has been or is currently available from BEI Resources (NR-142, NR-404, NR-570, NR-723, NR-724, NR-2673, NR-4367, NR-4368). This form of the protein has been recently designated LF-HMA by the manufacturer and is also produced in Bacillus anthracis. Note: LF-A has been reported to have 3-fold higher potency than LF-HMA in cell culture cytotoxicity assays and in rat lethality studies. LF is a zinc-dependent metalloprotease which cleaves the amino terminus of signaling proteins of the mitogen-activated protein kinase family (MAPKK), destroying their ability to signal. In vivo, recombinant LF binds to a cleaved form of recombinant protective antigen (PA), and is transported by PA into the cytosol of the macrophage where LF exerts its pathogenic effect. Each vial contains approximately 0.1 mg (lyophilized) of recombinant LF-A from Bacillus anthracis.