Since 1978, List Labs products are unsurpassed in quality, consistency, and reliability for the success of your research and development projects! Three proteins are collectively known as anthrax toxin: protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa) and edema factor (EF, 89 kDa). These proteins play a key role in the pathogenesis of anthrax. EF and LF have enzymatic functions associated with their carboxyl terminals, but require PA to achieve their biological effects. The amino terminal ends of EF and LF bind to PA and are responsible for translocation through the pore formed by the PA heptamer. PA 83 monomer, an 83 kDa protein, is secreted from rapidly growing B. anthracis cells where it is cleaved by cellular protease. This product is the full length pertaction, 83 kDa, produced recombinantly in the native host.