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 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. The LF is a zinc dependent metalloprotease which cleaves a specific bond in signaling proteins of the MAP kinase family destroying their ability to signal. MAP kinase pathways are involved in transduction of a variety of signals including those involved in cell proliferation and differentiation. LF is produced recombinantly in the native host and has the native alanine N-terminal preferred for most research..