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. Edema factoris a calmodulin-dependent adenylate cyclase.19 After cell entry, EF is activated when complexed with calmodulin, creating excess amounts of cellular cyclic-AMP. The increase in cyclic-AMP upsets water homeostasis and disrupts the intracellular signaling pathways. It is responsible for the swelling in cutaneous anthrax infections. Edema factor is produced recombinantly in the native host. This mutant has a Ser to Asn substitution located at position 447 decreasing adenylatecyclase activity