Anthrax Protective Antigen monoclonal antibody (PA6)

The exotoxin produced by B. anthracis is composed of three proteins: a cell-receptor binding protein known as Protective Antigen (PA), and two enzymes, Edema Factor (EF) and Lethal Factor (LF). An 83 kDa form of PA binds to a cell surface receptor and, upon proteolytic activation to a 63 kDa fragment, heptamerizes to form a membrane channel that mediates the entry of three molecules of LF or EF into the cells. PA and LF form Lethal Toxin, which is the dominant virulence factor produced by B. Anthracis and is the major cause of death in infected animals.