Protective antigen is the binding component of the toxins i

______ Protective antigen is the binding component of the toxins involved in anthrax; it also is important in allowing the release of the catalytic component from the plasma membrane of the target cell into the cytoplasm of the target cell. ______ Furan is a protein located on the membrane of the bacterium that cleaves lethal factor to make it active.

Solution

1. The answer is anthrax toxin. Anthrax toxin is a three protein exotoxin secreted by virulent strains of the bacterium, Bacillus anthracis. It is composed of cell binding protein, known as protective antigen (PA), and two enzyme components called edema factor and lethal; factor. It is also important in allowing the release of the catalytic component from the plasma membrane of the target cell into the cytoplasm of the target cell.

2. Upon binding, the PA is cleaved into two fragments by furin protease to form a 63kDa protein to bind with anthrax toxin receptor. cleavage of PA allows self association to occur which forms a ring shaped heptamer known as pore precursor.