Effect of pH on the catalytic function and zinc content of native and immobilized anthrax lethal factor.

Translocation of the zinc-dependent metalloendopeptidase anthrax lethal factor (LF) from the endosome to the cytosol requires an acidic endosomal milieu. In the current study, we utilized immobilized (to prevent protein aggregation below pH 5.5) and native LF to assess the effect of pH on the function and metal content of LF.