Patent ID: 8791074

Claim:
A method of targeting a compound to a cell over-expressing a matrix metalloproteinase, the method comprising the steps of: (i) administering to the cell a mutant protective antigen protein comprising a matrix metalloproteinase-recognized cleavage site in place of the native protective antigen furin-recognized cleavage site, wherein the mutant protective antigen is cleaved by a matrix metalloproteinase, wherein the matrix metalloproteinase is MMP-2 (gelatinase A), MMP-9 (gelatinase B), or membrane-type 1 MMP (MT1-MMP); and (ii) administering to the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site; wherein the lethal factor polypeptide binds to cleaved protective antigen and is translocated into the cell, thereby delivering the compound to the cell.