Abstract: The present invention provides methods of specifically targeting compounds to cells overexpressing matrix metalloproteinases, plasminogen activators, or plasminogen activator receptors, by administering a compound and a mutant protective antigen protein comprising a matrix metalloproteinase or a plasminogen activator-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 or a plasminogen activator overexpressed by the cell, thereby translocating into the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site.

Abstract: The present invention provides methods of specifically targeting compounds to cells overexpressing matrix metalloproteinases, plasminogen activators, or plasminogen activator receptors, by administering a compound and a mutant protective antigen protein comprising a matrix metalloproteinase or a plasminogen activator-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 or a plasminogen activator overexpressed by the cell, thereby translocating into the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site.

Abstract: The present invention provides methods of specifically targeting compounds to cells overexpressing matrix metalloproteinases, plasminogen activators, or plasminogen activator receptors, by administering a compound and a mutant protective antigen protein comprising a matrix metalloproteinase or a plasminogen activator-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 or a plasminogen activator overexpressed by the cell, thereby translocating into the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site.

Abstract: The present invention provides methods of specifically targeting compounds to cells overexpressing matrix metalloproteinases, plasminogen activators, or plasminogen activator receptors, by administering a compound and a mutant protective antigen protein comprising a matrix metalloproteinase or a plasminogen activator-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 or a plasminogen activator overexpressed by the cell, thereby translocating into the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site.

Abstract: The present invention provides methods of specifically targeting compounds to cells overexpressing matrix metalloproteinases, plasminogen activators, or plasminogen activator receptors, by administering a compound and a mutant protective antigen protein comprising a matrix metalloproteinase or a plasminogen activator-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 or a plasminogen activator overexpressed by the cell, thereby translocating into the cell a compound comprising a lethal factor polypeptide comprising a protective antigen binding site.

Abstract: The present invention provides compositions and methods for inhibiting abnormal cell growth. In particular, the invention provides nucleic acids encoding Diphtheria toxin fusion proteins comprising residues 1-388 of Diphtheria toxin, wherein the native furin cleavage site has been substituted for a matrix metalloproteinase or plasminogen activator cleavage site, and a heterologous polypeptide and the polypeptides encoded by such nucleic acids. In addition, the invention provides methods of treating cancer by administering such polypeptides.

Abstract: The present invention provides compositions comprising modified bacterial toxins and methods for using the modified bacterial toxins for targeting particular cell populations and for treating diseases.

Abstract: This invention pertains to methods for imaging the activity of extracellular proteases in cells using the anthrax binary toxin-system to target cells expressing extracellular proteases with mutant anthrax toxin protective antigens (?PrAg) that bind to receptors on the cells and are cleaved by a specific extracellular protease expressed by the cells, and ligands that specifically bind to the cleaved ?PrAg and are linked to a moiety that is detectable by an imaging procedure. The ?PrAg proteins used in the methods comprise a protease cleavage site that is cleaved by a specific extracellular protease and is in place of the furin cleavage site of the native PrAg. The methods are useful for diagnosing and treating diseases and undesirable physiological conditions correlated with the activity of extracellular proteases, and for optimizing the therapeutic efficacy of drugs used to treat such diseases and conditions.