Protease inhibitors are molecules that inhibit the function of proteases (enzymes that aid the breakdown of proteins), including proteins protease inhibitors, natural protease inhibitors, and synthetic protease inhibitors. (1). Antiprotozoal activity: protease inhibitors could be used against malaria and gastrointestinal protozoal infections; (2). Antiretrovirals: protease inhibitors were the second class of antiretroviral drugs developed widely used to treat HIV/AIDS and hepatitis C; (3). Anticancer activity: Researchers are investigating whether protease inhibitors could possibly be used to treat cancer. For example, nelfinavir and atazanavir are able to kill tumor cells in culture. Inhibitors of the proteasome, such as bortezomib are now front-line drugs for the treatment of multiple myeloma. Marimastat and batimastat are two of the matrix metalloproteinase inhibitors that can be used to treat cancer.

The Protease Inhibitor Library by TargetMol, containing 343 small protease and proteasome inhibitors, can be used for research in Chemical Genomics and drug screening.