Phenylmethylsulfonyl fluoride (PMSF) is a nonspecific, irreversible inhibitor of serine proteases and other enzymes, including acetylcholinesterase, palmityl coenzyme A deacylase, arylsulfatase A, chymotrypsin, and trypsin. It is used in protein solublization studies in order to deactivate proteases from digesting proteins of interest after cell lysis. Because PMSF specifically sulfonylates the hydroxal groups of active site serine residues of enzymes, it can be used as a chemical label to identify essential active site serines in an enzyme. PMSF is known to alter the actions of anandamide by blocking its metabolism and can produce cannabinoid effects in mice, including antinociception, hypothermia, and immobility with ED50 values of 86, 224, and 206 mg/kg, respectively.
