PMSF (Phenylmethylsulfonyl fluoride)

Specificity

Inhibits serine proteases such as chymotrypsin, trypsin, and thrombin, and the cysteine protease papain (reversible by DTT treatment). Does not inhibit metalloproteases, most cysteine proteases, or aspartic proteases.

Application

PMSF (C7H7O2SF) inhibits serine proteases such as chymotrypsin, trypsin, thrombin, and the cysteine protease papain (reversible by DTT treatment). It does not inhibit metalloproteases, most cysteine proteases, or aspartic proteases.
PMSF (phenylmethylsulfonyl fluoride) has been used for the preparation of protein extracts from tissues and cells prior to Western blotting.

Biochem/physiol Actions

PMSF (phenylmethylsulfonyl fluoride) functions as a non-specific inhibitor of multiple proteases and other enzymes, such as palmityl coenzyme A deacylase, arylsulfatase A, acetylcholinesterase, trypsin and chymotrypsin. It is an irreversible inhibitor, and sulfonylates hydroxyl groups of the serine residues present in the active site of enzymes.

Quality

Purity: Chromatographically homogeneous

Preparation Note

Activator: PK requires Mg²⁺ (or Mn²⁺, CO²⁺) and K⁺ (or NH⁴⁺, Rb⁺) for full activity.
Working concentration: 17 to 170 μg/ml (0.1 to 1 mM)
Working solution: Due to the short half-life of PMSF, fresh solution must be added at every purification step. Under certain conditions, such as alkaline pH values, PMSF may have a half-life of only 35 minutes. High-salt conditions (3 M), often used to precipitate proteins, may also reverse the inhibition of PMSF. Pefabloc SC is recommended as a non-toxic, water-soluble, and water-stable alternative.
Storage conditions (working solution): 15 to 25 °C
Stock solutions of PMSF in 100% isopropanol are stable for at least 9 months at 15 to 25 °C.

Reconstitution

Soluble to > 10 mg/ml in isopropanol, ethanol, methanol, or 1,2-propanediol. Unstable in aqueous solution. In 100% isopropanol, stable for at least 9 months at 15 to 25 °C.

Other Notes

Due to a short half-life, fresh solution must be added at every purification step. Under certain conditions, such as alkaline pH values, PMSF may only have a half-life of 35 min. High-salt conditions (3 M), often used to precipitate proteins, may also reverse the inhibition of PMSF. Pefabloc SC is recommended as a non-toxic, water-soluble, and water-stable alternative.