PMSF

Phenylmethanesulfonyl fluoride (PMSF)

Names
IUPAC name phenylmethanesulfonyl fluoride
Identifiers
CAS Number	329-98-6
ChEBI	CHEBI:8102
ChEMBL	ChEMBL190503
ChemSpider	4620
Jmol interactive 3D	Image
KEGG	C06747
MeSH	Phenylmethylsulfonyl+fluoride
PubChem	4784
InChI InChI=1S/C7H7FO2S/c8-11(9,10)6-7-4-2-1-3-5-7/h1-5H,6H2 Key: YBYRMVIVWMBXKQ-UHFFFAOYSA-N InChI=1/C7H7FO2S/c8-11(9,10)6-7-4-2-1-3-5-7/h1-5H,6H2 Key: YBYRMVIVWMBXKQ-UHFFFAOYAF
SMILES O=S(F)(=O)Cc1ccccc1
Properties
Chemical formula	C7H7FO2S
Molar mass	174.194
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

In biochemistry, phenylmethane sulfonyl fluoride or phenylmethylsulfonyl fluoride (PMSF) is a serine protease inhibitor commonly used in the preparation of cell lysates. PMSF does not inhibit all serine proteases. It is rapidly degraded in water and stock solutions are usually made up in anhydrous ethanol, isopropanol, corn oil, or DMSO. Proteolytic inhibition occurs when a concentration between 0.1 - 1 mM PMSF is used. The half-life is short in aqueous solutions (110 min at pH 7, 55 min at pH 7.5, and 35 min at pH 8, all at 25 °C).^[1]

PMSF binds specifically to the active site serine residue in a serine protease. It does not bind to any other serine residues in the protein. This is a result of the hyperactivity of that serine residue caused by the specific environmental conditions in the enzyme's active site. Because PMSF binds covalently to the enzyme, the complex can be viewed by X-ray crystallography; it can therefore be used as a chemical label to identify an essential active site serine in an enzyme.

Enzyme(active)Ser-O-H + F-SO₂CH₂C₆H₅ → EnzymeSer-O-SO₂CH₂C₆H₅ + HF

Serine protease + PMSF → Irreversible enzyme-PMS complex + HF

The median lethal dose is less than 500 mg/kg. PMSF is a cytotoxic chemical which should be handled only inside a fume hood.

PMSF is commonly used in protein solublization in order to deactivate proteases from digesting proteins of interest after cell lysis.

References

1. GT James (1978). "Inactivation of the protease inhibitor phenylmethylsulfonyl fluoride in buffers". Analytical Biochemistry 86 (2): 574–9. doi:10.1016/0003-2697(78)90784-4. PMID 26289.

External links

• The MEROPS online database for peptidases and their inhibitors: PMSF