PMSF

• α - toluenesulfonyl
• Benzylsulfonyl
• Phenylmethanesulfonyl

White needles

Fixed

92-93 ° C

Decomposition in water

Risk

200 mg · kg -1 ( LD50, mouse, oral)

Template: Infobox chemical / molecular formula search available

Phenylmethylsulfonyl fluoride ( PMSF ) is a chemical compound which is used as a protease inhibitor, especially in the application of biochemistry.

Biochemical Properties

PMSF inhibits especially serine proteases ( chymotrypsin, trypsin, and thrombin) by irreversibly binds to the active serine and the cysteine ​​protease papain, but the acetylcholinesterase of mammals, however, less effective than DFP. The substance is therefore toxic ( LD50 <500 mg / kg) and is suspected to cause cancer.

The inhibitory effect on the cysteine ​​protease is reversibly reduced by thiols and therefore for use in biochemical laboratories without the use of DTT or mercaptoethanol in lysis buffer and alternatives should be found ( either PMSF or a reducing agent).

High salt concentrations, limit the inhibitory action of a well.

Use

PMSF (often in combination with other protease inhibitors ) used to prevent unwanted protein degradation by proteases in the lysate was also located in the digestion of tissues and cultured cells. PMSF is added just before use, because aqueous solutions are unstable and degrade rapidly. It has in aqueous solution at a pH of 7 is only a half-life of 110 min, with the basic werdendem, but often with second-hand protein extractions medium is further decreased (for example, 55 minutes at pH 7.5 and 35 min at pH 8 ). Stock solutions are usually prepared from the solids in isopropanol, methanol or DMSO or corn oil; PMSF also dissolves well in ethanol, which, however, often contains water because of its hygroscopicity and therefore hydrolysis and thus inactivating can act on PMSF, and is thus rarely and then only absolute and not denatured used as solvents. The storage of the solutions are darkened at -20 ° C - for shorter storage (at least 9 months) is also refrigerator temperature ( 2-8 ° C ) is sufficient.

Alternatives

4 - (2 -aminoethyl)- benzolsulfonylfluorid ( AEBSF ), also called Pefabloc ® SC, is a stable, water-soluble serine protease inhibitor.