Phenylmethylsulfonyl fluoride

Structural formula
General
Surname	Phenylmethylsulfonyl fluoride
other names	α-toluenesulfonyl fluoride Benzyl sulfonyl fluoride Phenyl methanesulfonyl fluoride
Molecular formula	C 7 H 7 FO 2 S
Brief description	colorless solid
External identifiers / databases
CAS number 329-98-6 EC number 206-350-2 ECHA InfoCard 100.005.774 PubChem 4784 Wikidata Q411575
properties
Molar mass	174.19 g mol −1
Physical state	firmly
Melting point	92-95 ° C
solubility	Decomposes in water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-314 P: 260-280-301 + 310 + 330-303 + 361 + 353-304 + 340 + 310-305 + 351 + 338
Toxicological data	200 mg kg −1 ( LD 50 ,  mouse ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Phenylmethylsulfonyl fluoride ( PMSF ) is a chemical compound that is used as a protease inhibitor , primarily in biochemistry .

Biochemical properties

PMSF mainly inhibits serine proteases ( chymotrypsin , trypsin and thrombin ) by irreversibly binding to the active serine, as well as the cysteine ​​protease papain , but also the acetylcholinesterase of mammals, albeit less effectively than DFP . The substance is therefore toxic ( LD ₅₀ <500 mg / kg) and is suspected of causing cancer .

The inhibitory effect on cysteine ​​proteases can be reversed by reduced thiols , which is why DTT or mercaptoethanol in the lysis buffer should not be used in biochemical laboratories and alternatives (either for PMSF or for a reducing agent) should be sought.

High salt concentrations also limit the inhibitory effect.

use

PMSF is used (often together with other protease inhibitors) to prevent unwanted protein degradation by proteases that are also in the lysate when tissue and cultivated cells are disrupted. PMSF is only added shortly before use, because in aqueous solution it is unstable and degrades rapidly. In aqueous solution at a pH of 7, it only has a half-life of 110 min, which decreases further as the medium becomes more basic but is often used in protein extractions (e.g. 55 min at pH 7.5 or 35 min for pH 8). Stock solutions are usually made from the solid in isopropanol , methanol or also in DMSO or corn oil; PMSF also dissolves well in ethanol , which, however, often contains water because of its hygroscopicity and can therefore have a hydrolytic and thus inactivating effect on PMSF, and is therefore rarely used as a solvent and then only absolutely and not denatured. The solutions are stored in the dark at −20 ° C - for shorter storage periods (max. 9 months) a refrigerator temperature (2–8 ° C) is sufficient.

Alternatives

4- (2-Aminoethyl) -benzenesulfonylfluoride ( AEBSF ), also called Pefabloc SC ^® , is a more stable, water-soluble serine protease inhibitor.

Web links

• MEROPS : PMSF

Individual evidence

1. ↑ ^{a b c d e} entry to phenylmethanesulfonyl in the GESTIS database of IFA , accessed on January 8, 2020(JavaScript required) .
2. ↑ Phenylmethanesulfonyl fluoride data sheet from Sigma-Aldrich , accessed on April 19, 2011 ( PDF ).
3. ↑ GOLD AM, FAHRNEY D: SULFONYL FLUORIDES AS INHIBITORS OF ESTERASES. II. FORMATION AND REACTIONS OF PHENYLMETHANESULFONYL ALPHA-CHYMOTRYPSINE . In: Biochemistry . 3, June 1964, pp. 783-791. PMID 14211616 .