Phenyl methyl sulfonyl fluoride

Radiolabeled (3H, l4C, 35S, or l25I) protein or cell extract prepared in PBSA containing 10 3M phenyl methyl sulfonyl fluoride (PMSF) as proteinase inhibitor, and 0 5-1.0% nonionic detergent... 

Crude Cellulases. The culture filtrate obtained from four-day-old cultures was concentrated by lyophilization. The protease inhibitors, phenyl methyl sulfonyl fluoride (PMSF, 2.3mM) and ethylenediamine-tetraacetic acid (EDTA, 0.2mM) were added to the culture solution and the salt concentration was adjusted to 0.5M with NaCl. After stirring at 4°C for at least 30 min to release cellulases from any enzyme-substrate complex which might have formed, the culture solution was centrifuged... 

Preparation of rat heart tissue extracts. Lysis buffer containing 1% deionized Triton X-100 and 0.1% sodium azide in 50 mM Tris-HCl pH 7.5 was incubated with Chelex-100, for a minimum of 24 h at room temperature prior to use. Phenyl-methyl-sulfonyl-fluoride (PMSF) (final concentration 0.25 mM) was added to the buffer immediately prior to use. Rat hearts were frozen in liquid nitrogen, and stored at -SOX until analyzed. Lysis buffer was added to the homogenized tissue, the mixture was vortexed, sonicated for 1 min and incubated on ice for 30 min, with vortexing every 5-10 min. Aliquots were taken, centrifuged at 3,0(X) rpm for 15 min, and the supernatant analyzed for total protein and ferritin. Total protein was determined in the extracts by the BCA method (Pierce). 

The pellet is then suspended in 50 ml of ice-cold 50 mM Tris HCI, pH 7.5, 2 mM EDTA and 2 mM phenyl methyl sulfonyl fluoride (PMSF) and is subjected to 4 sonication bursts of 30sec each on ice. 

Diisopropyl fluorophosphate (DFP) was found to be five to ten times as active as AIA for induction of porphyrin fluorescence the alkali-hydrolyzed compound was only two to three times as active. Treatment with DFP for only 1 hour was insufficient to cause the overnight development of porphyrin. Another fluoride, phenyl methyl sulfonyl fluoride, did not induce, nor did its alkali-hydrolyzed product. 

Chicken embryo fibroblasts (CEFs) are obtained from embryonic day-10 chicken embryos, and cultured as described (Albertinazzi et al, 1998). Transient expression of proteins is achieved by transfection of CEFs by the calcium phosphate technique using 10 fig of plasmid DNA for each 6 cm diameter plate. 18-24 h after transfection, cells are extracted with lysis buffer (1% Triton X-100,150 mM NaCl, 0.5 mg/ml phenyl methyl sulfonyl fluoride (PMSF), 20 mM Tris-Cl, pH 7.5). Cell lysates are clarified by differential centrifugation for 10 min at 18,000g in a refrigerated microcentrifuge, and utilized for analysis by sucrose velocity gradient centrifugation. 

Phenyl-methyl-sulfonyl fluoride (PMSF), C7H7FO2S or C H5CH2S02F, is a highly toxic cholinesterase inhibitor. It is extremely destructive to the mucous membranes of the respiratory tract, eyes, and skin. It may be fatal by inhalation, ingestion, or skin absorption. Wear appropriate gloves and safety glasses and always use in a chemical fume hood. In case of contact, immediately flush eyes or skin with copious amounts of water and discard contaminated clothing. 

Both the chlorine and fluorine sulfonyl compounds strongly deshield the ortho aromatic hydrogens. The chemical shifts observed for the two phenyl compounds are extremely similar. A comparison of the para substituted compounds indicates identical shifts for the two para substituted methyl compounds, higher field shifts for the chlorine substituted sulfonyl fluoride but lower field shifts for the corresponding carboxylic acid substituted sulfonyl fluoride compared to the corresponding sulfonyl chlorides. 

Bromodifluoromethyl phenyl sulfone can be transformed to [difluoro(phenylsulfonyl)methyl]trimethylsilane which was employed for fluoride-induced (phenylsulfonyl)difluoromethylation (eq 4). Alternatively, the reaction of bromodifluoromethyl phenyl sulfone with aldehydes mediated by electron-transfer reagent, tetrakis(dimethylamino)ethylene (TDAE), yields (phenyl-sulfonyl)-difluoromethylated alcohols in good yields which can be further transformed to difluoromethyl alcohols and e/B-difluoroalkenes via reductive desulfonylation and Julia olefination, respectively (eq 5). ... 

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