Phenylmethyl sulphonyl fluoride

Plasmin is a serine proteinase (inhibited by diisopropylfluorophosphate, phenylmethyl sulphonyl fluoride and trypsin inhibitor) with a high specificity for peptide bonds to which lysine or arginine supplies the carboxyl group. Its molecular weight is about 81 Da and its structure contains five intramolecular disulphide-linked loops (kringles) which are essential for its activity. 

Since cells contain a variety of proteases with different modes of action, it is necessary to add a cocktail of protease inhibitors to deal with them all e.g., phenylmethyl-sulphonyl fluoride (PMSF) to inhibit serine proteases EGTA to inhibit Ca2+-acti-vated proteases and p-hydroxymercuribenzoate (PHMB) to inhibit cysteine proteases. Maintaining pH neutrality offers protection against aspartate proteases. 

Pertwee RG, Fernando SR, Griffin G, Abadji V, Makriyannis A (1995) Effect of phenylmethyl-sulphonyl fluoride on the potency of anandamide as an inhibitor of electrically evoked contractions in two isolated tissue preparations. Eur J Pharmacol 272 73-78... 

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