Chloromethyl 2-phenylethyl ketone

Toluenesulfonyl-amido-2-phenylethyl chloromethyl ketone (TPCK)... 

The facile reaction of CAA and BAA with nucleosides and nucleotides is one example of many of the applications of the bifunctional reactivity of halogenated aldehydes and ketones in modification of biomolecules. In an early example of the extensive use of halogenated ketones as protease substrate analogues, l-V-tosylamido-2-phenylethyl chloro-methyl ketone (TPCK) 30 was synthesized as a chymotrypsin substrate analogue. Stoichiometric inhibition was accompanied by loss of one histidine residue as a result of alkylation by the chloromethyl moiety68. A host of similar analogues were subsequently prepared and used as selective enzyme inhibitors, in particular for the identification of amino acid residues located at enzyme active sites69. 

TOSYLAMIDO-2-PHENYLETHYL CHLOROMETHYL KETONE see THH450 6-(N-TOSYL)AMINOCAPROIC ACID DIAZOMETHYL KETONE see THH460... 

Histidine 57 is another critical amino acid residue in chymotrypsin. Chemical labeling again provides the evidence for involvement of this residue in the activity of chymotrypsin. In this case, the reagent used to label the critical amino acid residue is A -tosylamido-L-phenylethyl chloromethyl ketone (TPCK), also called tosyl-L-phenylalanine chloromethyl ketone. The phenylalanine moiety is bound to the enzyme because of the specificity for aromatic... 

Structure of N-tosylamido-L-phenylethyl chloromethyl ketone (TPCK), a labeling reagent for chymotrypsin [R represents a tosyl (toluenesulfonyl) group]... 

Reflect and Apply An inhibitor that specifically labels chymotrypsin at histidine 57 is N-tosylamido-L-phenylethyl chloromethyl ketone. How would you modify the structure of this inhibitor to label the active site of trypsin ... 

A protease inhibitor, L-l-tosylamido-2-phenylethyl chloromethyl ketone (TPCK), specific for chymotrypsin, has been shown to exert a number of effects on platelet processes. This compound also interferes with arachidonic acid metabolism in platelets. The 12-lipoxygenase was inhibited by TPCK, but the main effect was an irreversible inhibition of thromboxane synthetase [157]. 

Showell, H.J., Naccache, P.H., Walenga, R.W. et al. (1981). The effects of quercetin, 1-tosylamido-2-phenylethyl chloromethyl ketone, cytochalasin A and nordihydroguaiaretic acid on lysosomal enzyme secretion, arachidonic acid metabolism and Ca fluxes in rabbit neutrophils.. Journal of the Reticuloendothelial Society, 30, 167-181. 

Bums and Turner (2) subjected proteins to either alkylation with iodo-acetic acid (3) or performic acid oxidation (4) to render them susceptible to enzymatic digestion. The treated proteins were then dissolved in ammonium bicarbonate buffer (0.05 M, pH 8.4) to a concentration of 2 mg/ml and TPCK-treated trypsin [L-(l-tosylamide-2-phenylethyl chloromethyl ketone] was added to give a final enzyme-to-substrate ratio of 1 75. The digest is incubated for 5 h at 30 C, freeze-dried, and redissolved in 10% isopropanol for application to the plates. 

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