| Tosyl phenylalanyl chloromethyl ketone | |
|---|---|
| Identifiers | |
| CAS number | 402-71-1 |
| PubChem | 439647 |
| MeSH | Tosylphenylalanyl+Chloromethyl+Ketone |
| Properties | |
| Molecular formula | C17H18ClNO3S |
| Molar mass | 351.848 g/mol |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Tosyl phenylalanyl chloromethyl ketone (TPCK) is a protease inhibitor. Its structural formula is 1-chloro-3-tosylamido-4-phenyl-2-butanone.
TPCK is the irreversible inhibitor of chymotrypsin. Also inhibits some cysteine proteases such as papain, bromelain or ficin. It does not inhibit trypsin or zymogens.
TPCK is chosen for the chemical labelling of active histidine in enzyme analysis. The phenylalanine moiety is bound to the enzyme because of specificity for aromatic amino acid residues at the active site (as in chymotrypsin, in which it binds to the Histidine-57 residue in the active site).[1]