alpha-chymotrypsin has been researched along with alanyl-alanyl-phenylalanine-chloromethyl-ketone* in 2 studies
2 other study(ies) available for alpha-chymotrypsin and alanyl-alanyl-phenylalanine-chloromethyl-ketone
Article | Year |
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Effects of an inhibitor of tripeptidyl peptidase II (Ala-Ala-Phe-chloromethylketone) and its combination with an inhibitor of the chymotrypsin-like activity of the proteasome (PSI) on apoptosis, cell cycle and proteasome activity in U937 cells.
AAF-AMC is not a specific TPP II substrate, since it is also hydrolyzed by purified proteasomes. Moreover, AAF-cmk, claimed to be a specific TPP II inhibitor, also inhibits the chymotrypsin-like activity of the proteasome. While AAF-cmk itself is mildly cytostatic to U-937 cells and induces cell cycle block in G1, its combination with PSI does not induce an increase in the cytostatic/cytotoxic effects. This suggests that TPP II is possibly less important for cell metabolism than it was previously believed and it is less probable that it can be able to fully compensate for the loss of the proteasome function. Topics: Amino Acid Chloromethyl Ketones; Aminopeptidases; Animals; Apoptosis; Cell Cycle; Chymotrypsin; Cysteine Endopeptidases; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Flow Cytometry; Humans; Multienzyme Complexes; Protease Inhibitors; Proteasome Endopeptidase Complex; Serine Endopeptidases; Trypsin Inhibitors; U937 Cells | 2001 |
Inactivation of chymotrypsin and human skin chymase: kinetics of time-dependent inhibition in the presence of substrate.
The reaction of chymase, a chymotryptic proteinase from human skin, and bovine pancreatic chymotrypsin with a number of time-dependent inhibitors has been studied. An integrated equation, relating product formation with time, has been derived for the reaction of enzymes with time-dependent inhibitors in the presence of substrate. This is based on a two-step model in which a rapidly reversible, non-covalent complex (EI) is formed prior to a tighter, less readily reversible complex (EI)*). The equation depends on the simplifying assumption [I] much greater than [E], but is applicable to reversible and irreversible slow-binding and tight-binding inhibitors whether or not they show saturation kinetics. The method has been applied to the reaction of chymase and chymotrypsin with the tetrapeptide aldehyde, chymostatin, basic pancreatic trypsin inhibitor and Ala-Ala-Phe-chloromethylketone (AAPCK). The irreversible inhibitor, AAPCK, showed the expected saturation kinetics for both enzymes and the apparent first-order rate constants (k2) and dissociation constants (Ki) for the non-covalent complexes were determined. Chymostatin was a much more potent inhibitor which failed to show a saturation effect. The second-order rate constant of inactivation (k2/Ki), the first-order reactivation rate constant (k-2), and the dissociation constant of the covalent complex (Ki*) were determined. Basic pancreatic trypsin inhibitor, a potent inhibitor of chymotrypsin, had similar kinetics to chymostatin but failed to inhibit chymase. The applicability of the two-step model and the integrated equation to slow- and tight-binding inhibitors is discussed in relation to a number of examples from the literature. Topics: Amino Acid Chloromethyl Ketones; Aprotinin; Binding Sites; Chymases; Chymotrypsin; Enzyme Reactivators; Humans; Kinetics; Mathematics; Oligopeptides; Serine Endopeptidases; Serine Proteinase Inhibitors; Skin; Trypsin Inhibitors | 1988 |