Disulfiram is a potent inhibitor of proteases of the caspase family

Chem Res Toxicol. 1997 Dec;10(12):1319-24. doi: 10.1021/tx970131m.


We have recently shown that dithiocarbamate (DC) disulfides inhibit proteolytic processing of the caspase-3 proenzyme in Jurkat T lymphocytes treated with anti-CD95 (Fas/APO-1) antibody. Because the processing can be accomplished by caspase activity, we investigated the effect of DC disulfides, such as disulfiram (DSF), on active caspases. DSF showed a dose-dependent inhibition was prevented by including dithiothreitol (DTT) in the reaction buffer, thiol-disulfide exchange between inhibitor and target is suggested. Direct interaction of DSF with caspases was confirmed by its inhibition of the purified Ac-DEVD-AMC cleaving protease, caspase-3 (CPP32/apopain). An apparent rate constant (K(app)) for this inhibition was estimated to be 0.45 x 10(3)M(-1)s(-1). DSF was also observed to inhibit the purified Ac-YVAD-AMC cleaving enzyme, caspase-1 (interleukin-1 beta-converting enzyme, ICE), with a K(app) of 2.2 x 10(3) M(-1)s(-1). In this case protein mixed disulfide formation between DSF and caspase-1 was directly demonstrated using 35S-labeled DSF. The physiological disulfide GSSG was also observed to influence the activity of caspases. A glutathione buffer (5 mM) with a GSH:GSSG ratio of 9:1 decreased the Ac-DEVD-AMC cleaving activity in S100 cytosolic extracts by 50% as compared to GSH controls without GSSG. In conclusion, our study shows that caspases are quite sensitive to thiol oxidation and that DSF is a very potent oxidant of caspase protein thiol(s), being 700-fold more potent than glutathione disulfide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Deterrents / pharmacology*
  • Blotting, Western
  • Cysteine Endopeptidases / drug effects*
  • Cysteine Proteinase Inhibitors / pharmacology*
  • Disulfiram / pharmacology*
  • Dose-Response Relationship, Drug
  • Electrophoresis, Polyacrylamide Gel
  • Glutathione / pharmacology
  • Glutathione Disulfide / pharmacology
  • Humans
  • Jurkat Cells / drug effects
  • Jurkat Cells / enzymology*
  • Kinetics


  • Alcohol Deterrents
  • Cysteine Proteinase Inhibitors
  • Cysteine Endopeptidases
  • Glutathione
  • Disulfiram
  • Glutathione Disulfide