title: On the interaction of human liver aldehyde dehydrogenase E1 isoenzyme with disulfiram and iodoacetamide.
abstract: The E1 isoenzyme of human liver aldehyde dehydrogenase (Km acetaldehyde = 30uM, pH 7.0), when incubated with disulfiram at a stoichiometry of four moles disulfiram/tetrameric E1, is immediately inhibited to within 10% of control activity. The inhibition is reversed by 0.1% (v/v) mercaptoethanol, indicating disulfide bridge formation. An indirect attempt to locate, on maps, a peptide binding disulfiram has yielded inconsistent results. Iodoacetamide inhibits E1 slowly; inhibition is facilitated in the presence of NAD, resulting in loss of ca. 90% of control activity. Incubation with 14C iodoacetamide labels a 16,000 dalton CNBr peptide, and a ca. 4,000 dalton tryptic cleavage product. These fragments can be equated with those which have been suggested by disulfiram.
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000037:antagonists & inhibitors*; D004221:Disulfiram / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007460:Iodoacetamide / Q000494:pharmacology*; D007461:Iodoacetates / Q000494:pharmacology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008099:Liver / Q000201:enzymology*
chemical_list: D007461:Iodoacetates; D007527:Isoenzymes; D000445:Aldehyde Oxidoreductases; D004221:Disulfiram; D007460:Iodoacetamide