title: Inactivation of enzymes and an enzyme inhibitor by oxidative modification with chlorinated amines and metal-catalyzed oxidation systems.
abstract: Oxidative inactivation of various key enzymes and alpha-1-proteinase inhibitor (alpha-1-PI) was studied by treatment with N-chloramines and the metal-catalyzed oxidation (MCO)-systems ascorbate/Fe(III) and ascorbate/Cu(II). Chlorinated amines completely inhibited alpha-1-PI, fructose-1,6-bis phosphatase (Fru-P2ase) and glyceraldehyde phosphate dehydrogenase (GAPD) at a low molar excess, and glucose-6-phosphate dehydrogenase (G6PD) at a high molar excess, but did not impair beta-N-acetylglucosaminidase (beta-NAG), alkaline phosphatase (AP) or lactate dehydrogenase (LDH). MCO-systems affected the activities of Fru-P2ase, GAPD, AP, LDH and G6PD, but not those of beta-NAG or alpha-1-PI. EDTA prevented inactivation of Fru-P2ase, G6PD and LDH by ascorbate/Cu(II) and of Fru-P2ase by ascorbate/Fe(III) suggesting a site-specific oxidation catalyzed by a protein-bound metal ion. In conclusion, N-chloramines and MCO-systems exhibited different properties with regard to oxidative inactivation, sulfhydryl-enzymes were susceptible to both systems, but other enzymes were only susceptible to one or neither system.
authors.affiliation: GSF-Forschungszentrum für Umwelt, Gesundheit, Projekt Inhalation, F.R.G.
authors.forename: K
authors.initials: K
authors.lastname: Maier
authors.forename: H
authors.initials: H
authors.lastname: Hinze
authors.forename: H
authors.initials: H
authors.lastname: Holzer
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002700:Chloramines / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005290:Ferric Compounds / Q000494:pharmacology*; D005635:Fructosediphosphates / Q000037:antagonists & inhibitors; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000037:antagonists & inhibitors; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D000515:alpha 1-Antitrypsin / Q000737:chemistry; D001619:beta-N-Acetylhexosaminidases / Q000037:antagonists & inhibitors
chemical_list: D002700:Chloramines; D005290:Ferric Compounds; D005635:Fructosediphosphates; D000515:alpha 1-Antitrypsin; D003300:Copper; C061126:iron(III)-ascorbic acid complex; D010088:Oxidoreductases; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D000469:Alkaline Phosphatase; D001619:beta-N-Acetylhexosaminidases; D001205:Ascorbic Acid