Biomaterial Database

Inhibition of catalase by sulfite and oxidation of sulfite by H2O2 cooperating with ascorbic acid. 1999

S Veljovic-Jovanovic, and L Milovanovic, and T Oniki, and U Takahama

Center for Multidisciplinary Studies, University of Belgrade, Yugoslavia.

An oxidative detoxification of sulfite, which originates from sulfur dioxide taken up into a leaf, has not yet been fully understood. In this study, we discuss that redox reactions between sulfite and H2O2 have an important role for the detoxification of sulfite. Sulfite was oxidized by H2O2 and during the redox reaction, oxygen consumption was observed. The oxygen consumption was partially inhibited by superoxide dismutase, indicating that O2- is generated during the redox reaction. Oxidation of sulfite by H2O2 was also observed in the presence of ascorbic acid, and during the oxidation, no significant oxidation of ascorbic acid and no consumption of oxygen were observed. Sulfite inhibited catalase of cell-free extracts of spinach, pea and broad bean leaves. These results suggest that when leaves are fumigated with SO2 in the light, catalase is inactivated resulting in the accumulation of H2O2 in leaves, which can oxidize sulfite without generating active oxygen species like O2- as long as ascorbate is present in leaves.

UI	MeSH Term	Description	Entries
D008658	Inactivation, Metabolic	Reduction of pharmacologic activity or toxicity of a drug or other foreign substance by a living system, usually by enzymatic action. It includes those metabolic transformations that make the substance more soluble for faster renal excretion.	Detoxication, Drug, Metabolic,Drug Detoxication, Metabolic,Metabolic Detoxication, Drug,Detoxification, Drug, Metabolic,Metabolic Detoxification, Drug,Metabolic Drug Inactivation,Detoxication, Drug Metabolic,Detoxication, Metabolic Drug,Detoxification, Drug Metabolic,Drug Inactivation, Metabolic,Drug Metabolic Detoxication,Drug Metabolic Detoxification,Inactivation, Metabolic Drug,Metabolic Drug Detoxication,Metabolic Inactivation
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002374	Catalase	An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.	Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D001205	Ascorbic Acid	A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.	Vitamin C,Ascorbic Acid, Monosodium Salt,Ferrous Ascorbate,Hybrin,L-Ascorbic Acid,Magnesium Ascorbate,Magnesium Ascorbicum,Magnesium di-L-Ascorbate,Magnorbin,Sodium Ascorbate,Acid, Ascorbic,Acid, L-Ascorbic,Ascorbate, Ferrous,Ascorbate, Magnesium,Ascorbate, Sodium,L Ascorbic Acid,Magnesium di L Ascorbate,di-L-Ascorbate, Magnesium
D013447	Sulfites	Inorganic salts of sulfurous acid.	Sulfite,Sulfites, Inorganic,Inorganic Sulfites
D017382	Reactive Oxygen Species	Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of SIGNAL TRANSDUCTION and GENE EXPRESSION, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.	Active Oxygen Species,Oxygen Radical,Oxygen Radicals,Pro-Oxidant,Reactive Oxygen Intermediates,Active Oxygen,Oxygen Species, Reactive,Pro-Oxidants,Oxygen, Active,Pro Oxidant,Pro Oxidants,Radical, Oxygen