Reaction of bovine‐liver copper‐zinc superoxide dismutase with hydrogen peroxide

Jewett, Sandra L.; Cushing, Susan; Gillespie, Frieda; Smith, Dean J.; Sparks, Shawn D.

doi:10.1111/j.1432-1033.1989.tb14683.x

Cited by 37 publications

(19 citation statements)

References 27 publications

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“…about 10 times faster on a molar basis than with SOD. Others have analyzed Sigma bovine Cu,Zn-SOD preparations and found less than 3% of the copper to be loosely bound (28). Analyses that we performed, by the method of Crow et al (5), gave results consistent with this figure.…”

Section: Catalysis Of Cysteine Autoxidation Bysupporting

confidence: 80%

Thiol Oxidase Activity of Copper,Zinc Superoxide Dismutase

Winterbourn

Peskin

Parsons-Mair

2002

Journal of Biological Chemistry

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The ability of copper,zinc superoxide dismutase (Cu,Zn-SOD) to catalyze autoxidation of cysteine and other thiols was investigated by measuring thiol loss and oxygen consumption. The reaction occurred equally well with the bovine and human enzymes and produced hydrogen peroxide and the corresponding disulfide. It did not occur with manganese SOD and is not, therefore, due to the dismutase activity of the enzyme. Cysteine and cysteamine were highly reactive: the K m for cysteine was 1.4 mM and V max (with 40 g/ml SOD) 35 M/ min; the equivalent values for cysteamine (with 20 g/ml SOD) were 1.4 mM and 36 M/min. With 1 mM thiol and 40 g/ml SOD, rates of oxidation of other thiols (M/min) were as follows: GSH, 1.0; dithiothreitol, 2.1; dihydrolipoic acid, 1.7; homocysteine, 1.6; cys-gly, 1.4; penicillamine, 0.6; and N-acetylcysteine, 0.1. SOD-mediated oxidation of cysteine, in the absence of chelating agents, proceeded only after a variable lag phase. The lag was decreased but not eliminated with Chelex-treated reagents and is attributed to interference by submicromolar concentrations of iron and possibly other transition metal ions. SOD-catalyzed oxidation of the other thiols was variably affected by adventitious metal ions and chelating agents. Reactions were all performed in the presence of desferrioxamine to obviate these effects. SOD-catalyzed oxidation of GSH and homocysteine was enhanced by cysteine through a thiol-disulfide exchange mechanism. This study characterizes a novel pro-oxidant thiol oxidase activity of Cu,Zn-SOD. It is a potential source of reactive oxidants and may contribute to the cytotoxicity of reactive thiols such as cysteine and cysteamine.

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Section: Catalysis Of Cysteine Autoxidation Bysupporting

confidence: 80%

Thiol Oxidase Activity of Copper,Zinc Superoxide Dismutase

Winterbourn

Peskin

Parsons-Mair

2002

Journal of Biological Chemistry

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“…Moreover, the histochemical method could be sensitive to the enzymatic activity/inactivity of SOD in the section, modulated by oxidative substances (Jewett et al 1989). It is therefore possible that the ratio of active SOD to inactive SOD results in a quantitatively different signal using SOD immunolocalization and SOD histochemistry.…”

Section: Discussionmentioning

confidence: 99%

Quantitative Histochemical Assay for Superoxide Dismutase in Rat Brain

Viggiano

Viggiano²,

Viggiano³

et al. 2003

J Histochem Cytochem.

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S U M M A R Y Superoxide anions are highly reactive radicals overproduced in many pathological situations such as inflammation and ischemia. One of the major factors in the protection from superoxide anions is the enzyme superoxide dismutase (SOD), which catalyzes the dismutation of superoxide to hydrogen peroxide. This study presents a quantitative histochemical method to estimate SOD activity in rat brain tissue sections. This method is based on the cerium capture method and 3,3 Ј -diaminobenzidine amplification of transition cerium compounds. Substrate for SOD was provided by reduction of oxygen during the autoxidation of riboflavin in the presence of UV light. This histochemical method reveals the overall activity of the three different forms of SOD described in mammalian tissues: cytosolic copper-zinc SOD, mitochondrial manganese SOD, and the high molecular weight extracellular SOD. Eventually, this method can be used to quantify SOD activity in tissue sections by image analysis.

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“…This results in a reduced metal affinity and, consequently, in the detachment of copper [42]. In fact, proteolytic susceptibility of H202-treated Cu,Zn-SOD has been shown to be preceded by an altered binding of copper ions to the protein's active site [38], suggesting that a metal-deprived protein is the actual protease substrate.…”

Section: Effects Of Copper On the Growth Of K562 Cellsmentioning

confidence: 99%

Copper-dependent metabolism of Cu,Zn-superoxide dismutase in human K562 cells. Lack of specific transcriptional activation and accumulation of a partially inactivated enzyme

Steinkühler

Carrı̀

Micheli

et al. 1994

Biochemical Journal

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The regulation of Cu,Zn-superoxide dismutase by copper was investigated in human K562 cells. Copper ions caused a dose- and time-dependent increase, up to 3-fold, of the steady-state level of Cu,Zu-superoxide dismutase mRNA. A comparable increase was also observed for actin and ribosomal protein L32 mRNAs, but not for metallothionein mRNA which was augmented more than 50-fold and showed a different induction pattern. The copper-induced mRNAs were actively translated as judged from their enhanced loading on polysomes, the concomitantly increased cellular protein levels and an augmented incorporation of [3H]lysine into acid-precipitable material. Cu,Zn-superoxide dismutase protein followed this general trend, as demonstrated by dose- and time-dependent increases in immunoreactive and enzymically active protein. However, a specific accumulation of Cu,Zn-superoxide dismutase was noticed in cells grown in the presence of copper, that was not detectable for other proteins. Purification of the enzyme demonstrated that Cu,Zn-superoxide dismutase was present as a reconstitutable, copper-deficient protein with high specific activity (kcat./Cu = 0.89 x 10(9) M-1.s-1) in untreated K562 cells and as a fully metallated protein with low specific activity (kcat./Cu = 0.54 x 10(9) M-1.s-1) in copper-treated cells. Pulse-chase experiments using [3H]lysine indicated that turnover rates of Cu,Zn-superoxide dismutase in K562 cells were not affected by growth in copper-enriched medium, whereas turnover of total protein was significantly enhanced as a function of metal supplementation. From these results we conclude that: (i) unlike in yeast [Carrì, Galiazzo, Ciriolo and Rotilio (1991) FEBS Lett. 278, 263-266] Cu,Zn-superoxide dismutase is not specifically regulated by copper at the transcriptional level in human K562 cells, suggesting that this type of regulation has not been conserved during the evolution of higher eukaryotes; (ii) copper ions cause an inactivation of the enzyme in intact K562 cells; and (iii) the metabolic stability of Cu,Zn-superoxide dismutase results in its relative accumulation under conditions that lead to increased protein turnover.

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Reaction of bovine‐liver copper‐zinc superoxide dismutase with hydrogen peroxide

Cited by 37 publications

References 27 publications

Thiol Oxidase Activity of Copper,Zinc Superoxide Dismutase

Thiol Oxidase Activity of Copper,Zinc Superoxide Dismutase

Quantitative Histochemical Assay for Superoxide Dismutase in Rat Brain

Copper-dependent metabolism of Cu,Zn-superoxide dismutase in human K562 cells. Lack of specific transcriptional activation and accumulation of a partially inactivated enzyme

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