Kinetics and Thermodynamics of the Steady State System of Catalase with Hydrogen Peroxide

Beers, Roland F.; Sizer, Irwin W.

doi:10.1021/j150504a007

Cited by 67 publications

(59 citation statements)

References 1 publication

(2 reference statements)

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“…This conclusion is supported by the lack of effect of SOD and Trolox. Of interest, we also observed that the endogenous SOD and catalase levels in neutrophils measured by standard methods [36,37], was significantly increased under hypoxic culture conditions (SOD activity after 20 h culture in 21% 02 was 10.05 + 0.287 U/mg protein and in 0% O2 was 18.68 + 3.32 U/mg protein (P < 0.05). Catalase activity after 20 h culture in 21% 02 was 125 + 13.83 U/rag protein and in 0% 02 was 263 + 32.71 U/protein (P < 0.05)).…”

Section: Resultsmentioning

confidence: 74%

Hypoxia prolongs neutrophil survival in vitro

et al. 1995

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~,bstract Neutrophil apoptosis represents a major mechanism ~nvolved in the resolution of inflammation. Since hypoxia induces apoptosis in several cell lines and is of particular relevance in many disease states, we studied the effect of oxygen concentration on neutrophil survival in vitro. Hypoxia caused a dramatic decrease in neutrophil apoptosis (% apoptosis 20 h: 78.7 + 2.2% in 21% 0 2, 61.4 _+ 6.5% in 2.5% 02, 23.1 + 3.2% in 0% 02, = 5). This was additive to the effect of GM-CSF (50 Ulml), not associated with induction of bcl-2 expression, and was not mimicked by methionine (5 raM), superoxide dismutase (200 pg/ml) or Trolox (10 mM) but was mimicked by catalase (250/zg/ml).Hence, hypoxia has a bcl-2-independent effect on neutrophil apoptosis that may adversely affect the clearance of these cells from an inflammatory focus.

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Section: Resultsmentioning

confidence: 74%

Hypoxia prolongs neutrophil survival in vitro

et al. 1995

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“…CuZnSOD activity was calculated by subtracting MnSOD activity from total SOD activity. CAT activity in solution was measured by directly monitoring the decomposition of H 2 O 2 as described previously (Beers and Sizer, 1952). GPx activity was measured by an indirect assay that monitors the disappearance of NADPH (Lawrence and Burk, 1976).…”

Section: Antioxidant Enzyme Activity (Spectrophotometric) Assaysmentioning

confidence: 99%

Manganese superoxide dismutase overexpression inhibits the growth of androgen-independent prostate cancer cells

et al. 2004

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“…The calibration proteins were Pseudomonas putida catabolic ornithine carbamoyltransferase ( M , = 420 000) [22], catalase ( M , = 240000), E. coli W ornithine carbamoyltransferase ( M , = 140000) [23], alkaline phosphatase ( M , = 78000) and hexokinase ( M , = 48000) which were assayed, respectively, according to Stalon et al [24], Beers and Sizer [25], Legrain et al [23], Garen and Levinthal [26] and Darrow and Colowick [27]. The column was equilibrated and eluted at 0 -4 "C with 60 mM potassium phosphate buffer, pH 7.5, 0.5 mM EDTA and 0.5 mM dithiothreitol.…”

Section: Molecular Weight Determination By Gel Sievingmentioning

confidence: 99%

Yeast Argininosuccinate Synthetase

Hilger

Simon

Stalon

1979

European Journal of Biochemistry

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Yeast argininosuccinate synthetase has been purified to homogeneity. The enzyme was found to have a molecular weight of 228000 as determined by gel sieving. It is composed of identical subunits of M , 49000 as shown by gel electrophoresis.The quaternary structure as determined by cross-linking of the subunits with glutaraldehyde, followed by gel electrophoresis with dodecylsulfate, is tetrameric.The saturation functions by citrulline and aspartate are hyperbolic ; with MgATP as the variable substrate a sigmoid character, dependent on the concentration of citrulline, aspartate, argininosuccinate and arginine, was observed. The positive cooperativity is reduced by increasing concentrations of citrulline and aspartate ; it is increased by argininosuccinate and arginine.Kinetic analysis provided evidence for a random addition of substrates. Initial velocity studies as well as product and dead-end inhibition studies comply with a rapid-equilibrium random model, except for the interconversion of the central quaternary complexes ; the different kinetic constants have been established on this basis.Yeast arginonosuccinate synthetase has a double metabolic function : anabolic in the biosynthesis of arginine, catabolic as the first enzyme of citrulline utilization as nitrogen source. The kinetic properties of the enzyme point to a physiologically well-adjusted activity for both roles and to an economic and efficient utilization of ATP.Argininosuccinate synthetase catalyses the penultimate reaction of the arginine biosynthetic pathway :Citrulline + aspartate + ATP + Argininosuccinate + AMP + pyrophosphate.

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Kinetics and Thermodynamics of the Steady State System of Catalase with Hydrogen Peroxide

Cited by 67 publications

References 1 publication

Hypoxia prolongs neutrophil survival in vitro

Hypoxia prolongs neutrophil survival in vitro

Manganese superoxide dismutase overexpression inhibits the growth of androgen-independent prostate cancer cells

Yeast Argininosuccinate Synthetase

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