The Application of ESR Spin-Trapping Technique to the Evaluation of SOD-<i>like</i> Activity of Biological Substances

Mitsuta, Keiichi; Mizuta, Yukio; Kohno, Masahiro; Hiramatsu, Midori; Mori, Akitane

doi:10.1246/bcsj.63.187

Cited by 137 publications

(86 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second-order rate constant for the reaction between the compound and hydroxyl radicals is calculated according to the kinetic competition model for ROS scavengers (Mitsuta et al, 1990). The constant for salicylate, 1.2 3 10 10 M 21 s 21 (Maskos et al, 1990), was used to calculate the constant for the competitor.…”

Section: Determination Of the Rate Constant For The Reaction Between mentioning

confidence: 99%

Galactinol and Raffinose Constitute a Novel Function to Protect Plants from Oxidative Damage

2008

View full text Add to dashboard Cite

Galactinol synthase (GolS) is a key enzyme in the synthesis of raffinose family oligosaccharides that function as osmoprotectants in plant cells. In leaves of Arabidopsis (Arabidopsis thaliana) plants overexpressing heat shock transcription factor A2 (HsfA2), the transcription of GolS1, -2, and -4 and raffinose synthase 2 (RS2) was highly induced; thus, levels of galactinol and raffinose increased compared with those in wild-type plants under control growth conditions. In leaves of the wild-type plants, treatment with 50 mM methylviologen (MV) increased the transcript levels of not only HsfA2, but also GolS1, -2, -3, -4, and -8 and RS2, -4, -5, and -6, the total activities of GolS isoenzymes, and the levels of galactinol and raffinose. GolS1-or GolS2-overexpressing Arabidopsis plants (Ox-GolS1-11, Ox-GolS2-8, and Ox-GolS2-29) had increased levels of galactinol and raffinose in the leaves compared with wild-type plants under control growth conditions. High intracellular levels of galactinol and raffinose in the transgenic plants were correlated with increased tolerance to MV treatment and salinity or chilling stress. Galactinol and raffinose effectively protected salicylate from attack by hydroxyl radicals in vitro. These findings suggest the possibility that galactinol and raffinose scavenge hydroxyl radicals as a novel function to protect plant cells from oxidative damage caused by MV treatment, salinity, or chilling.

show abstract

Section: Determination Of the Rate Constant For The Reaction Between mentioning

confidence: 99%

Galactinol and Raffinose Constitute a Novel Function to Protect Plants from Oxidative Damage

2008

View full text Add to dashboard Cite

show abstract

“…In our experiments, the DMPO concentration (670 mM) was sufficiently high to trap almost all of the superoxide anion. 22) Therefore, these results may suggest that selenomethionine and selenoethionine have the scavenging ability against superoxide anion (Fig. 1).…”

Section: Discussionmentioning

confidence: 87%

“…Estimate of the Effects of Selenium Compounds against AOS and Their Generating System ---Intensity of the DMPO adduct signal was expressed as the ratio of signal area of the adduct to that of Mn 2+ at the lowest magnetic field. To estimate the true scavenging activity of selenium compounds by the spin trapping method, experiments were carried out using the modified methods of Prónai et al 21) and Mitsuta et al 22) If selenium compounds has a scavenging ability against AOS, the competitive reactions are as following:…”

Section: Chemicalsmentioning

confidence: 99%

Enhancement of Hydroxyl Radical Formation from Superoxide Anion Radical in the Presence of Organic Selenium Compounds.

Okuno

Kawai

Hasegawa³

et al. 2001

JOURNAL OF HEALTH SCIENCE

View full text Add to dashboard Cite

The generation of superoxide anion or hydroxyl radical derived from the organic selenium compounds selenomethionine, selenoethionine, selenocystine, selenocystamine and selenocysteine-glutathione selenenyl sulfide (CySeSG) was investigated by the electron spin resonance (ESR) technique with 5,5-dimethyl-1-pyrroline Noxide (DMPO) as a spin trapping agent. The intensity of ESR signals of DMPO-OOH adduct formed by the reaction of the hypoxanthine/xanthine oxidase reaction system with DMPO decreased in the presence of selenomethionine or selenoethionine. However, the decrease of this ESR signal intensity was not due to superoxide anion-scavenging ability of these selenium compounds. When selenomethionine or selenoethionine existed in the superoxide anion generating system at a higher concentration, a new ESR signal was recognized. This signal disappeared with the addition of a hydroxyl radical-scavenging reagent and was similar to the signal of DMPO-OH adduct. The lack of structural change in selenomethionine or selenoethionine following reaction with components of the superoxide anion generating system suggested that these selenium compounds act as a catalyst. Such a phenomenon was not observed in the superoxide anion generating system in the presence of selenocystine, selenocystamine or CySeSG. These findings suggested that coexistence of selenomethionine or selenoethionine under mammalian physiological conditions generating superoxide anion may possibly form a hydroxyl radical.

show abstract

“…5,6) However, anti-oxidants, for example Na-Asc as already stated, scavenge DMPO-OH together with the OH radical, so it is not reasonable to evaluate the OH radical scavenging ability from the decrease in ESR intensity of DMPO-OH. Solid-state spin trapping, however, made it possible to separately measure the OH radical and DMPO-OH scavenging ability from the 10 and k values.…”

Section: Resultsmentioning

confidence: 99%

Solid-state Spin Trapping of the Hydroxyl Radical Formed by Gamma-irradiation in Ice and the Scavenging Effect of Sodiuml-Ascorbate

Yoshioka

Hasegawa

1996

Bioscience, Biotechnology, and Biochemistry

View full text Add to dashboard Cite

The Application of ESR Spin-Trapping Technique to the Evaluation of SOD-like Activity of Biological Substances

Cited by 137 publications

References 25 publications

Galactinol and Raffinose Constitute a Novel Function to Protect Plants from Oxidative Damage

Galactinol and Raffinose Constitute a Novel Function to Protect Plants from Oxidative Damage

Enhancement of Hydroxyl Radical Formation from Superoxide Anion Radical in the Presence of Organic Selenium Compounds.

Solid-state Spin Trapping of the Hydroxyl Radical Formed by Gamma-irradiation in Ice and the Scavenging Effect of Sodiuml-Ascorbate

Contact Info

Product

Resources

About