Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
Disease
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Query: UNIPROT:P47989 (
xanthine oxidase
)
8,633
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The use of triarylmethyl (trityl) free radical,
TAM
OX063, for detection of superoxide in aqueous solutions by electron paramagnetic resonance (EPR) spectroscopy was investigated.
TAM
is paramagnetic (EPR active), highly soluble in water and exhibits a single sharp EPR peak in aqueous media. It is also highly stable in presence of many oxidoreductants such as ascorbate and glutathione that are present in the biological systems.
TAM
reacts with superoxide with an apparent second order rate constant of 3.1 x 10(3) M(-1) s(-1). The specific reactivity of
TAM
with superoxide, which leads to loss of EPR signal, was utilized to detect the generation of superoxide in various chemical (light/riboflavin/electron/donor), enzymatic (xanthine/
xanthine oxidase
), and cellular (stimulated neutrophils) model systems. The changes in the EPR line-width, induced by molecular oxygen, were utilized in the simultaneous determination of consumption of oxygen in the model systems. The effects of flux of superoxide and concentration of
TAM
on the efficiency of detection of superoxide were studied. The use of
TAM
for detection of superoxide offers unique advantages namely, (i) the utilization of very low concentration of the probe, (ii) its stability to bioreduction, and (iii) its use in the simultaneous determination of concentrations of superoxide and oxygen.
...
PMID:Application of a trityl-based radical probe for measuring superoxide. 1468 Jun 84
