Oxidatively induced structural alteration of glutamine synthetase assessed by analysis of spin label incorporation kinetics: relevance to Alzheimer's disease.

Peroxynitrite-induced alterations in synaptosomal membrane proteins: insight into oxidative stress in Alzheimer's disease.

Peroxynitrite (ONOO ) is a highly reactive, oxidizing anion with a half-life of <1 s that is formed by reaction of superoxide radical anion with nitric oxide. Several reports of ONOO--induced oxidation of lipids, proteins, DNA, sulfhydryls, and inactivation of key enzymes have appeared. ONOO- has also been implicated as playing a role in the pathology of several neurodegenerative disorders, suc...

Biochemical and molecular analysis of glutamine synthetase gene in brassica napus L.

Elevation of brain glutathione by gamma-glutamylcysteine ethyl ester protects against peroxynitrite-induced oxidative stress.

Elevation of glutathione (GSH) has been recognized as an important method for modulating levels of reactive oxygen species (ROS) in the brain. We investigated the antioxidant properties of gamma-glu-cys-ethyl ester (GCEE) in vitro and its ability to increase GSH levels upon in vivo i.p. injection. GCEE displays antioxidant activity similar to GSH as assessed by various in vitro indices such as ...

Evidence for the Glutamine Synthetase/Glutamate Synthase Pathway during the Photorespiratory Nitrogen Cycle in Spinach Leaves.

Spinach leaf (Spinacia oleracea L.) discs infiltrated with [(15)N]glycine were incubated at 25 degrees C in the light and in darkness for 0, 30, 60 and 90 minutes. The kinetics of (15)N-incorporation into glutamine, glutamate, asparagine, aspartate, and serine from [(15)N]glycine was determined. At the beginning of the experiment, just after infiltration (0 min incubation) serine, and the amido...

A model for beta-amyloid aggregation and neurotoxicity based on free radical generation by the peptide: relevance to Alzheimer disease.

beta-Amyloid is a 39- to 43-amino-acid neurotoxic peptide that aggregates to form the core of Alzheimer disease-associated senile (amyloid) plaques. No satisfactory hypothesis has yet been proposed to explain the mechanism of beta-amyloid aggregation and toxicity. We present mass spectrometric and electron paramagnetic resonance spin trapping evidence that beta-amyloid, in aqueous solution, fra...