Accurate knowledge of the ambient extracellular glutamate concentration in brain is required for understanding its potential impacts on tonic and phasic receptor signaling. Estimates of ambient glutamate based on microdialysis measurements are generally in the range of ∼2-10μM, approximately 100-fold higher than estimates based on electrophysiological measurements of tonic NMDA receptor activit...

For tRNA-dependent protein biosynthesis, amino acids are first activated by aminoacyl-tRNA synthetases (aaRSs) yielding the reaction intermediates aminoacyl-AMP (aa-AMP). Stable analogues of aa-AMP, such as aminoacyl-sulfamoyl-adenosines, inhibit their cognate aaRSs. Glutamyl-sulfamoyl-adenosine (Glu-AMS) is the best known inhibitor of Escherichia coli glutamyl-tRNA synthetase (GluRS). Thermody...

Ornithine δ-aminotransferase (OAT, E.C. 2.6.1.13) catalyzes the transfer of the δ-amino group from ornithine (Orn) to α-ketoglutarate (aKG), yielding glutamate-5-semialdehyde and glutamate (Glu), and vice versa. In mammals, OAT is a mitochondrial enzyme, mainly located in the liver, intestine, brain, and kidney. In general, OAT serves to form glutamate from ornithine, with the notable exception...

Using western blottings, microdialysis, and functional assays we tested the hypothesis that phencyclidine (PCP) modifies the expression and function of glutamate (Glu) transporters in the rat frontal cortex. Western blotting studies revealed that administration of PCP (10 mg/kg/day; 7 days) increased significantly the expression of the astrocytic Glu transporter GLT-1/EAAT2. Functional studies ...

Irradiation of a mixture of 4-methoxyphenacyl-caged (S)-glutamate and 4,5-dimethoxy-2-nitrobenzyl-caged γ-amino butyric acid (GABA) on neurons, at ~260 nm, evokes selective photorelease of (S)-glutamate (Glu) whereas photolysis at 405 nm causes selective photorelease of GABA.

Amperometric l-glutamate (Glu) biosensors, based on both wild-type and a recombinant form of l-glutamate oxidase (GluOx), were designed and characterized in terms of enzyme-kinetic, sensitivity and stability parameters in attempts to fabricate a real-time Glu monitoring device suitable for future long-term detection of this amino acid in biological and other complex media. A comparison of the e...

Copper (Cu) is a key antibacterial component of the host innate immune system and almost all bacterial species possess systems that defend against the toxic effects of excess Cu. The Cu tolerance system in Gram-negative bacteria is composed minimally of a Cu sensor (CueR) and a Cu export pump (CopA). The cueR and copA genes are encoded on the chromosome typically as a divergent but contiguous o...

The distribution of glutamate-like immunoreactivity (Glu-LI) in the thalamic ventral posterolateral nucleus (VPL) of cats was studied with the EM immunogold technique in order to identify nerve terminal populations that may use glutamate as a neurotransmitter. The investigation was focused on cervicothalamic tract (CTT) terminals, which were labeled by WGA-HRP transported anterogradely from inj...

Longitudinal magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) studies reveal significant changes in brain structure and structural networks that occur together with cognitive and behavioral maturation in childhood. However, the underlying cellular changes accompanying brain maturation are less understood. Examining regional age-related changes in metabolite levels provides in...

The purpose of this study was to clarify a previously controversial issue concerning glutamate (Glu) immunoreactivity (IR) in the inner segment (IS) of photoreceptors by using in vivo cryotechnique (IVCT) followed by freeze substitution (FS), which enabled us to analyze the cells and tissues reflecting living states. Eyeballs from anesthetized mice were directly frozen using IVCT. The frozen ti...