Further studies of the retinal glutamate effect have shown that not only is glutaminase I decreased in glutamate-treated rat retinas, hut glutamic-aspartic transaminase is significantly increased. Direct competitive inhibition of glutaminase I by glutamate can be demonstrated. However, studies with labeled glutamate show that under the conditions of our experiments, retinal concentrations of gl...

Until recently, the two essential aspects of channel function seemed to be clearly distinct: a selectivity fi lter that discriminates among incoming ions and an intracellular gate that regulates the ion fl ux. As usual, reality is more complex, and this traditional view of ion channels is changing rapidly. Although a physical gate appears to operate at the intracellular part of the channel and ...

INTRODUCTION Proteins that undergo receptor-mediated endocytosis are subject to lysosomal degradation, requiring radioiodination methods that minimize loss of radioactivity from tumor cells after this process occurs. To accomplish this, we developed the residualizing radioiodination agent N(ϵ)-(3-[(*)I]iodobenzoyl)-Lys(5)-N(α)-maleimido-Gly(1)-D-GEEEK (Mal-D-GEEEK-[(*)I]IB), which enhanced tumo...

Despite evidence of a fundamental role of DARPP-32 in integrating dopamine and glutamate signaling, studies examining gene coding for DARPP-32 in relation to neural and behavioral correlates in humans are scarce. Post mortem findings suggest genotype specific expressions of DARPP-32 in the dorsal frontal lobes. Therefore, we investigated the effects of genomic variation in DARPP-32 coding on fr...

Although the bacterium Xanthomonas pruni utilizes the classic "tryptophan pathway" to synthesize nicotinic acid (Wilson and Henderson, J. Bacteriol. 85:221, 1963), evidence is accumulating that most bacteria do not exhibit a tryptophan-nicotinic acid relationship. The absence of such a relationship in Escherichia coli and Bacillus subtilis was reported by Yanofsky (J. Bacteriol. 68:577, 1954). ...

Ormsbee, Richard A. (Rocky Mountain Laboratory, Hamilton, Mont.), and Marius G. Peacock. Metabolic activity in Coxiella burnetii. J. Bacteriol. 88:1205-1210. 1964.-Purified suspensions of Coxiella burnetii were shown to utilize alpha-ketoglutarate, succinate, fumarate, malate, oxaloacetate, pyruvate, glutamate, and serine. The addition of nicotinamide adenine dinucleotide(+) was necessary to el...

The incorporation of the C14 of glutamate-2-CI4 and glutamate-5-C14 into fatty acids by epididymal fat pads and liver slices suggests the operation of the following metabolic pathway : a-ketoglutarate + isocitrate -+ cbaconitate + citrate + acetyl CoA + oxalacetate (referred to as the backward reaction of the Krebs cycle). Fatty acid-C14 recoveries from glutamate-2-C14, glutamate5-C14, and acet...

AÃ--(5-|Ar-(3,4-dihydro-2-methyl-4-oxoquinazolin-6-ylmethyl)-/Vmethylamino]-2-thenoyl)-i.-glutamic acid (ICI D1694) is a water-soluble, folate-based thymidylate synthase (TS) inhibitor designed to be a less toxic and more potent analogue of the clinically tested /V'u-propargyl-5,8dideazafolic acid. Inhibition of isolated L1210 TS by ICI D1694 is mixed noncompetitive (although tending toward com...

Efficient communication between neurons is essential for all activities ranging from muscle movement and motor coordination to higher-order information processing and cognitive functions such as learning and memory. The majority of fast excitatory synaptic transmission in the mammalian central nervous system is mediated by the release of glutamates from the presynaptic terminal and their bindin...