The first base pair of the acceptor stem A1-U72 and the discriminator base G73, as well as the anticodon nucleotides, characterize the tryptophan tRNA in E. coli. To determine the contribution of these nucleotides to the tryptophan acceptor activity, various transcripts of E. coli tryptophan tRNA mutants were constructed. Substitutions of the discriminator base G73, which is conserved within pr...

We investigated the role of serotonin in cognitive activation of the frontal cortex. The serotonergic system was affected by the administration of an amino acids mixture without tryptophan (tryptophan depletion). In a placebo-controlled double-blind cross-over study with 20 healthy volunteers, we tested the hypothesis that a tryptophan (serotonin) decrease affects the activation of prefrontal c...

INTRODUCTION Solutions that cause elective cardiac arrest are constantly evolving, but the ideal compound has not yet been found. The authors compare a new cardioplegic solution with histidine-tryptophan-glutamate (Group 2) and other one with histidine-tryptophan-cetoglutarate (Group 1) in a model of isolated rat heart. OBJECTIVE To quantify the fractal dimension and Shannon entropy in rat my...

BACKGROUND L-tryptophan is an aromatic amino acid widely used in the food, chemical and pharmaceutical industries. In Escherichia coli, L-tryptophan is synthesized from phosphoenolpyruvate and erythrose 4-phosphate by enzymes in the shikimate pathway and L-tryptophan branch pathway, while L-serine and phosphoribosylpyrophosphate are also involved in L-tryptophan synthesis. In order to construct...

The tryptophan-kynurenine metabolic pathway plays the most essential role in tryptophan metabolism, producing various endogenous bioactive molecules. activation of is linked to pathogenesis a wide range diseases. calibration levels and ratio kynurenines has been attempted search biomarkers diagnostic targets. This editorial introduces biosystems close interaction with kynurenine system potentia...

Recent discoveries of important pharmacological properties have drawn attention to the reactivity of HNO (azanone, nitroxyl) with biologically relevant substrates. Apart from its role in thiol oxidation, HNO has been reported to have nitrosative properties, for example, with tryptophan resulting in N-nitrosotryptophan formation. We have investigated the reactivity of HNO with tryptophan and sma...

Ferrous L-tryptophan-2,3-dioxygenase reacts with nitric oxide both in the presence and in the absence of L-tryptophan. Electron paramagnetic resonance studies suggest that the proximal ligand of the heme is a nitrogen atom, probably from an histidyl residue. The interaction of the protein with substrate changes both the symmetry of the paramagnetic center and the mode of interaction of the iron...

The metabolism of D- and L-[benzene ring-U-14C]tryptophan by dogs was studied. The distribution of label from each isomer in urine, feces, CO2 and various tissues was determined. Thirteen different urinary tryptophan metabolites were isolated by ion exchange cellulose chromatography. D-[14C]Tryptophan was poorly converted to 14CO2 relative to the L-isomer, while giving rise to nearly three time...

To estimate the tryptophan requirement of the kitten, six male and six female kittens were presented diets containing 0.7, 0.9, 1.1, 1.3, 1.5 and 3.0 g tryptophan/kg diet for six experimental periods lasting 10 d in accordance with a 6 X 6 balanced Latin-square design. Mean daily weight gain and nitrogen retention (N intake minus urinary and faecal N) plateaued at 1.1 g tryptophan/kg diet indic...