Since Phe-tRNA synthetase of Neurospora crassa reacts with tRNAV”’ of Escherichia coli to produce Phe-tRNAV&‘, the parameters that effect the reverse reaction were examined. Similarly, the interaction of Val-tRNA synthetase (E. coti) with Phe-tRNAVal and Val-tRNAVal (E. coli) was studied. Phe-tRNA synthetase (N. crassa) can catalyze the deacylation of both Phe-tRNAVa 1 (E. coli) and Val-tRNAV”’...

Hydroxyl radical converts Phe to para-, meta-, and ortho-Tyr (p-Tyr, m-Tyr, o-Tyr), while Phe is converted enzymatically to p-Tyr in the kidney and could serve as substrate for gluconeogenesis. Pathological isoforms m- and o-Tyr are supposed to be involved in development of hormone resistances. Role of Phe and the three Tyr isoforms in influencing insulin need was examined in 25 nondiabetic sep...

Microorganisms produce a large number of pharmacologically and biotechnologically important peptides by using nonribosomal peptide synthetases (NRPSs). Due to their modular arrangement and their domain organization NRPSs are particularly suitable for engineering recombinant proteins for the production of novel peptides with interesting properties. In order to compare different strategies of dom...

We investigated the effects of low ouabain concentrations on systolic (SAP) and diastolic (DAP) arterial pressures and on pressor reactivity in 3-month-old male spontaneously hypertensive rats (SHR). Arterial blood pressure (BP) and pressor reactivity to phenylephrine (PHE) were investigated before and after 0.18 μg/kg ouabain administration (N = 6). The influence of hexamethonium (N = 6), canr...

Since Phe-tRNA synthetase of Neurospora crassa reacts with tRNAV”’ of Escherichia coli to produce Phe-tRNAV&‘, the parameters that effect the reverse reaction were examined. Similarly, the interaction of Val-tRNA synthetase (E. coti) with Phe-tRNAVal and Val-tRNAVal (E. coli) was studied. Phe-tRNA synthetase (N. crassa) can catalyze the deacylation of both Phe-tRNAVa 1 (E. coli) and Val-tRNAV”’...

Acidosis is associated with inflammation and ischemia and activates cation channels in sensory neurons. Inflammation also induces expression of FMRFamidelike neuropeptides, which modulate pain. We found that neuropeptide FF (Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe amide) and FMRFamide (Phe-Met-Arg-Phe amide) generated no current on their own but potentiated H+-gated currents from cultured sensory neuro...

Geometries of aromatic/aromatic interactions in crystal structures small molecules from the Cambridge Structural Database (CSD) (benzene/benzene, toluene/toluene, and p-phenol/p-phenol interactions) protein Protein Data Bank (PDB) (Phe/Phe Tyr/Tyr were studied compared. The data show a larger influence packing/surrounding, more than substituents, on geometries interactions. While CSD preference...

Oligopeptide substrates of porcine pepsin (E) of the type A-Phe-Phe-B (S) that are cleaved solely at the Phe-Phe bond under the conditions of these studies, and bearing an amino-terminal fluorescent probe group (mansyl or dansyl), have been used for stopped-flow measurements of the rate of formation of the A-Phe product. These experiments were conducted under conditions of [E] greater than [S],...

A number of synthetic oligopeptides with the COOH terminus D-amino acid situated third from the potentially cleavable phenylalanyl-phenylalanyl bond, typified by < Glu-D-Phe-Pro-Phe-Phe-Val-D-Trp (Peptide VI) were shown to be potent competitive inhibitors of cathepsin D and pepsin. Peptide VI, which forms an equimolar nonproductive enzyme l inhibitor complex, inhibited the hydrolysis of methyl[...

PURPOSE To test whether changes in extracellular pH (pHe) in an in vitro preparation of the cat ophthalmociliary artery affect passive tone and agonist responses and whether the endothelial cells are mediators of any pH-induced effect. This will determine the ability of the ophthalmociliary artery to influence retinal and choroidal blood flow in response to metabolic stimuli. METHODS The isom...