Studies on purified 3-hydroxyanthranilic acid oxidase.
Explore the source record for details and available documents.
Acids↗
SEARCH · Search PubMed
Results for “ANTHRANILIC ACID”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Selection and characterization of a carrot cell line tolerant to glyphosate.
Cultured carrot (Daucus carota L.) cells were adapted to growing in 25 millimolar glyphosate by transfer into progressively higher concentrations of the herbicide. Tolerance was increased 52-fold, and the adaptation was stable in the absence of glyphosate. The uptake of glyphosate was similar for adapted and nonadapted cells. Activity of the enzyme 5-enolpyruvylshikimic acid-3-phosphate synthase was 12-fold higher in the adapted line compared to nonadapted cells, while activities of shikimate dehydrogenase and anthranilate synthase were similar in the two cell types. The adapted cells had higher levels of free amino acids-especially threonine, methionine, tyrosine, phenylalanine, tryptophan, histidine, and arginine-than did nonadapted cells. Glyphosate treatment caused decreases of 50 to 65% in the levels of serine, glycine, methionine, tyrosine, phenylalanine, and tryptophan in nonadapted cells, but caused little change in free amino acid levels in adapted cells.The adaptation reported here supports the growing body of evidence linking tolerance to glyphosate with increased levels of the enzyme 5-enolpyruvylshikimic acid-3-phosphate synthase. The elevated levels of aromatic amino acids, which may confer resistance in adapted cells, suggest that control of the shikimate pathway may be altered in these cells.
Journal Article↗
Origin of glutaminyl-tRNA synthetase: an example of palimpsest?
Sequence data and evolutionary arguments suggest that a similarity may exist between the C-terminal end of glutaminyl-tRNA synthetase (GlnRS) and the catalytic domain of glutamine amidotransferases (GATs). If true, this would seem to imply that the amidation reaction of the Glut-tRNA(Gln) complex was the evolutionary precursor of the direct tRNA(Gln) aminoacylation pathway. Since the C-terminal end of GlnRS does not now have an important functional role, it can be concluded that this sequence contains vestiges that lead us to believe that it represents a palimpsest. This sequence still conserves the remains of the evolutionary transition: amidation reaction-->aminoacylation reaction. This may be important in deciding which mechanism gave origin to the genetic code organization. These observations, together with results obtained by Gatti and Tzagoloff [J. Mol. Biol. (1991) 218:557-568], lead to the hypothesis that the class I aminoacyl-tRNA synthetases (ARSs) may be homologous to the GATs of the trpG subfamily, while the class II ARSs may be homologous to the GATs of the purF subfamily. Overall, this seems to point to the existence of an intimate evolutionary link between the proteins involved in the primitive metabolism and aminoacyl-tRNA synthetases.
Amino Acid Sequence↗
Structure, function, and regulation of amidophosphoribosyltransferase from prokaryotes.
Recent studies on the structure, function and regulation of amidophosphoribosyltransferase from E. coli and B. subtilis are reviewed and these properties compared with those of the enzyme from eukaryotes. The availability of large amounts of stable enzyme from the two microbial sources has facilitated the recent studies. The enzyme subunits from E. coli and B. subtilis are of similar size, 56, 395 and approximately 50,000, respectively. Catalytic properties and patterns for allosteric inhibition are similar but not identical. There are two major differences between these enzymes. In contrast to the enzyme from E. coli, B. subtilis amidophosphoribosyltransferase contains an essential Fe-S center. In addition, the enzyme from B. subtilis but not E. coli is inactivated in stationary phase by an oxygen-dependent mechanism which appears to have regulatory significance. As a consequence of the Fe-S center B. subtilis amidophosphoribosyltransferase is oxygen-sensitive in vitro. Amidophosphoribosyltransferase from mammalian sources is similar to the B. subtilis enzyme in its oxygen-sensitivity which may result from an Fe-S center. The amino acid sequence of E. coli amidophosphoribosyltransferase was deduced from the DNA sequence of the purF structural gene. The primary translation product contains 504 amino acid residues. Met-1 is removed by processing leaving an NH2-terminal cysteine residue. The NH2-terminal cysteine was specifically alkylated by the glutamine affinity analog 6-diazo-5-oxonorleucine and is thus identified as the cysteine residue involved in formation of the glutaminyl-enzyme covalent intermediate. The mechanism for glutamine utilization appears identical to other glutamine amido-transferases. Sequence homology was not detected in the glutamine amide transfer domains of E. coli anthranilate synthase and amidophosphoribosyltransferase.
Amidophosphoribosyltransferase↗
Use of affinity matrices in determining steric requirements for substrate binding: binding of anthranilate 5-phosphoribosylpyrophosphate phosphoribosyltransferase from Salmonella typhimurium to Sepharose-Anthranilate derivatives.
Explore the source record for details and available documents.
Amides↗
Quantitative Autoradiographic Demonstration of Changes in Binding to NMDA-sensitive [3H]Glutamate and [3H]MK801, but not [3H]AMPA Receptors in Chick Forebrain 30 min After Passive Avoidance Training.
Day-old domestic chicks (Gallus domesticus) were trained on a one-trial passive avoidance task in which the aversive stimulus was an unpleasant tasting substance, methyl anthranilate. Thirty minutes later, localization of N-methyl-d-aspartic acid (NMDA)-sensitive [3H]glutamate receptor binding sites, [3H]MK801 and [3H]AMPA binding sites in 17 regions of the forebrain of methylanthranilate-trained and control (water-trained) chicks was determined using quantitative receptor autoradiography. Significant differences in binding to both MK801- and NMDA-sensitive glutamate receptors, but not alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, were found in three regions of the forebrain of trained compared to control chicks; two of these regions have been implicated from previous lesion, biochemical and morphological studies as playing a key role in the process of memory formation and storage following passive avoidance training. For NMDA-sensitive [3H]glutamate receptors, significant elevations in binding were observed in two regions, the left intermediate and medial hyperstriatum ventrale (IMHV) (39%) and the lobus parolfactorius (LPO) (34%), at 30 min post-training, but a decrease (44%) occurred in binding to the lateral neostriatum. Significant increases in binding to MK801 receptors were observed in the left IMHV (19%) and right IMHV (13%), and left LPO (22%) at 30 min post-training, though there was a decrease in the right LPO (15%). These findings, coupled with those described in a previous paper from our group (Burchuladze and Rose, Eur. J. Neurosci., 4, 533 - 538, 1992), demonstrate that a glutamate receptor subtype is involved in learning and memory formation in the chick.
Journal Article↗
Expression of 5-Methyltryptophan Resistance in Plants Regenerated from Resistant Cell Lines of Datura innoxia.
Seventy-nine 5-methyltryptophan-resistant cell lines have been selected from haploid Datura innoxia Mill. cell cultures by plating suspensions in agar medium containing a growth inhibitory concentration of 5-methyltryptophan. Mutagen treatment increased the frequency of resistance. The eleven variants tested posses an altered anthranilate synthase less sensitive to feedback inhibition by tryptophan. All five of the variants which were analyzed for free amino acids contained elevated levels of free tryptophan (8 to 30 times the wild type level). None of the selected cell lines were auxin-autotrophic. Resistance to 5-methyltryptophan, altered anthranilate synthase, and high free tryptophan (4 to 44 times) were also expressed in leaves of plants regenerated from the variant lines and in cultures reinitiated from the resistant plants. These results show that the amino acid overproduction phenotype can be selected at the cellular level of organization and be expressed identically in whole plants regenerated from the selected cells.
Journal Article↗
Etofenamate fatty acid asters. An example of a new route of drug metabolism.
Etofenamate [2-(2-hydroxyethoxy)ethyl-N-(alpha, alpha, alpha-trifluoro-m-tolyl)-anthranilate] was administered to dogs by the oral route. Minor amounts of etofenamate (Eto) and its glucuronide were found in urine and feces. The main portion of metabolites was eliminated as flufenamic acid (Flu) and hydroxy derivatives of Eto and Flu. Furthermore, a highly lipophilic fraction was isolated (extraction and TLC) and further separated into several compounds (HPLC, GLC). These metabolites were identified as Eto oleate, palmitate, linoleate, stearate, palmitoleate, myristate, and laurate by NMR and MS. The structures were confirmed by comparison with authentic material. The conjugation of etofenamate with fatty acids is an example of a new route of drug metabolism.
Administration, Oral↗
Catabolism of tryptophan, anthranilate, and 2,3-dihydroxybenzoate in Trichosporon cutaneum.
Trichosporon cutaneum degraded L-tryptophan by a reaction sequence that included L-kynurenine, anthranilate, 2,3-dihydroxybenzoate, catechol, and beta-ketoadipate as catabolites. All of the enzymes of the sequence were induced by both L-tryptophan and salicylate, and those for oxidizing kynurenine and its catabolites were induced by anthranilate but not by benzoate; induction was not coordinate. Molecular weights of 66,100 and 36,500 were determined, respectively, for purified 2,3-dihydroxybenzoate decarboxylase and its single subunit. Substrates for this enzyme were restricted to benzoic acids substituted with hydroxyl groups at C-2 and C-3; no added coenzyme was required for activity. Partially purified anthranilate hydroxylase (deaminating) catalyzed the incorporation of one atom of 18O, derived from either 18O2 or H2(18)O, into 2,3-dihydroxybenzoic acid.
Carboxy-Lyases↗
Relationship between tryptophan biosynthesis and indole-3-acetic acid production in Azospirillum: identification and sequencing of a trpGDC cluster.
Screening the tryptophan (Trp)-dependent indole-3-acetic acid (IAA) production of different Azospirillum species revealed that A. irakense KA3 released 10 times less IAA into the medium than A. brasilense Sp7. A cosmid library of strain Sp7 was transferred into A. irakense KA3 with the aim of characterizing genes involved in IAA biosynthesis. Trp-dependent IAA production was increased in two transconjugants which both contained an identical 18.5 kb HindIII fragment from Sp7. After Tn5 mutagenesis, cosmids carrying Tn5 insertions at 36 different positions of the 18.5 kb fragment were isolated and transferred into strain KA3. IAA production by the recipient strains was screened by HPLC. The Tn5 insertions of 4 clones with decreased IAA production were mapped on a 2 kb SalI-SphI fragment. Recombination of Tn5 insertions at this locus into the genome of strain Sp7 led to Trp auxotrophic mutants. A 5.2 kb EcoRI-SalI fragment including the 2 kb SalI-SphI fragment was sequenced and six open reading frames were identified. Three of them were clustered and their deduced amino acid sequences showed significant similarity to TrpG, TrpD and TrpC, which are enzymes involved in tryptophan biosynthesis. One of the remaining open reading frames probably encodes an acetyltransferase. The region responsible for the enhanced Trp-dependent IAA production in strain KA3 corresponded to trpD, coding for the phosphoribosyl anthranilate transferase.
Acetyltransferases↗
Identification and nucleotide sequence of the Acinetobacter calcoaceticus encoded trpE gene.
The trpE gene from Acinetobacter calcoaceticus encoding the anthranilate synthase component I was cloned, identified by deletion analysis and sequenced. It encodes a predicted polypeptide of 497 amino acids with a calculated molecular weight of 55,323. Its primary structure shows 49% identical amino acids with the enzyme from Clostridium thermocellum, 45% with that of Thermus thermophilus and only 35% with that of Escherichia coli. The codon usage of the trpE genes encoding the most homologous enzymes differs greatly indicating selection for amino acid maintainance. The homologies are clustered in the C-terminal 200 amino acids of the sequences indicating that this part is important for enzymic activity.
Acinetobacter↗
The Rhizobium meliloti trpE(G) gene is regulated by attenuation, and its product, anthranilate synthase, is regulated by feedback inhibition.
In Rhizobium meliloti, the genes involved in biosynthesis of the amino acid tryptophan are found at three separate chromosomal locations. Of the three gene clusters, trpE(G), trpDC, and trpFBA, only the trpE(G) gene is regulated by the end product of the pathway, tryptophan. We found that trpE(G) mRNA contains a leader transcript that terminates at a stem-loop structure in a putative transcription attenuator. The level of this leader transcript was constant regardless of the amount of tryptophan in the growth medium. However, the level of full-length trpE(G) mRNA decreased as the amount of tryptophan increased. The beta-galactosidase activity of an R. meliloti strain carrying a trpL'-'lacZ fusion remained constant at different tryptophan concentrations, but the beta-galactosidase activity of the same strain carrying a trpE(G)'-'lacZ fusion decreased as the tryptophan concentration increased. These data indicate that transcription of the R. meliloti trpE(G) gene is regulated only by attenuation. We also found that the product of the trpE(G) gene, anthranilate synthase, is feedback inhibited by tryptophan.
Anthranilate Synthase↗
The biosynthesis of phytoalexins in Dianthus caryophyllus L. cell cultures: induction of benzoyl-CoA:anthranilate N-benzoyltransferase activity.
It has been shown that cell cultures of Dianthus caryophyllus L. c.v. Eleganz accumulate N-benzoyl-4-methoxyanthranilic acid, previously identified as the phytoalexin methoxydianthramide B, in response to treatment either with a crude elicitor isolated from the cell walls of Phytophthora megasperma f.sp. glycinea or with a commercial yeast extract. Cell-free extracts from the induced cells efficiently catalyzed the N-benzoylation of anthranilate in the presence of benzoyl-CoA. The partially purified transferase was shown to be specific for anthranilate with almost no activity toward 4-hydroxyanthranilate, whereas acyl donors other than benzoyl-CoA such as salicyloyl-, cinnamoyl-, or 4-coumaroyl-CoA were also accepted. Elicitor treatment of the cells additionally induced an S-adenosyl-L-methionine:N-benzoyl-4-hydroxyanthranilate 4-O-methyltransferase activity. We propose, therefore, that methoxydianthramide B is derived from N-benzoylanthranilic acid via N-benzoyl-4-hydroxyanthranilic acid. Dark-grown cells contained little N-benzoyltransferase activity (approx 8 mu kat/kg), which increased roughly ninefold within 6 h following the addition of the elicitor. In addition, phenylalanine ammonia-lyase activity of the cells increased about twofold under these conditions to a maximum (approx 40 mu kat/kg) at 5 h. The rapid induction of both enzyme activities suggests that the shikimate pathway is of crucial importance in the disease resistance response of carnation cells.
Acyltransferases↗
Thermodynamics of reactions catalyzed by anthranilate synthase.
Microcalorimetry and high performance liquid chromatography have been used to conduct a thermodynamic investigation of reactions catalyzed by anthranilate synthase, the enzyme located at the first step in the biosynthetic pathway leading from chorismate to tryptophan. One of the overall biochemical reactions catalyzed by anthranilate synthase is: chorismate(aq) + ammonia(aq) = anthranilate(aq) + pyruvate(aq) + H2O(l). This reaction can be divided into two partial reactions involving the intermediate 2-amino-4-deoxyisochorismate (ADIC): chorismate(aq) + ammonia(aq) = ADIC(aq) + H2O(l) and ADIC(aq) = anthranilate(aq) + pyruvate(aq). The native anthranilate synthase and a mutant form of it that is deficient in ADIC lyase activity but has ADIC synthase activity were used to study the overall ammonia-dependent reaction and the first of the above two partial reactions, respectively. Microcalorimetric measurements were performed on the overall reaction at a temperature of 298.15 K and pH 7.79. Equilibrium measurements were performed on the first partial (ADIC synthase) reaction at temperatures ranging from 288.15 to 302.65 K, and at pH values from 7.76 to 8.08. The results of the equilibrium and calorimetric measurements were analyzed in terms of a chemical equilibrium model that accounts for the multiplicity of ionic states of the reactants and products. These calculations gave thermodynamic quantities at the temperature 298.15 K and an ionic strength of zero for chemical reference reactions involving specific ionic forms. For the reaction: chorismate2-(aq) + NH4+(aq) = anthranilate-(aq) + pyruvate-(aq) + H+(aq) + H2O(l), delta rHmo = -(116.3 +/- 5.4) kJ mol-1. For the reaction: chorismate2-(aq) + NH4+(aq) = ADIC-(aq) + H2O(l), K = (20.3 +/- 4.5) and delta rHmo = (7.5 +/- 0.6) kJ mol-1. Thermodynamic cycle calculations were used to calculate thermodynamic quantities for three additional reactions that are pertinent to this branch point of the chorismate pathway. The quantities obtained in this study permit the calculation of the position of equilibrium of these reactions as a function of temperature, pH, and ionic strength. Values of the apparent equilibrium constants and the standard transformed Gibbs energy changes delta rG'mo under approximately physiological conditions are given.
Anthranilate Synthase↗
Synthesis of 3,4-dihydro-4-oxoquinazoline derivatives as potential anticonvulsants.
Twenty-three substituted 3,4-dihydro-4-oxoquinazolines or 3,4-dihydro-4-oxoazaquinazolines have been synthesized utilizing 2-amino-3-cyano-4,5-dimethylfuran and methyl acrylate as precursors for synthesis of the required substituted anthranilates. Six additional azaquinazolones were synthesized from 2-aminonicotinic or 3-aminopicolinic acid for comparison studies. All compounds were evaluated in mice with the maximal electroshock (MES) seizure and pentylenetetrazol (sc Met) seizure threshold tests for potential anticonvulsant activity and in the rotorod test to evaluate neurotoxicity. Nine of the twenty-nine compounds in the series demonstrated anticonvulsant action. The azaquinazolones were found to possess the most significant activity.
Animals↗
Dissimilation of aromatic compounds by Alcaligenes eutrophus.
The range of aromatic compounds that support the growth of Alcaligenes eutrophus has been determined, and the pathways used for the dissimilation of these substrates have been explored, largely by enzymatic analyses. The beta-ketoadipate pathway operates in the dissimilation of benzoate and p-hydroxybenzoate; the genetisate pathway, in the dissimilation of m-hydroxybenzoate; and the meta cleavage pathway, in the dissimilation of phenol and p-cresol. l-Tryptophan is oxidized via anthranilate; but the metabolic fate of anthranilate was not established. The metabolism of the three stereoisomers of muconic acid was also examined.
Adipates↗
3-Hydroxyanthranilic acid as an intermediate in the oxidation of the indole nucleus of tryptophan.
Explore the source record for details and available documents.
3-Hydroxyanthranilic Acid↗
Studies of tryptophan metabolism in protein-energy malnutrition (PEM).
Studies on tryptophan metabolism in PEM were performed. In this respect, the basal excretion of tryptophan and some of its metabolites, namely, kynurenine, 3 OH-anthranilic, anthramilic, indol-3-acetic, 5 OH-indol acetic and xanthurenic acids were determined. The response of these metabolites to oral tryptophan load, singly and in combination, with pyridoxine, were performed in kwashiorkor cases compared to normal controls. The study revealed that kynurenine leads to niacine pathway is hindered, Indole-3-acetic acid levels are lower and respond poorly to tryptophan loading in PEM. Increased levels of 5 OH-indol acetic were found in kwashiorkor compared to marasmus, although lower response to tryptophan was noted. Xanthurenic acid excretion is much higher in PEM and poorly responds to tryptophan load either singly or in combination with pyridoxine. These errors of tryptophan metabolism in PEM are suggested to be due to defects in the enzyme systems involved rather than to vitamin B6 deficiency.
Child, Preschool↗