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PubMed1982

Coexistence in human and primate neuromuscular junctions of enzymes synthesizing acetylcholine, catecholamine, taurine, and gamma-aminobutyric acid.

Coexistence of neurotransmitter-synthesizing enzymes choline acetyltransferase, cysteine sulfinic acid decarboxylase, tyrosine hydroxylase, and L-glutamic acid decarboxylase was demonstrated at human and primate neuromuscular junctions with specific antibodies directed against these enzymes. Motor end plates were identified in unfixed cryostat sections by standard cholinergic markers for acetylcholinesterase and the acetylcholine receptor. Each of the four transmitter-synthesizing enzymes was localized at end plates displaying these markers. The presence of any two of the four enzymes at a given end plate was established by (i) showing immunoreaction for one enzyme followed by elution and demonstration of immunoreaction for a second enzyme, and (ii) paired immunofluorescence with simultaneous demonstration of one enzyme with a rhodamine-labeled second antibody and of the other enzyme with a fluorescein-labeled second antibody. These findings imply that motor nerve terminals have the capacity for synthesizing not only acetylcholine but also taurine, catecholamines, and gamma-aminobutyric acid. These substances, in turn, may participate in the normal regulation of nerve-muscle interaction or be significant in specific disorders involving the motor unit.

Acetylcholine↗

PubMed2004

The catecholamine potentiates starch mobilization in transgenic potato tubers.

In human and animal cells, the catecholamines are involved in glycogen mobilization. Since the compounds are found in a potato, their function in starch mobilization was hypothesized. In order to verify this hypothesis, the transgenic potato plants Solanum tuberosum L. cv. Desiree overexpressing tyrosine decarboxylase (TD EC 4.1.1.25) cDNA from parsley has been generated. The cDNA expression was judged by the northern blot analysis and the enzyme activity measurements. Four independent transgenic lines with the highest TD mRNA expression were selected and analyzed. The expected substantial decrease in tyrosine content was followed by significant increase in tyramine and dramatic enhancement of norepinephrine synthesis was detected. The level of L-3,4-dihydroxyphenylalanin (L-Dopa) was only slightly increased and dopamine significantly decreased in most cases in these plants. The increase in norepinephrine was accompanied by changes in carbohydrate metabolism. The significant increase in glucose and sucrose and the decrease in starch content were characteristic features of TD overexpressed transgenic potato tubers. The features mentioned above indicate that catecholamines potentiate starch mobilization in potato plants in common with animal cells. The decrease in tyrosine content in transgenic plants is also compensated by significant increase in chlorogenic acid synthesis thus potentially increasing the antioxidant capacity of transgenic tubers. The glycoalkaloids content is changed in the transformants. This may originate from glucose accumulation and glycolysis activation. The obtained transgenic potato provides material for further detailed studies of the physiological function of catecholamines in plants.

Animals↗

PubMed1972

Improved procedure for identification of group D enterococci with two new media.

With the use of Pfizer selective enterococcus medium as a screening process, tyrosine decarboxylase (TD) medium and D-broth were devised for additional confirmation of the identification of group D enterococci. The semisolid TD medium was used in a method similar to inoculating a motility tube. TD activity was indicated by clarification of the medium near the line of inoculation because the insolubility of tyrosine provided an otherwise milky suspension. D-broth was used to show the tolerance of organisms to 6.5% NaCl at pH 8.2. In addition, enterococcal species (except Streptococcus durans) could also be demonstrated by the acid formation due to the fermentation of mannitol or arabinose. With this improved system, about 97% of enterococci could be accurately identified and confirmed.

Arabinose↗

PubMed2001

Biogenic amines in wines: role of lactic acid bacteria.

Biogenic amines have undesirable physiological effects when absorbed at too high a concentration. Several kinds of food and beverages contain biogenic amines. Lactic acid bacteria can decarboxylate amino acids. Since winemaking involves the growth of lactic acid bacteria for malolactic fermentation, biogenic amines may occur. However, not all bacterial strains carry these activities. In the same wine-producing area, some wines may contain very low amounts of biogenic amines while others may have relatively large quantities. It is now possible to detect the presence of undesirable histamine-producing strains by PCR test or DNA probe based on the presence of the gene encoding histidine decarboxylase. Other strains have the ornithine and/or tyrosine decarboxylase. When biogenic amine-producing strains are present, the winemaker is encouraged to inoculate selected malolactic starters to replace the indigenous microflora.

Biogenic Amines↗

PubMed1999

Biochemical activities of extracts from Hypericum perforatum L. 1st Communication: inhibition of dopamine-beta-hydroxylase.

Extracts from the herb "St. John's wort" (Hypericum perforatum L.) are used for the treatment of mental depression, nervousness, sleeplessness and for their wound healing, diuretic and antirheumatic properties. As one biochemical mechanism for depression lack of catecholamine neurotransmitters has been discussed. The results of this investigation show that alcoholic extracts from Hypericum perforatum L. on the basis of total hypericin content inhibit dopamine-beta-hydroxylase with an IC50 of 0.1 mu mol/l; pure commercial hypericin inhibits with an IC50 of 21 mu mol/l. Enzymes involved in the synthesis of dopamine from tyrosine, namely tyrosinase and tyrosine decarboxylase, are not influenced by hypericin at concentrations from 1 up to 10 mu mol/l.

Anthracenes↗

PubMed1990

Rapid enzymatic analysis of plasma for tyrosine.

In this rapid, simple, and convenient enzymatic method for measurement of tyrosine in plasma, tyrosine is converted to tyramine by action of tyrosine decarboxylase (EC 4.1.1.25) and the tyramine produced is oxidized to p-hydroxybenzyl aldehyde and hydrogen peroxide by action of tyramine oxidase (EC 1.4.3.9). The hydrogen peroxide is reacted with 4-aminoantipyrine and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-m-toluidine in the presence of peroxidase (EC 1.11.1.7) to obtain quinoneimine dye, the absorbance of which is measured at 570 nm. Thus tyrosine is measured in the visible range. The CV was 4.6% or less, and the measurement was unaffected by other amino acids, except for phenylalanine. The values obtained (y) correlated well with those obtained with an amino acid analyzer (x): y = 0.902x + 3.92 mumol/L (Syx = 12.3; r = 0.985; n = 54).

Autoanalysis↗

PubMed1976

Biochemical differentiation of mechanically dissociated mammalian brain in aggregating cell culture.

Mouse and rat brain cells were dissociated by a simple mechanical sieving technique and studied in culture for the formation of aggregates and the activities of choline acetyltransferase, acetylcholinesterase, glutamic acid decarboxylase, tyrosine 3-monooxygenase, aromatic L-amino acid decarboxylase, catechol methyltransferase, and monoamine oxidase. Cells from fetal and neonatal tissue formed aggregates but not cells from tissue older than two days after birth. The pattern of development of enzyme activities in these aggregates varied with the age of starting tissue. The highest levels of specific activity for the neuron-specific enzymes were found after 3-4 weeks in culture for aggregates of cells derived from relatively undeveloped brains.

Acetylcholinesterase↗

PubMedDate not supplied

Beta-1,3-glucooligosaccharide induced activation of four enzymes responsible for N-p-coumaroyloctopamine biosynthesis in potato (Solanum tuberosum cv.) tuber tissue.

Potato tuber disks, when treated with laminarin, a beta-1,3-glucooligosaccharide from Laminaria digitata, accumulate a hydroxycinnamoyl amide compound, N-p-coumaroyloctopamine (p-CO). The biosynthesis of p-CO was investigated by feeding experiments, in order to show that the precursors of N-p-coumaroyl and octopamine moieties of p-CO are L-phenylalanine and L-tyrosine, respectively. The treatment of potato tuber tissue with laminarin resulted in elevated activities of four enzymes which are putatively involved in p-CO biosynthesis: phenylalanine ammonia lyase (PAL; EC 4.3.1.5), 4-hydroxycinnamic acid:CoA ligase (4CL; EC 6.2.1.12), hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase (THT; EC 2.3.1.110) and tyrosine decarboxylase (TyrDC; EC 4.1.1.25). Among these, the response of TyrDC was specific to laminarin treatment, thus indicating that the regulation of TyrDC activity is critical for the accumulation of p-CO in potato tuber tissue.

Acyltransferases↗

PubMed1993

Characterization of the tyraminergic system in the central nervous system of the locust, Locusta migratoria migratoides.

Tyramine occurs in the central nervous system (CNS) of the migratory locust, Locusta migratoria migratoides. The distribution of tyramine within the CNS does not parallel that of octopamine. Tyramine is synthesised from tyrosine in the presence of tyrosine decarboxylase. A second decarboxylase in the CNS is active against 5HTP and DOPA. The locust ganglia incorporate tyramine by high- and low-affinity uptake processes that appear to be independent of dopamine and octopamine. Depolarisation of the locust ganglia by high potassium concentration results in calcium-dependent release of incorporated [3H]tyramine.

Animals↗

PubMed1981

A mechanism of L-canaline toxicity.

L-Canaline, a highly toxic structural analogue of L-ornithine, reacted with pyridoxal phosphate to form a stable, ninhydrin-positive complex. NMR analysis revealed the involvement of a Schiff's base in complex formation. Interaction of L-canaline with L-tyrosine decarboxylase, a known B6-containing enzyme, curtailed significantly enzyme-mediated decarboxylation. Spectral scans provided evidence that the loss in catalytic activity is associated with the reaction of canaline with the pyridoxal phosphate moiety of the enzyme. Thus, the marked antimetabolic properties of canaline are due in part of its ability to form a Schiff's-base-containing complex with the B6 moiety of the enzyme.

Aminobutyrates↗

PubMed1983

Apoenzyme content of serum aminotransferases in relation to plasma pyridoxal-5'-phosphate concentration.

To investigate the considerable variation in stimulation of serum aminotransferase activities by pyridoxal-5'-phosphate added in vitro, we determined the pyridoxal-5'-phosphate content of plasma, using the tyrosine decarboxylase reaction together with the catalytic activities of alanine aminotransferase and aspartate aminotransferase, with and without pyridoxal-5'-phosphate supplementation, within a group of normal human individuals. We found a very significant inverse linear relationship between plasma pyridoxal-5'-phosphate concentration and stimulation of the activities of these enzymes in serum after supplementation with pyridoxal-5'-phosphate. We conclude that the degree of stimulation of the apoenzyme of the two serum aminotransferases clearly depends on the pyridoxal-5'-phosphate concentration in vivo.

Apoenzymes↗

PubMed2003

Stress response in a juvenile hormone-deficient Drosophila melanogaster mutant apterous56f.

The apterous56f (ap56f) mutation leads to increases in juvenile hormone (JH) degradation levels and JH-esterase makes a greater contribution to the increase than JH-epoxide hydrolase. Dopamine levels in ap56f females, but not males, are higher than in wild-type. JH treatment of ap56f and wild-type females decreases their dopamine levels. ap56f females, but not males, produce less progeny. Survival under heat stress is dramatically decreased in ap56f females, but not males. ap56f flies show a stress reaction, as judged by changes in tyrosine decarboxylase and JH-hydrolysing activities, dopamine levels and fertility, but its intensity in the mutant females, but not males, differs significantly from wild-type. Thus, the ap56f mutation causes dramatic changes in female, but not male, metabolism and fitness.

Animals↗

PubMed2001

Induction of hydroxycinnamoyl-tyramine conjugates in pepper by Xanthomonas campestris, a plant defense response activated by hrp gene-dependent and hrp gene-independent mechanisms.

Inoculation of pepper leaves, Capsicum annuum cv. Early Calwonder ECW 10R, with strains of Xanthomonas campestris led to an accumulation of the phenolic conjugates feruloyltyramine (FT) and p-coumaroyltyramine (CT) 24 h postinoculation in nonhost- and gene-for-gene-determined incompatible interactions with X. campestris pv. campestris and X. campestris pv. vesicatoria, respectively. In contrast, neither compound was detected in compatible interactions with X. campestris pv. vesicatoria. The accumulation of FT and CT was preceded by an increase in the extractable activity of tyrosine decarboxylase as well as increases in the transcription of genes encoding phenylalanine ammonia-lyase and tyramine hydroxycinnamoyl transferase. No such changes were detected in compatible interactions. Very rapid accumulation of FT and CT occurred (4 h postinoculation) in pepper in response to a X. campestris pv. campestris mutant carrying a deletion of the hrp gene cluster. In contrast, hrp mutants of X. campestris pv. vesicatoria failed to elicit the production of FT and CT. These observations suggest the existence of hrp gene-dependent and -independent activation mechanisms of a defense response involving hydroxycinnamoyltyramines.

Anti-Bacterial Agents↗

PubMed1983

Radioenzymatic assay for direct measurement of plasma pyridoxal 5'-phosphate.

A radioenzymatic assay for measurement of pyridoxal 5'-phosphate (PLP) is described, based on the incubation of L-[3H]tyrosine (10(6) cpm, spec. acty. 1.88 Ci/mol) in the presence of the apoenzyme tyrosine decarboxylase (EC 4.1.1.25) from Streptococcus faecalis and PLP in phosphate buffer (0.1 mol/L, pH 5.5) at 37 degrees C for 60 min. The decarboxylated metabolite formed, [3H]tyramine, was selectively extracted into ethyl acetate, and the tritium radioactivity in the sample was determined by liquid scintillation counting. As little as 0.5 nmol of PLP can be detected per liter. The assay is specific, no cross reactivity having been noted for several compounds closely related to PLP. With this we could directly measure the concentrations of PLP in plasma without prior deproteinization and ether washing of the samples. Using the assay to determine plasma concentrations of PLP in healthy adult populations, we found results that were comparable with previously reported data.

Apoenzymes↗

PubMed2004

The effect of mutations altering biogenic amine metabolism in Drosophila on viability and the response to environmental stresses.

Dopamine (DA) content, tyrosine decarboxylase (TDC) activity and survival were studied under normal and environmental stress conditions in the ste and e strains carrying ebony mutation increasing DA level and the octopamineless strain Tbetah(nM18) of Drosophila melanogaster. Wild-type strains Canton S and Oregon R, and strain p845 from which Tbetah(nM18) strain was derived were used as controls. Sexual dimorphism of TDC activity, DA content, and survival in flies of all D. melanogaster strains under study was found. Tbetah(nM18) mutation sharply reduced TDC activity in females, while ebony had no such effect. DA content and survival under heat stress in Tbetah(nM18) flies did not differ from those in the wild type. ste and e flies had drastically increased DA content under normal conditions, dramatically decreased survival under heat stress, but increased survival under starvation. DA content and survival under heat stress were also studied in the reciprocal hybrids (males) F(1) of the cross D. virilis strains 101 (wild type) and 147 with X-linked mutation, which significantly increases DA content. 147x101 males had a considerably higher DA content and lower survival than 101x147 ones. Individuals of all D. melanogaster strains under study developed the stress reaction, as judged by changes in TDC activity and DA levels. The role of biogenic amines in the stress reaction development and adaptation to environmental stresses in Drosophila is discussed. Arch. Insect Biochem. Physiol. 55:55-67, 2004.

Adaptation, Physiological↗

PubMed1987

Subcellular Localization of Amines and Activities of Their Biosynthetic Enzymes in p-Fluorophenylalanine Resistant and Wild-Type Tobacco Cell Cultures.

Three levels of free amines and the activities of their biosynthetic enzymes were measured in subcellular fractions of two cell lines of Nicotiana tabacum L. cv Xanthi. The TX4 cell line, a p-fluorophenylalanine resistant culture which accumulates high levels of cinnamoylamides, was compared to the wild-type culture TX1. In cells harvested on day 6 of the growth cycle, nearly all free putrescine, spermidine, and tyramine was found in the supernatant fraction of both cell lines. Although a consistent portion of ornithine decarboxylase activity was detected in the nuclear-enriched fractions of TX1 and TX4, the largest levels of activity were in the supernatants of both lines. In TX1, arginine decarboxylase activity was low relative to that of ornithine decarboxylase, but, in the TX4 line arginine decarboxylase levels in the cytosol were substantially elevated. Tyrosine decarboxylase was not detected in 6-day-old TX1 cells, but significant amounts of activity were measured in the 1000g and supernatant fractions of TX4. S-Adenosylmethionine decarboxylase activity was low in both cell lines and was located predominantly in the supernatant.

Journal Article↗

PubMed2005

Improved multiplex-PCR method for the simultaneous detection of food bacteria producing biogenic amines.

This study describes a simple and rapid multiplex-PCR method to determine the ability to produce histamine, tyramine and putrescine by bacteria. The assay is an improved method based on an assay designed for lactic acid bacteria. This improved method includes a pair of primers based on sequences from histidine decarboxylases from Gram-negative bacteria. Under the optimised conditions, the assay yielded a 367-bp DNA fragment from histidine decarboxylases of Gram-positive bacteria, 534-bp fragment from histidine decarboxylases of Gram-negative bacteria, 924-bp from bacterial tyrosine decarboxylases, and 1446-bp fragment from bacterial ornithine decarboxylases. The method was successfully applied to several biogenic amine-producing bacterial strains, even when DNAs of several target organisms were included in the same reaction. This simple method could be easily incorporated in food control laboratories to detect potentially biogenic amine-producing bacteria in foods.

Bacteriological Techniques↗

PubMed1978

Rich culture medium for the radiochemical labeling of proteins and nucleic acids.

Yeast extract was treated with tyrosine decarboxylase and used to prepare a rich, complex medium virtually free of tyrosine. The medium supported maximal growth rates for Escherichia coli prototrophs, as well as for defined and undefined auxotrophs. It has made possible the efficient radiochemical labeling of cells growing optimally in complex medium and the characterization of mutants with undefined requirements. Similarly prepared media may be useful for the study of fastidious organisms and organisms for which no defined medium has been described.

Amino Acids↗