Publications

• Identification and characterization of a L-tyrosine decarboxylase in Methanocaldococcus jannaschii.

  Kezmarsky N.D., Xu H., Graham D.E., White R.H.

  Methanofuran is the first coenzyme in the methanogenic pathway used by the archaeon Methanocaldococcus jannaschii, as well as other methanogens, to reduce CO2 to methane. The details of the pathway for the biosynthesis of methanofuran and the responsible genes have yet to be established. A clear s ... >> More

  Methanofuran is the first coenzyme in the methanogenic pathway used by the archaeon Methanocaldococcus jannaschii, as well as other methanogens, to reduce CO2 to methane. The details of the pathway for the biosynthesis of methanofuran and the responsible genes have yet to be established. A clear structural element in all known methanofurans is tyramine, likely produced by the decarboxylation of L-tyrosine. We show here that the mfnA gene at M. jannaschii locus MJ0050 encodes a thermostable pyridoxal phosphate-dependent L-tyrosine decarboxylase that specifically produces tyramine. Homologs of this gene are widely distributed among euryarchaea but are not specifically related to known bacterial or plant tyrosine decarboxylases. << Less

  Biochim. Biophys. Acta 1722:175-182(2005) [PubMed] [EuropePMC]

• Discovery and inhibition of an interspecies gut bacterial pathway for Levodopa metabolism.

  Maini Rekdal V., Bess E.N., Bisanz J.E., Turnbaugh P.J., Balskus E.P.

  The human gut microbiota metabolizes the Parkinson's disease medication Levodopa (l-dopa), potentially reducing drug availability and causing side effects. However, the organisms, genes, and enzymes responsible for this activity in patients and their susceptibility to inhibition by host-targeted d ... >> More

  The human gut microbiota metabolizes the Parkinson's disease medication Levodopa (l-dopa), potentially reducing drug availability and causing side effects. However, the organisms, genes, and enzymes responsible for this activity in patients and their susceptibility to inhibition by host-targeted drugs are unknown. Here, we describe an interspecies pathway for gut bacterial l-dopa metabolism. Conversion of l-dopa to dopamine by a pyridoxal phosphate-dependent tyrosine decarboxylase from <i>Enterococcus faecalis</i> is followed by transformation of dopamine to <i>m</i>-tyramine by a molybdenum-dependent dehydroxylase from <i>Eggerthella lenta</i> These enzymes predict drug metabolism in complex human gut microbiotas. Although a drug that targets host aromatic amino acid decarboxylase does not prevent gut microbial l-dopa decarboxylation, we identified a compound that inhibits this activity in Parkinson's patient microbiotas and increases l-dopa bioavailability in mice. << Less

  Science 364:0-0(2019) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• The steady state kinetics of tyrosine decarboxylase from Streptococcus faecalis.

  Orlacchio A., Borri-Voltattorni C.

  The present study has explained the general reaction mechanism of the bacterial tyrosine decarboxylase. The rate equation for this mechanism has been presented. The steady state kinetics of tyrosine decarboxylase, as for tyrosine transaminase, have shown that the apoenzyme can bind not only the co ... >> More

  The present study has explained the general reaction mechanism of the bacterial tyrosine decarboxylase. The rate equation for this mechanism has been presented. The steady state kinetics of tyrosine decarboxylase, as for tyrosine transaminase, have shown that the apoenzyme can bind not only the coenzyme, but also the non-enzymatically formed Schiff base between the coenzyme and the substrate. Our data then have confirmed the importance of the non-enzymatically formed Schiff base in the B6-dependent enzymes, possibly in all of them which have a low affinity constant for the coenzyme, such that the coenzyme must be present in excess in respect to the protein to saturate the active center. The interaction between apotyrosine decarboxylase with pyridoxal-5'-phosphate and pyridoxamine-5'-phosphate has been studied. << Less

  Ital J Biochem 28:1-10(1979) [PubMed] [EuropePMC]

• Characterization of rice tryptophan decarboxylases and their direct involvement in serotonin biosynthesis in transgenic rice.

  Kang S., Kang K., Lee K., Back K.

  L-Tryptophan decarboxylase (TDC) and L-tyrosine decarboxylase (TYDC) belong to a family of aromatic L-amino acid decarboxylases and catalyze the conversion of tryptophan and tyrosine into tryptamine and tyramine, respectively. The rice genome has been shown to contain seven TDC or TYDC-like genes. ... >> More

  L-Tryptophan decarboxylase (TDC) and L-tyrosine decarboxylase (TYDC) belong to a family of aromatic L-amino acid decarboxylases and catalyze the conversion of tryptophan and tyrosine into tryptamine and tyramine, respectively. The rice genome has been shown to contain seven TDC or TYDC-like genes. Three of these genes for which cDNA clones were available were characterized to assign their functions using heterologous expression in Escherichia coli and rice (Oryza sativa cv. Dongjin). The purified products of two of the genes were expressed in E. coli and exhibited TDC activity, whereas the remaining gene could not be expressed in E. coli. The recombinant TDC protein with the greatest TDC activity showed a K (m) of 0.69 mM for tryptophan, and its activity was not inhibited by phenylalanine or tyrosine, indicating a high level of substrate specificity toward tryptophan. The ectopic expression of the three cDNA clones in rice led to the abundant production of the products of the encoded enzymes, tyramine and tryptamine. The overproduction of TYDC resulted in stunted growth and a lack of seed production due to tyramine accumulation, which increased as the plant aged. In contrast, transgenic plants that produced TDC showed a normal phenotype and contained 25-fold and 11-fold higher serotonin in the leaves and seeds, respectively, than the wild-type plants. The overproduction of either tyramine or serotonin was not strongly related to the enhanced synthesis of tyramine or serotonin derivatives, such as feruloyltyramine and feruloylserotonin, which are secondary metabolites that act as phytoalexins in plants. << Less

  Planta 227:263-272(2007) [PubMed] [EuropePMC]

• The decarboxylation of L-phenylalanine by Streptococcus faecalis R.

  McGILVERY R.W., COHEN P.P.

  J Biol Chem 174:813-816(1948) [PubMed] [EuropePMC]

• Tyramine functions independently of octopamine in the Caenorhabditis elegans nervous system.

  Alkema M.J., Hunter-Ensor M., Ringstad N., Horvitz H.R.

  Octopamine biosynthesis requires tyrosine decarboxylase to convert tyrosine into tyramine and tyramine beta-hydroxylase to convert tyramine into octopamine. We identified and characterized a Caenorhabditis elegans tyrosine decarboxylase gene, tdc-1, and a tyramine beta-hydroxylase gene, tbh-1. The ... >> More

  Octopamine biosynthesis requires tyrosine decarboxylase to convert tyrosine into tyramine and tyramine beta-hydroxylase to convert tyramine into octopamine. We identified and characterized a Caenorhabditis elegans tyrosine decarboxylase gene, tdc-1, and a tyramine beta-hydroxylase gene, tbh-1. The TBH-1 protein is expressed in a subset of TDC-1-expressing cells, indicating that C. elegans has tyraminergic cells that are distinct from its octopaminergic cells. tdc-1 mutants have behavioral defects not shared by tbh-1 mutants. We show that tyramine plays a specific role in the inhibition of egg laying, the modulation of reversal behavior, and the suppression of head oscillations in response to anterior touch. We propose a model for the neural circuit that coordinates locomotion and head oscillations in response to anterior touch. Our findings establish tyramine as a neurotransmitter in C. elegans, and we suggest that tyramine is a genuine neurotransmitter in other invertebrates and possibly in vertebrates as well. << Less

  Neuron 46:247-260(2005) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Crystal structure of tyrosine decarboxylase and identification of key residues involved in conformational swing and substrate binding.

  Zhu H., Xu G., Zhang K., Kong X., Han R., Zhou J., Ni Y.

  Tyrosine decarboxylase (TDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme and is mainly responsible for the synthesis of tyramine, an important biogenic amine. In this study, the crystal structures of the apo and holo forms of Lactobacillus brevis TDC (LbTDC) were determined. The LbTDC displa ... >> More

  Tyrosine decarboxylase (TDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme and is mainly responsible for the synthesis of tyramine, an important biogenic amine. In this study, the crystal structures of the apo and holo forms of Lactobacillus brevis TDC (LbTDC) were determined. The LbTDC displays only 25% sequence identity with the only reported TDC structure. Site-directed mutagenesis of the conformationally flexible sites and catalytic center was performed to investigate the potential catalytic mechanism. It was found that H241 in the active site plays an important role in PLP binding because it has different conformations in the apo and holo structures of LbTDC. After binding to PLP, H241 rotated to the position adjacent to the PLP pyridine ring. Alanine scanning mutagenesis revealed several crucial regions that determine the substrate specificity and catalytic activity. Among the mutants, the S586A variant displayed increased catalytic efficiency and substrate affinity, which is attributed to decreased steric hindrance and increased hydrophobicity, as verified by the saturation mutagenesis at S586. Our results provide structural information about the residues important for the protein engineering of TDC to improve catalytic efficiency in the green manufacturing of tyramine. << Less

  Sci. Rep. 6:27779-27779(2016) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Tyrosine decarboxylase from Lactobacillus brevis: Soluble expression and characterization.

  Zhang K., Ni Y.

  Tyrosine decarboxylase (TDC, EC 4.1.1.25) is an enzyme that catalyzes the decarboxylation of l-tyrosine to produce tyramine and CO2. In this study, a 1881-bp tdc gene from Lactobacillus brevis was cloned and heterologously expressed in Escherichia coli BL21 (DE3). Glucose was discovered to play an ... >> More

  Tyrosine decarboxylase (TDC, EC 4.1.1.25) is an enzyme that catalyzes the decarboxylation of l-tyrosine to produce tyramine and CO2. In this study, a 1881-bp tdc gene from Lactobacillus brevis was cloned and heterologously expressed in Escherichia coli BL21 (DE3). Glucose was discovered to play an important role in the soluble expression of rLbTDC. After optimization, recombinant TDC (rLbTDC) was achieved in excellent solubility and a yield of 224mg rLbTDC/L broth. The C-terminal His-Tagged rLbTDC was one-step purified with 90% recovery. Based on SDS-PAGE and gel filtration analysis, rLbTDC is a dimer composed of two identical subunits of approximately 70kDa. Using l-tyrosine as substrate, the specific activity of rLbTDC was determined to be 133.5U/mg in the presence of 0.2mM pyridoxal-5'-phosphate at 40°C and pH 5.0. The Km and Vmax values of rLbTDC were 0.59mM and 147.1μmolmin(-1)mg(-1), respectively. In addition to l-tyrosine, rLbTDC also exhibited decarboxylase activity towards l-DOPA. This study has demonstrated, for the first time, the soluble expression of tdc gene from L. brevis in heterologous host. << Less

  Protein Expr. Purif. 94:33-39(2014) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Identification of the Enterococcus faecalis tyrosine decarboxylase operon involved in tyramine production.

  Connil N., Le Breton Y., Dousset X., Auffray Y., Rince A., Prevost H.

  Screening of a library of Enterococcus faecalis insertional mutants allowed isolation of a mutant affected in tyramine production. The growth of this mutant was similar to that of the wild-type E. faecalis JH2-2 strain in Maijala broth, whereas high-performance liquid chromatography analyses showe ... >> More

  Screening of a library of Enterococcus faecalis insertional mutants allowed isolation of a mutant affected in tyramine production. The growth of this mutant was similar to that of the wild-type E. faecalis JH2-2 strain in Maijala broth, whereas high-performance liquid chromatography analyses showed that tyramine production, which reached 1,000 microg ml(-1) for the wild-type strain, was completely abolished. Genetic analysis of the insertion locus revealed a gene encoding a decarboxylase with similarity to eukaryotic tyrosine decarboxylases. Sequence analysis revealed a pyridoxal phosphate binding site, indicating that this enzyme belongs to the family of amino acid decarboxylases using this cofactor. Reverse transcription-PCR analyses demonstrated that the gene (tdc) encoding the putative tyrosine decarboxylase of E. faecalis JH2-2 is cotranscribed with the downstream gene encoding a putative tyrosine-tyramine antiporter and with the upstream tyrosyl-tRNA synthetase gene. This study is the first description of a tyrosine decarboxylase gene in prokaryotes. << Less

  Appl. Environ. Microbiol. 68:3537-3544(2002) [PubMed] [EuropePMC]

• Gut bacterial tyrosine decarboxylases restrict levels of levodopa in the treatment of Parkinson's disease.

  van Kessel S.P., Frye A.K., El-Gendy A.O., Castejon M., Keshavarzian A., van Dijk G., El Aidy S.

  Human gut microbiota senses its environment and responds by releasing metabolites, some of which are key regulators of human health and disease. In this study, we characterize gut-associated bacteria in their ability to decarboxylate levodopa to dopamine via tyrosine decarboxylases. Bacterial tyro ... >> More

  Human gut microbiota senses its environment and responds by releasing metabolites, some of which are key regulators of human health and disease. In this study, we characterize gut-associated bacteria in their ability to decarboxylate levodopa to dopamine via tyrosine decarboxylases. Bacterial tyrosine decarboxylases efficiently convert levodopa to dopamine, even in the presence of tyrosine, a competitive substrate, or inhibitors of human decarboxylase. In situ levels of levodopa are compromised by high abundance of gut bacterial tyrosine decarboxylase in patients with Parkinson's disease. Finally, the higher relative abundance of bacterial tyrosine decarboxylases at the site of levodopa absorption, proximal small intestine, had a significant impact on levels of levodopa in the plasma of rats. Our results highlight the role of microbial metabolism in drug availability, and specifically, that abundance of bacterial tyrosine decarboxylase in the proximal small intestine can explain the increased dosage regimen of levodopa treatment in Parkinson's disease patients. << Less

  Nat. Commun. 10:310-310(2019) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.