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Journal articles on the topic 'Pyruvoyl enzymes'

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Published: 4 June 2021
Last updated: 1 February 2022

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1

van Poelje, Paul D., and Esmond E. Snell. "Pyruvoyl-Dependent Enzymes." Annual Review of Biochemistry 59, no. 1 (June 1990): 29–59. http://dx.doi.org/10.1146/annurev.bi.59.070190.000333.

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2

Kim, Alexander D., David E. Graham, Steven H. Seeholzer, and George D. Markham. "S-Adenosylmethionine Decarboxylase from the Archaeon Methanococcus jannaschii: Identification of a Novel Family of Pyruvoyl Enzymes." Journal of Bacteriology 182, no. 23 (December 1, 2000): 6667–72. http://dx.doi.org/10.1128/jb.182.23.6667-6672.2000.

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ABSTRACT Polyamines are present in high concentrations in archaea, yet little is known about their synthesis, except by extrapolation from bacterial and eucaryal systems. S-Adenosylmethionine (AdoMet) decarboxylase, a pyruvoyl group-containing enzyme that is required for spermidine biosynthesis, has been previously identified in eucarya and Escherichia coli. Despite spermidine concentrations in the Methanococcales that are several times higher than in E. coli, no AdoMet decarboxylase gene was recognized in the complete genome sequence ofMethanococcus jannaschii. The gene encoding AdoMet decarboxylase in this archaeon is identified herein as a highly diverged homolog of the E. coli speD gene (less than 11% identity). The M. jannaschii enzyme has been expressed inE. coli and purified to homogeneity. Mass spectrometry showed that the enzyme is composed of two subunits of 61 and 63 residues that are derived from a common proenzyme; these proteins associate in an (αβ)2 complex. The pyruvoyl-containing subunit is less than one-half the size of that in previously reported AdoMet decarboxylases, but the holoenzyme has enzymatic activity comparable to that of other AdoMet decarboxylases. The sequence of theM. jannaschii enzyme is a prototype of a class of AdoMet decarboxylases that includes homologs in other archaea and diverse bacteria. The broad phylogenetic distribution of this group suggests that the canonical SpeD-type decarboxylase was derived from an archaeal enzyme within the gamma proteobacterial lineage. Both SpeD-type and archaeal-type enzymes have diverged widely in sequence and size from analogous eucaryal enzymes.
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3

Shik Park, Young, Nacksung Kim, Hajeong Kim, Dongkook Park, and Jeongbin Yim. "Expression and Characterization of Recombinant Drosophila 6-pyruvoyl tetrahydropterin Synthase." Pteridines 6, no. 2 (May 1995): 58–62. http://dx.doi.org/10.1515/pteridines.1995.6.2.58.

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Summary 6-Pyruvoyl tetrahydropterin synthase is involved in the synthesis of pteridine eye pigments in Drosophila. The purple gene which was known to be one of the target loci of the suppressor mutation su(sj2 has been identified to encode the enzyme, and its cDNA has been cloned recently. The cDNA encoding the 19.3 kDa subunit of the 6-pyruvoyl tetrahydropterin synthase was expressed as fusion proteins in E. coli. The recombinant protein was shown to be active and purified from the E. coli crude extract by metal-chelation chromatography. The fused metal-chelating oilgopeptide was removed by thrombin for further characterization. Apparent Km for the substrate dihydroneopterin triphosphate was determined to be 590 IlM, which was slightly higher than the value of the native enzyme. The isoelectric point of 6.4 was also different from the known value of 4.3 determined by the native enzyme. Heat stability and the stimulatory effect of reducing agents were similar to the native enzyme. The modification of cysteine residues in the recombinant enzyme, one of which is known to be conserved in human and rat enzymes, by iodoacetamide inhibited its activity by up to 80%.
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4

THÖNY, Beat, Günter AUERBACH, and Nenad BLAU. "Tetrahydrobiopterin biosynthesis, regeneration and functions." Biochemical Journal 347, no. 1 (March 27, 2000): 1–16. http://dx.doi.org/10.1042/bj3470001.

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Tetrahydrobiopterin (BH4) cofactor is essential for various processes, and is present in probably every cell or tissue of higher organisms. BH4 is required for various enzyme activities, and for less defined functions at the cellular level. The pathway for the de novo biosynthesis of BH4 from GTP involves GTP cyclohydrolase I, 6-pyruvoyl-tetrahydropterin synthase and sepiapterin reductase. Cofactor regeneration requires pterin-4a-carbinolamine dehydratase and dihydropteridine reductase. Based on gene cloning, recombinant expression, mutagenesis studies, structural analysis of crystals and NMR studies, reaction mechanisms for the biosynthetic and recycling enzymes were proposed. With regard to the regulation of cofactor biosynthesis, the major controlling point is GTP cyclohydrolase I, the expression of which may be under the control of cytokine induction. In the liver at least, activity is inhibited by BH4, but stimulated by phenylalanine through the GTP cyclohydrolase I feedback regulatory protein. The enzymes that depend on BH4 are the phenylalanine, tyrosine and tryptophan hydroxylases, the latter two being the rate-limiting enzymes for catecholamine and 5-hydroxytryptamine (serotonin) biosynthesis, all NO synthase isoforms and the glyceryl-ether mono-oxygenase. On a cellular level, BH4 has been found to be a growth or proliferation factor for Crithidia fasciculata, haemopoietic cells and various mammalian cell lines. In the nervous system, BH4 is a self-protecting factor for NO, or a general neuroprotecting factor via the NO synthase pathway, and has neurotransmitter-releasing function. With regard to human disease, BH4 deficiency due to autosomal recessive mutations in all enzymes (except sepiapterin reductase) have been described as a cause of hyperphenylalaninaemia. Furthermore, several neurological diseases, including Dopa-responsive dystonia, but also Alzheimer's disease, Parkinson's disease, autism and depression, have been suggested to be a consequence of restricted cofactor availability.
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5

Blau, Nenad, Beat Thöny, Claus W. Heizmann, and Jean-Louis Dhondt. "Tetrahydrobiopterin Deficiency: From Phenotype to Genotype." Pteridines 4, no. 1 (February 1993): 1–10. http://dx.doi.org/10.1515/pteridines.1993.4.1.1.

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Summary As a result of the selective screening worldwide during the last 18 years, approximately 250 patients with tetrahydrobiopterin deficiency were discovered. Most patients suffer from 6-pyruvoyl tetrahydropterin synthase deficiency (58%), followed by dihydropteridine reductase deficiency (35%), GTP cyclohydrolase I deficiency (3%), and “primapterinuria” (4%). The patients can be treated with neurotransmitter precursors, as well as with tetrahydrobiopterin. However, data on long term treatment are still scarce and it is therefore of great value to investigate all newborns with even mild hyperphenylalaninemia. Cloning of the enzymes involved in the biosynthesis and regeneration of tetrahydrobiopterin makes them to be easily accessible for biochemical and biological studies. So far, all proteins expressed heterologous are active in E. coli. Cloning of the wild type gene and mutant analysis of patients allow the rapid identification of the defective gene on the molecular level.
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6

Killivalavan, Asaithambi, Kyung Seo, Ningning Zhuang, Young Park, and Kon Lee. "Structural analysis of E. coli 6-carboxytetrahydropterin synthase." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C462. http://dx.doi.org/10.1107/s2053273314095370.

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The Escherichia coli 6-carboxytetrahydropterin synthase (eCTPS), a homolog of 6-pyruvoyl tetrahydropterin synthase (PTPS), possesses a much stronger catalytic activity to cleave the side chain of sepiapterin in vitro rather than the genuine PTPS activity and catalyzes the conversion of dihydroneopterin triphosphate to 6-carboxy-5,6,7,8-tetrahydropterin in vivo. We have determined crystal structures of a wild type apo-eCTPS and a Cys27Ala mutant eCTPS complexed with sepiapterin up to 2.3 and 2.5 Å, respectively. The structures are highly conserved at the active site and the Zn2+ binding site. However, comparison of the eCTPS structures with those of mammalian PTPS homologs revealed that two specific residues Trp51 and Phe55, not existing in the mammalian PTPS, kept the substrate bound by stacking it with their side chains. Replacements of these two residues by site-directed mutagenesis to the residues, Met and Leu, existing only in mammalian PTPS, converted the eCTPS to have the mammalian PTPS activity. Our studies confirm that these two aromatic residues in eCTPS play an essential role in stabilizing the substrate and for the specific enzyme activity different from the original PTPS activity. These aromatic residues Trp51 and Phe55 are a key signature of bacterial PTPS enzymes that distinguish them from mammalian PTPS homologs.
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7

Huynh, Q. K., and E. E. Snell. "Pyruvoyl-dependent histidine decarboxylases. Comparative sequences of cysteinyl peptides of the enzymes from Lactobacillus 30a, Lactobacillus buchneri, and Clostridium perfringens." Journal of Biological Chemistry 260, no. 5 (March 1985): 2794–97. http://dx.doi.org/10.1016/s0021-9258(18)89432-7.

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8

Kim, Seonhee, Ikjun Lee, Hee-Jung Song, Su-jeong Choi, Harsha Nagar, Sung-min Kim, Byeong Hwa Jeon, et al. "Far-Infrared-Emitting Sericite Board Upregulates Endothelial Nitric Oxide Synthase Activity through Increasing Biosynthesis of Tetrahydrobiopterin in Endothelial Cells." Evidence-Based Complementary and Alternative Medicine 2019 (October 31, 2019): 1–9. http://dx.doi.org/10.1155/2019/1813282.

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Far-infrared ray (FIR) therapy has been reported to exert beneficial effects on cardiovascular function by elevating endothelial nitric oxide synthesis (eNOS) activity and nitric oxide (NO) production. Tetrahydrobiopterin (BH4) is a key determinant of eNOS-dependent NO synthesis in vascular endothelial cells. However, whether BH4 synthesis is associated with the effects of FIR on eNOS/NO production has not yet been investigated. In this study, we investigated the effects of FIR on BH4-dependent eNOS/NO production and vascular function. We used FIR-emitting sericite boards as an experimental material and placed human umbilical vein endothelial cells (HUVECs) and Sprague–Dawley rats on the boards with or without FIR irradiation and then evaluated vascular relaxation by detecting NO generation, BH4 synthesis, and Akt/eNOS activation. Our results showed that FIR radiation significantly enhanced Akt/eNOS phosphorylation and NO production in human endothelial cells and aorta tissues. FIR can also induce BH4 storage by elevating levels of enzymes (e.g., guanosine triphosphate cyclohydrolase-1, 6-pyruvoyl tetrahydrobiopterin synthase, sepiapterin reductase, and dihydrofolate reductase), which ultimately results in NO production. These results indicate that FIR upregulated eNOS-dependent NO generation via BH4 synthesis and Akt phosphorylation, which contributes to the regulation of vascular function. This might develop potential clinical application of FIR to treat vascular diseases by augmenting the BH4/NO pathway.
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9

Steinerstauch, Petra, Yoshitomo Sawada, Walter Leimbacher, Sandro Ghisla, and Hans-Christoph Curtius. "Purification and Characterization of a Carbonyl Reductase from Human Liver, which is Competent in the Reduction of 6-Pyruvoyl-Tetrahydropterin." Pteridines 1, no. 4 (November 1989): 189–98. http://dx.doi.org/10.1515/pteridines.1989.1.4.189.

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Summary An enzyme which reduces 6-pyruvoyl-tetrahydropterin has been purified to apparent homogeneity from human liver. It consists of a single polypeptide chain with a molecular weight of 35 kDa, has an isoelectric point of 5.9 ± 0.1 and contains no glycosyl residues. The pure enzyme has a specific activity of 450 mU/mg protein at pH 7.0 in 10 mM potassium phosphate buffer. It converts 6-pyruvoyl-tetrahydropterin to 6-lactoyltetrahydropterin by transfer of the pro 4R-hydrogen of NADPH to form the side chain -OH at position C(2') of the substrate. Km values are 1.8 J..lM for 6-pyruvoyl-tetrahydropterin and 5.5 J..lM for NADPH. Polyclonal antibodies raised against the purified enzyme recognize 6-pyruvoyl-tetrahydropterin reductase in Western blot and ELISA but do not cross-react with human sepiapterin reductase. The enzyme appears to be identical with aldose reductase.
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10

RAMJEE, Manoj K., Ulrich GENSCHEL, Chris ABELL, and Alison G. SMITH. "Escherichia coli l-aspartate-α-decarboxylase: preprotein processing and observation of reaction intermediates by electrospray mass spectrometry." Biochemical Journal 323, no. 3 (May 1, 1997): 661–69. http://dx.doi.org/10.1042/bj3230661.

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The Escherichia coli panD gene, encoding l-aspartate-α-decarboxylase, was cloned by PCR, and shown to complement apanD mutant defective in β-alanine biosynthesis. Aspartate decarboxylase is a pyruvoyl-dependent enzyme, and is synthesized initially as an inactive proenzyme (the π-protein), which is proteolytically cleaved at a specific X–Ser bond to produce a β-subunit with XOH at its C-terminus and an α-subunit with a pyruvoyl group at its N-terminus, derived from the serine. The recombinant enzyme, as purified, is a tetramer, and comprises principally the unprocessed π-subunit (of 13.8 kDa), with a small proportion of the α- and β-subunits (11 kDa and 2.8 kDa respectively). Incubation of the purified enzyme at elevated temperatures for several hours results in further processing. Using fluorescein thiosemicarbazide, the completely processed enzyme was shown to contain three pyruvoyl groups per tetrameric enzyme. The presence of unchanged serine at the N-terminus of some of the α-subunits was confirmed by electrospray mass spectrometry (ESMS) and N-terminal amino acid sequencing. A novel HPLC assay for aspartate decarboxylase was established and used to determine the Km and kcat for l-aspartate as 151±16 μM and 0.57 s-1 respectively. ESMS was also used to observe substrate and product adducts trapped on the pyruvoyl group by sodium cyanoborohydride treatment.
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11

Giles, Teresa N., and David E. Graham. "Characterization of an Acid-Dependent Arginine Decarboxylase Enzyme from Chlamydophila pneumoniae." Journal of Bacteriology 189, no. 20 (August 10, 2007): 7376–83. http://dx.doi.org/10.1128/jb.00772-07.

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ABSTRACT Genome sequences from members of the Chlamydiales encode diverged homologs of a pyruvoyl-dependent arginine decarboxylase enzyme that nonpathogenic euryarchaea use in polyamine biosynthesis. The Chlamydiales lack subsequent genes required for polyamine biosynthesis and probably obtain polyamines from their host cells. To identify the function of this protein, the CPn1032 homolog from the respiratory pathogen Chlamydophila pneumoniae was heterologously expressed and purified. This protein self-cleaved to form a reactive pyruvoyl group, and the subunits assembled into a thermostable (αβ)3 complex. The mature enzyme specifically catalyzed the decarboxylation of l-arginine, with an unusually low pH optimum of 3.4. The CPn1032 gene complemented a mutation in the Escherichia coli adiA gene, which encodes a pyridoxal 5′-phosphate-dependent arginine decarboxylase, restoring arginine-dependent acid resistance. Acting together with a putative arginine-agmatine antiporter, the CPn1032 homologs may have evolved convergently to form an arginine-dependent acid resistance system. These genes are the first evidence that obligately intracellular chlamydiae may encounter acidic conditions. Alternatively, this system could reduce the host cell arginine concentration and produce inhibitors of nitric oxide synthase.
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12

Trip, Hein, Niels L. Mulder, Fergal P. Rattray, and Juke S. Lolkema. "HdcB, a novel enzyme catalysing maturation of pyruvoyl-dependent histidine decarboxylase." Molecular Microbiology 79, no. 4 (January 5, 2011): 861–71. http://dx.doi.org/10.1111/j.1365-2958.2010.07492.x.

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13

Forlani, Giuseppe. "Differential expression of 5-enol-pyruvyl-shikimate-3-phosphate synthase isoforms in elicitor-treated, cultured maize cells." Functional Plant Biology 29, no. 12 (2002): 1483. http://dx.doi.org/10.1071/fp02136.

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The expression of two 5-enol-pyruvyl-shikimate-3-phosphate synthase (EC 2.5.1.19) isoforms was investigated in Zea mays L. suspension-cultured cells following exposure to a fungal elicitor. Activity levels of isozyme II specifically increased soon after treatment, in strict connection with induction of phenylalanine ammonia-lyase (PAL) and attainment of a new free-phenylalanine homeostasis at a higher concentration. However, a few days later, activity of the other enzyme form was also significantly enhanced, concomitant with a sharp rise in overall amino acid content, a further increase in PAL level and a resumption of cell lysis. Besides strengthening the hypothesis that an entire set of genes encoding for shikimate pathway enzymes (whose expression is specifically involved in plant dynamic defence) may exist, a general change in the levels of several amino acids seems to point towards a reprogramming of their metabolism in elicited cells.
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14

Bale, Shridhar, Kavita Baba, Diane E. McCloskey, Anthony E. Pegg, and Steven E. Ealick. "Complexes ofThermotoga maritimaS-adenosylmethionine decarboxylase provide insights into substrate specificity." Acta Crystallographica Section D Biological Crystallography 66, no. 2 (January 22, 2010): 181–89. http://dx.doi.org/10.1107/s090744490904877x.

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The polyamines putrescine, spermidine and spermine are ubiquitous aliphatic cations and are essential for cellular growth and differentiation.S-Adenosylmethionine decarboxylase (AdoMetDC) is a critical pyruvoyl-dependent enzyme in the polyamine-biosynthetic pathway. The crystal structures of AdoMetDC from humans and plants and of the AdoMetDC proenzyme fromThermotoga maritimahave been obtained previously. Here, the crystal structures of activatedT. maritimaAdoMetDC (TmAdoMetDC) and of its complexes withS-adenosylmethionine methyl ester and 5′-deoxy-5′-dimethylthioadenosine are reported. The results demonstrate for the first time that TmAdoMetDC autoprocesses without the need for additional factors and that the enzyme contains two complete active sites, both of which use residues from both chains of the homodimer. The complexes provide insights into the substrate specificity and ligand binding of AdoMetDC in prokaryotes. The conservation of the ligand-binding mode and the active-site residues between human andT. maritimaAdoMetDC provides insight into the evolution of AdoMetDC.
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15

Hugo, E. R., and T. J. Byers. "S-adenosyl-l-methionine decarboxylase of Acanthamoeba castellanii (Neff): purification and properties." Biochemical Journal 295, no. 1 (October 1, 1993): 203–9. http://dx.doi.org/10.1042/bj2950203.

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S-Adenosyl-L-methionine decarboxylase (AdoMetDC) has been purified to near homogeneity from the Neff strain of Acanthamoeba castellanii. The holoenzyme molecular mass is 88.8 kDa, including two copies each of a 32.8 kDa alpha-subunit and a 10-15 kDa beta-subunit. The alpha-subunit contains the active site. It has an N-terminal pyruvoyl group, and the first 19 amino acids are 63 and 74% identical with comparable sequences from yeast and mammals, respectively. The apparent Km for S-adenosylmethionine (AdoMet) in the presence of 2 mM putrescine was 30.0 microM. The enzyme was stimulated 2-fold by putrescine, but was unaffected by spermidine. It was inhibited by the following anti-metabolites, listed with their Ki values: Berenil (0.17 microM), pentamidine (19.4 microM), propamidine (334 microM), hydroxystilbamidine (357 microM), methylglyoxal bis(guanylhydrazone) (604 microM) and ethidium bromide (1.3 mM). Activity of the enzyme fell to undetectable levels during cell differentiation (encystment).
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16

Nar, H., R. Huber, C. W. Heizmann, B. Thöny, and D. Bürgisser. "Three-dimensional structure of 6-pyruvoyl tetrahydropterin synthase, an enzyme involved in tetrahydrobiopterin biosynthesis." EMBO Journal 13, no. 6 (March 1994): 1255–62. http://dx.doi.org/10.1002/j.1460-2075.1994.tb06377.x.

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17

Guzman, Jaime, Gabriele Schoedon, and Nenad Blau. "Production of monoclonal antibodies against human 6-pyruvoyl tetrahydropterin synthase and immunocytochemical localization of the enzyme." Biochemical and Biophysical Research Communications 182, no. 2 (January 1992): 810–16. http://dx.doi.org/10.1016/0006-291x(92)91804-y.

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18

Iino, Teruhiko, Shin-Ichiro Takikawa, Toshio Yamamoto, and Hiroshi Sawada. "The Enzyme That Synthesizes Tetrahydrobiopterin from 6-Pyruvoyl-tetrahydropterin in the lemon Mutant Silkworm Consists of Two Carbonyl Reductases." Archives of Biochemistry and Biophysics 373, no. 2 (January 2000): 442–46. http://dx.doi.org/10.1006/abbi.1999.1561.

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19

BURGISSER, Daniel M., Beat THONY, Udo REDWEIK, Peter HUNZIKER, Claus W. HEIZMANN, and Nenad BLAU. "Expression and characterization of recombinant human and rat liver 6-pyruvoyl tetrahydropterin synthase. Modified cysteine residues inhibit the enzyme activity." European Journal of Biochemistry 219, no. 1-2 (January 1994): 497–502. http://dx.doi.org/10.1111/j.1432-1033.1994.tb19964.x.

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20

Kim, Nacksung, Jaeseob Kim, Dongkook Park, Christina Rosen, Dale Dorsett, and John Yim. "Structure and Expression of Wild-Type and Suppressible Alleles of the Drosophila purple Gene." Genetics 142, no. 4 (April 1, 1996): 1157–68. http://dx.doi.org/10.1093/genetics/142.4.1157.

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Abstract Viable mutant alleles of purple (pr), such as prbw, exhibit mutant eye colors. This reflects low 6-pyruvoyl tetrahydropterin (PTP) synthase activity required for pigment synthesis. PTP synthase is also required for synthesis of the enzyme cofactor biopterin; presumably this is why some pr alleles are lethal. The prbw eye color phenotype is suppressed by suppressor of sable [su(s)] mutations. The pr gene was cloned to explore the mechanism of this suppression. pr produces two PTP synthase mRNAs: one constitutively from a distal promoter and one in late pupae and young adult heads from a proximal promoter. The latter presumably supports eye pigment synthesis. The prbw allele has a 412 retrotransposon in an intron spliced from both mRNAs. However, the head-specific mRNA is reduced >10-fold in prbw and is restored by a su(s) mutation, while the constitutive transcript is barely affected. The Su(s) protein probably alters processing of RNA containing 412. Because the intron containing 412 is the first in the head-specific mRNA and the second in the constitutive mRNA, binding of splicing machinery to nascent transcripts before the 412 insertion is transcribed may preclude the effects of Su(s) protein.
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21

LEITNER, Karin L., Martina MEYER, Walter LEIMBACHER, Anja PETERBAUER, Susanne HOFER, Christine HEUFLER, Angelika MÜLLER, et al. "Low tetrahydrobiopterin biosynthetic capacity of human monocytes is caused by exon skipping in 6-pyruvoyl tetrahydropterin synthase." Biochemical Journal 373, no. 3 (August 1, 2003): 681–88. http://dx.doi.org/10.1042/bj20030269.

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Biosynthesis of (6R)-5,6,7,8-tetrahydro-l-biopterin (H4-biopterin), an essential cofactor for aromatic amino acid hydroxylases and NO synthases, is effectively induced by cytokines in most of the cell types. However, human monocytes/macrophages form only a little H4-biopterin, but release neopterin/7,8-dihydroneopterin instead. Whereas 6-pyruvoyl tetrahydropterin synthase (PTPS) activity, the second enzyme of H4-biopterin biosynthesis, is hardly detectable in these cells, PTPS mRNA levels were comparable with those of cell types containing intact PTPS activity. By screening a THP-1 cDNA library, we identified clones encoding the entire open reading frame (642 bp) as well as clones lacking the 23 bp exon 3, which results in a premature stop codon. Quantification of the two mRNA species in different cell types (blood-derived cells, fibroblasts and endothelial cells) and cell lines showed that the amount of exon-3-containing mRNA is correlated closely to PTPS activity. The ratio of exon-3-containing to exon-3-lacking PTPS mRNA is not affected by differential mRNA stability or nonsense-mediated mRNA decay. THP-1 cells transduced with wild-type PTPS cDNA produced H4-biopterin levels and expressed PTPS activities and protein amounts comparable with those of fibroblasts. We therefore conclude that exon 3 skipping in transcription rather than post-transcriptional mechanisms is a major cause of the low PTPS protein expression observed in human macrophages and related cell types.
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22

Hager, Sützl, Stefanović, Blaukopf, and Schäffer. "Pyruvate Substitutions on Glycoconjugates." International Journal of Molecular Sciences 20, no. 19 (October 5, 2019): 4929. http://dx.doi.org/10.3390/ijms20194929.

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Glycoconjugates are the most diverse biomolecules of life. Mostly located at the cell surface, they translate into cell-specific “barcodes” and offer a vast repertoire of functions, including support of cellular physiology, lifestyle, and pathogenicity. Functions can be fine-tuned by non-carbohydrate modifications on the constituting monosaccharides. Among these modifications is pyruvylation, which is present either in enol or ketal form. The most commonly best-understood example of pyruvylation is enol-pyruvylation of N-acetylglucosamine, which occurs at an early stage in the biosynthesis of the bacterial cell wall component peptidoglycan. Ketal-pyruvylation, in contrast, is present in diverse classes of glycoconjugates, from bacteria to algae to yeast—but not in humans. Mild purification strategies preventing the loss of the acid-labile ketal-pyruvyl group have led to a collection of elucidated pyruvylated glycan structures. However, knowledge of involved pyruvyltransferases creating a ring structure on various monosaccharides is scarce, mainly due to the lack of knowledge of fingerprint motifs of these enzymes and the unavailability of genome sequences of the organisms undergoing pyruvylation. This review compiles the current information on the widespread but under-investigated ketal-pyruvylation of monosaccharides, starting with different classes of pyruvylated glycoconjugates and associated functions, leading to pyruvyltransferases, their specificity and sequence space, and insight into pyruvate analytics.
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23

Samac, Deborah A., and Dawn Foster-Hartnett. "Effect of Glyphosate Application on Foliar Diseases in Glyphosate-Tolerant Alfalfa." Plant Disease 96, no. 8 (August 2012): 1104–10. http://dx.doi.org/10.1094/pdis-08-11-0715-re.

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Glyphosate, the active ingredient in Roundup herbicide, inhibits 5-enol-pyruvyl shikimate 3-phophate synthase (EPSPS), an enzyme found in plants, fungi, and bacteria. Plants engineered for glyphosate tolerance with a glyphosate-insensitive EPSPS take up and translocate the herbicide throughout the plant. In greenhouse experiments, we found that application of glyphosate at the recommended field application rate completely controlled alfalfa rust (Uromyces striatus) on 4-week-old plants inoculated with the fungus 3 days after glyphosate treatment. Control was effective in all seven cultivars tested. The level of protection declined with time after application, indicating that control transitory and protection declined with time after inoculation, suggesting that protective treatments have fungistatic activity. Complete control of rust was obtained when glyphosate was applied up to 10 days after inoculation with rust spores, indicating that the herbicide also has curative activity. Treatment increased protection from anthracnose, caused by Colletotrichum trifolii, a hemibiotrophic pathogen, and reduced symptom severity for spring black stem and leaf spot, caused by Phoma medicaginis, a necrotrophic pathogen. These results indicate that glyphosate could be used to help manage foliar diseases in glyphosate-tolerant alfalfa.
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Kim, Jaekwang, Hyunsuk Suh, Songhee Kim, Kiyoung Kim, Chiyoung Ahn, and Jeongbin Yim. "Identification and characteristics of the structural gene for the Drosophila eye colour mutant sepia, encoding PDA synthase, a member of the Omega class glutathione S-transferases." Biochemical Journal 398, no. 3 (August 29, 2006): 451–60. http://dx.doi.org/10.1042/bj20060424.

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The eye colour mutant sepia (se1) is defective in PDA {6-acetyl-2-amino-3,7,8,9-tetrahydro-4H-pyrimido[4,5-b]-[1,4]diazepin-4-one or pyrimidodiazepine} synthase involved in the conversion of 6-PTP (2-amino-4-oxo-6-pyruvoyl-5,6,7,8-tetrahydropteridine; also known as 6-pyruvoyltetrahydropterin) into PDA, a key intermediate in drosopterin biosynthesis. However, the identity of the gene encoding this enzyme, as well as its molecular properties, have not yet been established. Here, we identify and characterize the gene encoding PDA synthase and show that it is the structural gene for sepia. Based on previously reported information [Wiederrecht, Paton and Brown (1984) J. Biol. Chem. 259, 2195–2200; Wiederrecht and Brown (1984) J. Biol. Chem. 259, 14121–14127; Andres (1945) Drosoph. Inf. Serv. 19, 45; Ingham, Pinchin, Howard and Ish-Horowicz (1985) Genetics 111, 463–486; Howard, Ingham and Rushlow (1988) Genes Dev. 2, 1037–1046], we isolated five candidate genes predicted to encode GSTs (glutathione S-transferases) from the presumed sepia locus (region 66D5 on chromosome 3L). All cloned and expressed candidates exhibited relatively high thiol transferase and dehydroascorbate reductase activities and low activity towards 1-chloro-2,4-dinitrobenzene, characteristic of Omega class GSTs, whereas only CG6781 catalysed the synthesis of PDA in vitro. The molecular mass of recombinant CG6781 was estimated to be 28 kDa by SDS/PAGE and 56 kDa by gel filtration, indicating that it is a homodimer under native conditions. Sequencing of the genomic region spanning CG6781 revealed that the se1 allele has a frameshift mutation from ‘AAGAA’ to ‘GTG’ at nt 190–194, and that this generates a premature stop codon. Expression of the CG6781 open reading frame in an se1 background rescued the eye colour defect as well as PDA synthase activity and drosopterins content. The extent of rescue was dependent on the dosage of transgenic CG6781. In conclusion, we have discovered a new catalytic activity for an Omega class GST and that CG6781 is the structural gene for sepia which encodes PDA synthase.
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25

Bürgisser, Daniel M., Beat Thöny, Udo Redweik, Daniel Hess, Claus W. Heizmann, Robert Huber, and Herbert Nar. "6-Pyruvoyl Tetrahydropterin Synthase, An Enzyme With a Novel Type of Active Site Involving Both Zinc Binding and an Intersubunit Catalytic Triad Motif; Site-directed Mutagenesis of the Proposed Active Center, Characterization of the Metal Binding Site and Modelling of substrate Binding." Journal of Molecular Biology 253, no. 2 (October 1995): 358–69. http://dx.doi.org/10.1006/jmbi.1995.0558.

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26

Khairallah, Afrah, Özlem Tastan Bishop, and Vuyani Moses. "AMBER force field parameters for the Zn (II) ions of the tunneling-fold enzymes GTP cyclohydrolase I and 6‐pyruvoyl tetrahydropterin synthase." Journal of Biomolecular Structure and Dynamics, July 28, 2020, 1–18. http://dx.doi.org/10.1080/07391102.2020.1796800.

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27

Cho, Gyuhyeok, Eunju Lee, and Jungwook Kim. "Structural insights into phosphatidylethanolamine formation in bacterial membrane biogenesis." Scientific Reports 11, no. 1 (March 11, 2021). http://dx.doi.org/10.1038/s41598-021-85195-5.

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AbstractPhosphatidylethanolamine (PE), a major component of the cellular membrane across all domains of life, is synthesized exclusively by membrane-anchored phosphatidylserine decarboxylase (PSD) in most bacteria. The enzyme undergoes auto-cleavage for activation and utilizes the pyruvoyl moiety to form a Schiff base intermediate with PS to facilitate decarboxylation. However, the structural basis for self-maturation, PS binding, and decarboxylation processes directed by PSD remain unclear. Here, we present X-ray crystal structures of PSD from Escherichia coli, representing an apo form and a PE-bound complex, in which the phospholipid is chemically conjugated to the essential pyruvoyl residue, mimicking the Schiff base intermediate. The high-resolution structures of PE-complexed PSD clearly illustrate extensive hydrophobic interactions with the fatty acyl chains of the phospholipid, providing insights into the broad specificity of the enzyme over a wide range of cellular PS. Furthermore, these structures strongly advocate the unique topology of the enzyme in a lipid bilayer environment, where the enzyme associates with cell membranes in a monotopic fashion via the N-terminal domain composed of three amphipathic helices. Lastly, mutagenesis analyses reveal that E. coli PSD primarily employs D90/D142–H144–S254 to achieve auto-cleavage for the proenzyme maturation, where D90 and D142 act in complementary to each other.
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28

Stuecker, Tara N., Alex C. Tucker, and Jorge C. Escalante-Semerena. "PanM, an Acetyl-Coenzyme A Sensor Required for Maturation of l-Aspartate Decarboxylase (PanD)." mBio 3, no. 4 (July 10, 2012). http://dx.doi.org/10.1128/mbio.00158-12.

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ABSTRACTCoenzyme A (CoA) is essential for cellular chemistry in all forms of life. The pantothenate moiety of CoA is generated from the condensation of pantoate and β-alanine. β-Alanine is formed by decarboxylation ofl-aspartate catalyzed by PanD, a pyruvoyl enzyme that is synthesized by the cell as an inactive precursor (pro-PanD). Maturation of pro-PanD into PanD occurs via a self-cleavage event at residue Ser25, which forms the catalytic pyruvoyl moiety. We recently reported thatSalmonella entericaPanM was necessary for pro-PanD maturation, bothin vitroandin vivo. Notably, PanM is annotated as a Gcn5-likeN-acetyltransferase (GNAT), which suggested that lysine acetylation might be part of the mechanism of maturation. Here we show that PanM lacks acetyltransferase activity and that acetyl-CoA stimulates its activity. Results of experiments with nonhydrolyzable ethyl-CoA and genetically encoded acetyl-lysine-containing PanD support the conclusion that PanM-dependent pro-PanD maturation does not involve an acetyl transfer event. We also show that CoA binding to PanM is needed forin vivoactivity and that disruption of CoA binding prevents PanM from interacting with PanD. We conclude that PanM is a GNAT homologue that lost its acetyltransferase activity and evolved a new function as an acetyl-CoA sensor that can trigger the maturation of pro-PanD.IMPORTANCENε-lysine acetylation is increasingly being recognized as a widespread and important form of posttranslational regulation in bacteria. The acetyltransferases that catalyze these reactions are poorly characterized in bacteria. Based on annotation, most bacterial genomes contain several acetyltransferases, but the physiological roles of only a handful have been determined. Notably, a subset of putative acetyltransferases lack residues that are critical for activity in most biochemically characterized acetyltransferases. We show that one such putative acetyltransferase, PanM (formerly YhhK), lacks acetyltransferase activity but functions instead as an acetyl-coenzyme A (CoA) sensor. This work establishes the possibility that, like PanM, other putative acetyltransferases may have evolved new functions while retaining the ability to sense acetyl-CoA.
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Khairallah, Afrah, Caroline J. Ross, and Özlem Tastan Bishop. "Probing the Structural Dynamics of the Plasmodium falciparum Tunneling-Fold Enzyme 6-Pyruvoyl Tetrahydropterin Synthase to Reveal Allosteric Drug Targeting Sites." Frontiers in Molecular Biosciences 7 (September 25, 2020). http://dx.doi.org/10.3389/fmolb.2020.575196.

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